US2331910A - Pressure-cooker discharge device - Google Patents

Description

Qct. 19, 1943. HOLLY 2,331,910

PRESSURE-COOKER DISCHARGE DEVICE Filed June 13, 1941 2 Sheets-Sheet} lNVENTOR ANDREW P. HOLLY BY ATTORNEYS 2 Sheets-Sheet 2 6 m v a 4 U 8 A \\\S R mm, 5 0 H .G TH N I H G W. R n v Mm N T IWMA R D M N A FOL @f @ct, 19, 1943. A. P. HOLLY PfiESURE-COOKER DISCHARGE DEVICE Filed June 13, 1941 se 57 44% v Patented Oct. 19,1943

, 2,331,910 rnnssunn-oooxnn nus-cannon pnvron Andrew P. Holly, Memphis, Tenn.,

assignor to Y The v. D. Anderson Company, Cleveland, Ohio, a corporation of Ohio Application June 13, 1941, Serial No. 397,949 2 Claims. (c1. 23-290) The invention relates to apparatus .for processing oil bearing materials of animal or vege table origin whereby certain oils and usable solid by-products are recovered therefrom. It is particularly directed to novel and improved valve means for regulating the flow of materials through chambers where the oil bearing, materials are subjected to heat and pressure preparatory to the oil extracting step. As will appear, my improved valve means controls the pressure, usually maintained in such chambers, within a desired predetermined range, and simultaneously regulates the advance of the material from this pressure chamber either to the oil extracting press or to further chambers where the material may be suitably is actually extracted. An object of the invention is the provision of valve means sensitive to variations in pressure in a treating chamber for permitting continuous progressionof material through said treating chamber, while maintaining the pressure within a predetermined range.

While, as will appear, my improved valve means is adaptable to more general application, I have chosen to illustrate and describe it in connection with an oil press of the general type disclosed in the Anderson United States Patent No. 1,971,632, and will discuss it as applied to a pressure cooker for the treatment of cottonseed oil preparatory to the oil expressing step.

It is well known to those skilled in the art, and therefore not discussed ,at great length herein, that oil expressing processes of the type mentioned can be maintained at high efilciency only by very carefully controlling certain factors such as temperature, pressure, humidity, etc., and that failure to maintain the process within critical limits not only results in variations in the percentage yield of oil, but also may result in a deterioration in the quality of both the oil, and the solid by-product. It is further known, still referring particularly to the extractionof cottonseed oil, that relatively elevated temperatures to which the seed is subjected prior to pressing, in

conditioned before the oil order to give an efficient yield, may induce certain harmful organic developments in both the oil and the cake unless the temperature is closely controlled. It is nevertheless desirable, in order to decrease the length of the operative cycle, that the seed be brought up to temperature rapidly and that this temperature be maintained;

rather closely. It has been found that ideal conditions are realized, for example in expressing cottonseed oil, when the seed is maintained for.

- While the valve now to be a. brief period under a pressure of, say, two or three pounds pressure above atmospheric, developed when the material is cooked in a steamiacketed container, or pressure cooker.

Commercial efficiency requires that this be done as part of a continuous process and my present invention relates to improved discharge valve means whereby the appropriate pressure range may be maintained while the material is carried through the cooker and discharged through said valve, the valve operating means being sensitive to variations of pressure in the cooking chamber, and being suitably operated to permit periodic or continuous discharge of mate= rial from the chamber.

described may be arranged to close completely when the pressure in the cooking chamber drops below a certain predetermined point, and to open again when the pressure subsequently rises above said point, I prefer to adjust the valve so that, in normal operation, it remains in partially opened position. This permits a continuous discharge of material, modulated or controlled to the extent that any rise in pressure tends to move the valve. so as to increase the cross sectional area of the discharge opening, and a drop in pressure reverses this tendency so as to move the valve towards closed position. Under preferred, normal operation the material issues from the cooking chamher in a continuous jet. It is apparent that under conditions such as above described a stateof equilibrium will rapidly be reached between the various factors including, principally, temperature, pressure, and supply and discharge of material.

Before the present invention is described in I detail, it is to be understood that such invention is not limited to the details of construction. and/or the specific arrangement of parts herein illustrated and/or described, as the invention obviously may take other forms. It also is to be understood that the phraseology or terminology herein employed is for the purpose of description and not of limitation.

The invention will be described in connection with the accompanying drawings, in which Fig. l is a view in elevation of one form of mechanism embodying the present invention and illustrating such features of a pressure cooker,

a conditioning unit, and an extractor press as are necessary for a proper appreciation of the invention.

Fig. 2 is a sectional view, somewhat enlarged, taken on the line 2-2 of Fig. 1.

Fig. 3 is a section taken on the line'33 of Fig. 2.

Fig. 4 is a section taken on the line 4-4 of Fig. 2.

proved apparatus for pressure cooking and conditioning the material in' a continuous process as more fully described in Patent No. 2,269,898, granted January 13, 1942 to Raymond T. Anderson for Treatment of oleagnious material.

In said improved construction the material is first charged into a feed hopper ill whence it is advanced through a feed chamber H by means of a succession of worm flights I 2, and simultaneously compressed both by a decrease in pitch of the screw flights and a decrease in the total cross sectional area of the passage,- as now familiar to those skilled in the art.

At the end of the feed chamber the material, in a now somewhat compacted condition, passes through an inlet opening l3 into a pressure cooker l4 which may be of any suitable design but is here shown as having an upper cooker sec-,

tion II and a lower cooker section It which are respectively successively traversed by the material in the direction indicated by the arrows under the impelling influence of. sectional feed screws comprising a plurality of successive agitating flights II and conveyors Ila designed to agitate and advance 'the material towards the discharge valve l8, said valve being the subject of the present invention, which will later be more fully described.

In the cooker the material is subjected to heat and pressure. The heat may conveniently be applied by steam jacketing the cooker. By this means, and as a natural result of the vaporization of the moisture content of the material, the pressure rapidly builds up beyond atmospheric unless controlled in some way, for instance in the manner to be described. The material may also be subjected to the heating and sterilizing action of jets of live steam, which treatment also tends to increase the pressure in the chamber.

When material is released from the pressure cooker by said discharge valve, in a manner soon to be explained, it is conveyed, in the present exempliflcation, through a conditioner is, the purpose of which is to thoroughly agitate the material and deliver it to the press under uniform conditions of temperature, consistency, and humidity. The conditioner is vented to the atmosphere by means of an exhaust duct 28 and vents 28a. to permit escape of steam or other vapors entering the conditioner from the cooker.

When the material has been carried through the conditioner, preferably by agitator flights 2| and conveyor flights 2la, it is discharged into the feed chute 22 of the press and thence is advanced to the main press 23, as more fully disclosed in the aforesaid Anderson Patent No. 1,971,632.

This general sequence of the progress of the material through the feeder, the cooker, and. the conditioner, has been somewhat briefly outlined to make plain the function, manner of operation, and specific construction of the discharge valve II which constitutes a control element in the outlet between the cooker and the conditioner. As

and described, which uses involve a discharge control for pressure vessels of variou types. To clearly explain the operation of the invention I have shown in Fig. 1 an actual operating assem-' bly but it will be obvious that the feeder or the conditioner may be eliminated, or that other elements may be substituted therefor or appended thereto without materially affecting the principle of operation or essential construction of the valve.

As soon as the operative elements shown in Fig. 1 are put in operation, and material is supplied to the feeder, the friction between the feeder casing and the material compressed by the feed screw is sumcient in the present embodiment to close the inlet l3 to the cooker with a cork of compressed material, the sealing effeet at the said inlet beingsufllcient to hold moderate pressures.oi the type herein contemplated, namely, not in excess of about two atmospheres. The discharge outlet l8 will now be described, with special reference to Figs. 2, 3, and 4.

The lower portion of the outlet end of the cooker is provided with a discharge passage which in the present embodiment is divided into an upper cylindrical section 26 and a lower cylindrical section 21. A plate 28 is firmly secured between said upper and lower sections, and has a centrally perforated portion 29 provided with a laterally sliding valve member 30. As heretofore indicated, in normal operation the valve is not intended to close the discharge opening completely, but only to serve as a modulating control, to offset variations in pressure in the cooker by increasing or decreasing the cross sectional area of the discharge opening. As will appear, however, the construction is such that the valve may be adjustedto completely close the opening, if desired, and thereafter to alternately open and close the discharge opening to compensate for pressure changes, and permit what might be termed intermittent operation.

A slide support 3| carries grooved runway members 32 and 33 (Fig. 3) to guide the lateral movement of the valve slide, and endwise movement of the slide is stopped at fully closed position by slide stop 34, and at fully open position by abutment of a downwardly extending portion 38 of the slide 38 with slide support II.

The valve 38 is operated by a push rod 35 attached to said downwardly extending portion 38 of the valve slide. The push rod extends through an oversized aperture 36a in the lower cylindrical housing '21, and is reciprocally actuated by a power device 31 as follows. The power device shown in Fig. 2 includes a fluid pressure cylinder 31 attached to the lower portion of the cooker in any suitable manner, such as by bracket 38, and by additional securement to the end of plate 28 at 39. Within the cylinder is a movable abutment, in the form of a flexible diaphragm 48 secured between face plates 4|, 42, plate 42 being attached to push rod sleeve 43 at 43a. Plate 4| is readily removable for repair or replacement of the diaphragm, the outer edge of which is gripped between annular members 44, 45 which are held in compression by end plates 46, 41 and retaining bolts 48. End plate 41 of the housing carries a perforated bushing 48 which provides a bearing for, endwise reciprocation of sleeve 43, the sliding fit between the description prgceeds it will be apparent that 78 bushing and sleeve at 50 being sealed by packing washers and packing gland 62. End plate 48 is provided with an oversize aperture-53 which permits free reciprocation of the push rod sleeve 43 and also vents the diaphragm to'atmosphere on one side thereof. A suitable trap or aperture may be provided at 54 to prevent condensation from building up on the atmospheric pressure side of the diaphragm and interfering with predetermined factors which control the operation thereof as will appear.

The outer end of the push rod 35 is suitably threaded to carry adjusting means such as lock nuts 55, 56, it being apparent that endwise adjustment of rod 35 with relation to sleeve 43 may be obtained by movement of said nuts along .the threaded portion of the rod. Under normal operational conditions I prefer to adjust the nuts 55, 56 so as to maintain the valve in slightly open position, but it is apparent that it may also be adjusted to permit complete closure of the opening, the operation thereafter being intermittent until a re-adjustment is made.

A bracket 5? carried by the housing has pivotally mounted thereon, at 58, a bell crank lever having an abutment arm 59 and a counterweight lever arm 5t. Arm 5% abuts the end of push rod 35 and it is apparent that by changing the position of counterweight ti on arm lit, the force tending to maintain the push rod 35 and sleeve G3 in the position shown in Fig. 2 may be increased or decreased as desired.

The annular wall 35 of the cylinder is perforated at 62 for connection thereto of a fiuid pressure conduit 53, the. other end of which communicates directly with the pressure cham bers of cooker id.

Said annular wall may also be provided with a drain plug 65. In actual operation I prefer to fill the space on the pressure side of the diaphragm with water, which conveniently serves to transmit pressure while protecting the diaphragm against the possible harmful effect of continuous contact on one surface with live steam. "The water may be added through a fitting 78 in the pressure line 63.

The operation of the valve 3t and its manner of control of the discharge outlet of the cooker are as follows. To start the operation material is charged into feeder i i and, as heretofore mentioned, the material is advanced toward the passage l3 between the feeder and the cooker and compressed so as to provide a moving cork or seal for said passage. On entering the cooker the material is simultaneously sterilized by jets of live steam, then further heated by contact with the steam jacketed walls, and rapidly advanced through the upper and lower cooking chambers toward the discharge opening l8. Irrespective of the position of the leading surface of the material, as soon as the pressure result-' ing from the heat and the steam jets builds up to a point where the pressure through conduit 63 on diaphragm 5G exceeds the-force exerted on push rod 35 by bell crank arm 59 as determined by the setting of counterweight 6 l, the diaphragm will move to the left (Fig. 2) carrying with it sleeve &3, and, through abutment of the sleeve against lock nuts 55, 5B the valve rod 35 will also move to the left, causing slide 30 to enlarge the discharge opening Hi. Pressure in the cooker drops as the valve opens and as soon as it falls below that amount necessary to raise the counterweight lever the valve will again'tend to close.

In this arrangement the slide valve 30, together with the operating mechanism therefor,

is of particular and desired advantage from several standpoints. In the'flrst place, it is selfcleaning and unlikely to get out of order in serv ice by the collection on the valve or its seat of fragments or masses of solid material being processed. As the valve moves back and forth it constantly frees itself and the seat on which it slides of any material which otherwise might remain there. Moreover, the weight of the material in the cooking container exerts no effect whatever upon the valve tending to move it toward either open or closed position, quite contrary to the effect when the valve is of pivoted or swinging form. The weight of the material does no more than hold the valve to its seat. Therefore, the

only duty imposed upon the valve operator (in this case the motor diaphragm and the weighted lever) is to move the valve back and forth. Therefore, it is extremely sensitive to small variations in the pressure above atmospheric within the cooking vessel and the pressure to be maintained in the vessel, as determined by the position to which the weight 65 is adjusted, is maintaned fairly uniform within close limits. Because valve motion is unaffected byuthe weight of the material resting on the valve, the pressure in the container is not affected by variations in the quantity of charge of materialin the container.

When the material being simultaneously agitated and advanced through the cooker arrives at the discharge valve it is forced out through the opening both by the pressure transmitted through the material and derived from the worm 'iiights, and also by the outrushing pressure of with direct pressure coupling to the chamber, the

sliding valve operated thereby being free of any tendency to move, resulting from gravity eflfect of the material resting on the valve. Various other embodiments will occur to those skilled in the mechanical arts after a consideration of the above described device. Another embodiment is shown in Fig. 5 of the accompanying drawings. wherein the fluid pressure operated device l5 need not be powerful enough to operate the valve directly, but need only be adequate to open and close a relay, including the switch points it which control the fiow of line current to an op erating solenoid 1i Solenoid H actuates the valve push rod '52, corresponding'to rod 35 in Fig. 2, and as before valve 36 is a slidable valve. While the solenoid is deenergized the valve is biased to closed position by the spring 13. The device may be adjusted to operate at various basic pressures by varying the adjustment of one oi the points it, for instance by the adjusting nut H. In the embodiment shown in Fig. 5, the motor cylinder i5 is directly connected to the pressure cooker by conduit 76. When the pressure "in the cylinder builds up to a predetermined point,

switch in is closed and solenoid H is energized so as to move push rod 12 to valve-open position, thereby reducing the pressure towards valveclosing value as aforesaid. 1

It is apparent that a valve control or this latter type will come to rest in one of two extreme positions, usually corresponding to fully open and fully closed, although mechanical stops might be provided, by means not shown, which would aflect this operation. Such open-and-shut mode of operation, generally termed hunting," does not result in as high a degree of accuracy in pressure control as does the modulating valve type first disclosed hereinabove where the valve action is floating" rather than hunting.

What I claim is:

1. Apparatus oi the character described, com- ,prising a container wherein solid proteinaceous material is treated under pressure, heating means therefor, said container being provided with a material supply opening and with a discharge passage, a slidable plate iorm valve member movable to closed and open positions for sealing and unsealing said passage, and means sensitive to the pressure within said container for actuating said valve member.

2. Apparatus or the character described, comprising a container wherein proteinaceeus material is treated under pressure, heating means therefor, said container being provided with a material supply opening with a discharge passage, a slidable plate i'orm valve member for sealing and unsealing said passage movable in a plane transverse to the direction of movement or the material leaving the container by way of said discharge passage, and means including a power device sensitive to variations in pressure in the container for actuating said slidable valve member. ANDREW P. HOLLY.

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