US2182750A - Retort - Google Patents

Description

Dec. 5, 1939. .F. POPE 2,182,750

RETORT Filed Sept. 3, 1938 6 Sheets-Sheet l 3 INVENTOR;

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'BY gl/hwwk ATTORNEY.

Dec. 5, 1939.

F. POPE RETORT Filed Sept. 3, 1938 6 Sheets-Sheet 2 i K aw- INVENTOR. 5P,

rA z-pf/P/czr POPE iqu kam ATTORNEY.

Dec. 5, 1939. F, P 2,182,750

RETORT F iled Sept. 3, 1938 6 Sheets-Sheet 3 INVENTOR,

ATTORNEY.

Dec.

F. POPE RETORT Filed Sept. 5, 1958 576 6 Sheets-Sheet 4 I E -29 5 1] I INVENT OR.

g MMMMTORNEY.

F. POPE RETORT Dec. 5, 1939.

Filed Sept. 3, 1938 6 Sheets-Sheet 5 INVENTOR. F/PFfiF/P/C/I POPE" BY ATTORNEY.

Dec. 5, 1939. F. POPE 2,182,750

RETORT Fi'led Sept. 3, 1938 6 Sheets-Sheet 6 INVENTOR. Fixer/war 02 ATTORNEY.

Patented Dec. 5, 1939 PATENT OFFICE RETORT Frederick Pope, Wilton,

American Cyanamid Company,

C'onn., assignor to New York,

N. Y., a corporation of Maine Application September 3, 1938, .Serial No. 228,282

Claims.

The present invention relates to a retort useful for many purposes but particularly adapted for the heat treatment of Wood, coal and the like and. from which distillation or destructive distillation 5 products may be recovered.

The principal object of the invention is. the provision of mechanism which may be readily manufactured and assembled into a retort capable of withstanding the temperatures to which it 0 may be normally subjected with minimum warpage and destruction, which will have high capacity for material to be treated and products to be re covered therefrom.

To this end, the invention contemplates a series of heating elements adapted to be superimposed one on the other to a vertical stack around a central stationary supporting column, which may be hollow, so as to form a continuous, circuitous heating flue. Each of the heating elements is provided with a substantially horizontal heating surface adapted to receive the Wood or other material to be heat treated. Conveyors are provided for carrying the material to be treated around the annular heating surfaces and to drop 5 such material through an aperture provided in each heating element onto the element beneath it and so on seriatum downwardly through the stack of heating elements.

The conveyors are moved by reason of a framework to which they areattached, theframework including a centrally located gear operating from the periphery thereof. The retort is provided with a stationary outer casing, with water seals between this stationary part of the mechanism and the rotating gear assembly. Means to supply products of combustion are provided so that the hot gases therefrompass upwardly through the stack of hollow heating elements and are discharged from the top thereof into a waste heat boiler if desired. A separate take-off for products of combustion may be supplied to furnish heat to a waste heat boiler where this is found to be advantageous.

A plurality of take-offs for distillation products 5 are connected into the space between the outside of the heating elements and the inside of the stationary casing and such products may then be passed to a suitable recovery and/or purification system as desired. By locating take-ofifs at 50 difierent vertical points of the retort, the character of distillation products recovered may be varied. Means are also provided for supplying the material to be heat treated to the horizontal surface of the uppermost heating element for 55 moving it peripherally thereof and for discharging the spent material after it has been removed from the lowermost heating element. Where desired, this spent material may be used to generate combustion gases for supplying heat to the retort. 5

The invention further consists in the novel arrangement, combination and construction of parts more fully hereinafter described and shown in the drawings, in which: i

Fig. 1 is an elevation generally showing assembly;

Fig. 2 is a fragmentary sectional elevation of the retort of Fig. 1 showing the details of construction and assembly;

Fig. 3 is a sectional plan along the line 3-3 16 of Fig. 2; 7

Fig. 4 is an elevation of the retort showing the outside stationary casing in dot and dash lines and illlustrating the manner of feeding the heating medium to the heating elements, for moving the conveyors and for taking off the distillation products;v

Fig. 5 is a bottom plan view of one of the heating elements;

Fig. 6 is-a half sectional-half elevational view 2 along the line 66 of Fig. 5 and showing the details of the heating element construction;

Fig. 7 is a detail sectional view along the line 'l-'-'| of Fig. 6;

Fig. 8 is a fragmentary plan View along the 30 line 8-8 of Fig. 4

Fig. 9 is a partial perspective of the upper part of the frame assembly.

Referring now to the particular embodiment illustrated in Fig. 1, an outer stationary casing 35 is shown to consist of the two parts I and 2, the latter being suitably mounted upon a base 3 and the former. being carried by any suitable overhead support not shown. The lower part of the upper casing section I dips into a water or other liquid seal 4 (Fig. 4) while a similar seal 5 is carried by the upper portion of the lower section 2 of the outer casing into which dips a cylindrical section 6 depending from a framework 1. This framework will be more fully hereinafter described with relation to other functions, it being necessary only to mention .it at this time in order to make clear that the outer casing is stationary and forms the body of the retort proper.

On the base 3 (Fig. i) is located a platform 8 the 10 carrying -a supporting column 9 either hollow or not, as desired. On an upwardly extending portion of the platform 8 is located an annular plate l0 carrying the lowermost heating element and servingas a support for those heating eles above it. This plate is provided with a central annulus through which the products 01 combustion used f or heating pass on their way to th upper heating elements. An aperture I2 near the periphery of the plate is located immediately over one end of the discharge screw I3 used for removing the spent material from the retort.

Each of the individual heating elements arranged above the annular plate In is of a similar construction and comprises two substantially hemispherical hollow sections I4 and I5, (Figs. 5 and 6), the latter having an aperture Hi therein, bolted together as shown in Fig. 7, the element as a whole being generally of inverted frustoconical formation. Each element, therefore, has a substantially horizontal upper heating surface El and a deflecting lower portion l8 which serves to deflect the products distilled from the material undergoing treatment to the space between the periphery of the heating elements and the outside stationary chamber. Near the inner annulus of the heating surface ll of each heating element is a peripheral rib l9 (Fig. 2) adapted to receive, between it and the inner wall of the heating element annulus, the lowermost edge of the deflecting portion l8 of the heating element immediately above. In this way, each heating element serves as a support for the heating element above it.

Beneath the heating surface ll of each heating element is a series of depending fins 2D curved as shown in Fig. 5. These fins serve the dual purpose of first assisting heat transfer from the combustion gases going through the heating elements to the heating surface I! and, second, due to their curvature, they tend to create a swirling motion of the heating gases and, consequently, prolong their contact with the heating elements. In this way, maximum heat transfer efiiciency is obtained.

Also surrounding the supporting column 9 is a series of clay or firebrick deflectors 2| (Fig. 2) of an annular nature, the outer periphery of which extends between the portions l! and I8 of each of the heating elements. These serve to direct the heat away from the column and into the heating elements. By arranging the lower surface of the deflectors 2| in the form of a substantially inverted frusto-conical configuration which merges into a cylindrical portion, they more or less conform to the somewhat similar shape of the portions l8 of the heating elements. Consequently, a generally uniform passageway for the heating medium is provided. As indicated, each of the upper deflectors 2| rest upon the top of the one immediately beneath it while the lowermost deflector rests upon the top of a cylindrical member 22 (Fig. 4) of the some composition so as to protect the column from the deleterious effects of heat.

Operating on the horizontal surface I! of each heat element is a conveyor for moving the material to be treated over the heating surface. This is shown in Fig. 3 to consist of an inner hub portion 23 with an outer rim 24 with curved scrapers 25 extending therebetween. The height of these last three elements will depend upon the character of the material undergoing heat treatment. It is contemplated, however, that the compartments defined by the space between the hub, outer rim and two adjacent curved scrapers will be maintained substantially full of the material undergoing treatment. As shown in Fig. 2, the inner hub 23 is arranged tolie outside of the annular rib I9 on the heating element surface ll. Consequently, the conveyors are guided thereby in their travel around the heating surface and this insures the maintenance of their concentricity.

As shown in Fig. 3, pairs of outwardly projecting fingers 26 are provided on the outside of the outer rim 2 1 to engage T-irons 2! which extend vertically within the retort. The T-irons are connected at the top and bottom with strengthening L.-members 28 (Fig. 4). The entire structure comprising the T-irons 21 and the L-members at the top and bottom thereof is carried by the framework 7 by means of upwardly and downwardly'projecting arms 29 secured to the Ts in any suitable manner.

The framework 1 also carries a master gear 39 (Figs. 1 and 2) which extends between the upper and lower sections of the outside stationary casings and 2. This gear 39 is supported on rollers 3| mounted on the top of standards 32 anchored in the base 3. It is preferable that three such rollers be provided in order to assure a steady support to the gear. Inasmuch as there is a loose slip connection between the fingers 26 and the Ts 2'1, any unevenness of motion of either the gear or the conveyors will not be transmitted to the other.

The gear 30 is provided with peripheral teeth 33 with which meshes drive worm 34 connected by shaft 35 to a motor or other type of prime mover 36. This same motor is utilized to drive the feed and discharge mechanism for the material undergoing treatment through pinion 31, telescopic shafts 38 and worm gear trains 39, all in synchronism.

In assembling the mechanism so far described and with reference to Fig. 4, the lowermost conveyor is placed over the supporting column 9 to rest on the lower annular heating plate Hi, the inner hub 23 lying immediately outside or the annular rib I9. The clay or firebrick cylinder 22 is then placed over the column and the first annular deflector 2| similarly moved into position to rest on the top of the part 22. Two halves of the lowermost heating element are now assembled around the column and bolted together, dowel pins 40 (Fig. '7) fitting into strengthening flanges 4| on theheating elements assisting in maintaining parts in proper alignment. It is important at this point to arrange the aperture I6 in this heating element out of alignment with the aperture l2 (Fig. 3) in the plate ill in a clockwise direction inasmuch as in the present embodiment, the conveyors are designed to move in a clockwise direction. This is for the reason that it is desired to have the material undergoing treatment on the upper surface of each heating element to travel under impetus of the conveyor, completely around that element, drop through its aperture onto the next element and so on down the stack of elements.

Locking keys are provided between heating elements in order to maintain them in a stationary position and to prevent relative movement therebetween.

In the same manner, successive conveyors, deflectors and heating elements are assembled until the entire stack of these parts are in their proper position.

As the heating elements are assembled, it is important that the pairs of fingers 26 be made to straddle and engage their respective T- irons 21.

After all of the heating elements have been put into place, an exhaust stack section 42'- (Fig. 4) is fitted within the upstanding peripheral rib" IQ of the uppermost section. The exhaust gases are conducted away and disposed of in a The spent material discharged from thelast heat- .ing element drops onto worm l3 (Fig. 4) for disposal or, if desired, to the furnace for supplying heating gases.

Heat is generated for the retort'in a furnace 5 45 using either oil fed through line 45 or other fuel including waste from the retort, as may be found most expedient. The combustion gases from the furnace pass through the neck t! and into the chamber 48 and from thence through the annulus surrounding the lower part of the supporting column 9 and into the first heating element as in Figs. 1 and 4.

, Inasmuch as it may be desirable to utilize steam in purifying the products discharged from the retort, the discharged heating medium still containing some sensible heat, may be passed through a waste heat boiler 49 and from thence back into the circulation system through the downcomer 56. A- feed water heater 5i is likewise provided int-o which the exhaust heating gases may-be by-passed by suitable manipulation of the damper 52. On the other hand, if for any reason it is found unnecessary to abstract remaining heat from the exhaust gases, they may be vented to the atmosphere through stack 53. To

facilitate recirculation of the exhaust gases, fan

56 is provided. I v

The operation of the device is as follows: Combustion gases are generated in furnace 45 and passed through chamber 48 into the first heating element admixed or not with exhaust gases coming from the downcomer 50. It is preferable that the combustion gases entering the first heating element be at a temperature of from 1400 to 1500 F. and for this purpose, dilution with the cooler exhaust gases may be desirable in order to maintain this temperature within the required range. Actually the temperature to be used in the retort will depend upon the character of material undergoing treatment and the character of distillation products desired. In distilling and destructive distilling resinous woods, red wood, coal or the like, it has been found desirable to introduce the heating gases at say from 1400 to 1500 F. and to discharge them at from about 900 to 1000 F.

The material undergoing treatment in a suitable form of subdivision is fed in through the hopper 43 and reaches the top of the uppermost heating element, falling within the confines of the hub23, outerrim 24 and the curved scrapers 25. The conveyor moves preferably in a clockwise direction and, consequently, moves the finely divided material around the top of the uppermost heating elementuntil it finally drops through the aperture therein onto the next heating-element. It is to be noted that due to the fact that the scrapers 25 are curved, they have no difi'iculty in passing over the joint between the substantially hemispherical sections of the heating elements and, consequently, have no tendency to become temporarily stopped in case the heating elements or the scraper becomes warped from the heat. In a similar manner, the material undergoing treatment moves around each heating element and drops down through its aperture onto the heating element immediately below.

In case the material undergoing treatment becomes-caked or otherwise agglomerated so that there would be a tendency for it to pass over the aperture in any heating element, concentrically curved and downwardly extending blades 55 (Figs. 2, 5 and 6) having inclined bottom edges 56 are provided on the lower section of each heating element immediately above the aperture in the heating element below. Consequently, as the agglomerated cake is pushed around, when it reaches the aperture through which it should pass, the top of it engages thebottom of the depending deflector blades and they force the cake to be broken up and to drop through the aperture onto the heating element beneath.

The volatile natural products or distillation or destructive distillation products from the material undergoing the heat treatment pass upwardly between the outer stationary casing and the heating elements and out of either or both flues 51 and 59 to one or more suitable recovery systems. Obviously the products thus recovered may be further purified or separated as desired.

It has been found desirable in some instances to separately collect products generated in different parts of the retort. In order to make this possible in the present apparatus, an annular plate 58 (Figs. 2 and 4) is provided which rests on continuous flanges on the lower section 2 of the outer casing and the outer edge of one of the heating elements respectively. The upright 'T-irons 2'! pass through corresponding slots in this plate and the latter moves around withthe Ts and their framework as the master gear rotates. In this way, the retortis effectively separated into two compartments. The products from the lower compartment, that is, that section beneaththe plate 58 may be taken off through the port 59 and separately recovered and/or purified. Obviously the plate 58 and port 59 may be located in any desired relative vertical position depending upon the character of products to be recovered and the character of the material undergoing treatment. If there is no desire to separate such products, the port 53 may be suitably connected to the flue 5"! and all pro'ductscollected together.

- Asabove mentioned, the spent waste is dischargedthrough the worm i3 for disposalv as desired.

From the above it will be apparent that a retort has been devised which is particularly desirable for the purpose specified. It will, of course, be obvious that inasmuch as retorts of this character are subjected to high temperatures, there is a great tendency toward Warpage or even destruction of the parts subjected to the intense heat. Consequently, it is desirable that theoutside casing which, perhaps, is of the greatest area of-any part in the entire mechanism should be firmly fixed upon its foundation in a stationary manner, for were it permitted to move, it would be difficult to maintain it in proper alignment and relationship with the remaining parts of the equipment. In the present assembly, the initially moving parts are the master gear and those elements immediately connected thereto. These are supported in an entirely satisfactory manner and in a way which will not interfere with the stability or alignment of the outside casing. There being no fixed and immovable connection between the master gear assembly and the conveyor assembly, each part is free to move without causing distortion of the other and with a minimum amount of friction.

While the invention has been shown and described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto but it is to be construed broadly and limited only by the scope of the claims.

I claim:

1. A retort comprising a stationary outside casing, a stack of superimposed hollow heating elements therein, means to supply heat to the interior of the heating elements and to take the exhaust gases therefrom, means to supply material to be heat treated onto the uppermost heating element, conveyor means for moving the said material peripherally on each heating element and to drop the same downwardly onto the next heating element of the stack, said conveyor means having a drive element projecting outwardly beyond the stationary outside casing and between the top and bottom thereof, means to drive said element, means for discharging waste material from the retort and take-off means for the distillation products from the material being heated, in which the drive element is located substantially midway between the top and bottom of the stationary casing and projects therethrough so as to divide the easing into upper and lower sections, means for making a stationary water seal between the upper part of the lower casing and the drive means and a traveling water seal carried by the drive means and making a seal between the drive means and the lower part of the upper casing.

2. A retort comprising a stationary outside casing, a stack of superimposed hollow heating elements therein, means to supply heat to the interior of the heating elements and to take the exhaust gases therefrom, means to supply material to be heat treated onto the uppermost heating element, conveyor means for moving the said material peripherally on each heating element and to drop the same downwardly ontothe next heating element of the stack, said conveyor means having a drive element projecting outwardly beyond the stationary outside casing and between the top and bottom thereof, means to drive said element, means for discharging waste material from the retort and take-off means for the distillation products from the material being heated, in which the take-off means comprises a plurality of ports spaced apart vertically of the retort, with means between the take-offs to shunt distillation products below it into the lower take-01f.

3. A retort comprising a stationary outside casing, a stack of superimposed hollow heating elements therein, means to supply heat to the interior of the heating elements and to take the exhaust gases therefrom, means to supply material to be heat treated into the uppermost heating element, conveyor means for moving the said material peripherally on each heating element and to drop the same downwardly onto the next heating element of the stack, said conveyor means having a drive element projecting outwardly beyond the stationary outside casing and between the top and bottom thereof, means to drive said element, means for discharging waste material from the retort and take-01f means for "the distillation products from the material being heated, in which the take-off means comprises aiplurality of ports spaced apart vertically of the retort, with plate means between the take-offs to shunt distillation products below it into the lower take-ofi, said plate being annular and carried between the stationary outer casing and a heating element and relatively movable thereto.

4. A retort comprising a stationary outside casing, a stack of superimposed hollow heating elements therein, means to supply heat to the interior of the heating elements and to take the exhaust gases therefrom, means to supply material to be heat treated onto the uppermost heating element, conveyor means for moving the said i material peripherally on each heating element and to force the same downwardly onto the next heating element of the stack, said conveyor means having a drive element projecting outwardly beyond the stationary outside casing and between the top and bottom thereof, means to drive said element, means for discharging waste material from the retort and take-01f means for the distillation products from the material being heated in which the means for forcing material downwardly comprises ribs depending from the bottom of a heating element, said ribs being of a depth increasing in extent in the direction of travel of the material being treated.

5. A retort comprising a stationary outside casing, a stack of superimposed hollow heating elements therein, means to supply heat to the interior of the heating elements and to take the exhaust gases therefrom, means to supply material to be heat treated onto the uppermost heating element, conveyor means for moving the said material peripherally on each heating element and to drop the same downwardly onto the next heating element of the stack, said conveyor means having a drive element projecting outwardly beyond the stationary outside casing and between the top and bottom thereof, means to drive said element, means for discharging waste material from the retort and take-off means for the distillation products from the material being heated, with refractory deflectors arranged around a central flue, said deflectors projecting into the hollow heating elements whereby heat passing up the fine will be forced by the deflectors radially into the heating elements.

FREDERICK POPE.

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