USRE398E - Improvement in furnaces for burning wet fuel - Google Patents

Description

UNITED lSTATES PATENT OFFICE.

MOSES THOMPSON, OF .NEW ORLEANS, LOUISIANA.

IMPROVEMENT IN FUR'NACES FOR BURNING WETFJEL.

Specification forming part of Leiters Patent-No. 12,678, dated April 10, 1,855; Reissue No. 39B. dated october v, 185s. Y

To al whom, it may' concern/ Be it known that I, MOsEs THOMPSON, formerly of Henrico couuty,and State ofVirginia, and now of New Orleans, in the State of Louisiana, have invented a new-and useful Improvement in burning tan-bark, bagasse, saw-dust, and other kinds of fuel ina wet state, for the purpose of creating heat to generate steam or to be employed in heating or drying operations; aud I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to t-he accompanying drawings, forming part of this specification, in which- Figure 1 is a horizontal section of a furnace constructed according to my invention. Fig. 2 is a vertical section of the same in the line .r' 1/ of Fig.

Similar letters o1' reference indicate corresponding parts in the several iigures.

The main object of my invention is to effect the more economical use,for fuel,of tan-bark,

bagasse, or other trashy matters in a wet state, or very green or wet wood.

' arrangement is for the purpose of effecting the process of heating the wet charge to an intense degree in a nearly air-tight chamber, decomposing it to some extent, mingling the gasses from the different re-chambers, and admitting a free supply of air to promote rapid combustion in the mixingchamber,to be conducted without interruption to the operation which the heat generated is intended to effect. To enable others Skilled in the art to make and use my invention, I will proceed to describe itsconstruction and operation.

The furnace shown in the drawings has three {ire-chambers, A A A. Three is the number -shown, as I consider that number in many cases to be best adapted to practical operation. In some cases two may be sufheient, and in others it requires more than three. In making these variations as to the number ofchambers the builder is to be guided by the quantity of heat required, size of chambers, and character of fuel to be used.

The fire-chambers are 'of a square but may' be of other form, with grate-bottoms B B B and arched tops; or said tops may be used or built of any other form adapted to the kind of fuel to be used. They are separated by a wall of fire-proof material and lined throughout with iire-brick,and in case of burning Wet tan frebrick grate should be used.

Each burning-chamber is provided with a door, C, in front for the purpose of lighting and tending the fire, with an opening, D. at the top for the purpose of supplying the fuel when it consists of tan-bark or other material of similar nature, and with an opening, E, at the back end of the chamber, which leads to theflue F or thc'mixing-chainber. The opening maybe provided Witha damper, K. Each fire chamber has a separate ashpit, G, below it, which is furnished with the door H, to regulate the admission of air. Thev flue or mixing-chamber F extends across the baci; of all the three fire-chambers, and the chimney may be at one end or may be placed in the rear,with the flueI leading to it from the flue F.

If the furnace is used for generating steam,

the best place for the boiler will bein the iue I, which will be made of a proper size to receive and nearly surround it. If used for other purposes, any arrangement may be made best adapted to the application of said heat. The thing to be heated ought to. be. elevated from two to three feet above inside top o f the fnelchambers.

The current from the mixing-chamber, in passing to the place of use in the case of burning wet tan or other very-Wet fuel, should descend or pass under a bridge to the place of use equal to about one-half of the depth of the i increased to about threefold capacit -of that used for very wet fuels, to be vari 1n proportion tothe wetness or dryness of said fuel.

In case of burning of sawdust or green or wet wood, the chambers should Abe about double the. grate-surface of what is commonly used for burning of wood to accomplish the same object; but for wet tan it should be increased to about fourfold.'

The mode of conducting the operation of the furnace is as follows: Fires being lighted in all of the lire-chambers with dry fuel, and the masonry heated to a high degree, two of the three chambers A A- are fed with wet fuel, and have their ash-pits closed and the damper K K partially closed,- though this is not absolutely necessary. The other tire-chamber, having its charge partially dry, in the meantime has the damper K open, and the door of the' ash-pit II opened far enough to admit any quantity of air which may be required to pro-.

mote such a degree of combustion in thecham bers as may be' neceary to generate the amount of heatrequired. There should be no artificial blast, and if aY high stack be used there should be a damper in it to moderate the draft. When the fuel in the open chamber is reduced to a desirable degree, its ash-pit is closed and the chamber recharged, and another opened and supplied with air until the fuel within is reduced, when it is closed, recharged, and another opened, nach in its turn being opened and supplied with airto generate and supply the requisite amount of heat while the others are closed, and successively supplied with fresh fuel to heat and decompose the same to such a degree as is desirable before allowing rapid Acombustion to take place.

Each Vfire-chamber should be supplied successively with fuel at proper intervals by any convenient means either through the hole D or door C in front.

The principal advantage of a furnace and v process of this description consists in heating the charge without any further loss of heat than is absorbed by the comparatively non-conducting material of whichthe furnace is constructed, 'and decompose itinto such as will, when mingled in the mixingchamber with the products of combustion from the active chamber, cause the most perfect y combustion of the "gases and smoke to be efing a certain quantity of heat/and high1yheated fuel in reserve in theclosed chambers, which may be immediately brought into action by opening one or more of the chambers. A similar but inferior rult might be produced by having several gratesaud ash-pits to the same fire-chamber, cach grate charged succeively, and its ash-pit for a time closed immediatelyaer fresh 'ng to exclude the air. I have described this in my caveat,

on which my application is based, but do not use it because of its inferiority in practice, although it involves my principle.

-Alter ample experiments I have discovered that any results which can b e produced by the use ot' dry fuel are inferior to wet in proporing witha draft and its cooling and wasteful influence, and rendering the combustion so perfect that no smokeis visible. Y

In'burning tau and sawdust where a larg quantity ofheat is tobe made, 'in order to save the ncreaseiof theirnumber, I put the chambers in twice as long' aswide, and use two openings D to feed through, and thereby accomplish double to eachchamber..

I do not claim the within-described arrangement of a series of fire-chambers to communicate with one common flue irrespective of the purpose for which and the manner' in which I employ thesaid arrangement; but Y What-I doclaim as my invention, and desire to secure by Letters Patent, is-

The combustion, for the purposes of a high degree of heat, of Y refuse tan, sawdust, and other wet refuse substance, or very wet andgreen wood, by the employment of a series of fire-chambers arranged in any man-l ner, substantially as described, to communicate with one common line or mixing-cham` ber, when any number of 'said chambers are nearly closed to theV admission of air when first charged, as described, while the remaining chamber or chambersareiufull commun cation with the flue, and has a free supply of 4air admitted, and the ash-pit of each chamber in its turnis nearly closed andthen opened, and has air admitted, whereby the heat required is rendered continuons and comparatively uniform, while the fuel in some of the chambers is being heated and decomposed to a desirable degree, as herein s et forth.

` Moslls THOMPSON.

In presence 0f A. WoomuN, Jas. SALTER.

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