US2278701A - Vacuum moistening apparatus - Google Patents

Description

April 7, 1942. A. D. KARR VACUUM MOISTNING APPARATUS Filed OCT.. 3, 1940 lNvE Hind BY Q H sfATroRNEY.

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Y moisten the grain so that Patented Apr. 7, 19,42

VACUUM MoIsrENiNG APPARATUS Aurea D. xm, Newark, N. J., assigner to Ingersoll-Rand Company, New York,

N. Y., a

. corporation ot New Jersey Application October 3, 1940, Serial No. 359,510

s claims. v(ci. ais-27) This invention relates to a Vacuum moistening apparatus, and, more particularly, to an apparatus for processing grain, and the like, by removing uids and moisture entrained inthe grain and moistening the grain.

As a part of the manufacture of certain grain products, it is desirable to treat the grain in its natural state to remove' iiuids, kill or remove harmful bacteria, fungi, and the like, and to moisten the grain. This is accomplished by wetting the grain and subjecting it to a lowl absolute pressure to remove air and inherent moisture in remaining and kill living organisms and further it will have a predetermined desired moisture content.

Apparatus for processing grain in this manner may be divided into two general types, the batch type and the continuous type. In the batch type the grain must be inserted in the apparatus while theapparatus is inactive and, after processing, the apparatus must be rendered inactive before the grain can be removed. In the con-4 tinuous type of apparatus, the grain is processed as it ows through the apparatus. In this form the grain is continuously fed to the apparatus for processing and is continuously being discharged from the apparatus after processing. This latter type of apparatus, needless to say, will handle a greater quantity, of grain for a given period of time and requires much less attention to operate. The present invention relates to the continuous type of apparatus and an object of the invention is to provide such apparatus in which the grain is processed as it iiows therethrough.

Another object is to provide a grain processing apparatus of the continuous ow type wherein Y the grain is subjected to a vacuum.

A further object is to provide a grain Processing apparatus of the continuous flow type wherein the medium employed to heat the grain assists in the movement'of the -grain through the apparatus.

Still another object is to provide a grain processing apparatus wherein utilized to -move the grain through the apparatus.

Yet another object is to provide a grain processing apparatus of the continuous ow type wherein the grain is sprayed with water before it is subjected to a low absolute pressure, or while it is under a low absolute pressure, and is then heatedA and moistened before being subjected to t atmospheric pressure prior to discharge from the apparatus.

apparatus which is simple and economical to operate and requires a minimumof attention.

, These and other objects will appear from the following description of which the drawing forms a part.

In the drawing, the bin, or hopper, I is designed to receive the grain to be processed from a grain Y elevator or a continuous belt. Directly belowthe the grain, heating the grain to dnve of: any vair bin I is a primary evacuating chamber 3 to which the bin is connected by the throat 5.

'Extending through the wallV of the throatis `a damper, or gate 1, provided ,with a handle 9.

This damper serves to control the rate of flow of the grain from the hopper I to the primary evacuating chamber 3 and the -distance'that it extends into the throat 5 is slidably adjustable.

Surrounding thethroat at a point below the damper is an annular casing 2 which communicates with the interior of the throat through the orifices 4 formed in the wall of the throat. Water is supplied to this casing through the water supply line 6 and the rate of ilow is governed by the valve 3. With this varrangement it is possible to spray the grain iiowing through the throat with water.

At one side of the primary evacuatlng chamber 3 is the conduit II opening into the chamber. A lip I3 is formed in this chamberso as to protect the conduit l I and prevent any grain from falling into this conduit. At the other end of the Acon'- duit is the steam evacuator Il. The steam evacuator is shown as discharging to the atmosphere but. if it is desirable, it may condenser' (not shown).

Steam to actuate the evacuator I1 is supplied through the pipe I9 which is connected to the steam supply conduit 2|. Appropriate valves 23 and 25 are provided respectively in the steam The evacuator Il serves to remove air and some moisture in the primary evacuating chamber. and

the force of gravity s Another object is to provide a grainprocessing 5 may be of such design that 'the pressure in the evacuating chamber 3 will be constantly maintained at 15" of mercury absolute pressure.

The second throat 21 connects the primary v4evacuating chamber 3 with the secondary evac uating chamber 29. .Atrestriction 3| formedby an annular depression in the wall of thei throat 21 serves to keep the throat full of grain and retard the leakage of air from primary evacuating chamber 3 to evacuating chamber 29. Within the secondary evacuating chamber 29 are placed baiiles 33 to lengthen the path of the grain through the chamber. l

discharge to an after-v toiojiinect the chamber with a tertiary 4 The chamber 2l is provided with a lip 3l corresponding to the lip i3 in chamber 3 and the balies 33 are so designed as to prevent any possibility of the grain entering the conduit 31 that opens into the chamber at one side thereof.

The conduit 31 is connected to a secondary steam evacuator I i The steam evacuator 4i has a supply pipe 43 and control valve 4B through which steam is conducted from the steam supply conduit Ziand to which it is connected.

'I'he discharge from the secondary evacuator Il is directed to animer-condenser 41 supplied with water through pipe 49 having a regulating valve 5i and discharging the water and condensate from the tail-pipe, or drain, 53 to a sump or sewer line (not shown).

Obviously, there will be some non-condensable gases discharged to the inter-condenser I1 and,

sure of the preceding chamber, a portion of will be no substantial leakage through throats 21 and il between their respective connected evaporating chambers as the grain ows therethrough, thus preventing any tendency toward equalization of pressures in the evaporating chambers.

y During operation of the apparatus the evacuators 'are constantly removing iluid from the evaporating chambers and, as the pressure in each successive chamber is lowerthan the presthe surface moisture on the grain is evaporated whenever the grain, in its flow through the apparatus, reaches a zone of low pressure, that is, Y

when the vapor pressure of the surface moisture exceeds the vapor pressure existing in such zone,

in order to remove these gases. the steam ejector Il is appropriately connected at one side to the inter-condenser. Steam is supplied to actuate this ejector through the pipe l1 connected directly with the steam supply conduit 2i.

A third or tertiary evacuating lies belowl the secondary evacuating chamber 29 and is connected thereto by the throat 3i having a restriction 63 similar to the restriction 3l in the throat 21. This chamber is provided with a lip B5 and baille plates $1 in the same manner as the secondary evacuating chamber Il. It also has acommunicating conduit 3l ,which corresponds to the -conlduits Il and 31 steam evacuator 1i corresponding to evacuators i1 and 4i. Steam is supplied to actuate the evacuator 1| through pipe 13 and the ow therechamber '59 The condenser 11 receives the discharge fromv the evacuator 1I and the condenser is cooled by cooling water 4supplied through the cooling water supply line 13 having a control valve 3l. condensate and `cooling water are discharged from the condenser 11 through the tail, or discharge pipe, 32. The non-condensable gases in the condenser 11 are removed therefrom by the secondary steam evacuator 4I which communicater directly therewith by means of the pipe 33.

With this arrangement the grain flows by gravity from the bin I through the throat i to the primary evacuating chamber 3. The rate of iiow, as above pointed out, is regulated by the damper 1 and, as the grain ilows through the throat, it is moistened by the water sprayed thereon from the orifices I.' The reason for 1 spraying water `on the grain is to moisten the grain` so that water will fill the interstices beform of flow' controlling device such as rotary vvaries (not shown) may be used and the damper is only one illustration. If this were not done, there would be acontinual fluctuation oi' pressure in chamber 3 since air at atmospheric pressure would enterV with the grain.

As the grain flows through chamber 3 a certain amount of this surface moisture will evaporate and be removed, but suiiicient, surface moisture will remain on the grain so that there evaporation of a portion of the surface moisture occurs and equalizes the vapor pressure of the surface moisture with the vapor pressure of the zone. Evaporation of this moisture results in cooling the surface of the grain but this cooling does not affect the interior of the grain particles due to the insulating properties of the grain. The surface moisture evaporation will continue until the temperature has been lowered to such an extent that vapor pressure is materially decreased. When this occurs, practically none of the remaining water on the grain surfaces can be evaporated or removed. 'Howeven throughout the process, the lowering of the temperature of thewater on the grain surfacehas no material effect on the temperature of the inherent moisture in the grain which is at a higher temperature. Consequently, the inherent mois-l ture will ash and escape-from the grain and will carry with it any air present ln the kernels As a result, when the grain is finally discharged from the tertiary evacuating chamber practically all of the air and some ot the inherent moisture 'in the'grain will have beenremoved but some of the moisture on the grain surfaces will re.

main.

During the above procedure the grain will have Vbeen moved through the' apparatus by gravity,

assisted by the difference in pressure existing between the successive evaporating chambers, but, as will be seen from the drawing, at the discharge end of the tertiary evacuating chamber a steam nozzle 3l is provided in the steam ejector, generally indicated at I3, to which steam is led by the conduit 31. in order-to continue the movement ot the grain. An appropriate regulating valve 33 controls the introduction of steam into the grain and the steam propels the grain through the throat Il to the inlet of the steam ejector, generally indicated at 33.

The steam ejector 33 comprises a nozzle- Il, appropriately supplied with steam through the pipe 31 and valve 3l, and the throat, or diirusor, lli. The discharge end o! the steam ejector 33 communicatesdirectly witlra steam chamner the. nozzle Il directs steam into the grain and carries it to the steam ejector 13, which in turn propels the grain, while moistening it. into the steaming chamber |33. Thus, the-pteam-not only moves the grain through theapa'ratus, but it also serves to drive the surface moisture into the grain in order that the desired. moisture content may be obtained. 1

Near the lower portionof chamber |33 is a connection Ill-opening into the condenser ist4 .which the steaming' 'e chamber it is at a low absolute chamber communicates with the condenser |09.

( Jooling water is supplied Vto the condenser |09 by the inlet and is removed with the condensed liquids through the tail-pipe H3 to an appropriate sump (not shown). At the top of the condenser is a steam ejector ||5 to remove non- |03 will notl increase to atmospheric pressure.

'I'he pressure or vacuum in the steam chamber may be increased or decreased by adjusting valve in the air bleed pipe ||1 provided at the top of condenser |09. Thus, the amount of vacuum in the steaming chamber may be constantly controlled so that the pressure of the steam necessary to meisten the grain may be attained.

Upon Y reaching the bottom of the steaming chamber |03, the grain has been thoroughly moistened and, since the excess steam not necessary for moistening is removed to the condenser |09, the grain is now ready to be discharged from the apparatus. At this point the grain being. at a low absolute pressure must be re-subjected to atmospheric pressure before discharging it from the apparatus. To this end the ejector |20 having a nozzle |2| is located at the bottom of the steaming chamber |00 and is arranged to direct its exhaust through a throat |23 and diffusor |25.

Instead of actuating the ejector |20 by steam which would further meisten and overheat the grain, the nozzle l2| issupplied with a iluld such as air under pressure by the pipe |21 controlled by the valve |20. 'I'he air under pressure discharged from the nozzle will force the grain through the throat |23 and diifusor |25 into the atmospheric chamber |30. 'I'he expansion of the compressed air through nozzle I2| will result in onsiderable reductionof temperature, which in turn will cool the grain and prevent undue loss of moisture during and after ejection. At the top of this chamber is an air vent line |35 and blnatlon of a plurality of chambers arranged vertically in series for continuously moving the grain therethrough, means to reduce the pressure in each chamber to a lower pressure than the pressureA of the preceding chamber of said series, a steaming chamber for moistening the grain, steam ejector means to remove the'grain from the last said chamber of said series and discharge it to said steam chamber, a discharge chamber,

and means to remove the grain from the steam an ejector to remove said grain from the final chamber of said series, a grain moistening cham ber to receive the grain removed from said series of chambers by the ejectors, a motivating ejector to remove the grain from the moistening chamber, and a delivery chamber to receive the grain from the motivating ejector and subject itA to atmospheric pressure. Y.

4. In a grain moistening apparatus, the combination of a grain hopper, a primary evacuating chamber arranged to receive grain from the hopper, a, secondary evaporating chamber arranged to receive grain from the Iprimary evaporating chamber, a tertiary evapdrating chamber arranged to receive grain from the secondary evaporating chamber, evacuators to reduce the pres. sure in each said chamber adapted to reduce the pressure in said secondary ejector to a pressure less than the pressure in the primary chamber and in the tertiary chamberto a pressure less than the pressure inthe secondary chamber, a

within the chamber are plates |32 so disposed that any grain blown out of the diilusor into the chamber cannot be blown up into this air vent to be lost, or retard the discharge of air. I

The bottom of the atmospheric chamber |30 gradually converges into a rthroat or discharge pipe lll having a regulating damper |33 similar in construction and function to the damper l.

With this arrangement, therefore, the grain may be moistened to any particular degree by controlling the amount of steam to which it is subjected by the design of the steam entry nozzles 85 and 0 5 and by regulation of the pressure in chamber |03, and when the grain is removed from the system it is adequately moistened and at atmospheric presure. Y

I claim:

Vl. In a grain moistening apparatus, the combination of a plurality of chambers arranged vertically in series for continuously moving the grain therethrough by gravity, meansto evacuate each chamber to progressively lower pressures,` means including a steam ejector to discharge and moisten the grain from the nal chamber of said series, and fluid lpressure operated means to remove the grain from the last means and subject the grain to atmospheric pressure. i

2. In agrainmoistening apparatus, the cbmsteaming chamber moisten the grain. steam ejectors to vremove the grain from the tertiary chamber and discharge it to the steam chamber, a 'discharge chamber vented to atmospheric pressure, and an air actuated ejector to remove grain from the steam chamber, cool it and discharge it to the discharge chamber wherein the grain is subjected -to atmospheric pressure before removal therefrom.

5. In a grain moistening apparatus, the combination of a plurality of chambers arranged in series to receive the grain. evacuators to reducev the pressure in each chamber Ato a pressure lower than the pressure of the preceding chamber of said series, a steam chamber, a pair'of steam actuated ejectors to remove the grain from the last chamber of the series and discharge it to the steam chamber wherein the grain is moistened, a discharge chamber open to atmosphere-and an Aair actuated ejector to remove the grain from the steam chamber, cool it and discharge-it to the discharge chamber wherein the grain is subjected to atmospheric pressure before -removal therefrom. i

6. In a grain moistening apparatus, the combination of a plurality of chambers arranged vertically in series for continuously moving the grain therethrough by gravity, means to wet the surface of the grain before entry into the chambers, means to evacuate each chamber to a progressively lower pressure than the preceding chamberto remove uid from the grain passing therethrough, means including a steam ejector to discharge and meisten the grain after discharge from the final chamber of said series, and means to remove the grain from the last means beiore discbarae from the apparatus.

'1. In a grain moistening apparatus, the cubination of a plurality of chambers arranged in series to receive the grain. means to wet the surface of the grain before entry into the nrst chamber of the series. means between adjacent chambers of the series to restrict the flow of grain, evacuawrs to reduce the pressure in each chamber to a pressure lower than the pressure ot the preceding 'chamber of said series to remove uuid fromthe grain passing therethrough, a steam chamber, a pair of steam actuated ejectors to remove the grain from the last chamber of the series and discharge it to the steamchamber wherein `the grain is'moistened, a discharge chamber open to atmosphere, and an air actuated ejector to remove the grain from the steaming chamber, cool it and discharge it to the discharge chamber-.wherein the grain is subjected to asmospheric pressure before removal thereand subject the grain to atmospheric pressure I 8. a grain moistening apparatus.l the com bination o! a grain hopper, a primary evacuating chamber arranged to receive grain from the hopper.meanstowetthesur!aoeofthegrain before entry into the primary evacuating chamv ber, a secondary evaporating chamber to receive grain from the primary evaporatlng chamber. means between the primary evacuating chamber and the secondary evaporating chamber to restrict the now of grain. a tertiary evaporating chamber arranged to receive grain from se aecondary evaporating chamber, means between the second evaporating chamber' and the tertiary Y

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