US 1995873 A
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March 1935- J. N. VANDEGRIFT ET AL 1,995,873 I RETORT Original Filed Feb. 10, .1928 2 Sheets-Sheet 1 1 1/ INVENIO y ML 6 M P ATTORNEY March 1935- J. N. VANDEGRIFT ET AL 1,995,373
RETORT 2 sheets sheet 2 Original Filed Feb. 10. 1928 Patented Mar. 26, 1935 UNITED STATES PATENT OFFICE RETORT Application February 10, 1928, Serial No. 253,479 Renewed August 18, 1934 3 Claims.
The present invention relates to retorts for treating carbonaceous materials, and while it is capable of use for many different purposes, one of the principal objects is to provide a retort for treating coal for extracting. the various volatiles and gases therefrom, reducing the body or substance of the material to the form of coke. Heretofore, in the process of extracting various products or byproducts from carbonaceous material such as coal, it has been necessary to pass the material first through a retort for the purpose of extracting as much moisture as possible from the coal, and then afterwards the coal was passed through another retort, heated to a higher temperature for the actual separation of the various volatile products. Even where this double treatment was resorted to it was difllcult to retain the coal-in the loose, separated condition necessary to extract the'products. If any moisture remains in the coal while it is being handled in the retort, it has a tendency to coke and the particles so adhere together as to form lumps or deposits and in some cases completely clog the retort. The object of the present invention is to provide a retort wherein the various products may be removed from the coal by heat treatment in a single operation, or by a single passage of the material through the retort; and to give a greater yield of products than even those processes heretofore employing a double treatment of the material. The present retort ls of the'type in which a revolving cylinder forms the retort chamber and this cylinder is disposed in substantially horizontal position with only sufiicient inclination to cause the solids to progress through the same by gravity. Instead of the vapors being conducted the entire length of the retort before being discharged therefrom, we have arranged to withdraw the vapors from a revolving retort cylinder at different points, so that the vapors first evolved near one end of the retort, and which usually consist primarily of water, may be withdrawn during the first passage of the solids along the retort and the remaining products are withdrawn toward the opposite or discharge end of the cylinder. In this manner we are able to effect substantially a separation within the retort, of those volatiles which consist primarily of water from those consisting primarily of other volatiles, such as oil, tar, fixed gases, and other products.
Another object of our'invention is to provide means for balancing the suction action by which the volatiles are withdrawn from opposite ends of the retort chamber, in order to maintain a substantially neutral point or dividing line at a deflnite location in the retort cylinder, in order that the products withdrawn at opposite ends of the cylinder may remain substantially uniform. Without this balancing action the suction device for withdrawing the water content vapors from the primary end of the retort mightin some cases withdraw those vapors intended to be withdrawn from the opposite end of the cylinder, and vice versa. However, with the employment of the balancing device herein shown and described, the action of the suction devices may be so automatically controlled that the suction at each end will withdraw the products intended by them. Other objects and advantages will be set forth in the following detailed description of our invention.
In the drawings forming part of this application,
Figure 1 is a vertical, sectional view through the retort with the device for taking off and condensing the vapors shown in elevation, the electric wiring being omitted from this view, as it is shown in detail in Figure 2,
Figure 2 is an elevation on an enlarged scale, of the device for effecting and controlling the take off of the vapors from the retort cylinder, and
Figure 3 is a vertical sectional view of the feed end of the retort showing a modification of my invention.
It may be here stated that if desired the several features shown in the patent of Lars G. Nilson, 1,742,273, may all be incorporated and used in the present device for the advantages and purposes set forth in said application.
In the present drawings we have shown an enclosure within which the revolving retort cylinder may operate, and this enclosure, which is preferably made of fire brick or other refractory material, consists of a top wall 1 which surrounds the greater portion of the interior cylinder and a bottom wall 2 which lies below the cylinder. The revolving cylinder is shown at 3 and may consist of a long tube of metal forming a chamber 4 of considerable length, through which the material to be treated is passed. This cylinder, which is inclined slightly from the horizontal, is disposed concentrically with relation to the upper wall 1 of the enclosure to provide the fuel space 5 and heating space 6 which is divided in the direction of the length of the device by arch-shaped walls '7 projecting laterally from the enclosure structure 1 toward and close to the outer periphery of the cylinder 3. These dividing walls extend only partially around the cylinder, so that the annular space above these walls extends throughout the length of the retort to allow the products of combustion from all of the spaces between the dividing walls 7 to pass in a common stream to the outlet flue or chimney 8 which is disposed preferably near the inlet end of the retort cylinder. Below and partially around the retort cylinder we arrange oil, gas or other burners 9 for the purpose of applying flames to the under portion of the cylinder for heating the latter and the product contained therein.
The retort cylinder may be revolvably mounted in the manner shown in said Patent No. 1,742,273; that is, on each end of this cylinder there are shown annular members 10 of I-shaped cross section, rigidly secured to the exterior of the cylinder and these rest upon and revolve in relation to the revolvable supporting trunnions 11 disposed under the members 10 and at opposite sides of the vertical center line of the cylinder.
The higher or left hand end of the retort cylinder in Figure 1 may be considered the inlet end, where the material to be treated is first introduced. There is a hopper 12 into which the carbonaceous material or coal is introduced and it travels downwardly in this hopper to a longitudinally extending, tubular portion 13 in which the feeding screw 14 is arranged upon a shaft 15 and adapted to be revolved from outside the hopper by power applied to the sprocket wheel 16. This screw forces the material toward the right in Figure 1 to pass it along the tubular member 13 and to discharge it through the head 1'7 of theretort cylinder and into the forward end of the cylinder. The interior of the retort cylinder is provided with longitudinally extending lifters 18 which serve to carry the material upwardly and drop it, so that the carbonaceous material is continually agitated. The material fed from the tubular member 13 into the retort cylinder advances along the cylinder from left to right in Figure l, by gravity, and it is continually agitated as it is carried up and dropped by the lifters i8, and while the material is gradually passing along the interior of the retort cylinder it is gradually heatedin the several heat zones by the action of the various burners in the compartments 5. While the carbonaceous materialfis traveling from the inlet end of the cylinder to the line of the first dividing wall '7 it is gradually raised in temperature to a point where substantially all of the aqueous vapor is evolved. In passing from the line represented by the first dividing wall 7 to the line represented. by the second dividing wall 7, which is the second heat zone of the retort cylinder, the carbonaceous material is raised to a higher temperature, so that other volatiles may be liberated. After passing the line of the second dividing wall 7 the temperature of the material is further increased to a point where all of the remaining volatiles are liberated from it. It will be obvious that the number of heat zones may be lesser or greater than the number shown herein.
The carbonaceous material, after passing to the right hand or lower end of the retort cylinder drops into a discharge tube 19 which is stationarily arranged adjacent the discharge end of the retort cylinder. This tubular member surrounds the discharge end of the cylinder and is provided, preferably, with a packing 20 resting against the surface of the cylinder to prevent the escape of the volatiles. This tubular member 19 is pref- 23 arranged below the tubular feeding member 13 and there is a head 17 on the forward end of the retort cylinder provided with a packing 24 which contacts with the outer surface of the cylindrical Wall for the purpose of preventing escape of the vapors, This head 1'7 encloses the feeding tube 13 and below it forms a passageway 25 from which extends a tube 26 which projects inwardly within the feeding end of the retort cylinder. The open end of this tube is preferably chamfered as shown at 27 in order that the carbonaceous material which is carried up by the lifters 18 in the cylinder and dropped, will not pass into the tube 26 but the volatiles freed from the carbonaceous material may pass freely into the open end of this tube, and thence pass through the space 25 into the vertically arranged discharge receptacle 23. It will be understood that in the preferred construction, as shown herein, the vapor collecting tube 23 does not follow the motion of the retort cylinder but is stationarily mounted. In the lower end of the collecting chamber 23 some of the volatiles drawn from the retort cylinder will be condensed into liquid as indicated at 28 and to limit the depth of this liquid we have shown an outlet trap 29 through which the liquid may overflow when it reaches a certain predetermined level and the trap will prevent the escape of any vapors with the liquid. There'is a vapor discharge pipe 30 having its open end disposed adjacent the maximum level of the liquid in the collecting chamber 23 and this vapor discharge pipe runs to the coil of the condenser 31 which may be of any ordinary or special type. The purpose of this condenser is to reduce all vapors which discharge through the pipe 30 into the liquid phase and the liquid thus condensed discharges through a nozzle 32 into the liquid collecting chamber 33 from which the liquid may be withdrawn through the valve 34. To withdraw the vapors through the tube 26 the collecting chamber 23 and into the condenser 31, we have shown a pipe 35 leading from the chamber 33 and this pipe connects by a Y- shaped coupling with the pipe 36 and the pipe 37 and the latter connects with a pump 38 for creating a suction in the Y-shaped coupling. This pump is connected by a discharge pipe 39 with any well known form of condenser (not shown).
The vapors passing from the right hand or discharge end of the retort cylinder pass upwardly in the cylindrical chamber 19 and thence through an outlet pipe 41 into a vapor collecting chamber 42. Any vapors precipitated in the form of liquid in this chamber may be drawn off through the pipe 43. 44 having its open end arranged in the collecting chamber 42 above the liquid level; and this pipe conducts the vapors from this collecting chamber into a condenser 45 in which the vapors are condensed to the liquid phase and are discharged There is a discharge pipe through a valve 46 into a liquid collecting tank 47 from which the liquid may be discharged by means of the valve 48. Suction is created in the collecting chamber 42 the vapor discharge pipe 44 and the condenser 45 by means of the pump 38 which acts through the discharge pipe 44connected to the top of the liquid collecting chamber 19. The pump 38, therefore, operating through the Y-shaped'connection 36 serves to create suction at both ends of the retort chamber.
To maintain a balance in the suction action, that is to say, to so balance the suction at opposite ends of the retort chamber that the products or va, ors withdrawn from opposite ends will remain substantially uniform, we have provided an automatic balancing device which is preferably constructed as follows: At one end of one leg of the Y-shaped coupling there is connected a well known vacuum tube 49 which includes a U- shaped tube containing a liquid and this tube is in communication with one leg of the Y-shaped coupling so that the suction in this branch of the coupling will affect the liquid in the vacuum tube 49, so that as the vacuum pressure increases the liquid will rise in the leg 51 of the vacuum tube and correspondingly fall in the leg 52 and vice versa. As the vacuum pressure decreases, the height of the liquid in the leg 51 will decrease, and it will correspondingly rise in the leg 52. There is a float 53 resting on the liquid in the leg 52 and this float is provided with a stem 54 which is adapted to press upwardly on one arm 55 of the lever pivoted to rock on the pin 56. As the float 53 rises under the action of the liquid in the vacuum tube, the pin 56 lifts the lever arm 55 until this arm comes into contact with the contact point 57 which is connected with an electric circuit, including the conducting wire 58. The arm 55 may be considered as being connected with the positive or plus side of an electric circuit, or with the feed wire 59. When the float 53 moves downwardly, due to the lowering of the level of the liquid in the arm 52, of the vacuum tube, the lever arm 55 may descend until it comes into contact with the stationary contact member 60 which latter is connected with the conducting wire 61.
, There is a similar vacuum tube 62 connected with the other arm 36 of the Y-shaped connect on and it is also provided with liquid in the arms thereof which liquid is affected by the suction in the branch 36 of the Y-shaped connection, so that this vacuum tube is affected according to the vacuum exerted at the right hand end of the retort cylinder, just as the vacuum tube 49 is affected by the vacuum at the left hand end 'of the retort chamber. In the vacuum tube 62 there is a float 64 corresponding with-the float 53 and rising and falling in accordance with the level of the liquid in the leg 65. There is a rod 66 extendingupwardly from this float and it is adapted to act on the lever arm 67 to raise the same into contact with the contact member 68 which is connected with the conducting wire 58 which conducting wire is When the leverarm 67 the conducting wire 74. This wire '74 and the wire 61 are joined and they connect with the brush 75 of the motor. There is a valve 76 arranged in the pipe 35 for increasing and decreasing the flow through this pipe for the purpose of regulating the vacuum in the lefthand end of the retort cylinder. There is a lever arm '77 on' this valve by means of which the valve may be operated; and this lever arm is operated by a pitman 78 which is pivoted to a gear '79 the latter being operated from the motor '70, through the worm 80, worm gear 81, and the gear 82 which meshes with the gear '79. There is a similar valve 83 arranged in the pipe 36 for regulating the flow in this pipe for increasing anddecreasing the vacuum affecting the righthand end of the retort cylinder. This valve has an arm 84 by which it is operated, and thepitman 85 is adapted to actuate the arm 84 of the valve to regulate this valve. The pitman 85 is also pivoted to the gear '79.
Operation The carbonaceous materialfed into the hop per 12 is propelled by the screw 14 through the tubular feeding member 13 and it is dcposited'into the left hand end of the retort cylinder, so that this material falls onto the inner surface of the cylinder and is continually being lifted by the lifters 18 and dropped again; and the material progresses by gravity gradually through the cylinder from left to right in Figure 1. The pump 38 operates through the Y-shaped connection 36; that is, through one leg thereof, to create a suction at the mouth of the vapor discharge tube 26 and this suction acts through this vapor tube, through the collecting chamber 23, the discharge tube 30, the condenser 31, the liquid collecting chamber 33, the pipe 35, through the Y-shaped coupling and the pump and the vapors discharged from this pump pass into any form of receiver. At the same time the pump creates a partial vacuum at the right handend of the retort cylinder, which suction draws the vapors through the pipe 41 into the collecting chamber 42, thence through the pipe 44, into the condenser 45, thence through the liquid collecting chamber 47, through the pipe 36 of the Y-shaped coupling to the pump; and the vapors and fluids drawn to the pump are discharged into any form of receiver the same as the fluids arriving through the opposite leg of the Y-shaped coupling.
The collecting tube 26 being arranged near the left hand end of the retort cylinder or near the feeding end thereof, will act directly on the vapors, initially evolved from the carbonaceous material, and as these vapors are generally water and carbon dioxide vapors they are carried off substantially before the oil and other vapors begin to evolve and they are removed from the presence of the carbonaceous material as soon as they begin to evolve, so that these water vapors do'not have to pass over the whole body of material under treatment. The result is that while the carbonaceous material is passing through the first heat zone of the cylinder, substantially all of the aqueous vapors and carbon dioxide are evolved, and this is equal to or superior to the first step or treatment referred to inprevious methods of handling carbonaceous materials. The result is that by the time the carbonaceous material reaches the second heat zone located between the dividing walls 7 all, or nearly all, of
the aqueous vapor has been evolved and has been withdrawn through the tube 26. This aqueous vapor will be partially precipitated into liquid phase in the collecting chamber 23 and whatever is not reduced to the liquid phase will be conducted through the pipe 30 into the condenser 31 where it will be further condensed to be discharged in the form of liquid into the liquid collecting chamber 33. Such liquid as is precipitated in the collecting chamber 23 will flow out through the trap 29 into any suitable receptacle, and the vapors will be prevented by the liquid in this trap from following with the liquid.
It is desirable that the suction acting in opposite ends of the retort chamber be balanced so that the suction at opposite ends will remain substantially uniform. When the pump 38 is in operation the suction is maintained at opposite ends of the retort, and if for any reason the suction pressure should rise or fall at one end of the retort more than the other, so that the neutral or balanced point is shifted, then the balance will be restored automatically by the device shown herein. If, for instance, the suction through the tube 26 at the left hand of the retort should increase, so that oil vapors pass through this tube where only aqueous vapors are intended to pass, the increase of suction at this side of the apparatus will cause the float 53 to descend in the tube 52 until the lever arm 55 comes into contact with the contact point 60. This will form a circuit through the positive wire 59, through the lever arm 55 and contact point 60, through the wire 61 to the brush 75 of the motor 70. At the same time the lever arm 67 will contact with the point 68 so that a circuit will be established between the negative wire 72, the lever arm 67, the contact 68 and the wire 68' to the brush 69 of the motor. This closing of the circuit will cause the motor 70 to operate in one direction and the motion will be transmitted through the worm all, the worm gear 81, the gear 82, to the gear 79. The latter gear will shift, to draw the pitman 78 and the lever arm 77 into the dotted line position, and this movement will partially close the valve 76 to decrease the suction action" of the pump 38 through one side of the Y-shaped coupling, and therefore decrease the suction through the pipe 26 until the balance has been restored in the retort, whereupon the float 53 will return to a neutral point with the arm 55 intermediate the contacts 57 and and when the latter occurs the circuit to the motor '70 will be broken. If the suction increases beyond the desired point at the right hand end of the retort, then the float 64 will be lowered and the arm 67 will move downwardly to the position shown, into contact with the point 73, whereupon a circuit is established between the negative wire 72, the lever arm 67, the contact 73, and the wire 74 to the brush 75. At the same time the lever arm 55 will contact with the point 57 and establish a circuit between the positive wire 59, the arm 55, the point 57, and the wire 58 to the brush 69. The motor will now be operated in the reverse direction to that above described, whereupon the gear 79 will move clockwise and the valve 83 will be partially closed, and the valve 76 will be partially opened. This condition will exist until the balance is restored, whereupon the lever arms 55 and 67 will remain in neutral position with the motor 70 out of operation. From this it will be apparent that if the suction at either end of the retort rises above or decreases below the desired degree, and thereby upsets the balance, suction will be automatically modified to restore the balance. In this way the products or vapors taken off at opposite ends of the retort may be controlled so that the aqueous vapors and other vapors will be removed separately.
In some cases it may be desirable, or even necessary, to supply air or gases to the end of the retort where the aqueous vapors are removed, and in Figure 3 we haveshown simple means for this purpose. In this construction the retort cylinder and surrounding structure, as well as the means for feeding the carbonaceous material, remain the same. The tube 26 in this construction is omitted so that the vapors pass directly into the passage 25. There is a pipe 86 having its open end extending outside of the wall 1 where it is provided with a valve 87 to control the entrance of external air into the pipe 86. This pipe extends through an aperture in the wall 1 and thence horizontally through the fuel space 6 so that the air passing through this pipe is heated by the products of combustion in the flue space 6. The pipe extends through the head of the wall 1. thence turns downwardly at 88 and thence runs horizontally through the head 17 of the retort, and thence horizontally at 89 to a point in the first heat zone of the retort cylinder where it will discharge air. The valve 87 may be opened more or less to regulate the quantity of heated air which discharges from the end 89 of the pipe into the retort chamber. This heated air will be drawn of! with the vapors which are evolved at the left hand end of the retort. This heated air is necessary in treating certain types of bituminous coal whereas in other cases it is not required or desirable. We have shown a branch 90 extending from the pipe 86 and having its open end within the flue space 6, so that the products of combustion may be fed into the pipe 86, instead of external air where even greater heat is required. This branch 90 may be controlled by a valve 91 the spindle of which extends through the wall 1 and may be operated from the exterior of the retort. In certain cases it may be desirable to conduct the products of combustion through the pipe 86 instead of external air because of the greater heat obtained, and because the external air applied to some products might cause combustion within the retort chamber.
Having described our invention, what we claim is:
1. In an apparatus for distilling solid, carbonaceous material, a retort chamber consistin of an inclined revolvable retort cylinder adapted to contain solid carbonaceous material, means exterior thereof for heating the retort, means for withdrawing vapors from remote parts of said retort, and for conducting said vapors away in separate paths, means for creating suction in said conducting means, and automatic means for modifying the suction action in said conducting means to maintain a balance in the suction action of both conducting means, said automatic means being controlled by the suction in said several conducting means.
2. In an apparatus for distilling solid carbonaceous material, a retort cylinder, means for heating the same, means for withdrawing vapors from opposite ends of said retort and for conducting said vapors away in separate paths, means for creating suction in said conducting means, and means for modifying the suction action in said conducting means to maintain a balance, including liquid level vacuum gauges acted on by the suction in each of said conducting means,
and means controlled by said vacuum gauges for modifying the flow of vapors in each of said conducting means.
3. In an apparatus for distilling solid, carbonaceous material, the combination of an inclined, revolvable retort cylinder having a stationary head, means surrounding said cylinder and forming therewith comblustion chambers and a flue space, means for conducting vapors from opposite ends of said retort in separate paths, means for creating controlled suction in said conducting means'so that a neutral point at atmospheric pressure is maintained in said cylinder, and a pipe lying partially in said flue space and extending through said stationary head to discharge into said retort chamber.
JAMES N. VANDEGRIF'I.