US2241294A - Discharge valve for vacuum pans - Google Patents

Description

My 6, 1943 J. R. CARRERAS ETAL 1 DISCHARGE VALVE FOB VACUUM A*PAHs Filed May 16, 1939 's sheets-sheet 1 iNVENToR JOSE R. CARRERAS LEONER A. LUGO BY THEIR ATTORNEYS- May 5, 1 941. J. R CARRERAS ErAL 2,241,294

DISCHARGE VALVE FOR VACUU PANS INVENTOR x Y 1 JDSE R. CARRERAS l v l BY lTHEIR,AVroRNEYs LEONER A. LUGO 7M 'MM- DISCHARGE VALVE FOR VACUUH PANS HRM A LEONER V BY THEIR ATTORNEYS A. LUGO PatentedMay 6, 1,941

nrsonAneE vALvE Foa VACUUM rims Jos B. Carreras and Leoner A. Lugo, San luan, Puerto Rico, asslgnors to Sucesores de Abarca, San Juan, PuertoA Rico, a partnership consist# in; of Angel Abarca Portilla, Portilla, and Felipe F. Vidal Juan Abarca.

Application May .16, 1939, Serial No. 274,058

7 Claims.

This invention relates to vacuum pans and more particularly to discharge valves for vacuum pans of the Calandria type and it is an object of this invention to provide an improved V,discharge valve for vacuum pans of the typ'e de-- scribed of such construction that the volume of the zone below the heated surfaces of the pan may be kept at the minimum permissible .for the proper iiow of the contents of the pan, the valve contributing to the! reduction"` in the zone volume; that the valve may be positioned atv the central-and lowest point of the pan and of such'capacity as to insure complete and rapid discharge from the pan; and that the valve will serve to distribute anddeect .outwardly the downwardly flowing currents in the pan. It is also an object of this invention to provide an I operating means for the valve described which will serve to operate the valve rapidly and positively to and from either .its open or closed' position with a minimum of labor on the part of the operator.

In the drawings,- in which preferred embfxli-fy ments of this invention are shown,

Figure 1 is a view, partly in elevation and partly in vertical section of the lower portion of a vacuum pan provided with a discharge valve in accordance with this invention, the valve being shown in closed position; y l

Figure 2 is a view in elevation, drawn to a larger scale, of the valve controlling means shown in Figure 1;

Figure 3 is a partial view, in taken as on line 3--3 of Figure 2, of the valve controlling means of Figurel 2, the parts being shown as in the closed position for the valve of Figure 1;

Figure 4 is a view similar to Figure 3 with the parts shown as in the open position vfor'the valve of Figure 1;

Figure 5 is a taken as on line 5-5 of Figure 3 and looking in the direction of the arrows;

Figure 46 -is a fragmentary view, similar to Figure l, showing the valve inthe open or discharge position;

` Figure '1 is a view in elevation and Figure 8 a top plan view of a block for securing the valve and its operating means in the closed position of the valve, as shown in Figures 1, 2 and 3; and

Figure 9 is a vertical sectional view of a valve of modiiied construction arranged to operate oppositely to the operation of the valve of Figure 1.

Inl the drawings, in which only suiilcient of a vertical sectionv partial horizontal sectional view vacuum pan is shown to illustrate the application of this invention thereto, there is shown the bottom I of a Vacuum pan, the bottom having brackets 2 by which it is mounted upon a suit'- able support (not shown) Secured to the upperl edge or rim of the bottom I is a heating section 4 having an annular steam jacket portion 6 to which steam is supplied through the steam .passages 8 and through which extends a number of pipes I0 through which the liquid passes upwardly while being heated, the liquid returning downwardly through the open center portion I2A ofthe section 4.

'The bottom I is provided with a number of inlet openings I4 arranged about a large central opening in which is fitted a discharge outlet casing I6, its upper surface being flush with the inner face of the bottom I, and having a flange I'I which ts about the opening in engagement with the outer face of the bottom I and is secured thereto.l The casing I6, as applied Vto the bottom I is substantially a hollow, inverted truncated cone, open at the top and having its wall cut away, as at I8, to provide a discharge open,-

,ing. The inner face of the wall is finished at the top to provide an inclined valve seat I9 and below the valve seat, is grooved to provide a seat for a spider 20 formed with a central hub 2l which .is bored to receive and. guide the stem 22 of a valve 24 arranged to engage the valve seat I9. The valve 24 is formed in two parts, a lower part 24ab having an annular wall connected at its top by a, transverse wall or web to which the stem 22` is secured and recessed at its upper outer edge to form a seat for the upper substantially conical valve portion 24h. which is secured to 'the lower portion 24 by the screws 26. The face of the valve 24 is dished or curved outwardly slightly so as to merge into the face of the outlet casing vI6 and the inner face of the pan bottom I in a.

smooth curve. At -its lower edge the lower portion 24 is iinshed to provide an inclined valve face. corresponding to the valve seat I9 and'is recessed to receive a sealing or packing ring 28.

The` stem 22 of the valve is extended throughv the bottom of the discharge' outlet casing I6 and between the hub 2l and the bottom of the casing I5 the stem 22 is enclosed within a sleeve 29 which is held in position by the spider 20.

To operate the valve 24, 4a power cylinder 30 is secured to the bottom of the casing I6 and is provided with a piston 32 therein iixed on the stem 22, the stem 22 being of suicient'length to project beyond the lower head of the cylinder 30 at all times. The piston 32 may be operated by suitable fluid pressure and to control the operation ofthe piston there is provided a valve chest 34 attached to the cylinder 36 by suitable means and having a Valve chamber in which a piston valve 36 is slidably mounted. The valve 36 is formed with a spaced port controlling surfaces 36a and 36h, the surface 36a controlling a port 38 which is connected by a passage 39 to one side of the piston 32 while the surface 36n controls the port 40 which is connected by the passage 4| to the opposite side of the piston 32. Besides the ports 38 and 40 the valve chest is provided with a port 42 through which a fluid under suitable pressure is supplied to the valve chamber between the surfaces 36a and 36b of the valve from a passage 43 which is connected to the fluid supply pipe 44 and it is also provided with a port 45 which is open to the exhaust passage 46 and exhaust pipe 41 and with a foy-v passport 48 which connects the opposite ends of the valve chamber around the valve 36.

The valve'36 is provided with a stem 50 which projects beyond the valve cage 34 and has adjustably mounted on its outer end a cross bar 52, the ends of which are rotatably secured in levers 54 intermediate the ends thereof. 'I'he lower ends of the levers 54 are pivotauy connected to ends of short. links 56 the other ends of which are pivotally secured to ends of a cross Ybar 58 rotatably mounted on the lower end of the stem 22 and secured thereon by the'nuts 60. 'I'he upper ends of the levers 54 are 'connected to the lower ends of links 62 which extend on opposite sides of the valve chest 34 and have their upper ends pivotally connected to a cross bar 64 which is threaded onto a screw 66. 'I'he screw 66 is mounted for rotation in a .bracket 68 attached tothe end of the valve chest 34 but is held against longitudinal movement therein and rotation of. the cross -bar 64 and links 62 is prevented so that rotation of the screw 66 causes `longitudinal movement of the links 62 and, through the levers 54, longitudinal movement of the valve 36. 'I'he screw 66 projects beyond the bracket 68 and is provided with a hand wheel 18 adjacent the valve chest and with bevel gears 12 which may be operatedV through a shaft 14 whereby the valve 36 may be operated from a position at the valve chest 34 or at a distance therefrom.

In Figure 3 the piston 5321s shown in position to hold the valve 24 in closed position and the valve 36 `is in closed position, the position to which it would be movedv by its connection through the levers 54 with the stem 22 as the valve 24 is moved to closed position. With the parts as shown in Figure 3, movement of the valve 24 from its closed position, owing to the vacuum inthe pan and the leakage of uid from the cylinder 30, would shift the valve 36 to open communication from the pressure supply port 43 through port 42, chamber of valve 36, port 38 and passage 39 to the'cylinder 30 above the piston 32 causing the piston to return the valve 24 and the valve 36 to their closed positions. In this construction, however, undesired openings of the valve 24 can be prevented by means of a block or chock 16 formed with a hollow tapering lower portion 16B which is open down one side and at the bottom and partially closed at the top by a transverse web 16b so that the block may be itted about the stem 22. Parallel side members 16c extend upwardly from -the web on opposite sides of the opening for the stem and handles 11 attached to the lower portion\facili tate the handling of the block. The block 16 is placed in position against the stern 22 when the valve 24 is in closed position, the lower portion 16El resting on a collar 18 which is threaded on the stem 22 and the side portions 16c are alined with the central boss on the adjacent cylinder head. The collar 18 is then rotated on the stem 22 to force the side members 16`= in its closed position. With the block 16 in position, a-s shown in Figure 3, it is necessary that the, collar 18 `be rotated to free the block and the block removed ibefore the valve 36 is operated to shift the valve 24 to its open position.

With the block 16 removed from its position as shown in Figure 3, to operate the valve 24 to its open position the screw 66 is operated to shift the cross bar 64 and .links 62 from the solid line position, as shown in Figure 3, to a position as shown in dotted lines'in Figure 3, shifting the levers 54 and valve 36 to their dotted line positions, also. Shifting the Valve 36 opens lboth ports 38 and 40, connecting the port 38 through the valve chamber with the port 45 so the uid in the cylinder 30 above the piston 32 may pass to the exhaust through ports 39 and 36, the valve chamber, ports 45 and 46 and the pipe 41 while port 40 is open, through the valve chamber to the port 42 -so uid underpressure may pass from the pipe 44, ports 43 and 42, valve chamber and ports 40 and 4| to the cylinder 30 beneath the piston 32 to raise the piston 32 and shift the valve 24 toits open position, as shown in Figure 6, the piston 32 and valve 36 then being positioned as shown in Figure 4. Movement of the piston 32 from its position, as shown in Figure 3, towards its position as shown in Figure 4 tends to shift the valve 36 to cut olf the supply of fluid under pressure to the cylinder 30, an arrangement which permits of the valve 24 being opened partially, as a result of a partial operation of the valve 36, and then being maintainedv in the partially opened position, as any movement of the valve 24 would result in a corresponding movement of the valve 36, an opening of the ports to supply fluid under pressure to cylinder 30 to restore the piston 32 and valve 24 to the desired positions and a movement of the valve 36 to close the ports 38 and 40 as the piston 32 and valve 24 are returned to the dem sired positions. For the operation of the vaive 24 to' its fully opened position the valve 36 is moved its full stroke 'so that as the piston 32 moves the valve 24 to its fully opened position the valve 36 is returned to close the ports 36 and 40. Movement of the valve 24 and piston 32 from the fully opened position of the valve will shift the valve 36 to open port 40 for the supply of fluid under pressure beneath the piston 32 causing the return of the piston 32 and valve 24 to the fully opened position of the valve' and the return of valve `36 to close the port 46 so that so long as the screw 66 is not operated the valve 24 is maintained in its fully opened position.

To return the valve to its closed position the screw 66 is operated to shift the valve 36 from the full line position to the dotted line position as shown in Figure 4 venting fluid from beneath the piston 32 through ports 4I and46, by-pass -48, ports 45 and 46 and exhaust pipe 41 while uid under pressure is supplied to the cylinder 30 above the piston 32 from the pipe 44, ports 43 and 42, the valve chamber and ports 38 and 39, returning the piston 32 and valve 24 to the closed position of the valve 24 andthe valve 36 to close the ports 38 and 40. Where necessary or desired a lubricator 80 and a trap 82 may be connected to the fluid supply pipe 44 in the usual manner, as shown in Figure 2.

While the valve 24 of Figures 1 to 6 has been shown arranged to be moved to its open position by a movement inwardly of the pan, it is not necessary that the valve be so arranged as the valve may be arranged to be withdrawn into the discharge casing during its opening movement. A valve so arranged is shown in Figure 9 in which the valve 24| is arranged to be seated against a valve seat 19| formed on the discharge outlet casing |6| by a movement inwardly of the pan. rIhis construction necessitates no change in the bottom of the vacuum pan and the valve 24| necessarily differs from the Valve 24 only in recessing the lower end of the power portion 24|n to form a surface shaped to cooperate with the valve seat I9| of the casing |6|. Ihe lower portion 24|a is closed at both its top and bottom by webs, the lower web serving to brace or reinforce the seat engaging portion of the valve. The casing |6| is substantially cylindrical in shape, with an inclined bottom sloping to a discharge opening at one side and of sufficient depth to provide the desired opening past the valve 24| when the valve is drawn down into the casing 16|. In this arrangement the danger of the valve 24| being shifted to open position by the vacuum in the pan is removed, the vacuum tending to hold the valve closed.

In the constructions of both Figures 1 and 9, the construction of the discharge valve permits of it being centrally positioned at the lowest point of the pan bottom and provides a large unobstructed discharge passage whereby the pan is readily, quickly and completely discharged of its contents. The position of the valve in line with the large opening in the heating section 4 permits o`f the pan bottom I being made shallow regardless of the height to which the valve projects upwardly and the volume of the valve reduces the capacity of the pan bottom to that extent. The projection of the valve upwardly into the downwardly moving currents of liquid in the pan and the merging by an easy and gradual curve of the surface of the valve with the surfaces of the discharge casing and pan bottom facilitates the dispersion and deflection of the downwardly moving currents and their redirecting upwards through the tubes I0 whereby the circulation of the liquid in the pan and the efciency of the pan is increased.

The operating means provides a rapid and positive operation of the valve to the full opening thereof and Without undue exertion upon the port of the operator so that the vacuum pan is rapidly discharged and the valve closed and time between operations of the pan reduced to a minimum.

What is claimed is:

l. In a vacuum pan, a dished bottom'having ing a discharge opening at the lowest point thereof, a plurality of inlet openings arranged about said discharge opening and a discharge valve in said discharge opening, said valve projecting into said pan and having a downwardly and outwardly extending surface curved to merge into the surface of the bottom and serving to deflect liquid currents outwardly from said valve on said pan bottom.

2. In a dished vacuum pan having a large central area for descending currents of liquid, -a bottom having a centrally positioned discharge opening at the lowest point thereof, a plurality of inlet vopenings arranged about .said discharge opening and a discharge valve in said discharge opening, said valve projecting into said descending liquid currents and having a downwardly and outwardly extending surface curved to merge with the surface of the bottom and serving to deflect said descending liquid currents outwardly from said valve on said pan bottom.

-3. In a vacuum pan, a shallow dished pan valve.

4. In a vacuum pan, a shallow dished pan bottom having a central discharge opening at the lowest point thereof, a plurality of inlet openings arranged about said discharge opening and a discharge valve having-a tapering body closing said discharge opening -and projecting into the pan,

said valve body being shaped to provide a concave surface curving outwardly to deflect descending liquid currents away from said valve.

5. In a vacuum pan, a shallow dished pan bottom having a central discharge opening at the lowest point thereof, a plurality of inlet openings arranged about said discharge opening and a discharge valve for closing said discharge opening, said discharge valve having a tapering body projecting into the pan and lessening the capacity of the pan bottom and said valve body having a concave surface curving outwardly to merge into the inner surface of the pan body and deflecting descending liquid currents outwardly from said valve on said pan bottom.

6. In a vacuum pan, a shallow dished pan bottom having a central discharge opening at the lowest point thereof, a plurality of inlet openings arranged about said discharge opening and a disl charge valve for closing said discharge opening, said discharge valve having a tapering body projecting into said pan and having a surface curving outwardly gradually from the inner end of the valve body to merge into the inner face of the pan bottom in the closed position of the valve.

7. In a vacuum pan, a shallow dished pan bottom having a central discharge opening at the lowest point thereof, a plurality of inlet openings arranged about said discharge opening, a discharge valve fitting said discharge opening and projecting into said pan, said valve having a tapered dished body flared outwardly to its rim to deect descending liquid currents along theV pan bottom, power operated means for operating said discharge valve, a valve for controlling said power operated means and means for operating said control valve by said power operated means to maintain said power operated means and discharge valve in a. given position.

JOSE- R. CARRERAS. LEONER A. LUGO.

CERTIFICATE CE CORRECTION. Patent No. 2,2LI1,29LI.' May 6, 19m.

'l 'I' JOSE R. CARRERAS, ET AL. E

It is hereby Certified'y that error'appears inthe printed specificationof the above numbered patent requiring correction as follows: Page, second column, line 1, claim 2`, strike out "dished and insert the same be? fore "bottom" in line 5, same ciaim; and tpt the said Letters Patent should be read with this correction therein that the same may conform to the record of the oase in the Patent Office. I l

signed and sealed this 17th day of June, A. D. 19141 Henry Van Arsdale,

(Seal) 4-ctng Commissioner of Patents.A

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