CA2219295A1 - Device for drying crystalline substances - Google Patents
Device for drying crystalline substances Download PDFInfo
- Publication number
- CA2219295A1 CA2219295A1 CA002219295A CA2219295A CA2219295A1 CA 2219295 A1 CA2219295 A1 CA 2219295A1 CA 002219295 A CA002219295 A CA 002219295A CA 2219295 A CA2219295 A CA 2219295A CA 2219295 A1 CA2219295 A1 CA 2219295A1
- Authority
- CA
- Canada
- Prior art keywords
- stirring blade
- residual moisture
- drying
- stirring
- angle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000001035 drying Methods 0.000 title claims abstract description 101
- 239000000126 substance Substances 0.000 title claims abstract description 27
- 238000003756 stirring Methods 0.000 claims description 126
- 238000000034 method Methods 0.000 claims description 35
- 230000008569 process Effects 0.000 claims description 35
- 239000000463 material Substances 0.000 claims description 32
- 239000007787 solid Substances 0.000 claims description 22
- 239000002872 contrast media Substances 0.000 claims description 15
- 239000000725 suspension Substances 0.000 claims description 10
- 239000000084 colloidal system Substances 0.000 claims description 9
- 239000000839 emulsion Substances 0.000 claims description 9
- 235000000346 sugar Nutrition 0.000 claims description 9
- 150000002772 monosaccharides Chemical group 0.000 claims description 7
- 238000010521 absorption reaction Methods 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 238000005054 agglomeration Methods 0.000 claims description 4
- 230000002776 aggregation Effects 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 4
- 150000008163 sugars Chemical class 0.000 claims description 3
- 230000005855 radiation Effects 0.000 abstract description 4
- 230000001105 regulatory effect Effects 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 3
- 238000013021 overheating Methods 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 3
- 229940039231 contrast media Drugs 0.000 description 2
- 239000000032 diagnostic agent Substances 0.000 description 2
- 229940039227 diagnostic agent Drugs 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- IPCSVZSSVZVIGE-UHFFFAOYSA-N hexadecanoic acid Chemical compound CCCCCCCCCCCCCCCC(O)=O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000012800 visualization Methods 0.000 description 2
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- 235000021314 Palmitic acid Nutrition 0.000 description 1
- 241000906446 Theraps Species 0.000 description 1
- 238000005411 Van der Waals force Methods 0.000 description 1
- 230000035508 accumulation Effects 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 229930182830 galactose Natural products 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000011859 microparticle Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- WQEPLUUGTLDZJY-UHFFFAOYSA-N n-Pentadecanoic acid Natural products CCCCCCCCCCCCCCC(O)=O WQEPLUUGTLDZJY-UHFFFAOYSA-N 0.000 description 1
- 239000000825 pharmaceutical preparation Substances 0.000 description 1
- 229940127557 pharmaceutical product Drugs 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000011146 sterile filtration Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/70—Feed lines
- H05B6/707—Feed lines using waveguides
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
- F26B11/12—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in stationary drums or other mainly-closed receptacles with moving stirring devices
- F26B11/14—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in stationary drums or other mainly-closed receptacles with moving stirring devices the stirring device moving in a horizontal or slightly-inclined plane
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B3/00—Drying solid materials or objects by processes involving the application of heat
- F26B3/32—Drying solid materials or objects by processes involving the application of heat by development of heat within the materials or objects to be dried, e.g. by fermentation or other microbiological action
- F26B3/34—Drying solid materials or objects by processes involving the application of heat by development of heat within the materials or objects to be dried, e.g. by fermentation or other microbiological action by using electrical effects
- F26B3/347—Electromagnetic heating, e.g. induction heating or heating using microwave energy
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/70—Feed lines
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2206/00—Aspects relating to heating by electric, magnetic, or electromagnetic fields covered by group H05B6/00
- H05B2206/04—Heating using microwaves
- H05B2206/046—Microwave drying of wood, ink, food, ceramic, sintering of ceramic, clothes, hair
Landscapes
- Engineering & Computer Science (AREA)
- Microbiology (AREA)
- Electromagnetism (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Biotechnology (AREA)
- Biomedical Technology (AREA)
- Health & Medical Sciences (AREA)
- Drying Of Solid Materials (AREA)
- Constitution Of High-Frequency Heating (AREA)
- Accessories For Mixers (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Mixers Of The Rotary Stirring Type (AREA)
Abstract
A device is disclosed for drying solutions of substances. Drying is performed by means of microwave radiation. Agitators R 1 and R 2 in the drying chambers TK 1 and TK 2 also aid the drying process. The energy from a generator G
reaches each of the drying chambers TK 1 and TK 2 through a microwave coupler 1 subdivided by a parting surface into a front and a rear part. A control unit S regulates both the amount of energy supplied and the speed of rotation of the agitators.
reaches each of the drying chambers TK 1 and TK 2 through a microwave coupler 1 subdivided by a parting surface into a front and a rear part. A control unit S regulates both the amount of energy supplied and the speed of rotation of the agitators.
Description
CA 0221929~ 1997-10-24 Device for Dry~ing ~rystalline 5ubstances The invention relates to a deviee for drying mat:erial solutions, crystalline substances with residual moist;ure, and also solids with residual moisture, suspensions, emu]sions and/or colloids. The drying is done with the aid of microwaves and a m~eh~n;eal stirrer. The invention also eomprises a proeess for the produetion of sugar-eontaining ultrasonie eontrast media by means of a deviee according to the invention. The application claims the German priority of 4/26/1995 with the offLcial file number 195 16 254.
For drying solutions, especially sugar solutions, various proeess-eontrol proeedures are known. The basie proeess steps of these t~chn;cal systems are determined by driers, miLls, and stirrers. In this case, the solutions are temperatw~e-equalized, the liquid is expelled, and the solids are mechanicaLly worked up. The advanee of drying is not determined during this process, but the output of the microwave energy is regulated IDY the surfaee temperature. Central elements of sueh mierowave driers are transmitters, conductors, and hot chambers. From the publication by Erich Pehl, Mikrowellentechnik, Wellenleitungen und Leitungsbausteine tMic:rowave Technology, Transmission Lines, and Concluetion Components]; Volume 1, p. 173; Heidelberg, calculation principles for antenna, i.e., transmitters, are know;n, by which length L1 ean be ealculated for a conical taper of a eylindrical pipe aecording to the relation L1 = n ~ ~/2 (n =
integral with L1 >> ~). Transformation elements are recommended CA 0221929~ 1997-10-24 for the transitions from rectangular waveguides to c~lindrical pipes or conical tapers of cylindrical waveguides. srhis is described in the publications of Meinke Gundlach; Taschenbuch der Hochfrec~uenztechnik [Handbook of High-Frequency Technology], Fourth Edition, Volume 2, p. 40 ff, Berlin, Heidelberg New York Tokyo, 1986 and H. Puchner, Warme durch Mikrowellen, Grundlagen, Bauelemente, Schaltungstechnik [Heat from Microwaves, Principles, Components, Circuit Engineering]~ Philips Technische Bibliothek tPhilips Technical Library] 1964.
Temperature-equalizal:ion is done in this connection by supplying heat energy with the aid of microwave radiation of 0.5-1~ GHz, preferably 0.915 and 2.45 GHz. In the case of these design solutions, the dra~back arises that local overheating develops in the applicato~s. As a result, the products that are to be dried are partially decomposed thermally. This overheating occurs especially in the areas where product accumulations occur on splatters of the material on conducting and non-conducting surfaces on the inside surfaces of the applicator.
In publication EP O 312 741 A2, a device for drying plastics is described. In this case, the device comprises a cylindrical drying chamber in which a stirrer for moving plastics is arranged. In addition, the device has a microwave c:oupler, which connects a microwave generator to the drying chamber.
It is disadvantageous that the particles that are to be dried can make direct con,tact with the generator ancl that irradiation is not well suited for solutions and crystalline substances with residual moisture. The generator is not adec~ately protected against pollution and overheat:ing, and the drying value of substances that are not plastics is ~nsatisfactory.
CA 0221929~ 1997-10-24 2a In publication FR 2 500 218, a device for drying with microwaves is described. In this case, the device comprises a drying chamber that is connected by a microwave coupler to a microwave generator. In this case, two separating surfaces, which are arranged perpendicular to the propagation axis of the microwave radiation, are located in the microwave coupler. In this case the microwave coupler is a rectangular hallow body in which the separating surfaces are settled somewhat concentrically. The shape of the microwave coupler is disadvantageous. Satisfactory drying crystalline substances with residual moisture and a material solution is not possible.
The object is thus 1:o dry crystalline substancles that are dissolved or have residual moisture, without local l~verheating occurring and the product thus being destroyed. In particular, differing material properties and varying diffusion properties are to cause no pro~lems in drying.
The object is achieved by a device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the device comprises at least one basically cylindrical or prism-shaped drying chamber (TK l and TK 2) that can be evacuated and temperature-equalized and in which a stirrer is placed, whereby the device comprises at least one microwave coupler (l), (a) the microwave coupler is connected to drying chamber (TKl or TK2);
(b) a separating surface (2), which is aligned basically perpendicular to longitudinal axis L of the microwave coupler, is arranged in the microwave coupler;
(c) the microwave coupler is designed with a taper, whereby the opening of the cone with the larger cross-section points toward the drying chamber;
and (d) the microwave coupler has the following proportions:
:L.4 < L1/D2 < g.o and :2.0 < Ll/L2 < 7.0;
in this case the values :L1, L2, D1 and D2 are characterized as follows:
L1 = a ~ A/2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of longitudinal axis L, which points from separating surface (2) in the direction away from drying chamber (TKl or TK2), L2 = partial length of longitudinal axis L, which points from separating surface (2) toward drying chamber (TK1 or TK2), and CA 0221929~ 1997-10-24 D2 = diameter of micrc>wave coupler (1) at the level of separating surface (2), ancl Dl = diameter of microwave coupler (1) at the level of the opening to drying chamber ~TKl or TK2).
The device preferably comprises several drying chambers, most preferably two drying chambers. At least one microwave coupler is connected to each drying chamber. Preferred are several microwave couplers per drying chamber. The drying chamber also has at least one stirring system. The microwave coupler and the stirring system can be controlled by known control units. The microwave couplers (tapers) are made cone-shaped, where~y the larger cross-section points towarl~ the drying chamber, and ~he smaller cross-section is connected t~D the generator. A separating surface, whose position is determined according to the previously mentioned proportions and dimensions, is placed between the two c:one openings. The diameter of the separating surface should be no less than 120 mm. The distance between the large cone opening and the separating surface should be at least 100 mm. In this case, the surface of the separating surface has a m; n; ~m absorption coefficient, so that the spatters of the solutions clo not spread on the surface.
Microwave drying usually also comprises a stirring process.
Here, it is possible to use known stirrers.
A device according to the invention in which the material of the separating surface has a minimum absorption coefficient is preferred. As a result, local hot spots can be successfully avoided. Preferred is a device according to the invention in CA 0221929~ 1997-10-24 ~ 1 5 which (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids comprise sugars.
More preferred are monosaccharides. Still more preferred are material solutions, crystalline substances with residual moisture, or solids with residual moisture, which comprise a contrast medium. Most preierred is an ultrasonic contrast medium. Such ultrasonic contrast media are described in European publications EP-A 0 052 57C~ (date of application 11/17/81) and EP-A 0 365 467 (date of application 4/6/89). The production processes are also explaine~d in detail in these publications.
More preferred is a device according to the invention in which stirrer (R 1) comprises a stirring shaft to which at least one L-shaped stirring blade is fastened;
whereby the stirring blade is characterized by the following proportions and dimensions:
(0.9 < B1 < 1.3) ~ ~ ~ (TKl) exp (-1/2) 1.5 < B2/B1 < 2.5 (0.65 < B3 < 1.35) ~ ~/2;
in this case, values ]31, B2 and B3 are characterized as follows:
B1 = the width oE the long leg of stirring blade (3);
B2 = the length of the short leg including the width of the long leg, and B3 = the width of the short leg of stirring blade (3), the stirring blades have angles to the rotational plane, CA 0221929~ 1997-10-24 in this case, the cross-sec~tion of the stirring blades is triangular and has a stirring blade lower surface, a stirring blade back surface, and a stirring blade upper surface; in this case the stirring blade back surface points in the direction of the short leg, whereby the angles are characterized by the following values:
c~-angle between stirr:ing blade back surface and rotational axis has the value of 5~ to 15~;
B-angle between stirr:ing blade lower surface and rotational plane has the vaLue of 2~ to 10~; and ~-angle between stirr:ing blade upper surface and rotational plane has the vaLue of 25~ to 40~.
Thermal decomposition of the products is success,fully avoided by the combination of the special microwave coupler and the stirring blades. The aLmount of microwave energy added can be controlled specifically as a function of the advance of the drying and the physical material properties that are thus altered insicle the product. Thus, elevated diffusion resistances that accompany solidification are successfully compensatec,L. Caking and overheating of the product are successfully avoic'led. The drying process proceeds in a directed manner. A procluct results that meets even the high requirements that are set for pharmaceutical products.
The device according to the invention has the aclvantage that sticking and thermal destruction of the product are reliably avoided by the special embodiment of the microwave coupler, especially by the defined size and position of the separating CA 0221929~ 1997-10-24 surface of the coupler in connection with specifically configured stirrers of the drying pro<ess -- preferably under a vacuum -- by measuring the amount of condensate and a control that prevents the set temperature limits from being exceeded inside the product that is to be dried, and d~ying of the product up to a defined value is made possible. The advance of drying is det.ermined from the amount of condensate o:E the amount of li~uid that. is evaporated. With increasing solid content, the diffu.sion resistance of the product :increases relative to the ~olvent that is to be separated. With the smaller evaporating sol.vent stream, less energy is dissipated ;lt constant energy supply. In this case, the temperature of the product increases. In t.he case where energy is supplied by means of microwave radiat:ion, this temperature increase occurs mainly inside the product: and in this case is either unmeasurabl,_ or only slightly measurable on the surface.
This physical process can be reproduced with the advance of drying and is taken into consideration in the regulat:ion process such that at various points along the way (amounts of condensate of the separated solvent, .specific portion of solvent:), the difference between the internal and external temperat:ures of the product is determined under identical drying conditions. In this case, various sizes and types of product agglomerations or product concentrations must be taken into consideration. The product temperature that is thus determined is a regulating variable for the control unit, which in turn determines the energy supply of the microwave radiation.
CA 0221929~ 1997-10-24 Preferred is a device according to the invention in which the adva~ce of the drying 1Ls determined and is controlled; during the advance of the drying, the diffusion resistance of the product is used as a regulating variable as a function of the advance of drying.
Preferred is a device according to the invention in which stirrer (R2) that projects into drying chamber (TK2) has at least one stirring blade and also one or more breaking-up stirring blades that are mounted ofiset over-one another, which are arranged at distance (A1 . An) from the lower rotational plane of slirrer (R2), have leg width (B4), and in this case comprise the following proportions and dimensions:
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-An = 60 mm to 100 mm.
Study of individual arLgles compared to the rotat.ional plane revealed that some angles aLre more preferred. As a result, a device according to the invention is produced in which the breaking up stirring blade-, have an angle to the rota.tional plane;
whereby the cross-section of the breaking-up sti.rring blades is trapezoidal, and whereby the cross-section of the breaking-up sti.rring blades is determined by the angle with the following values:
~-angle between the lower side of the stirring blade and the rotational plane has the value of 5~ t:o 15~;
CA 0221929~ 1997-10-24 ~-angle between the inclined stirring blade upper side and the rotational plane has the value of 20~ to 45~;
and ~-angle between the back side of the ~tirring blade and axis of rotation has the value of 5~ to ~5~
Especially advantageous is a device according to the invention in which the special shape and arrangement of the stirring blades of the stirrer in the first drying chamber and the additional breaking-up stirring blades in the sec~ond drying chamber interact in a sensible way. optimum breaking-up and thorough mixing of the product are ensured by a spec:Lfic cross-section shape and arrangem.ent of the stirring blades. Therefore, not only is the mixed material pushed back and forth by the stirring blades, but also the drying process is accelerated with the stirrer and optimally configured. An especially advantageous effect is achieved with a device according to the invention in that in a known way, the shell of the drying chambers is temperature-equalized, so that, depending on the advance of solidification and the variation in the change in toughness that is achieved by slightly increasing or decreasing the wall temperature, the shearing forces between the inside surface of the drying chamber and the product are influenced in a positive manner.
The invention also comprises a process for drying (i) material solutions, (ii) crystalline substances with. residual CA 0221929~ 1997-10-24 moisture, (iii) solids Wit]l residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the proce!ss comprises the following steps:
aa) Production of the solution, bb) optionally filtr.ation, cc) microwave drying using a device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) col]oids, whereby the device comprises at least one basically cylindrical or prism-shaped drying chamber"
in which a stirrer is arranged, in this case the device comprises at least one microwave coupler (1), (a) the microwave coupler is connected to the drying chamber;
(b) arranged in the microwave couple:r is a separa.ting surface, which is aligned basically perpendicular t:o longitudinal axis L of the microwave coupler;
(c) the mi.crowave coupler is designed with a taper,.
whereby the opening of the cone with the :Larger cross-section points toward the drying chamber;
and CA 0221929~ 1997-10-24 (d) the microwave coupler has the following proportions:
1.4 < L1/D2 < 9.0 and 2.0 < L1/L2 < 7.0;
in this case values L1, L2, D1 and D2 are characterized as follows:
L1 = a ~ ~/2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of lonc~itudinal axis L, which points from the separating surface in the direction away from the drying chamber, L2 = partial length of long:itudinal axis L, which points from the separating s,urface toward the drying chamber, D2 = diameter of the microwaLve coupler a,t the level of the separating surface, aLnd D1 = diameter of the microwave coupler at the level of the opening to the drying chamber;
d) final drying and e) crush'Lng.
Filtration can be sterile filtration or ultrafiltration or a combination of the two.
CA 022l929~ l997-l0-24 , 12 The product that results from the final drying k,as a residual moisture of 1% by weight, and preferably 0.5~ by weight or less.
The product that is produced by this process can be marketed as a diagnostic agent.
Preferred is a process according to the invention, whereby the material of the separating surface has a minimum absorption coefficient.
Very advantageous is a process according to the invention, whereby the (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residua:L moisture comprise sugar.
Preferred is a process, whereby the sugar is a monosaccharide.
More preferred is a process according to the invention, whereby the (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residua;l moisture comprise a contrast medium.
Most preferred is a process according to the invention, whereby the ~i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise an ultrasonic contrast medium.
Advantageous is a process according to the invention, whereby stirrer (R 1) comprises a stirring shaft, to which at least one L-shaped stirring blade is fastened;
whereby the stirring blade is characterized by the following proportions and dimensions:
CA 0221929~ 1997-10-24 , 13 (0.9 < B1 ~ 1.3) ~ ~ (TK1) exp (-1/2) 1.5 < B2/B1 < 2.!, (0.65 < B3 < 1.35) ~ ~/2;
in this case, values ~31, B2 and B3 are characterized as follows:
Bl = the width o:E the long leg of the stirring blade;
B2 = the length of the short leg including the width of the long leg, anl~
B3 = the width of the short leg of the stirring blade, the stirring blades have a:ngles to the rotational plaLne, in this case, the cross-section of the stirring blades is triangular and has a stirring blade lower surface, a stirring blade back surface and a stirring blade upper surface, in this case the stirring blade back surface points in the direction of the short leg, whereby the angles are characterized by the fol:Lowing values:
~-angle between stirring blade back surface and rotational axis has the value of 5~ to 15~;
B-angle between stirring blade lower surface and rotational plane has the va.lue of 2~ to 10~; and ~-angle between stirring blade upper surface and rotational plane has the vaLlue of 25~ to 40~.
Preferred is a process according to the invention/ whereby stirrer (R2) that projects into drying chamber (TK2) has at least CA 0221929~ 1997-10-24 one stirring blade and in addition one or more breaking-up stirring blades that are mounted offset over one anot.her, which are arranged at distance (A~ . An) from the lower rotational plane of s-tirrer (R2), have leg width (B4), and in this case comprise the following proportions and dimensions:
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-An = 60 mm to 100 mm.
More preferred is a process according to the invention, where.by the breaking-up stirring blades have angles t:o the rotational plane; whereby the cross-section of the breaking-up stirring blade is trapezoidal, and whereby the cross-section of the breaking-up stirring blades is determined by the angle with the following values:
~-angle between the lower side of the stirring blade and the rotational plane has the value of 5~1to 15~;
~-angle between the inclined stirring blade upper side a.nd the rotational plane ha~; the value of 5~ to 15~;
and ~-angle bet:ween the back side of the stirring blade and axis of rotation has the value of 5~ to 15~.
Most preferred is a process according to the invention for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) CA 022l929~ l997-l0-24 suspensions, (v) emulsions and/or (vi) colloids, whereby the process comprises the following steps:
a) Production of the solution, b) optionally filtration, c) microwave drying using the device, d) final drying, e) crushing and f) agglomeration.
The purpose of the agglomeration is to convert a crushed substance, which is difficult to handle and to transport, into a form that does not involve these problems. In this ~_ase, however, the property to pass quickly into solution is not to be impaired. The particles are held together in the agglomerite elements by van der Waals forces.
The product that is aLchieved by the above-described process is the substance that is reasonably marketed. It is easily possible to incorporate the product into solutions. Then, it can be injected into patients. It makes it possible to execute imaging diagnoses on human or animal bodies, whereby data material is created that allows the physician, based on his specific knowledge and his technical expertise, to propose a suitable treatment therap~y. More preferred is a process according to the invention in which the material solution contains an ultrasonic col~trast medium; most preferred is an ultrasonic contrast medium that comprises a monosaccharide. In this case, contrast media that are described in detail in the previously mentioned publications EP-A 0 052 575 and EP-A 0 365 -CA 022l929~ l997-l0-24 467 are especially preferred. The diagnostic agents Echovist and Levovist comprise gas-containing microparticles basecL on galactose, without or with palmitic acid.
Very preferred is a process according to the imrention, whereby the material solution contains an ultrasonic contrast medium.
Most preferred is a process according to the in~ention, whereby the ultrasonic contrast medium comprises monosaccharide.
The device according to the invention is described below by way of example.
Figure 1 shows a diagrammatic visualization of 1:he device.
Figure 2 shows a diagrammatic visualization of 1_he microwave coupler.
Figure 3 shows a top view of the stirring blade, and a section through a stirring blade of the stirrer of the first drying chamber along section A-A.
Figure 4 shows a top view of the stirring blades and a section through a breaking-up stirring blade of the stirrer of the second drying chamber along section B-B.
A device for drying solutions is diagrammatically depicted in Figure l. In this case, these are sugar-containing liquids, namely either an echovist or a levovist. The device consists of a first dryil~g chamber TK l with a stirrer Rl and a second drying chamber TK 2 with a stirrer R2. On the cover of the drying chambers are microwave couplers l with generators G as well as a control unit S. Between 1:he two drying chambers is arranged a crushing machine of a known type. Through an intake opening, CA 022l929~ l997-l0-24 , 17 which i5 not depicted in more detail, the product to be dried is put into first drying chamber TK 1. After the device is turned on, suitable microwave energy in drying chamber TK 1 is introduced from generator 1~ via microwave coupler 1. At the same time, stirrer R 1 is cause~d to start rotating. The clrying process is based on both of these activities. The surface temperature and advance of drying are measured by known sensors, which also are not depicted in the figure, and relayed to control unit S. The latter regulates, as a function of the advance of drying il~ the above-described way via an established regulating program, the amount of energy for microwave coupler ~ of drying chamber TK 1 and also the rpm of stirrer R 1.
Then, the drying process in second drying chamber TK 2 is continued. Also in the second drying stage, the amolmt of energy for microwave coupler 1 and for the rpm of stirrer R 2 is regulated in approximately the same way as previously described.
Figure 2 shows a microwave coupler 1. It is conical in design. The opening with the smaller cross-section points toward generator G and is designed in the form of a square. The opposite opening, which is connected to the drying cllamber, has a round cross-section. Microwave coupler 1 is divided into two sectors by a separating surface 2. The surface of separating surface 2 is perpendicular to the longitudinal axis of microwave coupler 1 and is divided into two sectors by separating surface 2. The surface of separating surface 2 is perpendicular to the longitudinal axis of micrc,wave coupler 1. For this purpose, the longitudinal axis is divided into two partial length~. Partial CA 022l929~ l997-l0-24 ' , 18 length L l points from separating surface 2 toward generator G or away from drying chamber TK l or TK 2. Partial lengt;h L l extends from separating surface 2 to drying chamber ~K l or TK 2.
The sum of partial lengths L l and L 2 yields the to1:al length of longitudinal axis L. The separating surface has a d:Lameter D 2, The opening of the microwave coupler, which points toward the drying chamber, has a diameter D l. The relation of the individual lengths, namely L l, L 2, D l and D 2, was presented in the prior text of the description, It goes without saying that the proportions that are pictured in Figure 2 a~e not binding; rather it is a diagrammatic view.
Three stirring blades 3 of stirrer R l are depi~-ted in Figure 3. Stirring blades, 3 are L-shaped. The direction of rotation of the stirring blades is basically parallel to the floor surface of drying ch,amber TK l, A stirring shaft 8 of stirrer R l is perpendicular to the floor surface. The stirring blades are depicted in Figure 3 both in top view and in the section along sectional plane A - A. In this case, the width of the long leg of stirring blade 3 is referred to as B l and the width of the short leg is referred to as B 3. The length of the short leg has designation B 2. The proportions of length dimensions B l, B 2 and B 3 were explained in detail in the previous text. Also in this case, the proportions depicted are defined only diagrammatically.
The cross-section that is indicated by section A - A of one of stirring blades 3 has a triangular shape. Such a stirring blade 3 has three surfaces, namely a stirring blade lower surface CA 0221929~ 1997-10-24 ' ~ 19 5 that points downward, a stirring blade upper surfare 6 that points upward, and a stirring blade back surface 7 t]nat points basically to the side. Three angles are essential for the actual orientation of the previously mentioned three stirring blade surfaces, namely angles ~, ~ and ~. Angle ~ is form~_d by stirring blade back surface 7 and the axis of rotation; angle is formed by stirring bladLe lower surface 5 and the rotational plane, and angle y is formed by stirring blade upper surface 6 and the rotational plane.
Figure 4 shows the shLape of breaking-up stirring blades 4 in top ~iew and in section, whereby the section is made along plane B - B. Breaking-up stirring blades 4 are arranged with a stirring shaft 8 of stirrer R 2 at a specific distance away. The total clistance is the sum of A1 to An~ Breaking-up stirring blades 4 are arranged perpendicularly to stirring shaft 8 and are arranged in a spiral around stirring shaft 8. The width of one of breaking-up stirring blades 4 is referred to as B 4. In section B - B, the trapezoidal cross-section of one ~f breaking-up stirring blades 4 is shown. Characteristic of the arrangement of the surfaces of the trapezoid are the angles ~, ~ and ~.
Angle ~ is formed by the ~;tirring blade lower side and the rotational plane. Angle ~) is produced by the inclined stirring blade upper side and the rotational plane. Angle ~ is formed by the stirring blade back side and the rotational axis.
For drying solutions, especially sugar solutions, various proeess-eontrol proeedures are known. The basie proeess steps of these t~chn;cal systems are determined by driers, miLls, and stirrers. In this case, the solutions are temperatw~e-equalized, the liquid is expelled, and the solids are mechanicaLly worked up. The advanee of drying is not determined during this process, but the output of the microwave energy is regulated IDY the surfaee temperature. Central elements of sueh mierowave driers are transmitters, conductors, and hot chambers. From the publication by Erich Pehl, Mikrowellentechnik, Wellenleitungen und Leitungsbausteine tMic:rowave Technology, Transmission Lines, and Concluetion Components]; Volume 1, p. 173; Heidelberg, calculation principles for antenna, i.e., transmitters, are know;n, by which length L1 ean be ealculated for a conical taper of a eylindrical pipe aecording to the relation L1 = n ~ ~/2 (n =
integral with L1 >> ~). Transformation elements are recommended CA 0221929~ 1997-10-24 for the transitions from rectangular waveguides to c~lindrical pipes or conical tapers of cylindrical waveguides. srhis is described in the publications of Meinke Gundlach; Taschenbuch der Hochfrec~uenztechnik [Handbook of High-Frequency Technology], Fourth Edition, Volume 2, p. 40 ff, Berlin, Heidelberg New York Tokyo, 1986 and H. Puchner, Warme durch Mikrowellen, Grundlagen, Bauelemente, Schaltungstechnik [Heat from Microwaves, Principles, Components, Circuit Engineering]~ Philips Technische Bibliothek tPhilips Technical Library] 1964.
Temperature-equalizal:ion is done in this connection by supplying heat energy with the aid of microwave radiation of 0.5-1~ GHz, preferably 0.915 and 2.45 GHz. In the case of these design solutions, the dra~back arises that local overheating develops in the applicato~s. As a result, the products that are to be dried are partially decomposed thermally. This overheating occurs especially in the areas where product accumulations occur on splatters of the material on conducting and non-conducting surfaces on the inside surfaces of the applicator.
In publication EP O 312 741 A2, a device for drying plastics is described. In this case, the device comprises a cylindrical drying chamber in which a stirrer for moving plastics is arranged. In addition, the device has a microwave c:oupler, which connects a microwave generator to the drying chamber.
It is disadvantageous that the particles that are to be dried can make direct con,tact with the generator ancl that irradiation is not well suited for solutions and crystalline substances with residual moisture. The generator is not adec~ately protected against pollution and overheat:ing, and the drying value of substances that are not plastics is ~nsatisfactory.
CA 0221929~ 1997-10-24 2a In publication FR 2 500 218, a device for drying with microwaves is described. In this case, the device comprises a drying chamber that is connected by a microwave coupler to a microwave generator. In this case, two separating surfaces, which are arranged perpendicular to the propagation axis of the microwave radiation, are located in the microwave coupler. In this case the microwave coupler is a rectangular hallow body in which the separating surfaces are settled somewhat concentrically. The shape of the microwave coupler is disadvantageous. Satisfactory drying crystalline substances with residual moisture and a material solution is not possible.
The object is thus 1:o dry crystalline substancles that are dissolved or have residual moisture, without local l~verheating occurring and the product thus being destroyed. In particular, differing material properties and varying diffusion properties are to cause no pro~lems in drying.
The object is achieved by a device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the device comprises at least one basically cylindrical or prism-shaped drying chamber (TK l and TK 2) that can be evacuated and temperature-equalized and in which a stirrer is placed, whereby the device comprises at least one microwave coupler (l), (a) the microwave coupler is connected to drying chamber (TKl or TK2);
(b) a separating surface (2), which is aligned basically perpendicular to longitudinal axis L of the microwave coupler, is arranged in the microwave coupler;
(c) the microwave coupler is designed with a taper, whereby the opening of the cone with the larger cross-section points toward the drying chamber;
and (d) the microwave coupler has the following proportions:
:L.4 < L1/D2 < g.o and :2.0 < Ll/L2 < 7.0;
in this case the values :L1, L2, D1 and D2 are characterized as follows:
L1 = a ~ A/2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of longitudinal axis L, which points from separating surface (2) in the direction away from drying chamber (TKl or TK2), L2 = partial length of longitudinal axis L, which points from separating surface (2) toward drying chamber (TK1 or TK2), and CA 0221929~ 1997-10-24 D2 = diameter of micrc>wave coupler (1) at the level of separating surface (2), ancl Dl = diameter of microwave coupler (1) at the level of the opening to drying chamber ~TKl or TK2).
The device preferably comprises several drying chambers, most preferably two drying chambers. At least one microwave coupler is connected to each drying chamber. Preferred are several microwave couplers per drying chamber. The drying chamber also has at least one stirring system. The microwave coupler and the stirring system can be controlled by known control units. The microwave couplers (tapers) are made cone-shaped, where~y the larger cross-section points towarl~ the drying chamber, and ~he smaller cross-section is connected t~D the generator. A separating surface, whose position is determined according to the previously mentioned proportions and dimensions, is placed between the two c:one openings. The diameter of the separating surface should be no less than 120 mm. The distance between the large cone opening and the separating surface should be at least 100 mm. In this case, the surface of the separating surface has a m; n; ~m absorption coefficient, so that the spatters of the solutions clo not spread on the surface.
Microwave drying usually also comprises a stirring process.
Here, it is possible to use known stirrers.
A device according to the invention in which the material of the separating surface has a minimum absorption coefficient is preferred. As a result, local hot spots can be successfully avoided. Preferred is a device according to the invention in CA 0221929~ 1997-10-24 ~ 1 5 which (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids comprise sugars.
More preferred are monosaccharides. Still more preferred are material solutions, crystalline substances with residual moisture, or solids with residual moisture, which comprise a contrast medium. Most preierred is an ultrasonic contrast medium. Such ultrasonic contrast media are described in European publications EP-A 0 052 57C~ (date of application 11/17/81) and EP-A 0 365 467 (date of application 4/6/89). The production processes are also explaine~d in detail in these publications.
More preferred is a device according to the invention in which stirrer (R 1) comprises a stirring shaft to which at least one L-shaped stirring blade is fastened;
whereby the stirring blade is characterized by the following proportions and dimensions:
(0.9 < B1 < 1.3) ~ ~ ~ (TKl) exp (-1/2) 1.5 < B2/B1 < 2.5 (0.65 < B3 < 1.35) ~ ~/2;
in this case, values ]31, B2 and B3 are characterized as follows:
B1 = the width oE the long leg of stirring blade (3);
B2 = the length of the short leg including the width of the long leg, and B3 = the width of the short leg of stirring blade (3), the stirring blades have angles to the rotational plane, CA 0221929~ 1997-10-24 in this case, the cross-sec~tion of the stirring blades is triangular and has a stirring blade lower surface, a stirring blade back surface, and a stirring blade upper surface; in this case the stirring blade back surface points in the direction of the short leg, whereby the angles are characterized by the following values:
c~-angle between stirr:ing blade back surface and rotational axis has the value of 5~ to 15~;
B-angle between stirr:ing blade lower surface and rotational plane has the vaLue of 2~ to 10~; and ~-angle between stirr:ing blade upper surface and rotational plane has the vaLue of 25~ to 40~.
Thermal decomposition of the products is success,fully avoided by the combination of the special microwave coupler and the stirring blades. The aLmount of microwave energy added can be controlled specifically as a function of the advance of the drying and the physical material properties that are thus altered insicle the product. Thus, elevated diffusion resistances that accompany solidification are successfully compensatec,L. Caking and overheating of the product are successfully avoic'led. The drying process proceeds in a directed manner. A procluct results that meets even the high requirements that are set for pharmaceutical products.
The device according to the invention has the aclvantage that sticking and thermal destruction of the product are reliably avoided by the special embodiment of the microwave coupler, especially by the defined size and position of the separating CA 0221929~ 1997-10-24 surface of the coupler in connection with specifically configured stirrers of the drying pro<ess -- preferably under a vacuum -- by measuring the amount of condensate and a control that prevents the set temperature limits from being exceeded inside the product that is to be dried, and d~ying of the product up to a defined value is made possible. The advance of drying is det.ermined from the amount of condensate o:E the amount of li~uid that. is evaporated. With increasing solid content, the diffu.sion resistance of the product :increases relative to the ~olvent that is to be separated. With the smaller evaporating sol.vent stream, less energy is dissipated ;lt constant energy supply. In this case, the temperature of the product increases. In t.he case where energy is supplied by means of microwave radiat:ion, this temperature increase occurs mainly inside the product: and in this case is either unmeasurabl,_ or only slightly measurable on the surface.
This physical process can be reproduced with the advance of drying and is taken into consideration in the regulat:ion process such that at various points along the way (amounts of condensate of the separated solvent, .specific portion of solvent:), the difference between the internal and external temperat:ures of the product is determined under identical drying conditions. In this case, various sizes and types of product agglomerations or product concentrations must be taken into consideration. The product temperature that is thus determined is a regulating variable for the control unit, which in turn determines the energy supply of the microwave radiation.
CA 0221929~ 1997-10-24 Preferred is a device according to the invention in which the adva~ce of the drying 1Ls determined and is controlled; during the advance of the drying, the diffusion resistance of the product is used as a regulating variable as a function of the advance of drying.
Preferred is a device according to the invention in which stirrer (R2) that projects into drying chamber (TK2) has at least one stirring blade and also one or more breaking-up stirring blades that are mounted ofiset over-one another, which are arranged at distance (A1 . An) from the lower rotational plane of slirrer (R2), have leg width (B4), and in this case comprise the following proportions and dimensions:
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-An = 60 mm to 100 mm.
Study of individual arLgles compared to the rotat.ional plane revealed that some angles aLre more preferred. As a result, a device according to the invention is produced in which the breaking up stirring blade-, have an angle to the rota.tional plane;
whereby the cross-section of the breaking-up sti.rring blades is trapezoidal, and whereby the cross-section of the breaking-up sti.rring blades is determined by the angle with the following values:
~-angle between the lower side of the stirring blade and the rotational plane has the value of 5~ t:o 15~;
CA 0221929~ 1997-10-24 ~-angle between the inclined stirring blade upper side and the rotational plane has the value of 20~ to 45~;
and ~-angle between the back side of the ~tirring blade and axis of rotation has the value of 5~ to ~5~
Especially advantageous is a device according to the invention in which the special shape and arrangement of the stirring blades of the stirrer in the first drying chamber and the additional breaking-up stirring blades in the sec~ond drying chamber interact in a sensible way. optimum breaking-up and thorough mixing of the product are ensured by a spec:Lfic cross-section shape and arrangem.ent of the stirring blades. Therefore, not only is the mixed material pushed back and forth by the stirring blades, but also the drying process is accelerated with the stirrer and optimally configured. An especially advantageous effect is achieved with a device according to the invention in that in a known way, the shell of the drying chambers is temperature-equalized, so that, depending on the advance of solidification and the variation in the change in toughness that is achieved by slightly increasing or decreasing the wall temperature, the shearing forces between the inside surface of the drying chamber and the product are influenced in a positive manner.
The invention also comprises a process for drying (i) material solutions, (ii) crystalline substances with. residual CA 0221929~ 1997-10-24 moisture, (iii) solids Wit]l residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the proce!ss comprises the following steps:
aa) Production of the solution, bb) optionally filtr.ation, cc) microwave drying using a device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) col]oids, whereby the device comprises at least one basically cylindrical or prism-shaped drying chamber"
in which a stirrer is arranged, in this case the device comprises at least one microwave coupler (1), (a) the microwave coupler is connected to the drying chamber;
(b) arranged in the microwave couple:r is a separa.ting surface, which is aligned basically perpendicular t:o longitudinal axis L of the microwave coupler;
(c) the mi.crowave coupler is designed with a taper,.
whereby the opening of the cone with the :Larger cross-section points toward the drying chamber;
and CA 0221929~ 1997-10-24 (d) the microwave coupler has the following proportions:
1.4 < L1/D2 < 9.0 and 2.0 < L1/L2 < 7.0;
in this case values L1, L2, D1 and D2 are characterized as follows:
L1 = a ~ ~/2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of lonc~itudinal axis L, which points from the separating surface in the direction away from the drying chamber, L2 = partial length of long:itudinal axis L, which points from the separating s,urface toward the drying chamber, D2 = diameter of the microwaLve coupler a,t the level of the separating surface, aLnd D1 = diameter of the microwave coupler at the level of the opening to the drying chamber;
d) final drying and e) crush'Lng.
Filtration can be sterile filtration or ultrafiltration or a combination of the two.
CA 022l929~ l997-l0-24 , 12 The product that results from the final drying k,as a residual moisture of 1% by weight, and preferably 0.5~ by weight or less.
The product that is produced by this process can be marketed as a diagnostic agent.
Preferred is a process according to the invention, whereby the material of the separating surface has a minimum absorption coefficient.
Very advantageous is a process according to the invention, whereby the (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residua:L moisture comprise sugar.
Preferred is a process, whereby the sugar is a monosaccharide.
More preferred is a process according to the invention, whereby the (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residua;l moisture comprise a contrast medium.
Most preferred is a process according to the invention, whereby the ~i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise an ultrasonic contrast medium.
Advantageous is a process according to the invention, whereby stirrer (R 1) comprises a stirring shaft, to which at least one L-shaped stirring blade is fastened;
whereby the stirring blade is characterized by the following proportions and dimensions:
CA 0221929~ 1997-10-24 , 13 (0.9 < B1 ~ 1.3) ~ ~ (TK1) exp (-1/2) 1.5 < B2/B1 < 2.!, (0.65 < B3 < 1.35) ~ ~/2;
in this case, values ~31, B2 and B3 are characterized as follows:
Bl = the width o:E the long leg of the stirring blade;
B2 = the length of the short leg including the width of the long leg, anl~
B3 = the width of the short leg of the stirring blade, the stirring blades have a:ngles to the rotational plaLne, in this case, the cross-section of the stirring blades is triangular and has a stirring blade lower surface, a stirring blade back surface and a stirring blade upper surface, in this case the stirring blade back surface points in the direction of the short leg, whereby the angles are characterized by the fol:Lowing values:
~-angle between stirring blade back surface and rotational axis has the value of 5~ to 15~;
B-angle between stirring blade lower surface and rotational plane has the va.lue of 2~ to 10~; and ~-angle between stirring blade upper surface and rotational plane has the vaLlue of 25~ to 40~.
Preferred is a process according to the invention/ whereby stirrer (R2) that projects into drying chamber (TK2) has at least CA 0221929~ 1997-10-24 one stirring blade and in addition one or more breaking-up stirring blades that are mounted offset over one anot.her, which are arranged at distance (A~ . An) from the lower rotational plane of s-tirrer (R2), have leg width (B4), and in this case comprise the following proportions and dimensions:
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-An = 60 mm to 100 mm.
More preferred is a process according to the invention, where.by the breaking-up stirring blades have angles t:o the rotational plane; whereby the cross-section of the breaking-up stirring blade is trapezoidal, and whereby the cross-section of the breaking-up stirring blades is determined by the angle with the following values:
~-angle between the lower side of the stirring blade and the rotational plane has the value of 5~1to 15~;
~-angle between the inclined stirring blade upper side a.nd the rotational plane ha~; the value of 5~ to 15~;
and ~-angle bet:ween the back side of the stirring blade and axis of rotation has the value of 5~ to 15~.
Most preferred is a process according to the invention for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) CA 022l929~ l997-l0-24 suspensions, (v) emulsions and/or (vi) colloids, whereby the process comprises the following steps:
a) Production of the solution, b) optionally filtration, c) microwave drying using the device, d) final drying, e) crushing and f) agglomeration.
The purpose of the agglomeration is to convert a crushed substance, which is difficult to handle and to transport, into a form that does not involve these problems. In this ~_ase, however, the property to pass quickly into solution is not to be impaired. The particles are held together in the agglomerite elements by van der Waals forces.
The product that is aLchieved by the above-described process is the substance that is reasonably marketed. It is easily possible to incorporate the product into solutions. Then, it can be injected into patients. It makes it possible to execute imaging diagnoses on human or animal bodies, whereby data material is created that allows the physician, based on his specific knowledge and his technical expertise, to propose a suitable treatment therap~y. More preferred is a process according to the invention in which the material solution contains an ultrasonic col~trast medium; most preferred is an ultrasonic contrast medium that comprises a monosaccharide. In this case, contrast media that are described in detail in the previously mentioned publications EP-A 0 052 575 and EP-A 0 365 -CA 022l929~ l997-l0-24 467 are especially preferred. The diagnostic agents Echovist and Levovist comprise gas-containing microparticles basecL on galactose, without or with palmitic acid.
Very preferred is a process according to the imrention, whereby the material solution contains an ultrasonic contrast medium.
Most preferred is a process according to the in~ention, whereby the ultrasonic contrast medium comprises monosaccharide.
The device according to the invention is described below by way of example.
Figure 1 shows a diagrammatic visualization of 1:he device.
Figure 2 shows a diagrammatic visualization of 1_he microwave coupler.
Figure 3 shows a top view of the stirring blade, and a section through a stirring blade of the stirrer of the first drying chamber along section A-A.
Figure 4 shows a top view of the stirring blades and a section through a breaking-up stirring blade of the stirrer of the second drying chamber along section B-B.
A device for drying solutions is diagrammatically depicted in Figure l. In this case, these are sugar-containing liquids, namely either an echovist or a levovist. The device consists of a first dryil~g chamber TK l with a stirrer Rl and a second drying chamber TK 2 with a stirrer R2. On the cover of the drying chambers are microwave couplers l with generators G as well as a control unit S. Between 1:he two drying chambers is arranged a crushing machine of a known type. Through an intake opening, CA 022l929~ l997-l0-24 , 17 which i5 not depicted in more detail, the product to be dried is put into first drying chamber TK 1. After the device is turned on, suitable microwave energy in drying chamber TK 1 is introduced from generator 1~ via microwave coupler 1. At the same time, stirrer R 1 is cause~d to start rotating. The clrying process is based on both of these activities. The surface temperature and advance of drying are measured by known sensors, which also are not depicted in the figure, and relayed to control unit S. The latter regulates, as a function of the advance of drying il~ the above-described way via an established regulating program, the amount of energy for microwave coupler ~ of drying chamber TK 1 and also the rpm of stirrer R 1.
Then, the drying process in second drying chamber TK 2 is continued. Also in the second drying stage, the amolmt of energy for microwave coupler 1 and for the rpm of stirrer R 2 is regulated in approximately the same way as previously described.
Figure 2 shows a microwave coupler 1. It is conical in design. The opening with the smaller cross-section points toward generator G and is designed in the form of a square. The opposite opening, which is connected to the drying cllamber, has a round cross-section. Microwave coupler 1 is divided into two sectors by a separating surface 2. The surface of separating surface 2 is perpendicular to the longitudinal axis of microwave coupler 1 and is divided into two sectors by separating surface 2. The surface of separating surface 2 is perpendicular to the longitudinal axis of micrc,wave coupler 1. For this purpose, the longitudinal axis is divided into two partial length~. Partial CA 022l929~ l997-l0-24 ' , 18 length L l points from separating surface 2 toward generator G or away from drying chamber TK l or TK 2. Partial lengt;h L l extends from separating surface 2 to drying chamber ~K l or TK 2.
The sum of partial lengths L l and L 2 yields the to1:al length of longitudinal axis L. The separating surface has a d:Lameter D 2, The opening of the microwave coupler, which points toward the drying chamber, has a diameter D l. The relation of the individual lengths, namely L l, L 2, D l and D 2, was presented in the prior text of the description, It goes without saying that the proportions that are pictured in Figure 2 a~e not binding; rather it is a diagrammatic view.
Three stirring blades 3 of stirrer R l are depi~-ted in Figure 3. Stirring blades, 3 are L-shaped. The direction of rotation of the stirring blades is basically parallel to the floor surface of drying ch,amber TK l, A stirring shaft 8 of stirrer R l is perpendicular to the floor surface. The stirring blades are depicted in Figure 3 both in top view and in the section along sectional plane A - A. In this case, the width of the long leg of stirring blade 3 is referred to as B l and the width of the short leg is referred to as B 3. The length of the short leg has designation B 2. The proportions of length dimensions B l, B 2 and B 3 were explained in detail in the previous text. Also in this case, the proportions depicted are defined only diagrammatically.
The cross-section that is indicated by section A - A of one of stirring blades 3 has a triangular shape. Such a stirring blade 3 has three surfaces, namely a stirring blade lower surface CA 0221929~ 1997-10-24 ' ~ 19 5 that points downward, a stirring blade upper surfare 6 that points upward, and a stirring blade back surface 7 t]nat points basically to the side. Three angles are essential for the actual orientation of the previously mentioned three stirring blade surfaces, namely angles ~, ~ and ~. Angle ~ is form~_d by stirring blade back surface 7 and the axis of rotation; angle is formed by stirring bladLe lower surface 5 and the rotational plane, and angle y is formed by stirring blade upper surface 6 and the rotational plane.
Figure 4 shows the shLape of breaking-up stirring blades 4 in top ~iew and in section, whereby the section is made along plane B - B. Breaking-up stirring blades 4 are arranged with a stirring shaft 8 of stirrer R 2 at a specific distance away. The total clistance is the sum of A1 to An~ Breaking-up stirring blades 4 are arranged perpendicularly to stirring shaft 8 and are arranged in a spiral around stirring shaft 8. The width of one of breaking-up stirring blades 4 is referred to as B 4. In section B - B, the trapezoidal cross-section of one ~f breaking-up stirring blades 4 is shown. Characteristic of the arrangement of the surfaces of the trapezoid are the angles ~, ~ and ~.
Angle ~ is formed by the ~;tirring blade lower side and the rotational plane. Angle ~) is produced by the inclined stirring blade upper side and the rotational plane. Angle ~ is formed by the stirring blade back side and the rotational axis.
Claims (21)
1. Device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the device comprises at least one basically cylindrical or prism-sha,ped drying chamber (TK 1 and TK 2) in which a stirrer is placed, in this case the device comprises at least one microwave coupler (1), (a) the microwave coupler is connected to dryring chamber (TK1 or TK2);
(b) a separating surface (2), which is aligned basically perpendicular to longitudinal axis L of the microwave coupler, is arranged in the microwave coupler;
(c) the microwave coupler is designed with a taper, whereby the opening of the cone with the larger cross-section points toward the drying chamber;
and (d) the microwave coupler has the following proportions:
1.4 < L1/D2 < 9.0 and 2.0 < L1/L2 < 7.0;
in this case the values L1, L2, D1 and D2 are characterized as follows:
L1 = a ~ .lambda./2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of longitudinal axis L, which points from separating surface (2) in the direction away from drying chamber (TK1 or TK2), L2 = partial length of longitudinal axis L, which points from separating surface (2) toward drying chamber (TK1 or TK2), D2 = diameter of microwave coupler (1) at the level of separating surface (2).
(b) a separating surface (2), which is aligned basically perpendicular to longitudinal axis L of the microwave coupler, is arranged in the microwave coupler;
(c) the microwave coupler is designed with a taper, whereby the opening of the cone with the larger cross-section points toward the drying chamber;
and (d) the microwave coupler has the following proportions:
1.4 < L1/D2 < 9.0 and 2.0 < L1/L2 < 7.0;
in this case the values L1, L2, D1 and D2 are characterized as follows:
L1 = a ~ .lambda./2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of longitudinal axis L, which points from separating surface (2) in the direction away from drying chamber (TK1 or TK2), L2 = partial length of longitudinal axis L, which points from separating surface (2) toward drying chamber (TK1 or TK2), D2 = diameter of microwave coupler (1) at the level of separating surface (2).
2. Device according to claim 1, whereby the material of separating surface (2) has a minimum absorption coefficient.
3. Device according to claim 1 or 2, whereby (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise sugars.
4. Device according to claim 3, whereby the sugar is a monosaccharide.
5. Device according to one of the preceding claims, whereby (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise a contrast medium.
6. Device according to claim 5, whereby (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise an ultrasonic contrast medium.
7. Device according to one of the preceding claims, whereby stirrer (R1) comprises a stirring shaft (8), to which at least one L-shaped stirring blade (3) is fastened;
whereby stirring blade (3) is characterized by the following proportions and dimensions:
(0.9 < B1 < 1 3) ~ .pi. ~ (TK1) exp (-1/2) 1.5 < B2/B1 < 2.5 (0.65 < B3 < 1.35) ~ .lambda./2;
in this case, values B1, B2, and B3 are characterized as follows:
B1 = the width of the long leg of stirring blade (3);
B2 = the length of the short leg including the width of the long leg, and B3 = the width of the short leg of stirring blade (3), stirring blades (3) have angles to the rotational plane, in this case the cross-section of stirring blades (3) is triangular and has a stirring blade lower surface (5) a stirring blade back surface (7), and a stirring blade upper surface (6) in this case stirring blade back surface (7) points in the direction of the short leg, whereby the angles are characterized by the fallowing values:
.alpha.-angle between stirring blade back surface and rotational axis has the value of 5° to 15°;
.beta.-angle between stirring blade lower surface and rotational plane has the value of 2° to 10°; and .gamma.-angle between stirring blade upper surface and rotational plane has the value of 25° to 40°.
whereby stirring blade (3) is characterized by the following proportions and dimensions:
(0.9 < B1 < 1 3) ~ .pi. ~ (TK1) exp (-1/2) 1.5 < B2/B1 < 2.5 (0.65 < B3 < 1.35) ~ .lambda./2;
in this case, values B1, B2, and B3 are characterized as follows:
B1 = the width of the long leg of stirring blade (3);
B2 = the length of the short leg including the width of the long leg, and B3 = the width of the short leg of stirring blade (3), stirring blades (3) have angles to the rotational plane, in this case the cross-section of stirring blades (3) is triangular and has a stirring blade lower surface (5) a stirring blade back surface (7), and a stirring blade upper surface (6) in this case stirring blade back surface (7) points in the direction of the short leg, whereby the angles are characterized by the fallowing values:
.alpha.-angle between stirring blade back surface and rotational axis has the value of 5° to 15°;
.beta.-angle between stirring blade lower surface and rotational plane has the value of 2° to 10°; and .gamma.-angle between stirring blade upper surface and rotational plane has the value of 25° to 40°.
8. Device according to claim 7 whereby stirrer (R2) that projects into drying chamber (TK2) has at least one stirring blade (3), and in addition one or more breaking-up stirring blades (4) that are mounted offset over one another, which are arranged at a distance (A1 ... An) from the lower rotational plane of stirrer (R2) have leg width (B4), and in this case comprise the following proportions and dimensions:
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-An = 60 mm to 100 mm.
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-An = 60 mm to 100 mm.
9. Device according to claim 8 whereby breaking-up stirring blades (4) have an angle to the rotational plane;
whereby the cross-section of breaking-up stirring blades (4) is trapezoidal and whereby the cross-section of breaking-up stirring blades (4) is determined by the angle with the following values:
.epsilon.-angle between the stirring blade lower side and the rotational plane has the value of 5° to 15°;
~-angle between the inclined stirring blade upper side and the rotational plane has the value of 20° to 45°;
and .delta.-angle between stirring blade back side and rotational axis has the value of 5° to 15°.
whereby the cross-section of breaking-up stirring blades (4) is trapezoidal and whereby the cross-section of breaking-up stirring blades (4) is determined by the angle with the following values:
.epsilon.-angle between the stirring blade lower side and the rotational plane has the value of 5° to 15°;
~-angle between the inclined stirring blade upper side and the rotational plane has the value of 20° to 45°;
and .delta.-angle between stirring blade back side and rotational axis has the value of 5° to 15°.
10. Process for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the process comprises the following steps:
aa) Production of the solution, bb) optionally filtration, cc) microwave drying using a device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions, or (vi) colloids, whereby the device comprises at least one basically cylindrical or prism-shaped drying chamber (TK 1 and TK 2), in which a stirrer is arranged, in this case the device comprises at least one microwave coupler (1), (a) the microwave coupler is connected to drying chamber (TK1 or TK2), (b) arranged in the microwave coupler is a separating surface (2), which is aligned basically perpendicular to longitudinal axis L of the microwave coupler;
(c) the microwave coupler is designed with a taper, whereby the opening of the cone with the larger cross-section points toward the drying chamber;
and (d) the microwave coupler has the following proportions:
1.4 < L1/D2 < 9.0 and 2.0 < L1/L2 < 7.0;
in this case values L1, L2 and D2 are characterized as follows:
L1 = a ~ .lambda./2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of longitudinal axis L, which points from separating surface (2) in the direction away from drying chamber (TK1 or TK2), L2 = partial length of longitudinal axis L, which points from separating surface (2) toward drying chamber (TK1 or TK2), D2 = diameter of microwave coupler (1) at the level of separating surface (2);
d) final drying and e) crushing.
aa) Production of the solution, bb) optionally filtration, cc) microwave drying using a device for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions, or (vi) colloids, whereby the device comprises at least one basically cylindrical or prism-shaped drying chamber (TK 1 and TK 2), in which a stirrer is arranged, in this case the device comprises at least one microwave coupler (1), (a) the microwave coupler is connected to drying chamber (TK1 or TK2), (b) arranged in the microwave coupler is a separating surface (2), which is aligned basically perpendicular to longitudinal axis L of the microwave coupler;
(c) the microwave coupler is designed with a taper, whereby the opening of the cone with the larger cross-section points toward the drying chamber;
and (d) the microwave coupler has the following proportions:
1.4 < L1/D2 < 9.0 and 2.0 < L1/L2 < 7.0;
in this case values L1, L2 and D2 are characterized as follows:
L1 = a ~ .lambda./2 a = 6, 7, 8, 9, 10, 11, 12, 13 or 14;
L1 = partial length of longitudinal axis L, which points from separating surface (2) in the direction away from drying chamber (TK1 or TK2), L2 = partial length of longitudinal axis L, which points from separating surface (2) toward drying chamber (TK1 or TK2), D2 = diameter of microwave coupler (1) at the level of separating surface (2);
d) final drying and e) crushing.
11. Process according to claim 10, whereby the material of separating surface (2) has a minimum absorption coefficient.
12. Process according to claim 10 or 11, whereby (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprises sugars.
13. Process according to claim 12, whereby the sugar is a monosaccharide.
14. Process according to one of the preceding claims 10 to 13, whereby (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise a contrast medium.
15. Process according to claim 14, whereby (i) material solutions, (ii) crystalline substances with residual moisture, or (iii) solids with residual moisture comprise an ultrasonic contrast medium.
16. Process according to one of the preceding claims 10 to 15, whereby stirrer (R 1) comprises a stirring shaft (8), to which at least one L-shaped stirring blade (3) is fastened;
whereby stirring blade (3) is characterized by the following proportions and dimensions:
(0.9 < B1 < 1.3) ~ .pi. ~ (TK1) exp (-1/2) 1.5 < B2/B1 < 2.5 (0.65 < B3 < 1.35) ~ .lambda./2;
in this case, values B1, B2 and B3 are characterized as follows:
B1 = the width of the long leg of stirring blade (3);
B2 = the length of the short leg including the width of the long leg, and B3 = the width of the short leg of stirring blade (3), stirring blades (3) have angles to the rotational plane in this case the cross-section of stirring blades (3) is triangular and has a stirring blade lower surface (5), a stirring blade back surface (7), and a stirring blade upper surface (6), in this case stirring blade back surface (7) points in the direction of the short leg, whereby the angles are characterized by the following values:
.alpha.-angle between stirring blade back surface and rotational axis has the value of 5° to 15°;
.beta.-angle between stirring blade lower surface and rotational plane has the value of 2° to 10°; and .gamma.-angle between stirring blade upper surface and rotational plane has the value of 25° to 40°.
whereby stirring blade (3) is characterized by the following proportions and dimensions:
(0.9 < B1 < 1.3) ~ .pi. ~ (TK1) exp (-1/2) 1.5 < B2/B1 < 2.5 (0.65 < B3 < 1.35) ~ .lambda./2;
in this case, values B1, B2 and B3 are characterized as follows:
B1 = the width of the long leg of stirring blade (3);
B2 = the length of the short leg including the width of the long leg, and B3 = the width of the short leg of stirring blade (3), stirring blades (3) have angles to the rotational plane in this case the cross-section of stirring blades (3) is triangular and has a stirring blade lower surface (5), a stirring blade back surface (7), and a stirring blade upper surface (6), in this case stirring blade back surface (7) points in the direction of the short leg, whereby the angles are characterized by the following values:
.alpha.-angle between stirring blade back surface and rotational axis has the value of 5° to 15°;
.beta.-angle between stirring blade lower surface and rotational plane has the value of 2° to 10°; and .gamma.-angle between stirring blade upper surface and rotational plane has the value of 25° to 40°.
17. Process according to claim 16 whereby stirrer (R2) that projects into drying chamber (TK2) has at least one stirring blade (3) and in addition one or more breaking-up stirring blades (4) that are mounted offset over one another, which are arranged at a distance (A1 ... An) from the lower rotational plane of stirrer (R2), have leg width (B4), and in this case comprise the following proportions and dimensions:
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-A = 60 mm to 100 mm.
B4 = 0.3 ~ B 1 to 0.8 ~ B 1 A1-A = 60 mm to 100 mm.
18. Process according to claim 17, whereby breaking-up stirring blades (4) have an angle to the rotational plane;
whereby the cross-section of breaking-up stirring blades (4) is trapezoidal, and whereby the cross-section of breaking-up stirring blades (4) is determined by the angle with the following values:
.epsilon.-angle between the stirring blade lower side and the rotational plane has the value of 5° to 15°;
~-angle between the inclined stirring blade upper side of the stirring blade and the rotational plane has the value of 20° to 45°;
and .delta.-angle between the stirring blade back side and the rotational axis has the value of 5° to 15°.
whereby the cross-section of breaking-up stirring blades (4) is trapezoidal, and whereby the cross-section of breaking-up stirring blades (4) is determined by the angle with the following values:
.epsilon.-angle between the stirring blade lower side and the rotational plane has the value of 5° to 15°;
~-angle between the inclined stirring blade upper side of the stirring blade and the rotational plane has the value of 20° to 45°;
and .delta.-angle between the stirring blade back side and the rotational axis has the value of 5° to 15°.
19. Process according to one of claims 10 to 18 for drying (i) material solutions, (ii) crystalline substances with residual moisture, (iii) solids with residual moisture, (iv) suspensions, (v) emulsions and/or (vi) colloids, whereby the process comprises the following steps:
a) Production of the solution, b) optionally filtration, c) microwave drying using the device, d) final drying, e) crushing and f) agglomeration.
a) Production of the solution, b) optionally filtration, c) microwave drying using the device, d) final drying, e) crushing and f) agglomeration.
20. Process according to one of claims 10 to 19, whereby the material solution contains an ultrasonic contrast medium.
21. Process according to claim 20, whereby the ultrasonic contrast medium comprises monosaccharides.
List of Reference Symbols Used 1 Microwave coupler 2 separating surface 3 stirring blade 4 breaking-up stirring blade stirring blade lower surface 6 stirring blade upper surface 7 stirring blade back surface 8 stirring shaft TK 1, TK 2 drying chamber R 1, R 2 stirrer G generator S control unit B 1, B 2, B 3, B 4 stirrer dimensions D 1, D 2 diameter
List of Reference Symbols Used 1 Microwave coupler 2 separating surface 3 stirring blade 4 breaking-up stirring blade stirring blade lower surface 6 stirring blade upper surface 7 stirring blade back surface 8 stirring shaft TK 1, TK 2 drying chamber R 1, R 2 stirrer G generator S control unit B 1, B 2, B 3, B 4 stirrer dimensions D 1, D 2 diameter
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19516254.4 | 1995-04-26 | ||
| DE19516254A DE19516254A1 (en) | 1995-04-26 | 1995-04-26 | Device for drying material solutions, crystalline substances with residual moisture, especially for liquids containing sugar |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2219295A1 true CA2219295A1 (en) | 1996-10-31 |
Family
ID=7760989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002219295A Abandoned CA2219295A1 (en) | 1995-04-26 | 1996-04-25 | Device for drying crystalline substances |
Country Status (15)
| Country | Link |
|---|---|
| EP (1) | EP0824662A1 (en) |
| JP (1) | JPH11504752A (en) |
| KR (1) | KR19990008067A (en) |
| CN (1) | CN1182476A (en) |
| AU (1) | AU5761396A (en) |
| BR (1) | BR9608073A (en) |
| CA (1) | CA2219295A1 (en) |
| CZ (1) | CZ339897A3 (en) |
| DE (3) | DE19516254A1 (en) |
| HU (1) | HUP9802481A3 (en) |
| IS (1) | IS4592A (en) |
| NO (1) | NO974929L (en) |
| PL (1) | PL322970A1 (en) |
| TR (1) | TR199701244T1 (en) |
| WO (1) | WO1996034239A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108981328A (en) * | 2018-06-30 | 2018-12-11 | 湖州全优电工材料有限公司 | A kind of new high-efficiency silica powder drying machine |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2192980B2 (en) * | 2002-01-16 | 2006-06-01 | Baucis, S.A. | MICROWAVE-DRYER-REACTOR MIXER. |
| UA86702C2 (en) * | 2007-09-11 | 2009-05-12 | Закрытое Акционерное Общество "Технологический Парк "Институт Монокристаллов" | Drier for bulk dielectric materials |
| KR102084611B1 (en) * | 2019-05-13 | 2020-05-04 | 김태영 | Apparatus for treating organic sludge |
| CN110986525B (en) * | 2019-12-25 | 2021-08-13 | 常州市华夏干燥制粒设备有限公司 | Rotary flash dryer |
| CN115493363A (en) * | 2022-09-26 | 2022-12-20 | 董清臣 | Microwave drying and sterilizing equipment |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4330946A (en) * | 1980-09-23 | 1982-05-25 | Ralph S. Tillitt | High efficiency material drying |
| FR2500218A1 (en) * | 1981-02-19 | 1982-08-20 | Auhfa | Hyperfrequency applicator for drying, sterilising etc. - has two dielectric plates spaced in waveguide and axially movable by screw threaded adjuster to vary impedance |
| EP0312741A3 (en) * | 1987-08-29 | 1990-01-31 | Nissui Kako Co., Ltd. | Method and apparatus for the microwave drying of plastic material |
| AU627056B2 (en) * | 1989-09-28 | 1992-08-13 | Nikken Corporation | Raw sewage drying apparatus |
| US5105555A (en) * | 1990-01-11 | 1992-04-21 | Shoji Nakagomi | Plastic drying apparatus |
-
1995
- 1995-04-26 DE DE19516254A patent/DE19516254A1/en not_active Withdrawn
- 1995-04-26 DE DE19549494A patent/DE19549494A1/en not_active Withdrawn
-
1996
- 1996-04-25 EP EP96914119A patent/EP0824662A1/en not_active Ceased
- 1996-04-25 WO PCT/EP1996/001726 patent/WO1996034239A1/en not_active Application Discontinuation
- 1996-04-25 HU HU9802481A patent/HUP9802481A3/en unknown
- 1996-04-25 CA CA002219295A patent/CA2219295A1/en not_active Abandoned
- 1996-04-25 JP JP8532172A patent/JPH11504752A/en active Pending
- 1996-04-25 CN CN96193518A patent/CN1182476A/en active Pending
- 1996-04-25 KR KR1019970707591A patent/KR19990008067A/en not_active Withdrawn
- 1996-04-25 BR BR9608073A patent/BR9608073A/en not_active Application Discontinuation
- 1996-04-25 AU AU57613/96A patent/AU5761396A/en not_active Abandoned
- 1996-04-25 CZ CZ973398A patent/CZ339897A3/en unknown
- 1996-04-25 DE DE19680284T patent/DE19680284D2/en not_active Expired - Lifetime
- 1996-04-25 TR TR97/01244T patent/TR199701244T1/en unknown
- 1996-04-25 PL PL96322970A patent/PL322970A1/en unknown
-
1997
- 1997-10-16 IS IS4592A patent/IS4592A/en unknown
- 1997-10-24 NO NO974929A patent/NO974929L/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108981328A (en) * | 2018-06-30 | 2018-12-11 | 湖州全优电工材料有限公司 | A kind of new high-efficiency silica powder drying machine |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0824662A1 (en) | 1998-02-25 |
| IS4592A (en) | 1997-10-16 |
| PL322970A1 (en) | 1998-03-02 |
| MX9708022A (en) | 1997-11-29 |
| HUP9802481A3 (en) | 1999-04-28 |
| NO974929L (en) | 1997-12-23 |
| JPH11504752A (en) | 1999-04-27 |
| DE19680284D2 (en) | 1999-07-01 |
| DE19549494A1 (en) | 1997-10-02 |
| AU5761396A (en) | 1996-11-18 |
| HUP9802481A2 (en) | 1999-02-01 |
| TR199701244T1 (en) | 1998-02-21 |
| WO1996034239A1 (en) | 1996-10-31 |
| CZ339897A3 (en) | 1998-06-17 |
| DE19516254A1 (en) | 1996-10-31 |
| CN1182476A (en) | 1998-05-20 |
| BR9608073A (en) | 1999-01-26 |
| NO974929D0 (en) | 1997-10-24 |
| KR19990008067A (en) | 1999-01-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |