US2071448A - Cereal dehydration plant - Google Patents

Description

Feb. 23,1937. ZJHLER 2,071,448

Y CEREAL DEHYDRAYTION PLANT Filed Nov. 4, 1935 a sheets-sheet} Feb. 23, 1937. ZIHLER' CEREAL DEHYDRATION PLANT I 5 Sheets-Sheet 2 Filed Nov. '4, 193:5

Feb. 23, 1937. L. ZIHLER [CEREAL DEHYDRATION PLANT Filed Nov. 4, 1935 3 Sheets-Sheet 5 Patented Feb. 23, 1937 UNITED STATE ATENT OFFICE 1 Claim.

The invention relates to improvements in cereal dehydration processes and particularly to the dehydration of green malt and consists of means for returning the heated air used in the dehydration process back to the mixing chamber a plurality of times through a stack auxiliary to the drying kiln.

An object of the invention is to improve the character and aromatic properties of the cereal in the kiln by reheating air which has previously traversed the layers of cereal lying upon the drying floors and is saturated with the kiln flavor.

A further object of. the invention is to effect a saving in fuel by utilizing air which has previously passed through the cereal, thus avoiding the continual introduction of fresh cold air and its constant expulsion through the discharge cowl at the top of the kiln.

A further object of the invention is to provide selective suction to any of a plurality of return charged and the amount of air returned through any or all of the stacks by means of an instrument board preferably situated adjacent to the furnaces.

With the above more important objects in view and minor objects which will appear as the specification proceeds, the invention consists essentially in the method and arrangement hereinafter more particularly described, reference being had to the accompanying drawings, in which:

Fig. l is a sectional elevation of a drying kiln showing a return air stack, an associated passage to the furnace, the furnace, the drying floors, the fan room, the discharge cowl and return conduit on the roof.

Fig. 2 is a plan view taken on the line 2-2 of Figure 1.

Fig. 3 is an elevation taken on the line 33 of Figure 1.

Fig. 4 is an elevation taken on the line 4-4 of Figure 3.

Fig. 5 is a cross section taken on the line 55 of. Figure 1.

Fig. 6 is an elevation of the fan room taken on the line 6-45 of Figure 1.

Fig. 7 is a perspective view of the louvres used for regulating the intake of cold air to the furnaces.

In the drawings like characters of reference indicate corresponding parts in the several figures.

Each of the furnaces l is situated between heating and air intake chambers 2 which receive cold air through the louvres 3. The air is impelled upwardly by means of the fans 4 and becomes thoroughly mixed with the hot gases in the mixing chamber 5. The air then continues upwardly between the fans percolating through the floors 6 and 1 upon which the cereal is spread for the process of drying. The air is then sucked into the fans 4 and from thence by means of the conduits 8 to escape through the cowls 9 or proceed to be returned through external return conduits ii]. Concrete stacks H, connected to the exterior conduits It, convey the air downwardly to ground level and thence through the return air passage 92 and then into the central and heating chambers 2.

It will be noticed that these central air intake and heating chambers with which the return air passages connect are larger than those on the outer sides of the furnace and the means for mixing fresh air admitted through the louvres with the hot gases from the furnace is efficiently accomplished by means of the hood is with which each furnace is supplied.

In the process of drying cereals and most especially in the drying of malt to which this invention particularly applies, the regulation of temperature, humidity and volume of air are of. supreme importance and to this end, a shaft It extends down the side of each stack and by means of a lever arm situated adjacent the junction .of the external return conduit and the stack, connects to a second shaft i4 and to a valve is disposed at the junction of the discharge cowl 9 and the return conduit it. This valve and associated mechanism is manually operable from the lever it at the base of the stack to regulate the discharge or return of air which has travelled upwardly within the kiln. A second valve I1 is also operable from an adjacent location to the valve IE to regulate the discharge of air from the central fan to either of the two stacks or to either of the discharge cowls.

It should be noted here that I do not wish to limit myself to two stacks or three fans as illustrated in the drawings which accompany this specification, this number being merely shown for convenience and simplicity.

The space I 8, in which the levers l6 and all instruments and regulating mechanism are contained, is a short passage extending between the wall of the stack and the wall of the kiln and all the instruments and regulating mechanism situated therein are attached to the wall of the stack.

In the case of drying malt, the green or moist freshly germinated malt travels from the germinating vats through the screw conveyors l9 and is spread over the upper drying floor I by means of the discharge conduits 20.

When the malt or other cereal has been partially dried on the upper floor, it is dumped through into the drying chamber 6 which is, of course, of considerably higher temperature since it is nearer the furnaces. When the cereal on the lower floor is sufficiently dried, the furnaces are damped down and it is dumped onto the floor of the mixing chamber 5 and thence through into the hoppers 2| which are shown in Figure 3 as extending the whole length of the kiln.

It is well known in the art of drying cereals and especially malt to convey it in the manner described. The method of mixing fresh air with furnace gases in a mixing chamber and conveying the air upwardly by means of fans to escape through a cowl in the roof of a kiln is also well known in the art but the method of utilizing the heated air a plurality of times is not known and has never hitherto been used for the purpose of drying cereals.

In the process of kiln drying malt, temperature, humidity and volume of air are, as previously mentioned, of utmost importance in order to produce character, aroma and color. The improved method which I have described constitutes a considerable advance in the art of kiln drying cereals. The flavor which was formerly carried off into the atmosphere is by my method returned and allowed to permeate the cereal. Also, during the process of drying, certain acids and gases are formed which have a bleaching effect on the malt and by using a portion of the returned air, these acids and gases are retained and fuller use is made of them in the way of bleaching the malt and thus enabling it to acquire the requisite color. The saving in fuel is also a very important consideration in my process.

I am of course aware that return air systems are in use for various purposes to economize in fuel but in this instance, this feature is merely incidental to the improvements effected in color, flavor and aroma which are accomplished by this process.

I wish it understood that I do not desire to be restricted to the actual structure described in the accompanying drawings, these being intended as illustrative only and not to be regarded in a limiting sense and I desire only such restrictions placed upon my invention as are specifically expressed in the claim attached hereto.

What I claim as my invention is:

The combination with a drying kiln for malt and the like consisting of a building-like structure having a plurality of superposed, vertically spaced, air pervious, drying floors, a superjacent supply chamber providing means for precipitating material upon the subjacent floor, a blower in said supply chamber operable to draw air from said floors and an air receiving, air mixing and air heating chamber below the lowermost of said drying floors, of a cowl outlet communicating with said blower upon the blowing side thereof, a horizontally disposed duct communicating with said cowl outlet, said duct also communicating with a vertically disposed stack erected alongside said building-like structure, a subterranean passageway communicating with the base of said stack, said passageway also communicating with said air receiving, air mixing and air heating chamber and a valve located at the communicating junction of said cowl outlet and said duct, manually controllable from a point adjacent said air receiving, air mixing and air heating chamber to permit the discharge of air from within said building-like structure through the cowl outlet into the atmosphere or circulate the same through said duct, down said stack, along said passageway and back into said air receiving, air mixing and air heating chamber.

LEON ZIHLER.

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