US1490354A - Process for carbonizing coal - Google Patents

Description

April 15, 1924. 1,490,354

G. w. WALLACE ET AL PROCESS-FOR CARBONIZING COAL Filed Dec. 21. 1921 2 Sheets-sheaf. 1

Q INVENT E NW 97% w im- 147* Toe/vs Y5 April 15 1924.

G. W. WALLACE ET AL PROCESS FOR CARBONIZING COAL Filed Dec. 21, 1921 2 She'ts-Sheet 2 WIWHWT Fl o GEORGE W. WALLACE, OF EAST ST. LOUIS, ILLINOIS, AND ARTHUR W. WARNER, '01 MEDIA, PENNSYLVANIA, ASSIGNORS TO WALLACE COKE, OIL AND BY-PRODUCTS COMPANY, OF EAST ST. LOUIS, ILLINO IS, A

CORPORATION OF ILLINOIS. f

' PROGESS FOR CARBONIZING COAL.

Application filed December 21, 1921. Serial No. 523,910.

To all whom it may concern.

Be it known that we, GEORGE W. WAL- LACE, and ARTHUR W. WARNER, citizens of the United States, residing in the city of East St. Louis, Illinois, and Media, Pennsylvania, respectively, have invented a certain new and useful Improvement in Processes for Carbonizing Goal, of which the following is a full, clear,and-exact description, such as will enable others skilled in the art to Which it appertains to make and use the same.

This invention relates to tion of'coal. u a

The main object-ofour invention is to provide a novel process'for carbonizing coal that, roduces hard, low volatile coke and gas oi a relatively high Btu. value and insures the recovery of a relatively high quan tity of a good quality of oils.

Another object is to provide a process of the character described that can be easily controlled and which can be practiced in an apparatus of simple design.

And still another object is to provide an eflicient process by which low temperature products and high temperature products can be produced simultaneously and kept separate in the same carbonizingchamber. Other objects and desirable features of our invention will be hereinafter pointed out.

Briefly described, our process consists in heating coal in a carbonizing chamber,

the Jcarbonizacausing the liquids, gases and vapors that are evolved at the low temperatures, or, in other words, up to the oint where the material in the chamber orms a plastic film and begins to assume a coke-like structure, to travel through the coolest portion of the material in the chamber and escape. from said chamber befor they can undergo secondary decomposition, carbonizing ata high temperature the coked residue, maintaining a plastic film in the body of material in the chamber that effectively separates and protects the liquids, vapors and gases escaping through the coolest portion of the material from the high heat used to carbonize the coked residue and from contact with the high temperature gases evolved from said coked residue, and causing the high'temperature' gases evolved during the carbonizatlon of the coked residue to escape freely from the chamber through an outlet separate and distinct from the outlet through which the low temperature products escape.

Figure 1 of the drawings is a vertical sectional view of oneform of apparatus that can be usedin practicing our process.

Figure 2 is an enlarged vertical sectional view, illustrating the seal at the lower end of the take-01f duct; and

Figure 3 is an enlarged vertical sectional.

View, taken at right angles to Figure 2. Said apparatus consistsof a carboni'zing chamber A, closed at its upper and lower ends and of any preferred cross-sectional shape and dimensions, a means for externally heating said chamber A,such, for example, as a combustion chamber B that surrounds the carbonizing chamber A, a means C such as a perforated take-01f duct that forms a center take-01f passageway in the body of material in the chamber A, an outlet D at the lower end of said take-off duct arranged at such a point that it will be maintained at a much lower temperature than the portion of said duct surrounded by the material inthe chamber A, and a gas outlet E at the upper end of the carbonizing chamber. In the apparatus herein illustrated the take-ofi duct C is arranged centrally within the chamber A and the upper end of same terminates at a point below the top or removable cover F at the upper end of the carbonizing chamber, said duct being provided at its upper end with a device K so as to enable it to be connected with a means (not shown) that is used for withdrawing the take-off duct upwardly through the upper end of the carbonizing chamber to remove the charge. Means isprovided for sealing the outlet D of the take-ofi duct when said duct is in operative position in the carbonizing chamber andfor maintaining said outlet at a lower temperature than the portion of said duct surrounded by the material in the carbon'izing chamber, and in the apparatus herein illustrated said means consists of a water filled tank G in which a manifold gas and vapor outlet L is submerged, the lower end of the outlet D of the take-ofi' duct projecting into the upwardlyprojeoting portion of the gas and vapor outupper end of the take-off duct. WVhen the apparatus is in operation any dirt or coke breeze falling to the bottom of the carbonizing chamber drops downwardly to the bottom of the tank G from which it can be easily removed.

In practicing our process the chamber A is charged with coal so as to cover the upper end of the take-off duct and fill the space between said take-ofi' duct and the side walls of the chamber, and heat is then applied externally to the chamber. penetrates inwardly the coal starts to soften and melt, resulting in the formation of liquids, gases and vapors, and when a temperature of approximately 825 F. is attained, a plastic film :0 forms in the body of.

material in the chamber A. As the carbonizing proceeds the film travels .inwardly towards the take-ofi' duct, thus leaving a coked residue y between said film and the externally heated portion of the chamber.

The gases, vapors and liquids that are evolved at the lower temperatures, namely, up to-the point where the material constituting the plastic film m begins to form acokelike structure, travel inwardly into the takeoff duct C through the cooler material a lying: between the plastic film w and the take-off duct, and upon entering the takeofi duct, are withdrawn without reheating,

through the outlet D at the lower end of the duct, thereby preventing secondary decomposition. Th heat supplied to the walls of the chamber is'uniform throughout the carbonizing period and should loe maintained sufficiently, high to overcome any temperature drop due to the insulating quality of the hot coke already formed and to still supply theheat necessary to form the plastic film. The farther this film travels away from the walls of the. chamber, the slower it travels. Regardless of the rate at which the film travels inwardly, the conditions under which the oils and vapors form within this film are nearly constant. Any ordinary temperature. variation in the carbonizing chamber afi'ects therate of inward travel of the film but not the quality of the oils.

and vapors produced within the film. As the carbonizing proceeds, the heat at the side walls of the chamber causes the coked residue to be carbonized at a high temperature, and the high temperature gases that are evolved. from said coked residue are As the heat a measea compelled to escape freely from the chamber A through the outlet E at the upper end of the chamber.

In practicing our process it is essentia that suflicient coal be introduced into the chamber A to cover the upper end of the take-ofl' duct C to a depth approximately equal to or in excess of the thickness of vthe mass of material between the take-off duct and the side wall of the chamber, and it is also essential that suficient heat be applied to the upper end portion of the chamber to cause the coal that extends over the upper end of the take-off duct 0 to be subjected to practically the same amount of heat as the coal between the take-off duct and the side Walls of the chamber. The purpose of operating the carbonizing. chamber in this manner is to cause the plastic film w to assume such a form that it will compel the gases, vapors and liquids produced inside of the film to escape through the center off-take passageway, protect them from the high heat used to carbonize the coked residue on the outside of said film and also 'from contact with the high temperature gases evolvedfrom said coked residue and also cause said high'temperature gases to escape through the outlet at the upper end of the carbonizing chamber. 'The plastic film as may be capable of withstanding a pressure of 30"-40" (water) before gases can break through same, and as it forms practically a continuous barrier that divides the interior of the carbonizing chamber into a low temperature zone and a high temperature zone, it makes it practicable to obtain in one chamber from one source of heat, low temperature products and high temperature products, and to recover them separately. The particular shape or form of the film w is, of course,

immaterial, but ingeneral outline it may i be said to resemble an inverted bell on account of the fact that it comprises a top portion that extends over the upper end of thetake-ofi duct anda side portion" that surrounds the take-ofl' duct and which is integrally connected to said top portion.

The process above described produces hard, low volatile coke, gas of relatively high B. t. u. value and a relatively high yield of oils of a good quality that have a higher commercial value than the tar produced as a product of the ordinary high temperature carbonization of coal. Moreover, the quality of the. high temperature gases that are obtained fromthe coked residue is high to the termination of the procem. The above process can be practiced in an apparatus of simple design and it can be easily controlled, as any short circuiting of the high heat or high temperature gases through the plastic film a: cuts down the yield of oils and results in the formation of ma am oil coke in the duct C, which is a very simple indication to an ordinary operator of the efliciency of the carbonizing chamber.

While we have herein described our process as being carried out-in an apparatus comprising a carbonizing chamber anda hollow, perforated member inside of said chamber that forms a center take-ofi' duct or off-take passageway for the low temperature products, we wish it to be understood that our process is not limited to use with an apparatus in which the take-ofl' passageway for the low temperature products is formed by a hollow, perforated member arranged at the center of the mass of material in the carbonizing chamber. The essential thing, so far as the escape. of the low temperature products is concerned, is that said low temperature products travel through the coolest portion of the material in the carbonizing chamber in escaping therefrom. Accordingly, the apparatus that is used for practicing our process may take various forms and may be quite difierent, structurally, from the apparatus herein illustrated.

Having thus described our invention, what we desire to secure by Letters Patent is:

1. A process for carbonizing coal, characterized by heating coal' in a carbonizing chamber, providing a take-off passageway at the center of the mass of material in the chamber and causing the gases, vapors and liquids that are evolved up to the point where .the material begins to assume a coke-like structure to enter said passageway and escape, without reheating, from the chamber, carbonizing the coked residue at a high temperature and permitting the evolved gases to escape freely from the chamber through a separate outlet, and maintaining a plastic film in the body of material in the chamber of such form as to effectively separate and protect the low temperature products from the high temperature products.

2. A'process for carbonizing' coal, which consists in heating coal in a 'carbonizingchamber, causing the gases-vapors and liquids that are evolved while the material is in amolten or plastic state to travel through the coolest portion of" the material in the chamber and-escape from the chamber before they can undergo secondary decomposition, carbonizing the coked residue at a hi h temperature and withdrawing the evolve gases through an outlet at the upper end of the chamber, andmaintaining acontinuous plastic film in the body of material in the chamber so as to effectively separate the high temperature zone from the low temperature zone.

3. A process for carbonizing coal, consisting in charging coal into a carbonizin chamber provided with a center take-0% duct, to such a depth as to completely cover the upper end of the take-ofi' duct, applying heat externally to the chamber in such a way as to cause a plastic film to form in the material in the chamber between said take-ofi' duct and the side walls and top of the chamber, withdrawing through said take-off duct the gases, vapors and liquids evolved inside 'by said carbonization to escape freely through an outlet at the upper end of the chamber.

4. A process for carbonizing coal, characterized by subjecting coal to a hi h temperature carbonization in a closed 0 I, amber in such a way-as to cause the coal to melt and produce a plastic film in the form of a practically continuous barrier in the body of material in said chamber thatdivides the interior of said chamber into a high temperature zone and a low temperature zone, and withdrawing simultaneously from said zones through separate outlets the low temperature products and the high temperature pro- I ducts produced in the respective zones.

5. A combined low and high temperature process for carbonizing coal, characterized -low temperature products from the high temperature products, removing the low temperature products as they are evolved in such a way as to prevent secondary decomposition, and simultaneously removing the high temperature products through a separate passageway.

i GEORGE W. WALLACE.

. ARTHUR W. WARNER.

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