US1541115A - Extracting material - Google Patents

Description

June 9, 1925. i1,541,115

F. J. E. CHINA EXTRACTLNG MA'ERIAL Filed May 19. 1923 Patented June 9, 1925.

UNITED lSTATES FREDERICK JOHN EDWIN CHINA, OF ESI-IER, ENGLAND.

EXTRACTING MATERIAL.

Application filed May 19,

To all 'whom it may concern.:

Be it known that I, FREDERICK JOHN ED- wIN CHINA, a subject of the King of Great Britain, residing at Esh'er, in the county of Surrey, England, have invented certain new and useful Improvements in Extracting Materials, of which thefollowing is a specification. i

My invention relates to the extraction of substances from solids, and it has been successfully employed in the pharmaceutical industry for the extraction ot' desired substances from meat and other anilnal tissues, as well as vegetable materials, such as woods, barks, leaves, grasses, roots, tubers, and other such tissues.

An object of my invention is to provide a method of extraction which will give a high percentage of the extractable substances in one short extracting operation.

Another object of my invention is to show how to extract desirable substances from solid matter in a quick and economical operation.

A still further object of my invention is to provide a system of extraction wherein the entire process is carried out continuously and in a closed circuit, whereby very volatile solvents may be employed without danger of their loss by evaporation.

III the methods heretofore used, extraction has ordinarily been accomplished by subjecting the solid matter to any one of the following processes: (I) percolation; (2) maceration; digestion; (4) distillation; or the combination of any or all f these. In such processes it is ordinarily necessary to subject the solid particles to successive re-treatments inorder to secure a satisfactory percentage yield of substances extracted, and even where ree-treatment has not been necessary, the process has generally been a protracted operation. These methods have proved to be tedious and costly.

Broadly speaking` my invention comprises subjecting the particles of solid matter to the forces at work within a film of solvent passing between surfaces moving past each lother at a relatively high velocity. rthough the exact theory of the action is notl fully determined, it is thought that the forces existing in such film cause a pumping of the liquid through the fibers or tissues of the solid. In other words, it is believed that. the result obtained is accom- 1923. Serial No. 640,284.

plished by reason of an action'similar to that which takes place within a sponge when alternately squeezed and allowed to expand under the surface of a liquid. The action is such as to rapidly and repeatedly present fresh solvent to the whole of the fiber or tissue of the substance in question, so that no concentration of extractive in the solvent can occur on any portion of the tissue or fiber. There appears to be a dis` tinct pumping action throughout the whole structure.

In order to carry out my invention, I have illustrated a machine in the accompanying drawings -for carrying out Iny process, as will hereinafter be more particularly set forth.

In the d 'awingsz Figure 1 is a longitudinal cross sectional View of my device taken through the axis of the rotor;

Fig. 2 `is a cross sectional view taken on the Vline 2--2 of Fig. l, looking in the direction of the arrows;

Fig. 3 is a detail view partly in section illustrating a modification of my device in which the input chamber is' made very small.

Referring to the. drawings for a detailed description, I have shown an extracting mill which comprises a base casting l adapted to be bolted to a suitable support (not shown) by means of a series of bolts 2. The casting 1 is formed with a lower annular flange 3 and an upper annular flange 4 through which the bolts 2 that hold the device 'In place pass. Formed within the casting l is a fluid containing chamber 5 having an inlet pipe 6, and an outlet pipe 7 leading into the chamber and adapted to discharge at a point near its top. The purpose of the inet and outlet pipes is to allow either heating or cooling fluid, such as steam or cooling brine, to be circulated in the chamber 5 to either raise or lower the temperature at which the extracting operation takes place.

Formed within the bottom portion of the casting 1 is an input duct 8 through which the comminuted solid substances and the solvent may be introduced by any suitable means, such as a pipe (not shown). Formed in the upper part of the casting .1 is a conical surface 9 and between the conical surface 9 and the input duct 8 is comprised a frusto-conical input chamber 11. The conical surface 9 is preferably ground smooth.

Mounted on thefcasting 1 is a cover plate lll() 12 which forms with the casting 1 an output chamber 13 from which an output duct 14 leads. A suitable valve 15 is provided for regulating the amount of material allowed to pass through the output duct 14. Thus the time during which the material is acted upon by the mill can be regulated. The casting 1 is formed with an annular shoul der 16 at its top, and the cover plate 12 is rovided with an annular groove 17 in `Wh1ch the shoulder 16 of the casting 1 fits.

Between the groove 17 and the shoulder 16 I insert suitable packing material 18.

The cover plate 12 is provided with an annular flange 19 which overlies the annular flange 4 of the casting 1. The bolts 2 which hold the casting l to the support pass through the flange 19, as well as the flanges 3 and 4 of the casting 1, and hold the cover plate firmly in place. For purposes of carefully adjusting the relative position of the cover plate 12 to the casting 1, I have provided a series of Wedges 21, one of which is shown in Fig. 1. The wedges are adapted to lie between the bolts 2 and in practice I have found that three wedges will enable good adjustment to be made. By means of these wedges, a careful adjustment of the relative position of the cover plate 12 to the casting l may be made, inorder to properly center the working parts.

- Mounted on top of the casting 1 is/ a support1ng structure 22. The su porting structure 22 is provided with a ange 23 at its lower end which is adapted to lie in contact with the topY of the cover pla-te 12.v The inner periphery of the flange 23 of the support piece is yadapted to abut against an annular shoulder 24 formed on the cover plate 12. A series of holding bolts 25 hold the support member 22 in position. The support member 22 has preferably integrally formed therewith upwardly extending su port spiders 26 which terminate at their upper extremity in a ring member 27, the interior surface of which 1s screw-threaded, as indicated at 28.

A bearing support piece 29 is provided on its downwardly extending annular por-v tion 31 with screw-threads 32 which are adapted to engage with the screw-threads 28.

of thelring member 27. permitting the bear- 1ng support 29 to be adjustable. A lock nut 33 is provided to lock the bearing support 29 in any adjusted position, and a pointer 34 is provided to co-operate with a scale on the periphery of the bearing support to ind1cate its relative adjustment.

My extracting mill `is provided. with a conical rotor 35 having a' smooth conical surface 36 adapted to lie adjacent the smooth conical surface'9 of the'castln 1. The rotor 35 is mounted .on a' s haff 3 and held s ecurel)7 on the shaft b means of a nut 38. On the upper end of t e shaft 37 are screwthreads 39 upon which are adapted to be screwed locking nuts 41. Below the screwthre'ads 39the shaft 37 has a slightly enla-rged portion 42 over which is adapted to lit anfinner upper ball race 43. An outer upper ball race 44 is adapted to fit in a cylindrical aperture 45 formed in the bearing support 29. Between the inner and outer ball races are two series of balls 46.

Below the portion 42 the shaft is slightly enlarged, as indicated at 47, and around the upper part of the portion 47 of the shaft is fitted a collar 48, whose upper end contacts with the upper inner ball race 43. The

bearing support 29 is provided with an inwardly extending annular shoulder. 49 having annular packing lglands 51 therein, in which is packed suitab e packing to prevent leakage of lubricant from the bearing. A journal box cover 52 is bolted by means of bolts 53 to the bearing support 29. The journal box cover 52 has a downwardly projecting annular lip 54, which holds the upper .outer ball race 44 firmly between the annular lip-54 and the shoulder 49 formed on the bearing support member 29.

The bearing structure comprising the inner and outer upper bearing races and the balls, operates as a thrust'and radial bearn the portion 47 of the shaft 37 is a drive pulley 55 which is keyed to the shaft. The cover plate 12 is provided with an annular recess 56 within which is mounted the lower bearing and packing structure which Iwill now describe. Mounted on the portion 47 of the shaft extending below the pulley 55 is acollar 57, whose upper end is adapted to engage the lower end of the pulley 55. The collar is mounted within a packing gland comprising a plate 58 which lies over the upper end of the annular recess 56, and is bolted by means of bolts 59 to the upper side of the cover plate 12. The plate 58 is provided with two annular recesses 61 on its inner periphery within which is placed a suitable packingto form a tight packlng joint around the collar 57.

Mounted below the collar 57 on an enlarged portion 62 of the shaft 37 is an inner ball race 63, whose lower end rests against the shoulder formed between the portion 62 of the shaft and an enlarged lower portion 64 of the shaft. j The upper portion of the inner ball race 63 is in contact with the lower portion of the collar 57. Arranged to slidably fit within the walls of the annular recess 56 is an outer ball race 65. Between the inner and outer ball race are series of balls 66. To prevent leakage of lubricant through the lower opening of the annular recess 56 through which the portion 64 of the shaft 37 passes, I have formed the annular recess 56 with an inwardly projecting annular shoulder 67. Below the shoulder 67 the inner walls of the recess 56 are inwardly tapered at 68, to the point atwhich the portion 64 of the shaft 37 passes through the lower part of the cover plate 12.

Fitting around the portion 64 of the sha-ft is a packing plate 69 having a shoulder 7l, lying above the shoulder 67 of the cover plate 12, with its outer periphery in engagement with the inner periphery of the annular recess 56. The packing plate 69 is :formed with a downwardly extending lip 72, which fits around the portion 64. of the shaft 37. Between the lower edge of the downwardly extending lip 72 and the sloped walls 68 in the cover plate, I have inserted packing material 73 to prevent leakage of lubricant.

To hold the packing plate 69 pressed against the. packing 73, I have formed an annular groove 74 in the wall of the recess 56. lVit'hin this groove I mount a split ring 7 5 whose elasticity whensprung into position keeps the packing plate 69 pressed against the packing 73. The packing gland so formed is adapted to ordinarily withstand a pressureof about twenty-tive pounds without leakage. This packing gland near the lower portion of the cover plate not only serves to prevent lubricant from. leaking out of the lower bearing structure, but at the same time provides means for preventing liquid within the output chamber ot' themll from passing into the lower hearing, should any considerable pressure be generated in this output chamber 13.

'lhe adjustment of the clearance between the conical surface 9 and the conical rotating surface 36 of the rotor 35, can be very .easily and accurately effected by loosening the lock nut 33 on the threaded portion 31 of the bearing support 29, and rotating the bearing support 29 until the exact adjustment is obtained. The lock nut 33 is then screwed in place. The pointer 34 en-A ables the. person performing the adjustment to accurately tell the degrees of rotation imparted to the bearing support 29. As before stated, the bearing support 29 is prefeably formed with a scale on its outer periphery for co-operation with the pointer 34 lto enable an accurate adjustment to be obtained.

'lhe whole upper bearing structure is either raised or lowered h v rotating the bearing support 29. 'lhe outer upper ball race 44 is moved with the bearing support and through the balls` carries the inner ball race 43 with it. The inner ball race is held against longitudinal displacement on the sha tt by the collar 48. whose lower end abuts the fixed pulley 55. and by the lock nuts 4l. ly reason of the fact that the lower inner hall race. 63 is held against longitudinal nuivement on the shaft by the shoulder formed between the portion 62 and 64 of the shaft, and by the collar 57, the lower inner ball race 63 must move with the shaft. The balls 66 cause the outer ball race 65 to slide either up or'down within the annular recess 56, in accordance with the adjustment of the shaft. i

It will be apparent 'by reason of the bearing moun-tings and the shaft structure that when the upper bearing support- 29 is either raised or lowered, the lower bearing moves with it.

One 42of the, supports 26 is made of less arcuate breadth than the other supports to permit a belt 76 to pass readily over the pulley l 55. A suitable source of power moves the belt 76, which imparts rotation to the pulley to cause the rotor 35 to rotate. The screw-threads which are, formed on the upper bearing support 29 are in such a direction, that the normal direct-ion of rotation of the belt 76 will cause the upper bearing support 29 to unscrew in case the lock nut is not tightly adjusted to prevent such an occurrence. This gives an added factor of safety, for should the proper tightening of the lock nut 33 not be effected. the normal operation of the machine will tend to continually increase the distance between the smooth conical working surfaces, thus preventing injury to the machine.

llt)

I have found that in extracting materials the clearance between the conical surface of the rotor and stationary conica-l Surface 9 should be approximately thirty one thousandths f-3T) of an inch 0r less. rlhe peripheral speed of the rotor may vary from approximately 200 feet a second to 500 feet a second. depending upon the operating conditions.

In Fig, 3 I have shown a modification ot my mill in which the input chamber l1 is materially reduced in size. Under certain conditions of operation, I have found a small input chamber to be advisable. The conical rotor revolving at high speed causes considerable suction in the input chamber 1l by reason of the centrifugal action on the liquid. 'Ihis action causes the feeding of material through the mill, but where there is a large input chamber, under certain conditions, a partial vacuum may 'be produced. The material is 4then fed in pulses, but where the input chamber is restricted in size.. there is not so much danger of pulsation, since a large quantity of the liquid cannot be evacuated from the input chamber at one time. llnder certain working conditions, the modification shown in Fig. 3 has been found the preferred form in practice.

In operation, the material from which the desired substance to be extracted is introduced into the input chamber of the mill. together with a suitable Solvent` therefor. The spacing apart of the conical stator and rotor surfaces of the machine is such that lllfi the particles of solid matter from which the extraction is to be obtained may normally pass freely 'between these surfaces. `It is convenient in practice to disintegrate the bark, root, or other fiber to a size that will readily pass through a screen having from of which meat is an example, do not have to be comminuted to a diameter that is equal to or less than the distance between the relatively moving surfaces. By reason of their softness, particles of such materials deform to a sufficient extent to permit them `to readily pass between surfaces, the distance between which is less than thefnormal size ofthe particles treated. It has been found that even relatively large particles of substances of this class are not disintegrated to any substantial extent `by my method of treatment. f

The material having been thus suitably prepared, is suspended and kept roughly agitated in the solvent which is suitable for the particular extractive under treatment. The concentration of original solid matter in the solvent Willbe varied to suit conditions, and may in general be within the limits of ten to thirty per cent. This factor is not important, because in many cases the percentage of extractive in the solid matter may be very small, in which case the solution from the first process will be used to treat fresh solid in the next operation. In fact, under certain conditions, fresh solids canbe treated in a cycle of operations such as may be carried on in a battery system, but. this procedure is usually not necessary.

The suspension of sol id matter in the suitable solvent is now passed through the mill under suitable conditions of temperature, relative velocity of moving faces, distance apart of moving faces, and pressure. It is found in practice that in almost every case complete extifaction takes place under these optimum conditions, in one treatment.

Under ordinary circumstances if the said solid had been merely digested with the same solvent for a like period of time, a very low percentage extract-ion would have taken place. Itis reasonable to suppose, therefore. that the treatment to which the solid matter has been subjectedl in the film in the presence of the solvent, has in some manner forced the solvent rapidly through the structure of the solid matter. t

The rapid motion of the solvent through the fibrous structure has been so complete as to remove all the extractable matter within it, and this action is articularly remarkable when one consi ers that the solid matter has only been subjected to this action within the film for a very small fraction of a second. The forces existing' between the relatively moving surfaces arev believed to be of such a nature that the solvent is caused almost instantaneously to penetrate every part of the structure of the solid treated. As at'first stated, it is believed that there isa pumping action existing in the film, whereby the solid particles in their lpassage between the surfaces have all portions of their interior structure subjeeted many times to fresh batches of the solvent.

The forces causing this action are not, it. is believed, due to the centrifugal action within the film but rather to the shearing act-ion between the surfaces moving past each other at a high velocity. The optimum conditions of the treatment are such that 'the speed of the relatively moving surfaces and the thickness of t-he film do not tend to cause any actual disintegration of the parti, cles Within the film, but are only suiicient to cause this high speed pumping of solvent through the particles in question.

Example 1.- iommercial ginger is previously prepared by grinding so that it will pass through a sieve having forty spaces to the linear inch.` Approximately three or less pounds of the prepared ginger are then stirred up in each gallon of water, preferably at a temperature of from fty to seventy degrees centigrade. This mixture is then run through the mill, which has previously been adjusted to have a clearance between the relatively movable surfaces of twenty-five to thirty one-thousandt-hs of an inch. The speed is arranged so that the relative velocities of the adjacentsurfaces of the mill is approximately 20() feet per second. The rate of flow ofY such a mixture can conveniently be adjusted to about live or six gallons per hour, and under these conditions the energy absorbed will be approximately I() horse power.

The resulting mixture ".will contain the ginger from which practically all of the ginger extract has been removed. together with the liquid containing the liquid extract. If a. little of the residual ginger be taken and simply` washed with water to remove the adhering ginger solution, it will be found that extraction has been so complete as to leave practically no taste of ginger in the solid. This. complete extraction is readily obtained by passing the liquid once only through the mill.

Era/infile Eef-A typical commercial cinchona. bark may be treated as follows:

The bark is` first disintegrated to pass a imesh of forty to the linear inch. It is then dried and mixed with a requisite quantity of lime in order `to liberate the crude quiniue bases from their original state of combination as tannates. A suitable solvent, such as coal tar naphtha containing ve per cent of fusel oil is now stirred up with from one to three pounds of prepared bark per gallon of solvent. The resulting mixture is passed through the mill under the same condit-ions'as given in the previous example. The temperature, however, need be but thirty to fo-rty degrees centigrade. It will be found that practically complete extraction of the cinchona bark has taken place after one operation and that substantially the whole of the crude bases are in solution in the solvent. The practical point to notice in this process is that very little coloring matter is removed from the bark in the short'time of treatment, and in general it will be found that the crude bases are yonly a very pale buff colo-r in appearance. This assists materially in producing a pure white quinine free from color, and makes the expense of re` fining the product extremely small.

Practically the same conditions of treatment apply in general to the extraction of such materials as quebra'cho', hyoscyamus mnticus, cascara sagrada, coco, and Mimosa bark; the correct solvents, of course, being used in each case, such solvents being exactly the same as are now used in existing commercial processes.

Example 3.-The process is particularly useful inextracting, animal fibers, such as meat, as it enables one to extract everything, includin albuminoids, in the cold. The meat is isintegrated to a suitable size and mixed with water in the proportions of approximately two pounds of meat to the gallon of water, to which may be added such aids tol extraction as glycerine, salt, etc.. The resulting mixture is passed through the mill under suitable conditions, depending on the structure of the actual meat fiber. It will be found that on passing the meat once or twice through the mill, a com lete extraction `will have taken place and t e, resulting meat fiber remains as a pinkish white4 slime.

In the same manner, extracts from animal organs giving pancreatic juices, pepsin, insulin, eantharides (from Chinese or Spanish cantharides ily) thyroid extracts, etc.may be obtained.

I have accomplished the extraction of desired substances from solid matter by utilizing the forces set up within a film ofsolvent, containing the solid matter, existing between closely adjacent surfaces moving past eachother at high velocity. The forces set up are such as to almost instantaneously cause the solvent to penetrate the entire mass of the solid treated and to thoroughly cleanse the fibers of the soluble substances. It is believed that the solids are subjected to a rapid series of pumping actions whereby successive fresh and unsaturated portions of the solvent are brought repeatedly into contact with the fibers of the solid subst-ance.

While I have shown and described the` from the spirit of the invention, or exceedv ing they scope of the appended claims. v

I claim 1. A method of obtaining an extract from a solid substance comprising, passing the solid substance together with a suitable solvent of the material to be extracted in a thin film between surfaces relatively movable Aone past the other at high velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness ofthe film eing suchthat the solid is not wholly disintegrated.

2. A method of obtaining an extract from a solid substance comprising, passing the solid substance together with a suitable solvent of the material to be extracted in a thin film between surfaces relatively movable one past the other at high velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness ofthe film being such that the solid is not disintegrated to any substantial extent.

3. A method of obtaining an extract from a solid Substance comprising, passingl the comminuted solid substance together with a,

suitable solvent of the material to be extracted in a thin filmbetween surfaces separated by a distance greater` than the size of the comminuted solid particles, and relatively movable one ast the other at high velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity. of movement of the surfaces past each other and the thickness ofthe filmbeing such that the solid is not wholly disintegrated.

4. Af method of obtaining an extract from a solid substance comprising, passing the comminuted solid substance, together with a suitable solvent of the material to be extracted, in a thin film between surfaces separated by a ydistance greater than the size of the comminuted solid particles, and rela-- ast the other at high rvelocity, whereby t through the fibers of the solid and'an extract of material obtained, the velocity of movement of the surfaces past each other and the. thickness of the film being such that the solid is not disintegrated to any substantial extent.

5. A method of obtaining an extract from relatively soft substances comprising, passing the comminuted substances, together with a suitable solvent of the material to be extracted, in a thin film between surfaces which may be separated by a `distance less than the size of the' comminuted particles and relatively movable one past the other at high velocity, whereby the solvent is washed through the fibers of the solid 'and an extract of material obtained, the `velocity of movement of' the surfaces past each other and the thickness of the film being such that the solid isnot wholly disintegrated.

6. A method of obtaining an extract from relatively soft substances comprising, passing the comminuted solid substances, together with a suitable solvent of the material to be extracted, in a thin film between surfaces which may be separated by a distance less than the size of the comminuted particles, and relativel movable one past the other at high velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the veloci\ty of movement of the surfaces past each other and the thickness of the film being such that the solid is not disintegrated to i any substantial extent.

7. A method of obtaining an extract from asolid comprising, passin the solid substance, together with a sultable solvent of the material to be extracted, in a thinfilm between smooth surfaces relatively movable one past the other at high velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness of the film being such that the solid is not disintegrated to any substantial. extent.

8. A method of obtaining an extract from a solid substance comprising, -passing the comminuted substance, to ether with a suitablesolvent of the material to be-extracted, in a thin film between smooth surfaces separated by a distance greater than or equal to the size of the comminuted 'particles ana any substantial extent.

relatively movable one pastk the other at high velocity, whereby thesolvent is washed through the fibers ofthe solid and an extract of material obtained, the velocity of the movement of the surfaces past each other and the thickness of thealfilm being such that the solid is not `disintegrated to 9. A methodof obtaininglan extract lfrom f relatively softsolid substances comprising,

passing the `comminuted solid substance, to-

gether with a suitable solvent of the matcrial to be extracted, in a thin film between smooth surfaces which may be se arated by a distance less than the size of t e comminuted particles and relatively movable one past the other at high velocity, whereby the solvent is washed through the fibers of the solid andan extract of material obtained, the velocity of' movement of the surfaces past each other and the thickness of the film being such that the solid is not disintegrated to any substantial extent.

10. A method of obtaining an extract from a solid comprising, passin the solid substance, tovether with av suita le solvent of the material to be extracted, in a thin film between smooth, equi-distantly spaced surfaces relatively movable one past the other at high velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces ast each other and the thickness of the fi m being such that the solid is not disintegrated to any substantial extent.

11. A method of obtaining'an extract not disintegrated to .any substantial extent.f

12. A method of obtaining an extract ,from relatively soft solid substances comprising, passing the comminuted solid substances, together with a suitable solvent of the material'to be extracted, in a thin film between smooth, equi-distantly spaced surfaces separated by a distance which may be I' less than the size of the comminuted particles and relatively movable one past the other at high velocity, whereby the solvent is washed through the fibers of-the solid and an extract of material obtained, thevvelocity of movement of thesurfaces past each other and t'he thickness of the film being such that the solid isnot disintegrated to any substantial extent. y

13. A method of obtaining an extract from a solid substance comprising, passing the solid substance, together with a suitable solvent of the material to be extracted, in a thin film between surfaces relatively movable one past the other at aspeed of from 200 to 500 eeta second, said surfaces being sEJaced apart a distance not greater than ty one thousandths (Hyg-6) of an inch,

whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other' and the thickness of the film being such that the. solid is not disintegrated to any substantial extent.l

14. A method of obtaining an extract from a solid substance comprising, passing the comminuted solid substance, together with a suitable solvent vof the materiall to be extracted, in a thin film between surfaces separatedv a distance not greater than thirty one thousandths (Tg-6) of an inch, the size of the comminuted solid particles being not greater than the spacing of these surfaces, said surfaces beingv relatively movable one past the other at a velocity of from 200 to 500 feet a second, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness ofthe film being such that the solid is not disintegrated to any substantial extent.

15. A method of obtaining an extract from relatively soft solid substances comprising, passing the comminuted solid substances, together with a suitable solvent of the material to be extracted, in a thin film between surfaces separated a distance not exceeding thirty one thousandths (T-g-G) of an inch, which distance may be less than the size of the particles, said surfaces being relatively movable one past the other at a velocity of from 200 to 500 feet per second, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness of the film being such that the solid is not disintegrated to any substantial extent.

16. A method of obtaining an extract from a solid substance comprising, passing the solid substance, together with a suitable solvent of the material to be extracted, in a thin film between smooth surfaces relatively movable one past the other at a speed of from 200 to 500 feet a second, said surfaces being spaced apart a distance not greater than thirty one thousandths (TT-393m) of an inch. whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness of the film being such that the so] id is not disintegrated to any substantial extent.

17. A method of obtaining an extract from a solid substance comprising, passing the comminuted solid substance, together with a suitable solvent of the material to be extracted, in a thin film "between smooth surfaces separated a distance not greater than thirty one thousandths (Tg3-0) of an inch, the size of the comminuted solid particlesbeing not greater than the spacing of these surfaces, sald surfaces being relatively movable one past the other at a velocity of from 20() to 500 feet a second, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness of the film being such that the solid is not disintegrated to any substantial extent.

18. A method of obtaining an extract from relatively soft solid substances comprising, passing the comminuted solid substances, together with a suitable solvent of the material to be extracted, in a thin film between smooth surfaces separated a distance not exceeding thirty one thousandths (-l--g) of an inch, which distance may be less than the sizeof the particles, said surfaces being relatively movable one past the other at a velocity of from 200 to 500 feet per second, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of movement of thelsurfaces past each other and the thickness of the film being such that the solid is not disintegrated to any substantial extent.

19. A method of obtaining an extract from a solid 'substance comprising, passing the solid substance, together with a suitable solvent ofthe material to be extracted, in a thin film between smooth, equi-distantly spaced surfaces relatively movable one past the other ata speed of from 200 to 500 feet a second, said surfaces being spaced apart a distance not greater that thirty one thousandths ,-g-Qm of an inch, whereby the solve-nt is washed through the fibers of the solidand an extract of material obtained, the velocities of movement of the surfaces past each other and the thickness of the film being such that the solid is not disintegrated to any substantial extent.

20. A method of obtaining an extract from a solid substance comprising, passing the comminuted solid substance, together with a suitable solvent of the material to be extracted, in a thin film between smooth, eqni-distantly spaced surfaces separated a distance not greater' than thirty one thousandths T-g-. of an inch, the size of the comminuted solid particles being not greater than the spacing of these surfaces, said surfaces being relatively movable one past the other at a velocity of from 200 to 500 feet a second, whereby the solvent is washed through the fibers of the solid and an extract prising, passing the comminuted solid substances, together with a suitable solventof the material to 'be extracted, in a thin film betweeny smooth, equi-distantly spaced surfaces separated ,a distance not exceeding thirty one thousandths (al-yh) of an inch, which may be less than the size of the particles, said surfaces being relatively movable one past the other at a velocity of from 200 to 50() feet per second, whereby the solvent is washed through the fibersgof' the solid and an extract of material obtained, the velocity of movement of the surfaces past each other and the thickness of the lm being such that the solid is not disintegrated to any substantial extent.

22. A method of obtaining an extract from a solid substance comprising passing the comminuted solid substance, together with a suitable solvent of material to be extracted, in a thin film between surfacesseparated by a distance equal to the size of the comminuted solid particles relatively mcvable one past the other athigh velocit-y,

fibers of the solid and an extract of material obtained, the velocity of movementof the surfaces past each other and the thickness of the film being suc-h that the solid is not wholly disintegrated.

23. A method of obtaining an extract from a solid substance comprising passing the comminuted solid substance, together with a suitable solvent of the material to be extracted, in athin film between surfaces separated by a distance equal to the size of the comminuted solid particles, and relatively movable one past the other athigh velocity, whereby the solvent is washed through the fibers of the solid and an extract of material obtained, the velocity of the movement of the surfaces past each other andthe thickness of the film being such that the solid is not disintegrated to any substantial extent.

In testimony whereof I afix my signature.

FREDERICK JOHN EDWIN CHINA.

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