US1731242A - clark - Google Patents

Description

Oct. 15, 1929. F. s. CLARK WOOD DISTILLATION Filed April 19, 1927 Inuehi'or:

fianklz'n LS: Clark L 1 M UWW ZZ Q- M N QNR awn/M52] W i g; I H. I I vi: a ate Illl/Ill Illl l I I I l l ll I Y Hnu F NN;nHHUHHHHHNHHHHH HHHHHMHI m em m Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE FRANKLIN S. CLARK, OF PALM BEACH, FLORIDA; L. YANCEY CLARK AND FRANKLIN S. CLARK, JR., EXECUTORS OF SAID FRANKLIN S. CLARK, DECEASED WOOD DISTILLATION Application filed April 19,

My present invention relates to a method for distilling wood, for the eflicient production of natural cducts and distillation products.

One of the principal objects of this inven-. tion is the regulation of the heat between certain ranges, for certain periods so that clean fractions may be secured without contamination from following or adjacent fractions.

This includes a separation of natural educts' from the products of destructive distillation. Another important object of the invention is the efiicient operation of an oven for distillation of woods which will be carried on at low cost, which will result in a minimum wear and tear on equipment, and which sepure the maximum yield of desirable distilate. I

Other objects and advantages will appear as the description proceeds.

To this end the invention contemplates the use of a still substantially rectangular in cross section and of an elongated form which may be fired from each end. The oven proper may be constructed of sheet iron, provided at the top and bottom withoutlets for distillation products, and in between with a track upon which may be run the cars containing the wood to be treated. I propose to make the tracks at substantially the ground level, so that no unnecessary equipment such as cranes or the like will be needed to charge or empty the retort.

The oven or retort itself is surrounded with flues for heating the same initially with a free fire from wood, coal, coke, gas, oil or the like, which fire, however, is not suflicient to cause distillation. This first and free fire is merely to initially heat the still or retort, to prevent condensation. The distillation temperature is reached by means of pressure steam contained in pipes hung from the car tracks or on the side walls. Sulficient open, free or unconfined steam is introduced into the bottom of the still to keep the distillation products moving through the apparatus. When the process is about complete, a certain amount of superheated steamsis let into the retortto finally drive out any remaining desirable products from the charcoal.

1927. Serial No. 184,937.

Suitable condensers, purifiers and other devices are provided in connection with the still or retort above mentioned to insure an efficient collection of products.

It is to be understood, that a very important feature of the invention is the initial heating of the retort with free fire, the maintaining of the distillation range with controlled pressure steam, the provision of slight How of open or free steam to keep the products moving, and the final clean out with superheated steam. Y

The invention further consists in the com bination, construction, and arrangement of parts and the various steps set out in detail in the specification andshown in the drawings.

In the drawings v Fig. 1 is a view partly in section of a device for carrying out my invention.

Fig. 2 is a longitudinal sectional view through the device.

Referring now with particularity to the embodiment illustrated, I have shown at l a sheet metal still or retort, elongated to take a series of wood carrying cars. The ground level is indicatedat 2.

Built up aroundthe still, I provide brick work 3 or the like having a series of fines 4 therein. The still is adapted to be heated by free fires built at each end thereof, the heat travelling circuitously toward'the center of the retort, upwardly, back to the fire region and then to the stack. In this manner the entire side walls are thoroughly heated while at the same time the'top and bottom are maintained relatively cool.

Mounted upon supports 5, I provide tracks 6 to receive the wood carrying trucks 7. As these tracks 6 are at ground level, the loading and unloading of the retort may be expeditiously carried out with the minimum amount of effort.

A series of steam pipes 8 is provided, hung from the track supports and substantially cover the longitudinal area of the retort. The pipes 8 are connected to a suitable source of steam under pressure, controlled by valve 9. By this system, the temperature within the retort may be absolutely maintained between admitting superheated steam through the pipe 13 controlled by valve 14, this last part of the products may be driven over.

The bottom 15 of the retort is preferably dished to permit the rosin melted out during the first part of the treatment, and the tar produced during the later part of the treatment to collect, and pass out through the pipe 16. This pipe has a low outlet 17 and an upper outlet 18. When valve'19 is open, the first product, namely, rosin passes out through the outlet 17. When upon increasing the temperature, tar is produced, the valve 19 is closed and the tar exits through the pipe 18 to a suitable container.

The roof 20 of the retort is likewise curved, and provision is made for a thermometer 21 therein. A take-off or gooseneck 22 is connected to a downcomer 23 which is provided with suitable valves 24 and 25 respectively,

and an air condenser 26. From the upper part of these air condenser coils, the products are conducted to a purifier 27 consisting of a tank provided with baffle plates 29. The tank is partially filled with an alkali such as caustic soda and the gaseous products are made to bubble through the caustic to removeany of the ligneous acids. After passing the purifier, the gases may be passed through the condenser 30 and the condensate collected.

The operation of the systemis substantially as\f7\c;llows.

hile this treatment is particularly adapted for the distillation and treatment of soft woods such as pine, and for the collection of the particular products of the soft woods, yet obviously other woods may be similarly treated efficiently. I will describe, however, the

. treatment of a batch of pine wood.

The cars 7 are loaded with wood to be treated, cut preferably into pieces of convenient length having no cross sectional measurement greater than four inches. This size has been found sufiiciently small to permit complete heatpenetra'tion without undue raise of temperature. Any number of cars may be utilized consistent with the length of the retort.

Fires are now built at each end of the retort to initially heat the same, although these .fires should be of such a character that a destructive distillation temperature cannot be reached with them alone. Suchwood fires may be advantageously used to cheaply raise the temperature to prevent condensation on the retort walls during the first stages.

As the temperature rises, pressure steam is introduced into the pipes 8, being fed from a boiler operating under substantially 200 lbs pressure. During the first fifteen hours of treatment, the temperature should be slowly raised and kept below 270 to 280 F. At this point destructive distillation begins, and one of the principal objects is to prevent a m 1X.- ture of the natural educts and the destruct1. e distillation products. If the temperature 1s not increased beyond this point, practlcally all of the rosin will melt and be collected through the outlet 17 the valve 19 bemg open, and a very good quality of turpentine Wlll be produced. Throughout this period a sufficient quantity of open or free steam 1s admitted throughihe pipe 10 to keepthe educts moving.

The vaporous educts not condensed by the air condenser pass upwardly, through the purifier, and then are eventually condensed at 30 and collected.

After this first period has been completed, with the controlled steam, and practically all of the natural educts clearly fractionated, the steam is turned off and destructive distillation begun by firing the free fires at the ends of the retorts.

When this later period begins, the valve 25 should be closed and valve 24 opened in order to permit the heavy oils to be condensed in the condenser 32 and not pass upwardly and contaminate the condenser 26 and beyond. At the same time, the valve 19 should beclosed astar will now be produced and pass out ofthe tar outlet 18. The separate condenser 32 is used to condense such of the distillate as now comes over.

After some hours of such treatment, the wood will be exhausted and only charcoal remains. Any remnants of desirable products contained in this wood may be forced out by introducing superheated steam through the pipe 13. As the charcoal at this stage is at a relatively high temperature the superheated steam will have no detrimental effect on it,

but will remove the last traces of distillate.

Upon cooling, the end doors or gates of the retort may be opened and the cars containing spent charcoal removed.

From the above operation, it will be noted that the equipment is only subjected to a high temperature for ashort period of time so that excessive wear and tear is avoided.

Due to the fact that during the first or natural educt period, the temperature is absolutely controlled, and there is no contamination of the distilled vapors by products of destructive distillation, a clean and efficient fractionis obtained,both as to distillate and melted out materials.

What is claimed is: v

A method of operating a wood distilling device which consists of a retort surrounded by a heating chamber, a furnace to heat such chamber, and having closed and open steam pipes within it, which comprises heating said retort first by fire within the furnace to a temperature which will prevent condensation of water or other vapors upon its Walls, then heating it to a temperature which will remove volatile substances existing in the Wood Without changing their chemical composition, then heating it by fire to a destructive dlstlllfltion temperature and maintainlng said heat until the wood is carbonized, free steam being passed into the retort throughout the last two heating periods in sufiicient quantity to convey away the vapors produced.

In testimony whereof, I affix my signature.

FRANKLIN S. CLARK.

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