US2029759A - Apparatus for the treatment of carbonaceous material - Google Patents

Description

4 Sheets-Sheet l WASTE. HEAT 5011.1?

l. H. DERBY Ef AL Original Filed Jan. 4, 1950 l l l I ll 0 EXHAUJ TER,

Feb. 4, 1936.

APPARATUS FOR THE'TREATMENT OF CARBONACEOUS MATERIAL Feb. 4, 1936. H. DERBY ET AL 2,029,759

' APPARATUS FOR THE TREATMENT 0F cARBoNAcEoUs MATERIAL Original Filed Jan. 4, 1930 4 Sheets-Sheet 2 COOLING w CHAMDEKJ com: DUCHAKGE 4 E HAN MEDIUM FLUID HEATLNG Z T'LUID HEATING '55 GAJ OFF TAKE Juc-m dk &

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APPARATUS FOR THE TREATMENT OF CARBONACEOUS MATERIAL Original Filed Jan. 4, 1930 4 SheacQs-Sheet' 4 Summers Bio/mom I 11/ 1/1 I //1 1 ///////1 /A 1 /7A6fl 7 1 1 1 1 1 z11/1/111r11 1/ 111/1 1//1 11/11 1/1 1 1 11 1 17/ 1 1 1 1/1 0. 1 1

Patented Feb. 4, 1 93 6 PATENT orrics APPARATUS FOR THE TREATMENT OF CABBONACEOUS MATERIAL Ira, H. Derby and Harold 8.. Homer, Indianapolis, Ind., assignors to Peter C. Reilly, Indianapolis,

Ind.

I Original application January 4, i930, Serial No.

418,612. Divided and this application July 29, 1933, Serial No. 682,873

9 Claims. (Cl. 202-99) This invention relates to an improved apparatus for the treatment of various carbonaceous materials, under such temperature and such conditions as. will yield/the greatest amount of valuable materials or substances, such as condensates, a considerable carbon residue and certain gases, and this under minimum operating costs.

By carbonaceous material we refer 'to such materials as coal, lignite, wood, oil shale, coal m tarpitch, pitch coke, andsuch otherlmaterials that when heated yield certain of the substances or bodies just above mentioned.

By condensate we mean all the condensible volatile matter resulting from the distillation of the above named material's. By valuable condensate we mean the condensate from the above materials, less its water content. 1 By gas we mean such substances as do not quefy under normal conditions.

The invention also has for one of its objects the production' of an apparatus wherein a coke possessing special characteristics will beproduced when coal is the carbonaceous material undergoing treatment.

The process, which'may be carried out'in the apparatus herein described and claimed, and

Jwhieh process forms the basis of our copending application, Serial No. H 418,612, filed January 4, 1980, in a generic'sense, may be said to comprise thecharging of a retort with the material;

to be operated upon; treating the upper layer of the charge for a period of time and at the "necessary temperature'to bring about the desired reaction or transformation in such portion of I the charge; elevating the charge as a whole, and

- without substantial internal disturbance of the mass, to an extent suflicient to raise the material which has been transformed by the heating action to a point where it can'be removed orsheered .46 oil from the underlying material; and carrying out such operations through a cycle until the entire charge within the retorthas been treated, transformed and discharged.

' top of the charge that portion which has been sufllciently transformed s w a The process also involves the downdrawlng of the evolved gases, vaporsandfumes through the 55 charge in such a manner-"that the entire charge While in the preferred operation of the apparawill be equally subjectedto the action of such gases, vapors and fumes.

In addition to the transformation of the material into carbonaceous residues of greater or less applicability such as, for example, the pro- 1 duction of domestic coke from the carbonization of coal, certain valuable condensates are produced as well as gases which, as abovenoted, do not liquefy under normal conditions and may be used for various purposes as for heating the retort 10 and the material therein, or for various commercial purposes which will readily suggest them selves.

During the ca yin out of the process, when carbonaceous material which will fuse and cake 15 when heated is employed, as for instance coals of caking varietyor coals that will fuse together, it has been found desirable to, in a sense, sub-- divide the charge. Such sub-division may be accomplished in several ways as will be hereing channels extending downwardly'through the en- 1 tire body of the charge and through which channels the gases maybe readily drawn. Such means so likewise provides for a substantial even distribu-; tion of the gases in-their passage downwardly through the charge with "the consequent even action of such gasesupon and throughout the entire mass.

Several embodiments of apparatus wherein the process may be carried out are shown in the annexed drawings along with a modified form of meansfor subdividing a charge with a view of securing even distribution of the throughgoing gas in the manner just alluded to. In-the drawings, v Figure 1 is a side elevation of an appara wherein our process may be carried out;

Figure 2 a vertical sectional view of the retort so and the associated chamber for receiving the transformed material. v m

Figure 3 a detail vertical sectional view of the upper portion of the retort. the gates or valves 7 employed to close oif said retort from thereso ceiving chamber and. the chamber which houses the ram employed to discharge the finished product;

Figure 4 a transverse horizontal section through the upper portion of the retort;

Figure 5 a detail sectional elevation of a heat exchange unit which may be employed incon- Junction with the finished product receiving essential so long as throughout its height it presents substantially the same cross area.

At its upper end the retort opens into a cham her 5, hereinafter denominated the combustion the valve chamber or or conversion chamber. Said chamber is of a length -greater than the width of the retort and atone side, Figure 2, houses a ram or pusher 6 normally closed off from the space directly above the retort by a valve denoted generally by I. Said valve, see Figure 3, is mounted for reciprocating movement in a suitable housing 8, the lower portion whereof within the chamber 5 is fashioned to provide opposed valve seats Sand. Ill. The valve, as shown in Figure 3, is of he two part gate type composed of leaves ll an l2 pivotally connected at their upper ends to a piston rod l3. The rod is attached to a piston 14 mounted for reciprocation in a hydraulic cylinder l5 into which extend mains l6 and I1 connected to any suitable source and controlled by valves not shown. Leaf l2 carries a refractory face or element l8 and leaf H is cut away so that the refractory face extends through the valve and protects all the metal parts from the heat of the combustion chamber. When the valve is lowered the lower portion of the leaves contact a wedge-shaped element l9 which spreads the leaves apart, ll acting as awedge and I2 sealing of! the chamber in which the ram 6 is mounted.

A clean-out door "or opening will preferably be provided below the member IS in order that housing-may bekept clear of foreign material. A similar valve is provided at the right hand side of the upper portion of the retort and inasmuch as the partsand the operation thereof are duplicates of the valve and its mechanism just described the same reference numerals are applied with the exponent a added. This right hand valve cuts off the right hand portion of the chamber 5 where it opens into the upper part of a chamber 2| employed to receive the finished product removed from the upper portion of the charge.

The ram 6 may be operated in any suitable manner but preferably by a piston rod 22 operated from a hydraulic cylinder 23 provided with suitable inlet and dischargepipes not shown.

In the upper wall of the chamber, directly over the retort proper, there is provided a man-hole 24 normally closed during the operation of the retort by a cover 25. Above said man-hole is a hopper 23 to which the material to be treated is fedin any suitable manner, as for instance by an endless conveyer 21; Figure 1.

The lower part of the hopper is provided with a gate 28 course, be the necessary degree, after is again replaced.

of conventional form which will, of

which the cover The finished product chamber 2| is likewiseprovided with a man-hole 29 normally closed by a cover 30. At its lower end it is provided with a discharge gate 3|.

closedwhen the retort is charged to drain for tar or other resulting liquids opens into the lower portion of the chamber 34, such drain being indicated by 31. The main leading from this drain may be connected to any suitable form ofapparatus, as for instance tar separators or the like not shown.

Mounted for reciprocation within the retort is a false bottom or lift 38. Said member is mounted and secured upon the upper end of a piston rod 39 which extends into a hydraulic cylinder 40 having suitable mains leading into the same to bring about the necessary and desired reciprocating motion to the lift or false bottom 38.

Extending upwardly from the pan and passing through openings formed in the false bottom is a series of rods or members 4|, said elements extending upwardly within the'retort to a point near the upper end thereof. These members, in the operation of the process, tend to produce channels through the material down which the evolved gases and vapors are drawn. In the coking zone the ducts formed by the rods or spacers remain in the plastic coal and persist throughto the surface of the charge as shown in Figure 2 at 60. As will be appreciated, the members remain in a fixed position being supported at all times from the pan located within the chamber 4. As the false bottom or lift 38 is lowered the material is charged into the retort and fills the same and the rods are surrounded thereby.

Instead of employing fixed rods or spacers 4|, as above set forth, the charge may otherwise be subdivided so as to produce channels. Thus-for instance, in the upper part of Figure 4 instead of employing rods or spacers we have shown paper or cardboard tubes, as 42, filled with inert material, such for instance as ground coke produced bytthe present process. These tubes-are positioned within the retort with their lower ends upon the false bottom 33 and the material to be treated is charged into the retort around such tubes. Thus it will be seen that the formation of channels within the charge may be produced in various ways and we do not, therefore, desire to be limited to any particular means for effecting this result.

The combustion and carbonizing chamber 5 may be heated in various ways. It may be of the conventional externally heated type where the top of the retort transfers the heat by conduction and radiation to the top layer of material. It also may be of the internally fired type using gas, oil or powdered fuel and allowing the flame as indicated at 43 and 44, into the combustion chamber 5 and onto the top layer of the material therein, heating it by contact with the hot combustion gases as well as by radiation. The heating is accomplished in this latter manner with ,the highest thermal efficiency.

Where a non-condensible gas of high calorific value is desired in place of a larger amount of low value gas, it is within the scope of this invention to employ the latent heat of superheated steam or superheated producer gas as the heating agency. These heated gases act similarly in the retort as the hot combustion gases.

When the apparatus is to be started the member 38 is raised to its uppermost position and a charge is fed into the retort. The member or lift 38 is gradually lowered as the charge is'fed in and the level of the charge is always at the same point, namely, at the level or substantial level of the ram 6. This method of charging the retort eliminates the outward pressure against the spacers 4| that would be produced by the falling coal. In other words, the section of the coal just above the end of the members 6| has already come to rest with respect to its lateral motion before it comes into contact with said members. After the retort is charged the exhauster 36 is started causing a reduced pressure throughout the system and retort. This reduced pressure is regulated at the combustion chamber 5 and under normal operating conditions from 1-3 in. of water is maintained at this point. The reduced pressure in the combustion chamb'er 5 acts similarly on a gas, pulverized, or liquid fuel burner, as does external air pressure in an ordinary burner. It is also possible to operate the retort on atmospheric or slightly positive pressure with the addition'of a blower on the air line to the burners. The exhauster 36 is slowed down causing the reduced pressure to drop in the system until the vacuum in'the combustion chamber 5 is reduced tozero. The secondary blower, not shown, is then started and the burners 44 function as in normal practice. The vacuum in the remaining parts of the system remain the same, that is, 1 to 3" of water. Inasmuch as such burners form no part of the present invention it is not deemed necessary to illustrate the same in detail.

The fuel mixture in the combustion chamber is ignited in the usual manner and by regulating the valves, either automatically or by hand, all the variation of combustion from a slow lazy flame with an excess of carbon monoxide and unburned hydrocarbons to a lean flame with an excess of oxygen may be obtained. In this manner the temperature of distillation and carbonization is controlled. The combustion gases, following their formation in the combustion chamber, play down and into the underlying mass, giving up their heat very rapidly to the top layer thereof. Where say coal is the material being transformed this upper layer reaches a temperature of approximately 700 C. in a relatively short time, approximately five minutes, and is held at this temperature throughout the run. It is'to be understood, however, that we do not wish to limit ourselves to the particular temperature just specified but in' ter which makes it a desirable domestic fuel since it burns with a smokeless flame and is easily ignited. The gases. as they are drawn down through the mass, give up their latent heat very rapidly. In the upper layer of the material, and which may be termed the coking zone, a distilling temperature of 350 C.'is very quickly obtained and within a period of 30 minutes, more or less, the material in this zone has been completely coked and brought to an average temperature of approximately 600 C.

This rapid coking, due to the rapid heat transfer in the first or coking zone, taking place on properly conditioned and pre-heated coal, acts to form a firm hard coke at the temperature above given. This behavior characterizes not only the commonlyycalled caking coals, but also the non-caking coals and makes our" process especially valuable for the treatment of low grade Indiana and Illinois coals.

The coking zone is indicated on Figure 2 in the space denoted by a. Below is what may be termed a distilling zone, indicated by b, and beneath is a drying zone, indicated generally by c.

The combustion gases with the products of distillation from the first or coking zone a pass on down through the distilling zone b. Within this zone the rise of temperature is much slower than in the upper zone and only reaches approximately 400 C. at the end of 60 minutes distillation.

- This is no doubt partly due to the fact that a large percent of distillate comes oif at 400 C. from the first zone and washing down into the second zone tends to equalize the temperature at this point. This is also due to the fact that the latent heat in the gases has been partially finally, at a relatively low temperature, 50-100 0., passing through the perforations in the false bottom 38 into the chamber 34 underlying the false bottom.

A large part of the condensate comes out the lower portion of the mass due to the good condensing efiect of the coal mass as a whole. The gas passes through the chamber 34 into gas main 35 through which it may be led to a condensing system, not shown where the final separation of condensate and non-condensable gases is made, while the tar passes through main 31. 7

When coals of the caking variety or coals that will fuse together with coking are used it has been found desirable to use the spacer rods or to sub-divide the charge by the interposition of inert materials, as above set forth. to produce channels to bring about an even distribution of the gases throughout the mass. In coking a seal is apt to be formed across the retort preventing the combustion gases from passing uniformly Where channels are artificially and initially produced by the rods or by the inert spacing or division of the charge by such spacing the downflowing gas acts to heat the charge evenly or sub stantially so throughout its entire mass. The exposed materials within the channels act similar to surface heaters and pick up the heat from the combustion gases and dissipate it to the charge by conduction and convection. This effect is most -pronounced in the first and second zones or where the coal is in its coked or plastic condition.

When the upper portion of the mass has reached the maximum temperature, say approximately 600 C., the false bottom 38 is raised, moving the charge upwardly as a whole withcut material internal disturbance thereof. This upward movement is continued until the upper coked layer is moved to the dotted line position shown in Figure 2 free of the walls of the retort. At this time it extends into the chamber 5 between the then lowered valves or gates I and 1 The false bottom is then brought to rest, the gates elevated and the ram 6 moved from the position shown in Figure 2 to the right, sheering oif the finished charge and forcing thesame to the coke receiving chamber 2|. The ram is then retracted, the valves or gates then lowered and the operation of carbonizing is continued. This cycle is continued until the entire charge has been treated. The'recharging of the retort proceeds simultaneously with the lowering of the lift as previously noted.

As will be appreciated, instead of raising the.

false bottom step by step it may have a continuous motion, relatively slow, and the ram 6 may be periodically operated.

Where a coke of exceptional hardness is desired, coal tar or a coal tar pitch may be introduced into the combustion chamber and onto the top layer of the charge. It may be intro-' duced through the burners and distributed by the combustion gases or through supplementary tuyeres not shown. This material acts as a binder and the combustion gases coke the coal mass and coal tar at the same time. The coal tar coke forms in the pores of the coal coke and makes an exceptionally hard coke from the poorest of Indiana non-caking coals. Similar beneficial results may be obtained by using a rich fuel mixture of pulverized coal. A part of the coal will burn but a part will be at the soft, plastic stage when it reaches the top layer of coal that is being treated in the retort. This soft, plastic dust will unite with the forming coke and add materially to its structural strength.

The temperature obtaining within the retort and the various zones may be determined by thermo-couples and in Figure 2 there is indicated two thermo- couple wells 45 and 46. Any number of such wells may be employed.

The heat from the .coke transferred to the chamber 2| may be utilized by the employment of any suitable heat exchange means. In the drawings we have shown a chamber 41 connected at its top to the upper portion of the coke receiving chamber 2| by a pipe 48 and its lower end connected by a pipe or conduit 49 including a suction fan 50. A coil 51 passing through the chamber 41 and forming a conduit for water or other medium absorbs the heat of the gas or air drawn out of the chamber 2|. This not only utilizes the heat but cools the coke so that it may be discharged from the chamber 2| at relatively short intervals.

.. In Figure 6 there is shown a section of a retort wherein, instead of employing rods to bring about the subdivision of the charge with a view of producing initial channels for the downward passage of the gases, 0. retort, designated by 52, is provided with a series of spaced vertically disposed partitions or walls 53 between which the material to be treated is placed. In this instance instead of having a single movable bottom or lift to elevate the charge there is provided a false bottom as 54 for each of the spaces between the partitions 53 or the outermost partitions and the adjacent wall of the retort. These members are supported by uprights 55 extending upwardly from a head 56, which latter is designed to be raised and lowered by a ram, designated generally at 51.

Suitable openings and/or notches 58 and 59, respectively, will be formed in the members 54 to provide forthe downward passage of the gas and the liquids produced during the distilling operation. The head 55 will likewise be provided with openings 56 -for the passage of such materials to the underlying pan as shown in Fig-' -ure 2.

The channels, however pre-formed in the charge, insure a proper distribution of the downgoing gases. Moreover, such channels act as centers for the radiation of heat which passes into the charge acting thereon throughout the various zones and thus bringing the mass to a condition such as when it reaches the combustion zone only a minimum of heat and time need be employed to convert the mass.

The coke produced by the method as above set.forth has certain characteristics which clearly identify it and render it valuable for various purposes. The coke as discharged may be said to be highly coked and low in volatile adjacent the point where the gas is passed down through a channel. At a point removed therefrom it may be said to be coked to a lesser degree and relatively high in volatile content. Stated in another way, a piece of coke formed between two channels would be at the channel portions thereof highly coked and low in' volatile whereas in the intermediate portion it would not be so highly coked and would contain more volatiles than the other portion. A

' Under the process as practiced in accordance with the above showing it has been found that we can secure a larger yield of tar than obtains with any other method of which we are aware. This is due to. the fact that the tar is removed from the zone of distillation as rapidly as produced without to any extent bringing the tar vaporinto contact with any material that is above the temperature at which it is produced. This eliminates any decomposition of the primary distillate. With our process we have secured a yield as high as 33 gallons per ton of coal.

The process as carried out by the apparatus described also brings about a rapid rate of distillation. In ordinary coking practice the advance of a given isotherm is at the rate of one inch per hour. Under our process, when operating with an apparatus as above described, a composite advance of ten inches per hour obtains.

This application is a division of our application Serial No. 418,612, filed January 4, 1930, now Patent #1,948,515, dated February 2'7, 1934, the division having been made pursuant to Patent Offlce requirements.

What is claimed is:

1. In an apparatus of the character described, the combination of a vertical retort; a lift movable upwardly therein, said lift forming the support for a charge of material whichmay be placed within the retort and to be treated therein;

means extending upwardly in the retort. for forming spaced channels through the charge for the passage of a gaseous heating medium downwardly through such channels in the charge placed in the retort and resting upon the lift; means for subjecting .the upper exposed surface of such charge to the direct action of a gaseous ieating medium; means for drawing such medium down through the channels; and means for removing the material which has been converted from the upper surface of the charge which is directly exposed to the action of the heatin medium;

2. An apparatus as set forth in claim 1, wherein the means for producing the channels in the charge comprises a series of rigid elements fixed with reference to the retort and extending upwardly therein in spaced relation.

' 3. An apparatus as set forth in claim 1, wherein the means for producing the channels in the charge comprises a plurality of stationary rods extending freely through the head of the lift and upwardly through the retort in spaced relation.

4.111 an apparatus of the character described, the combination of a retort; a lift movable upwardly therein; means for forming a plurality of vertically disposed and lateraJly displaced channels through a charge of material placed within the retort and resting on the lift; a combustion chamber located above the retort; means for introdu'cing a heating medium into the same; means for drawing said medium downwardly through the channels; and means for bodily removing the converted upper portion of the charge from the retort. I v p 5. An apparatus as set forth in claim 4, wherein the means for removing the converted portion of the charge comprises a ram.

6. An apparatus as set forth in claim 4, wherein the combustion chamber extends laterally at opposite sides of the retort; the means for removing the converted upper portion of the charge comprises a reciprocating ram; and a pair of valves are present to close off the laterally extending portions of the combustion chamber from the retort.

7. In an apparatus of, the character described, the combination of a. retort; a lifter mounted for vertical movement in said retort, said lifter having openings extending vertically therethrough; means for actuating the lifter; means for forming and maintaining a series of spaced and vertically disposed channels extending through a charge placed in the retort and resting upon the lifter; a combustion chamber located at the upper end of the retort; means for introducing"a combustion medium into contact with the exposed face of the charge; and means for creating a suction downwardly through the channels in the charge and through the openings-in the lifter.

8. An apparatus as set forth in claim 7, wherein the means for forming the channels comprises a series of fixed elements extending upwardly and freely through the openings in the lifter.

9. In an apparatus of the character described, the combination of a vertically disposed retort;

a lifter mounted for movement upwardly therein and forming in effect a movable bottom therefor, said lifter having a series of openings extending vertically therethrough; 'a combustion chamber located above the retort; means for introducing a fluid heating medium into the combustion chamber and into direct contact with the upper surface of a charge of material placed within the retort; means for elevating the lifter; means for removing the upper surface of the charge as desired; a plurality of rods extending upwardly from the base of the retort and upward- 1y therethrough and through the openings in the lifter, said rods being adapted to produce a series of spaced channels for the passage of gases and other material downwardly through a charge of material in the retort; and means for drawing the heating medium and the evolved gases downwardly through said channels.

IRA H. DERBY. HAROLD R. HORNER.

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