US3045692A - Fluid seal valve - Google Patents

Description

July 24, 1962 R. H. REYNOLDS ETAL 3,045,692

FLUID SEAL VALVE Filed Aug. 15, 1961 S, Mm, ne Wk Rmy V5HLW MWWW wn m RAw United States Patent 3,045,692 FLUID SEAL VALVE Richard H. Reynolds and Andrew L. Askew, Jr., Aransas Pass, Tex., assignors to United Carbon Company, Inc. (Maryland), Houston, Tex., a corporation of Maryland Filed Aug. 15, 1961, Ser. No. 131,541 1 Claim. (Cl. 137-440) This invention relates to athree-way valve which is of special value in the handling of hot mixtures of gases, vapors and solids, such as are found in the flues of car bon black reactors.

The flow of carbon black reactor flue gas is particularly difficult to handle by means of valves because of the large quantities of very fine carbonaceous material that are entrained in said gas and which tend to accumulate in and around the internal valve elements. Accumulations of solid material tend to plug any recesses in the valve parts and to work their way into spaces between a valve closure member and its seat, thus preventing normal closure. Under the very high temperature conditions commonly prevailing in carbon black reactor lines, a valve whose closure member or rotor contacts a seat or' recess in the valve body has a decided tendency to freeze thus rendering the valve inoperative. Freezing is the condition of inoperability characterized by a stubborn coherence between close-fitting parts which should normally move freely with respect to one another.

The above-stated difficulties constitute a long-standing problem in the carbon black industry and in the technology of other industries as well. Other inventors have previously made many attempts to relieve or solve this problem. For instance, two-way valves have been constructed which embody an apertured plug-type closure 7 member of circular cross section closely fitted into a smoothly surfaced multi-ported valve body of corresponding dimensions which has been partially cut away to leave hollow spaces between the plug and body Wherein a filmof molten metal may be maintained to lubricate the plug and to discourage freezing by minimizing the area of direct contact between the plug and the valve body. The molten metal is usually an alloy such as Woods metal or Roses metal and is supplied to the cavity under pressure.

The use of molten metal as a freezing deterrent suffers from several disadvantages inherent in the metal and the methodof applying it. First of all it is necessary to provide heated reservoirs to holdthe metal in a molten state. Also, rams must be utilized to create the pressure necessary to force the metal into the valve cavities. If independently heated reservoirs are to be dispensed with, the rams must be located quite close to the valve in order to absorb directly from the valve body and hot vapors therein the amount of heat needed to keep the metal molten. Since a small amount of molten metal is lost each time such a valve is reversed, it is nec- 3,945,6h2 Patented July 24:, 1962 (3) to provide a valve which is useful for handling materials of very high, moderate or very low temperatures; (4) to provide a valve having a fluid seal for continuously purging the internal working parts of said valve of solid materials which might otherwise tend to accumulate therein and render said valve inoperative; and (5) to provide a valve having a fluid-sealed rotor for selectively diverting amaterial to one of a plurality of outlet ports.

The present invention represents a departure from the fundamental nature of the prior art valves described above. Whereas a valve like thatdescribed above includes a valve plug which achieves its seal through close contact between the rotor and valve body over at least a portion of their adjacent surfaces, the valve of the present invention in its preferred form is constructed in a manner such that there is no contact whatsoever between the valve closure member and valve seat. Instead, the seal is achieved by maintaining a steady flow of sealing fluid through the space between the valve body and closure member. Suitable fluids include inert gases (CO N He, etc.), producer gas, natural gas, water, steam, air or other suitable fluids selected according to the application and environment in which the valve is to be used. The valve is constructed in a manner such that the flow of sealing fluid is always maintained in a direction contrary to the prospective movement of entrained solids into the spaces between the rotor and between the periphery of the rotor and the valve chamber Walls. The sealant fluid constantly purges the aforementioned spaces with the result that clogging and freezing of the valve are thereby greatly minimized. The expended sealant fluid joins the vapors which have entered through the valve inlet and are discharged therewith through one of the valves two outlets, the choice of outlets depending upon the position of the rotor.

The invention will be'further described'in connection with the accompanying drawing in which:

FIGURE 1 is a vertical section taken perpendicular to the axis of the valve rotor;

FIGURE 2 is another vertical section which is taken with the rotor in the same position as in FIGURE 1 and with the axis of the rotor in the plane of the paper;

FIGURE 3 is similar to FIGURE 1, but shows the rotor in its alternate position;

FIGURE 4 is an enlarged fragment of FIGURE 1.

FIGURES 5 and 6 are enlarged fragments of FIG- URE 2.

Referring now to the drawings, the valve as illustrated comprises: a valve chamber defined by a cylindrical body portion 10 having an inlet port 12 and two outlet ports 11 and 13, and by end walls 14 and 15, and an axially disposed rotor. Enclosing each of said ports is a short pipe. The rotor includes a rotatable tubular rotor shaft 16, journaled in sealed bearings 17, 18 (see FIGURES 2 and 5) in the side walls of the valve. Secured to the outer surface of tubular shaft 16" are three vanes andtwo discs which control the flow of hot vapors and fine solids from the inlet port to one of the outlet ports. The diameter of each disc is such that its periphery barely clears the interior surface of the cylindrical valve body (see FIGURES 4 and 6). One disc 19 is perpendicularly mounted on shaft 16 adjacent side wall 14. The other disc 20 is mounted in a similar manner adjacent side wall 15.

The three vanes 21, 22 and 23 are mounted upon and extend radially outward from the exterior of tubular shaft 16 between the discs 20 and 21, to which said vanes are attached along their radial edges. Two of said vanes 21 and 23 are hollow and are diametrically opposed to one another. The third vane 22 is mounted perpendicular to the first two and is solid. The dimensions of the vanes are such that there is a small free clearance between their outer edges and the cylindrical inner walls of the valve body 10. The radius of the discs 19 and 20 should be equal or very nearly equal to the radial projection of the vanes (see FIGURE 4). This clearance might differ in some embodiments of the invention; however, in valves employed-in the flues of carbon black reactors, this clearance should be about 0.005 inch to 0.1 inch. In adapting this invention to other uses, it may be necessary to routinely experiment with the aforesaid clearance, according to the operating pressure and the size of the entrained solids in the smoke.

The vanes should be bound into a rigid assembly with the discs and tubular shaft to insure that the proper clearance is invariably maintained. In a preferred embodiment the vanes should be fabricated from sheet metal and secured to the tubular member and to the discs by welding across their entire width and length. In this embodiment of our invention the hollow vanes are each fabricated of two plates which are more widely separated in the vicinity of the tube than at their extremities. It is advisable when preparing the hollow vanes from sheet stock to add some sort of internal bracing 24. The solid vane is also welded along the entire length of its inner edge to the shaft 16. The welds should be as continuous as practicable along the entire length of those edges of the vanes which are contiguous with the discs and rotor shaft. Continuous welds are desirable because of the importance of making the joints gas-tight, the reasons for which will soon become apparent. It should be observed that the spacing of the two plates of the hollow vanes at their radial extremities results in open slots 31 and 33 in hollow vanes 21 and 23 respectively (see FIGURE 4).

Communication between the interior of the shaft 16 and the interior of the hollow vanes is provided in the form of a plurality of apertures 25 in the wall of said rotor shaft between the interior walls of the hollow vanes 21 and 23. Communication between the exterior of the valve body and the space enclosed by the curved back wall 26 of the valve body, solid vane 22 and hollow vane 21 is achieved through a small connector 27 in said back wall. Similar connectors 28, 29 and 30 are provided in side walls 14 and 15 and in one end of the shaft 16 respectively. The other end of the shaft 16 is sealed.

When the valve is in use, the sealing fluid is steadily applied through the connectors at a pressure higher than then pressure developed in the valve clearances by the gases passing through the valve. As a result the sealant fluid fed to connector 30 proceeds into the tube 16, through the holes 25 into the hollow vanes 21 and 23, through the slots 31 and 33, and out through the clearance provided between the ends of the hollow vanes and the interior of valve body 10. The sealing fluid supplied through connectors 28 and 29 in the side walls 14 and 15 of the valve chamber flows from behind the discs 19 and 20 into the interior of the valve through the annular shaped clearance between the peripheries of said discs and the cylindrical inner surface of the valve body. Sealant fluid supplied to the connector 27 (as in FIGURE 1) flows into the volume defined by back valve wall 26, solid vane 22 and hollow vane 21 and steadily escapes from said volume through the small clearance provided between the outer tips of said vanes and the interior of the valve body. When the valve is in its alternate position (as shown in FIGURE 3) the aforementioned volume is then defined by back wall 26, solid vane 22 and hollow vane 23. Throughout the several views arrows are included to show the volumes purged by the sealing fluid and its direction of flow into and out of said volumes.

It is to be observed that the utility of the valve struc ture described above is not limited to high temperature applications. The vapor seal principle and unique configuration of the valve closure member make the valve quite useful in environments wherein the material carried by the valve tends to foul the valve by depositing granular, powdery or caking solids on the working parts. Furthermore, it will be evident to those skilled in the art that this invention has utility in other technologies, for instance, the pneumatic conveyer art. It will also be obvious to those skilled in the art that certain changes may be made in the details of constructing this valve without departing from the spirit of the invention embodied therein. Therefore ,it should be understood that the embodiment illustrated herein is given by way of illustration and should not be regarded as unnecessarily limiting the appended claim.

We claim:

A three-way valve having:

(a) a valve chamber comprising a main body portion of generally circular cross section and first and second end plates secured to opposite ends of said main body portion.

(b) two bearings with seals, each of said bearings being axially mounted on opposite end plates,

(c) an inlet port and two outlet ports communicating with said chamber,

(d) rotor rotatably mounted within said valve chamber for selectively directing a material introduced into said inlet port to either of said outlet ports, said rotor comprising:

(i) a tubular rotor shaft journaled in said bearings, at

least one end of said shaft protruding from the exterior of said valve;

(ii) a pair of opposed hollow vanes secured to said rotor shaft within the valve chamber and extending radially outward from said rotor,

(iii) said hollow vanes communicating with the interior of said shaft by means of apertures in the shaft wall,

(iv) one solid vane secured to said rotor shaft intermediate said hollow vanes, said solid vane extending radially outward from said shaft,

(v) a first disc secured to said rotor shaft inside of and in spaced apart parallel relationship with said first end plate, said first disc being disposed perpendicular to the axis of said shaft and being secured to each of the aforementioned vanes along all portions of said vanes which are contiguous to said disc,

(vi) a second disc secured to said rotor shaft inside of V and in spaced apart parallel relationship with said second end plate, said second disc being disposed perpendicular to the axis of said shaft and being secured to each of the aforementioned vanes along all portions of said vanes which are contiguous to said disc,

(vii) the radii of said discs and the radial projections of said vanes being such that a small clearance is maintained between the interior of the valve chamber and all portions of said vanes and discs which are adjacent thereto,

(e) a first sealing fluid connector communicating with the volume defined in part by said first end plate and said first disc,

(f) a second sealing fluid connector communicating with the volume defined in part by said second end plate and said second disc,

(g) a third sealing fluid connector for communication with the volume defined by the solid vane, portions of the first and second discs, by that portion of the value =body generally opposite the inlet port and by the hollow vane closest to said third connector. 5

(h) a fourth sealing fluid connector in that end of said shaft which protrudes from the exterior of said valve, whereby a fluid sealant may be supplied to the interior of said valve chamber through said shaft, apertures, connectors, hollow-vanes and slots under 10 sufiicient pressure to constantly purge the interior of said valve of clogging elements.

References Cited in the file of this patent UNITED STATES PATENTS Mantius Nov. 23, 1909 Renkin Jan. 27, 1920 Grindle Aug. 18, 1925 Burkhard Aug. 20, 1929 Meyer Jan. 7, 1930 Phillips Feb. 5, 1935 Holt Mar. 30, 1943

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