US1172291A - Drying plant. - Google Patents

Description

w.1. KENNY.

DRYING PLANT.

APPLICATION FILED MAR. 2. 1912.

1,l72,291 Patented Feb.22,1916.

2 SHEETS-SHEET l.

W. J. KENNEY.

DRYING PLANT.

APPLlcATmN FILED MAR.2.1912.

2 SHEETS-SHEET 2.

Patented Feb. 22, 1916.

" ,narran sTiaTns PATENT @Triton WILLIAM J. KENNEY, OF WILMIET'IE, ILLINOIS, ASSIGNOR TO UNDERFEED STOKER COMIANY OF AMERICA, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

DRYING- PLANT.

" Specification of Letters Patent.

Application led March 2, 1912. Serial No. 681,231.

To all lwhom t may concern Be it known that I, WILLIAM J. KENNEY, a citizen of the United States,` residing at Wilmette, county of Cook, State of Illinois, have invented a certain new and useful Improvement in Drying Plants, and declare the following to vbe a full, clear, and exact description of the same, such as will enable shall be efficient in operation and which will leave the material which has been dried in the best possible condition. Where the material to be dried is in a loose condition, as in the case of pulpy, fibrous, powdery or granular material, the dryingchamber mayy form part of the apparatus containing the furnace or heat-producing means; but it may sometimes happen that the drying operation must be otherwise conducted and in such cases my invention may be regarded as comprising a simple and economical means of producing a large volume of heated gases.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claim; but, for a full understanding of my invention and of its object and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawings, wherein:

Figure 1 is a longitudinal vertical section through a drying plant arranged in accordance with a preferred form of my invention; Figs? 2 and 3 are respectively sections on lines 2-2 and 3-3 of Fig. 1; Fig. 4 is a transverse horizontal section, on

.a larger scale than Figs. 1 to 3, through the furnace; and Fig. 5 is a partly front elevation and partly a section on line 5-5 of Fig. 4.

In the drawings I have illustrated my invention as embodied in a plant4 for drying the pulp remaining after the sugar has been extracted from beets. This pulp possesses a high food value when used as a food for stock and cattle; but to put the pulp in a satisfactory commercial form it must be dried and the drying must be accomplished 1n such a manner as not to produce burning and preferably without producing discoloration. Furthermore the drying must be accomplished in'such a manner as to prevent the pulp from being tainted and becoming unpalatable to stock land cattle. Consequently a' drying plant for beet pulp lmay be regarded as involving substantially all of the problems of care and economy which are apt to be encountered in drying material of any kind; and'l therefore I shall confine the detaileddescription to` this particular type of plant althoughit will of course be understood that I do 'not desire to be limited to any particular field or class of goods to be treated. Referring to the drawings, 1 represents furnace and 2 `a suitable receptacle or drum for containngthe material to be dried, the furnace being adapted to furnish gases heated to the proper temperature for passage .through the receptacle or drum in order to effect the drying of the drum.

3 represents a suction fan, a stack or other means for withdrawing the f'inoisture laden gases from the dryin receptacle and, in the case ofv a beet pulpp ant, for removing the light dry pulp from the drying chamber.

Jcontents of the The rate at which'the pulp dries is'dei pendent upon the volume and the temperature of the gases passed over or through it. The temperature is limited by the necessity for keeping the gases cool enough to avoid burning the pulp and consequently the volume of the heated gases isthe only factor whichcan be changed appreciably. Conseand the efliciency for any given capacity depends directly upon the volume of hot gases which the furnace can deliver. Furthermore, such gases should be free fromf unconsu-med combustiblematerial, that is, they should be as nearly smokeless as possible in order to avoid contamination or discolora- .tion of the materialwhich is being dried.

'quently the capacity of the drying plant are the combustion gases and the volume of these is definitely defined by the amount of air required to sustain satisfactory combustion. The volume of gases available for drying purposes can only be increased or decreased at the expense of a loss of eiiiciency in the furnace and with attendant smoke. Regulation of the volume of hot gases cannot successfully be obtained by drawing in free air independent of that coming through the grates to support combustion because an inlet for free air would disturb the draft conditions at the grate and would interfere with combustion, the ratio between the free lair and the air passing through the grates depending upon the resistance encountered by the free air and that iowing through the grates. Even if an arrangement could be designed to produce a satisfactory proportion between the two streams of air under given conditions, it would be impossible even approximately to maintain such proportions since the condition of the re is always changing, the depth of the fuel constantly varying and being different over different parts of the grate.

With a good fire, the gaseous products of combustion are much hotter than is necessary or practicable for drying purposes and therefore it is very desirable to have some means which will make it possible to reduce the temperature of the gases to the desired degree and at the same time utilize the excess heat for raising the temperature of air or other gases and make them available for drying purposes and it is to this end thatl my invention is directed. To attain this end I make use of apparatus which will make'the process of combustion independent of the draft through the drying receptacle, thus makingit possible to utilize this draft for the purpose of drawing in free air to 'be mixed with the combustion gases. By this means combustion and the amount of free air which is drawn in may be regulated independently of each other; the fire being always efficiently maintained at such a point as may be necessary to supply the requisite number of heat units to the drying gases, and the amount of free air being regulated so as to produce with the combustion gases the desired volume having the desired temperature.

In the furnace, instead of the old grates, li' prefer to place the retorts and the dead plates of the well known .Jones underfeed Stoker, the number of retorts employed depending upon the size of the furnace. In the drawings I have illustrated a single arrangement in which there are in the furnace two troduced by means of a suitable blower 8;v

the air passing up'from this chamber through the twyer blocks 9 of the retorts as is usual in this type of stoker. Coal is'fed from hoppers 10 in front of the retorts by means of the usual rams 11. As is customary with this type of Stoker, the speed of the blower and the rate at which the rams are reciprocated are controlled so as always to provide the requisite feed of coal and supply of air for producing the amount of heat desired.v The rear wall 12 of the furnace is arranged at some distance behind the bridge wall so as to provide behind the bridge wall what I shall term a mixing chamber. rIhe top of the furnace is formed of the usual arch 13 above which is placed a roof or cover 14;`

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the members 13 and 14 forming between I them an air chamber 15. In the front wall of the furnace I provide one or more openings 16 which lead from the outside air into the chamber above thearch. In the rear wall 12 I provide a suitable conduit which communicates at its upper end with the chamber 15 and at its lower end with the interior of the furnace. In the arrangement shown, the conduit is made. Ushaped as indicated at 17, one leg extending vertically through the wall near each side of the furl nace and the lowerlends` of the two legs being connected together by a passage or conduit which opens forwardly into the furnace below the top of the bridge wall as indicated at 18. The wall 12 has an opening 19 therethrough for the passage of combustion gases from the furnace to the drying receptacle.

When the plant is in operation thel fire `burns in the presence of air supplied by the furnace blower and the gases of combustion i" are drawn back throughthe drying receptacle by the draft producing device at the outlet endof the receptacle. At the same time air flows from the outside through the opening or openings 16 in the front wall of the furnace and across the top of the heated arch, taking up heat from the arch in its passa e and fiowing down through the conduit 1 into the space within the furnace just back of the bridge wall and. just below the outlet 19 for the combustion gases. rIhe air rises and mixes with the. combustion gases as they approach and while they are passing through the outlet 19, lowering the temperature of the combustion gases and increasing their volume so that the quantity of `gas Howling through the drying appakeeping down the temperature of the arch and prolonging its life., There is consequently a saving not only of the heat 'units but also in the furnace structure itself.

If desired, the front wall of the furnace may be provided with openings 20 controlled by suitable doors or covers 21 so that '1f a greater quantity of gas than that obtained in the manner heretofore described is desired, some or all of the doors or covers 21 may be wholly or partially opened, thus adl mitting additional free air into the system. This additional air which is admitted into the furnace directly over the fire hasvno disadvantageous effect on the fire because there are no unconsumed volatile matters in the combustion gases which might be cooled suiiciently to form smoke, all of the volatile matters being driven out of the fuel in the retorts and being consumed as they rise intol 2,5 the burning mass of fuel above.

While I have illustrated and described only a single preferred form of my invention, and one adapted for use in connection with an old formA of drying receptacle, I do not desire to be limited to the specific structural detailsthus illustrated and described, l

to the use of my invention in connection 4with any particular form of drying receptacle, or to .the field of Adrying beet pulp; for myV invention is capable of many structural variationsv and is/,capable of use in various fields as will be evident from the definitions of vmy invention constituting the ap- --pended claim.

I claim:

In a drying plant, a furnace having a hollow top wall, the interior of said top wall communicating with atmosphere, a rear wall having an outlet through the center thereof for the passage of the combustion gases, there being a conduit leading down through said rear wall from -the interior of the top wall and opening into the furnacebeneath said outlet, a bed in said furnace for supporting fuel, means for forcing the air necessary for combustion beneath said bed, a drying chamberV connected with said furnace' and adapted to receive the combustion gases flowing through said outlet, and means fory producing'a draft from the furnace through said chamber.

In testimony whereof, I sign this specification in the presence of two witnesses.

t WILLIAM J. KENNEY. Witnesses: Y

MARGARET FALAHEE, SUSAN FALAHEE.

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