US1559994A - Destructive distillation of wood - Google Patents

Description

Nov. 3, 1925- 1,559,994

D. P: SHAW DESTRUCTIVE DISTILLATION 0F WOOD Filed D90. 21, 1922 Patented Nov. 3, 1925.

UNITED STATES DUNCAN P, SHAVT, OIE FAYETTEVILLE, NORTH CAROLINA.

DESTRUGTIVE DISTILLATIO'N 0F WOOD.

Application filed December 21, 1922.

T 0 all whom it may concern:

Be it known, that I, DUNCAN P. SHAW, a citizen of the United States, and a resident of Fayetteville, county of Cumberland, and State of North Carolina, have invented a new and useful Improvement in Destructive Distillation of Wood, of which the following is a specification.

This invention relates to an improvement in the process of extracting from burning pine Wood the vapors emanating therefrom for producing turpentine, and other products from pine lightwood.

The invention relates more particularly to the extracting of the tar and the turpentine from lightwood which is burned in a kiln. It has been customary for many years to extract tar from the pine lightwood by means of kilns which are constructed of pine straw and earth. A trench or tunnel is formed in the ground which slopes gradually in length and at the lower and shorter end of the trench or tunnel a pit or receptacle is provided for catching the tar which drains from the tunnel through a longitudinal groove or ditch. The wood is laid generally lengthwise of the tunnel and the wood is of various lengths, the length of the wood not being material. After the wood has been piled throughout the length of the tunnel the pile of wood is completely covered with pine straw, sand or clay so that the pile is completely covered and closed at the lower end. This covering prevents air currents and keeps a fire which is on the back end from'drawing through and consuming the wood without producing tar. With kilns of this type the vapors which are produced by the burning and the destructive distillation of the wood have heretofore been lost as these vapors have been allowed to be drawn by the fire and consumed, and it is the purpose of this invention to recover these vapors which are produced by the destructive distillation of the wood.

In the accompanying drawing an apparatus is disclosed in connection with aki-ln as above described which may be employed for the recovery of the vapors produced by the destructive distillation, in which:

Figure l is a diagrammatical view in plan of the kiln and an apparatus for drawing the vapors from the kiln;

Figure 2 is a transverse vertical sectional view of one of the vapor collecting boxes;

Figure 3 is a detail view partially in ele- Serial No. 608,384.

of one of kiln and spaced at a suitable distance from each other are a plurality of vapor collecting boxes 6. These boxes or outlet conduits are preferably constructed of wood and provided with a plurality of perforations in three sides as indicated at 7, so that the vapors may enter the boxes. These boxes are laid crosswise of the kiln and upon or in the piled wood and have one end projecting through a side of the kiln. A pipe 8 is connected to these various boxes 6 by branch pipes 9, 9, each branch pipe being provided with a valve 10 for closing the same whereby the branch pipe may be closed after the fire has consumed the wood in the vicinity of the vapor box.

The pipeS leads" to a suitable condenser 10 and leadingfrom the condenser is a pipe 11 to which is connected a pipe 12 through which the condensed vapors are discharged into a suitable container. An upright, pipe 13 is connected to the pipe 11 and located at the upper end of thispipe l3 is inserted a steam or air pipe-14. This pipe le whieh delivers air or steam to the pipe produces a suction through the pipes 13, '11, condenser 10 and pipes 8 and 9 for drawing the vapors from the vapor boxes 6 into the condenser from which condenser the condensed vapors are delivered to the pipe 12.

duced by the distilling of the wood and' these vapors are collected in the vapor boxes 6 j 1 It is to be understood that this form of kiln and form of condenser with its various connections may be substituted by other forms that may be foundmore feasible for the type ofkiln or conditions of operations.

In the burning of a kiln of the character set forth, the fire is started at the large or back end of the kiln, and as the pile of wood is covered with sand or clay and pine straw, the combustion of the wood is slow,

so that there is a gradual and progressive burning of the wood, from one end of the kiln to the other in a horizonal direction. That is, the fire is of suflicient' intensity to consume the wood, but not to that degree that the wood would be consumed rapidly and thereby destroy the products, such as tar and like vapors that will issue from the wood when burned slowly. As the wood is consumed, the vapors emanating therefrom will be collected by the vapor box 6, which is closest to the burning wood, and these vapors will be drawn from the box 6 through the pipes 8 and 9' to the condenser. When the wood is consumed up to the vapor box, or the attendant believes that a particular box should be cut off, due to the proximity of the fire, the valve in the pipe 9,'will be shut off, and the vapors will then be collected inthe next or adjacent boxes 6. By closing the valve 10, of the box which is no longer in use, or can be used,

either due to the fact that the box has been consumed by the fire, or that the fire has progressed beyond the box, the vapors are prevented from escaping through the pipe leading to that particular box or boxes, or the drawing into the pipe line other vapors or gases not desired, such as gases of combustion which contain no tarry vapors to be mixed with, the vapors recovered from the burning wood.

In some instances it may be found advisable to employ steam during the combustion of the wood, and in such cases, steam pipes 16. have been provided, so that steam may be: injected into the heated zone in advance or-adjacent to the zone of the burning wood, by opening the valve on the pipe 16, and thereby causing the steam to assist in vaporizing the tarry products produced by the heat of the burning wood in the combustion zone. As soon as a pipe 16 is no longer needed by reason of the consumption of the kiln and pile, that pipe will be cut off from the main supply pipe 15, by the valve in the pipe 16.

It, will be readily understood from the foregoing'that provision-has been made for collecting the vapors produced in the destructive distillation of wood ina kiln which destructive distillation is caused by heat produced by burning-part of the wood, wherein the fire comes. in direct contact and consumes the wood, and drawing oif the tarry vapors from a distilling zone adjacent to, the, combustion ZOIlQ. to a suitable condenser. from which the condensed vapors may betakenand treated.

Heretofore,these-, vapors have been. lost and only the tar has been extracted from the wood, except in such cases where retorts are employed. The excessive costs attendant in the employment of a retort, and the location of the material, is such that it is often prohibitive to employ a retort, so that the operator has heretofore simply burned his wood in a kiln and recovered the tar, and allowed the vapors to be consumed in the fire and lost. With this invention, turpentine and like vapors as well as tar vapors are recovered from the distillation zone without being commingled with the combustion gases from the combustion. zone of burning wood.

Having described my invention what I claim as new and desire to secure by Letters Patent is:

1. The process of destructive distillation of wood, consisting in. progressively burning a mass of such woodfrom one end to the other of a kiln in a substantially horis zontal direction, and in withdrawing the distilled vapors from. a zone in advance of said progressively burning portion, and sub,- stantially avoiding the intermixing with, the distilled vapors of any gases of combustion which contain. no tar vapors. r

2. The process of destructive distillation of wood, consisting in slowly and gradually burning a mass of such wood progressively from one end to'the other of a kiln. in a substantially horizontal direction,v and in withdrawing the distilled vapors from a zone in advance of the burning portion, and substantially avoiding the intermixing with thedistilled vapors of any gases of combustion which contain no vapors.

3. The process of destructive distillation of wood, consisting in slowly and gradually burning a mass of such. wood progressively from one end to the other of a' kiln, in a substantially horizontal direction, subjecting the heated wood in advance of the burning wood to the, action of steam for distilling the distillates, and inwithdrawing the distilled vapors from a zone-in advance of the burning portion, and substantially avoiding the intermixing with the distilled v vapors of any gases of combustion which contain notar= vapors.

4:. The process of-destructive distillation of wood, consisting in progressively burning a mass of such wood from one end to the other of a kiln in 'a substantially horizontal direction, and in withdrawing the distilled vapors from said mass successively in advance of the burning portion, and substantially avoiding-the intermixing with the distilled vapors of any gases of combustion which contain no tar vapors.

DUNCAN P. SHAW;

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