US2830702A - Hydraulic grain unloading and washing system - Google Patents

Description

A ril 15, 1958 c, A EN 2,830,702

HYDRAULIC GRAIN UNLOADING AND WASHING SYSTEM Filed May 1, 1955 1N VEN TOR.

nited States Patent Ofiice 2,830,702 Patented Apr. 15, 1958 HYDRAULIC GRAIN UNLOADING AND WASHING SYSTEM Carl Hagen, Chicago, Ill.

Application May 1, 1953, Serial No. 352,546

4 Claims. (Ci. 209-1) This invention relates to a novel method for the unloading and simultaneous washing of leguminous grain. My invention is particularly adapted for the unloading and washing of corn and soy bean kernels.

One object of this invention is to provide means for unloading grain from box cars under conditions wherein no dust is produced. 7

Another object is to provide a grain unloading systern which substantially eliminates grain breakage.

Still another object is to provide a grain unloading and simultaneous washing system which removes rodent excretions much more completely than that which is possible with present day commercial grain unloading and cleaning systems.

In present day grain unloading procedure, such materials as corn kernels or soy beans are unloaded from box cars with either manually operated power shovels or airveyor nozzles. The grain is unloaded into hoppers from where it is conveyed to grain cleaners which are supposed to remove dut, red eye and rodent excretions. From the grain cleaners, the material is conveyed to either storage bins or into the grain processing system. During this whole period, namely, from the time the grain leaves the box cars up to the time wherein it enters a grain processing system such as dry milling, wet milling or cereal flake manufacture, considerable dust formation takes place. This grain dust has a high explosion hazard and it is necessary to resort to elaborate, expensive dust collecting systems to minimize this hazard. In addition to the dust factor, a considerable amount of grain breakage takes place, with resultant deleterious effects on subsequent grain processing. The mechanical, pneumatic air cleaning devices used to remove dust and rodent offal are unable to alfect a complete removal of these objectionable grain impurities. Insect residues and other minute ofral matter is particularly difiicult to eliminate and frequently grain which has been cleaned by these usual dry pneumatic methods contain a sufficiently large amount of objectionable residues to be rejected after government inspection.

In accordance with this invention, I overcome the difficulties inherent in a dry pneumatic grain cleaning system by providing an efiicient hydraulic unloading and washing system. The principle of my process is the utilization of high pressure water streams as a means for removing grain from a box car and also as a means for effecting a much more efficient separation of grain kernels from duts and offal. As soon as the grain has been thus thoroughly Washed, a stream of hot air is applied to instantly remove the residual water from the outer grain surface. The grain is exposed to water contact for only a short period of time and substantially none of the water penetrates the grain interior.

in carrying out my process, grain is unloaded from a box car by means of a high pressure water nozzle placed on a platform in front of the box car door. The nozzle can be directed in any direction into the box car and this is done until all of the grain is removed. The box car should be slightly pitched so as to facilitate water drainage and grain flow.

The grain flows out of the box car in a steady stream due to the large volume of water. It is then passed over gratings or rifiies which remove the larger non-grain particles and allow the grain to pass through. The grain and water then drop onto a scalping screen wherein the smaller non-grain foreign particles are removed and the grain passes through this screen and onto washing screens. Here, high pressure water nozzles using clean water wash out the dust and rodent excretions as well as insect fragments through the screen openings, leaving the grain clean but wet and dewatered. The grain now passes over a magnetic pulley where metal particles are removed. The wet grain is then spouted through a vertical Redler or bulk flow grain conveyor equipped with perforated stainless steel screens placed at the center of the vertical conveyor casing. A rapid stream of hot air is blown through these screen perforations. This instantly dries the wet grain as it is moving upwards in the conveyor. When the grain reaches the desired distributing point for processing, it is thoroughly cleaned and the grain surface thoroughly dried.

No dust collecting system is required. As soon as one car has been emptied and the next loaded car placed in an inclined unloading position, the empty car is placed in front of the dryer where a stream of high temperature air is blown in every direction until the car is dried out. The Water used for unloading the grain, plus the washing water, is pumped to cleanup screens where it drains to a storage tank and is subsequently used over again. The residue collected on top of the clean-up screen are conveyed to a flash drier and the dried material used for feed.

Example Referring to the drawing, the box car 1 which is loaded with corn is placed in a tilted or pitched position as indicated by inclined freight car track and wheels at 2. Water from the pressure nozzle 3 is directed into the grain of the box car. This causes a mixture of water and grain to flow out of the box car and drop onto the riifie 4 which contains metal panels spaced about one inch apart. The corn and water pass through these open spaces and non-grain material having a width greater than one inch is eliminated.

The water and partially cleaned corn drops onto the inclined, vibrating scalping screen 5 which consists of a trough which is about ten feet long, five feet wide and which is covered with a screen having openings of about one-half inch diameter. The corn and Water pass through this screen and non-grain material larger than the screen openings is eliminated. The stream of corn kernals now drops onto a Washing screen 6. This comprises an inclined vibrating trough equipped with a stainless steel screen having 7 inch diameter openings. High pressure water nozzles 7 and 8 operating at a pressure of about 50 p. s. i. cause the removal of fine dust, rodent ofial and insect fragments from the surface of the corn kernel. These materials pass through the washing screen while the washed corn remaining on top of the screen is moved onto the belt conveyor 9 equipped at its end with a mag netic pulley 10. As the wet corn passes over the magnetic pulley, metal impurities are removed.

At the end of the belt conveyor 9 the wet corn is vertically transported by means of a Redler or other type of bulk flow conveyance device 11. Vertical perforated stainless steel screens 12 and 13 are placed on the two sides of the conveyor casing. These perforated screens are ten feet high. As the grain moves vertically upwards in the conveyor, the wet corn kernels in the perforated screen area 14 are met by a strong blast of current of hot, dry air coming from 15. The air temperature should be within a range of 150 to 250 F. and the rate of air flow should be about 3500 cubic feet per minute. This will be sufficient to cause the instant drying of the wet corn kernels as they pass the perforated section 14. The air heating system can be any convenient type. The drawing shows a heating system comprising steam coils 16, air damper 17, and air filter 18. When the instantly dried corn kernels leave the vertical conveyor at 19, they can be distributed to storage bins or directly into a milling process.

A steam coil air heating system 20 is used to supply a blast of 300 F. air at 21 to cause the rapid drying of the box car as soon as all of the corn has been removed by the water nozzles 3.

The mixture of grain dust, dispersed offal and water which leaves the washing screen 6 at 22 is pumped to clean-up screens 23 equipped with #17 silk screens. The mixture of water and dispersed offal going through the silk screen drops into tank 24. The fine grain dust remains on top of the silk screen 23 and is passed by screw conveyor 25 into a mixer 26. Here it is blended with a part of dry material produced by the flash dryer 27. The mixture then drops into the flash dryer 27 and is then blow into cyclone 28. The dried material is then moved by the conveyor 29 to a feed bagging station. Material collected in the dust collector 30 is returned to the screw conveyor 29. The flash dryer 27 utilizes the hot air 31 coming from the wet corn drying section in the vertical conveyor at 14. The water in tank 24 is recirculated through pump 32. back to the water nozzle 3. Sediment deposited at the bottom of tank 24 is dumped to the sewer at 33.

In corn wet milling plants, the loss from corn breakage during dry unloading and pneumatic cleaning averages about 0.75 lbs. per bushel of corn. With my wet unloading process these losses are reduced to 0.25 lbs. per bushel.

In dry corn milling plants such as corn flakes or corn meal manufacture, the breakage losses with present procedure is much higher due to more extensive pneumatic cleaning exposure. In corn flake plants, present losses amount to 8 lbs. per bushel of corn. This 8 lbs. of broken corn kernels has to be channelled into feed instead of corn flakes. With the process of this invention, corn flake plant corn unloading breakage losses are reduced to 0.25 lbs. per bushel.

While this invention lends itself particularly well to corn and soya beans, the process can also be exploited in many leguminous or vegetable-kernel materials. Examples of other materials suitable for application with my process are wheat, barley, oats, rye, rice, peas, beans and various seeds. In place of air heated by steam coils, flue gases heated by oil burners or any other means may be used. Where the clean grain is subjected to wet processing, one may use process waters containing small amounts of processed grain or grain fractions. The pressure on the water nozzles and the rate of water delivery from said nozzles can be widely varied, depending upon the particular seed or kernel material being handled.

While I have illustrated and described a precise arrangement for carrying the invention into effective use, this is capable of many variations, modifications and alterations without departing from the spirit of the invention. I, therefore, do not wish to be limited by the description and drawings forming a part of this specification, but desire to avail myself of such changes as may fall within the spirit and scope of the appended claims.

I claim:

1. Method of unloading and washing grain which comprises injecting into a bulk mass of said grain a powerful stream of water with force sufficient to slush said grain from said mass to produce a flowing mixture of grain and water; screening the resulting mixture under conditions permitting passage of the grain and water but restraining the objects larger than the kernels of the grain; thereafter straining the grain from the Water and washing the strained grain with jets of water having sufficient force to remove therefrom adherent small particulate matter, and thereafter drying the washed and cleaned grain.

2. Apparatus for unloading grain from containers thereof which comprises means for directing a stream of Water under pressure into said containers to slush the grain therefrom in the form of a mixture of grain and water; a coarse screening means into which said mixture is directed for separating particulate matter larger than the kernels of said grain from the said mixture; means beyond said coarse screening means and fed thereby for separating the initial water from said grain, including shaking screens having openings small enough to retain the grain thereon; means for directing jets of clean water upon the retained grain to wash it; means for conveying the washed grain, including magnetic separating means for removing magnetically attracted materials therefrom; and a vertical grain conveyor for elevating said grain and means on said conveyor for substantially horizontally passing heated gases athwart the conveyor and over and around the grain thereon to dry the same.

3. The apparatus as per claim 2 in which the container is a box car.

4. The apparatus as per claim 3 in which means are provided for elevating the side of the box car opposite the door thereof so as to facilitate the flow of the water-grain mixture from the door of said car.

References Cited in the file of this patent UNITED STATES PATENTS 1,139,484 Bryan May 18, 1915 1,461,067 Moser July 10, 1923 1,716,240 Postweiler June 4, 1929 OTHER REFERENCES Coal Age, January 1948, pages 64-69.

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