US2051495A - Apparatus for continuous extraction - Google Patents

Description

Aug. 1s, 1936. Q E, RAMER 2,051,495

APPARATUS FOR CONTINUOUS EXTRACTION Filed March 20, 1934 4 Sheets-Sheet l RARSQER 'Y REL?- FRESH SUPPLY COVEIVJEAS RECOVER Y az l Aug. 1,8, 1936. Gf E, RAMER j 2,051,495

APPARATUS FOR CONTINUOUS EXTRACTION Filed Maron 2o, 1954 4 sheets-sheet 2 EXTRCT? EXTRAC Aug- 18, 1936. v G. EjRAMEl-ey 2,051,495

APPARATUS FOR CONTINUOUS EXTRACTION Fil'ed Marsh 2o, 19:54 '4 sheets-sheet :s

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N Mofaz-0R WMESS" 66a 17e Famer Aug. 18,1936. G. E. RAMER APPARATUS FOR CONTINUOUS EXTRACTION Filed March .20, 1954 4 Sheets-Sheet 4 Gf@ e s @fm/a In 4 /M/f/vral? /zFa/mef Y, ,i

Arm/May Patented Aug. 18, 1936 UNITED STATES y PATENT o-FFICE APPARATUS FOR CONTINUOUS EXTRACTION Application March 20, 1934, Serial No. 716,477

6 Claims.

'lhis invention is directed to ahmethod and apparatus for the continuous extraction of materials; more particularly, for the continuous extraction of resinous' wood, as, for example, pine stumps and roots.

The so-called steam and solvent process for the recovery of turpentine, other essential oils and rosin from dead stump wood of the southern pine is well known. This process involves steam- 10 :ing the chipped Wood with live steam for the distillation therefrom of turpentine and other essential oils, followed, aftera thorough drying ofthe steamed chips, by an extraction thereof with a rosin solvent, usually gasoline. The rosin gasoline :solution is subsequently evaporated, either before or after refining treatments, for the production of rosin, and the extracted chips are subjected to a second steam distillation for the recovery of the solvent remaining in them, after which they are usually burned as fuel for the operation of the plant. c

The customary and known procedure for carrying out these operations involves chipping the wood in suitable machines and transporting the 25 chipped Wood on a belt conveyor to a series of relatively tall extractors which are charged with the chips. In each of these extractors, all the operations described above are performed in sequence. That is to say; the chips are rst '30 steamed in the extractor, then dried, extracted with solvent and steamed again for solvent recovery. This utilization of a single extractor unit for all these varied operations involves numerous dfnculties, among which may be men- 35 tioned the harmful effect on the extractor of operation in rapid succession at different extremes of temperature. After the operations are over,

it is necessary to dig out the chips by hand 50 invention to provide a method and apparatus' whereby the steam and solvent extraction of the-l pine wood may be carried out continuously and without the disadvantages involved in a' batch operation.

55 Broadly, the method, iny accordance with this invention, involves the subjection of the chipped pine wood to one operation only, for example, steam distillation of the turpentine in one or more extractors, removal of the chipped wood 4from this extractor, or group of -extractors, into o a second group of extractors in which a second operation onlyewill be performed, for example, the dehydration of the chipped wood, and so on throughout the entire cycle of operations necessary for the complete processing of the wood.

'I'he apparatus, in accordance with this invention, will accordingly comprise, broadly, a series of extractors, separate groups of which will be designed and adapted for the performance of one operation only in connection with the ex- 15 traction of the wood, and means for moving the chipped wood in a continuous manner from extractor to extractor throughout the series until it is completely processed.

The practical embodiment of the method in accordance with this invention is most clearly shown by a description of the accompanying drawings, which show a preferred form o f apparatus in accordance with this invention, and in which- Fig. 1 is a diagrammatic representation of the complete apparatus in accordance With this invention, comprising extractors, cars for the transportation of chips through the extractors and the pipe lines, condensers, separators, etc. connected and associated with the various extractor units. l

Fig. 2 is a diagrammatic representation showing the sequence of operation of various valves and controls associated with one complete cycle of extraction.

Fig. 3 is a longitudinal section through one of the extractor units and through the car in place in the unit.

Fig. 4 is a cross section through one of the 40 extractor units and through the car in place in the unit.

Fig. 5 is a cross section through one of the extractor units showing diagrammatically the pipes, valves and electrical controls associated with each extractor unit in its operation.

As shown in Fig. 1, the ,apparatus in'accordance with this invention comprises a number of cylindrical extractors (12 are shown in Fig. 1, but any desirable number, either lesser or greater, maybe employed) laid horizontally end to end and separated by gate valves VA--L VA, VB, etc., cars running on tracks extending through these extractors, each' car being adapted to closely fit in each extractor unit, and the pipes, 55

pumps, condensers, separators and control valves associated with the extractors.

Each extractor unit comprises (reference now being made to Figs. 3, 4 and 5) a shell 1, which, together with the gate valves 2, forms a closed cylinder. The extractor is adapted to be supplied, through the header 4 and connections l,

with steam, dehydrating vapors, or solvent, as the case may be, depending upon which phaseof the operation is to be conductedvin this extractor. This steam, dehydrating vapors or solvent may escape from the extractor through pipes 1 and the header 6. v

A cylindrical car l, divided into sections I by partitions therein and with its lower and upper surfaces perforated as shown at III and hinged at Il to permit loading and unloading thereof, is carried in the extractor by means of the wheels H travelling on the rails I2 which form a part of the extractor. The car may be moved into or out of the extractor by means of the gears I3, which engage with a pinion I4 carried on the bottom of the car. The gears are driven by a main drive shaft I6 through a clutch l5. A vapor seal between the body of the car and the body of the extractor is provided by gaskets i..

The gate valves 2, which close the ends of the extractor, are operated by the hydraulic cylinders 20, which are provided with a piston Il and with intake and exhaust lines 2| and 42, respectively. A retarding valve Il is provided in line 2l to prevent too rapid descent of the piston oi' the gate valve. l

The various operations taking place in each extractor unit are controlled in the following manner:

The headers 4 and 6' are connected with pipe lines 3i and 32, respectively, in which are placed electrically operated valves 21 and 28, respectively, as well as manually operated valves 36 and 35, respectively. 'I'he manually operated valves are for emergency use only and are normally lalways open, .the control of the vapors or liquids passing through lines 3l and 22 being performed by the electrically operated valves.

T'he operation-of the gears I3 which serve to move the car is controlled by solenoid ll operating through lever 31 and the clutch I5. Similarly, the operation of the gate valves 2 is controlled by electrically operated valve 2l placed in the line 2i supplying the cylinder 2l. 'l'his line4 has also a manually operated valve 33 for emergency use.

All these electrically operated valves, clutches, etc., not only those associated with the extractor which has been described, but also the similar controls of the other extractors, are controlled by the operation of cams on the cam shaft 25, which is driven at the proper ratio by the main shaft I 6. This control operation is shown diagrammatically in Fig. 5, where electrically operated valve 21 is controlled by the making and breaking of contacts 26 upon rotation of the cam shaft. The speed at which the cam shaft is driven and the position of the various contacts for operating the electrically controlled mechanisms are so determined that the various operations necessary for the completion of the entire cycle of extraction follow each other in' the proper sequence, as will be described below.

The operation in each extractor is very simple. 'I'he steam, dehydrating vapors, or solvent, as the case may be, is admitted into the extractor after the car, loaded with chipped wood, is in' place therein, through pipes l, so incidentally serving to keep the gears Il well cleaned. and

up through the chips through the perforations I0 in the cars. 'Ihe vapors or solvent then passes out through pipe 1 and on to condensers, separators or evaporators, as the case may be.

Referring to Fig. 1, it will be seen that two extractors, A and B, are used for the steam distillation of turpentine from the fresh wood. In these extractors, live steam is admitted through valves V-II and V--I2 and passes out together with the turpentine vapors through valves VV-II and VV-I2, passing normally through the heat exchangers 11E-2, IIE-3', etc., into the condenser C|, and from there to the separator S--I in which the turpentine is separated from the condensed water. In extractors C and D, which. are used for dehydrating, the dehydrating vapor, which may be solvent vapors, as, for example, gasoline vapor, or furnace'gas, passes into the extractors through valves V--S and V-il and out through valves VV-l and VV-ID to the condenser C-2 and from there to the separator 8 2. A pump P--i is used to maintain a vacuum in extractors C and D.

Into extractors E to K, inclusive, which are used for rosin extraction of the dehydrated wood,` the liquid solvent, for example, gasoline, is passed countercurrently; thus into extractor K through valve V-3, out through valve VV-3 through strainer ST-2 and heat exchanger HE-2 into extractor J through valve V-4; thence through strainers and heat exchangers into' extractors H, G, F and E in sequence, out of extractor E through valve VV-O into evaporator E-I, from which the solvent vapors pass to condenser 0 3, separator S-3, and from there, by means of pump P-2, through heat exchanger HE-I and back into extractor K through valve V-4. Any fresh solvent which may be required is pumped from the solvent supply by means of pump P-I through heat exchanger HE-L Extractors L and M are used for the recovery of solvent by steam distillation. Into these extractors steam is passed through valves V-l and e V--2 and out through valves VV-I-I and VV-2.

The steam, together with the solvent vapors, passing out of the extractors, goes through heat exchanger HE--I and from there into condenser C-.I and separator S-4, from which the solvent is returned to the system through pump P-3 The operation of the apparatus .as a whole involving, as it does, the transfer of each car from one extractor to the next in series after completion of the operation inthe first extractor may best be described starting with the entire apparatus full of cars. That is to say, with reference to Fig; 1, there are I2 cars in the extractors A to M, inclusive, each car undergoing the treatment peculiar to the extractor in which it is.

Assumethat one step of the cycle has been completed and it is necessary to move ahead to the next step of the cycle.

As it takes considerable time to change all oi.'

the cylinders, it will be necessary to change them progressively while all other operations are still to gradually decrease to atmospheric pressure.

Valve VV-IA will then be closed and valve VM opened.

Ih'e car containing the material processed will then be withdrawn from cylinder M. Valve VM wlllthenbecloscd. Valve V-I wlllthenbez;

opened, admitting steam into cylinder M in order to bring the pressure up to the same condition as now exists in cylinder L. Valve VL will then be opened and the car of material in process in 5 cylinder L will be passed into cylinder M.

Valve VL will then be closed and valve VV-I opened, allowing steam to pass out of cylinder M.

Valves V-2 and VV2 will be closed, shutting the steam off of cylinder L. Valve VV--2A will l be opened until the pressure is reduced to atmospheric in cylinder L. Valve V-3l will then be opened, admitting solvent into cylinder L until the cylinder is full, which will be indicated at the outlet of the vent line. Valve VV-2A will l5 then be closed.

When cylinder L is full of solvent, it will be at the same pressure as cylinder K, at which time valve VK will be opened and the car of material in process passed from cylinder K into cylinder L,

after which valve VK is closed,

, Steam will then be passed into the top of cylinder L by opening valve VV2 and closing valve VBP-I, and the solvent in cylinder L forced out through the bottom through valve V-3I into cylinder K and so into the system.

When cylinder L is empty of solvent, it will be indicated by steam appearing at sample line SL.

Valve V-3I will then be closed and valve VBP-I opened. Valve V-2 is then opened, ad-

80 mitting steam to the bottom of the cylinder, which will drive out the residual solvent in the material to be processed, through valve VV-2, through the heat exchanger, and thence through the condenser C A, in the same manner as the process which has already taken place and is taking place in cylinder M.

Cylinder K now having no car therein, a car of material in process can pass from J to K by opening valve VJ, and, when the car has passed, closo ing VJ.

Another car can pass from cylinder H to cylinder J by opening valve VH, passing car and closing VH.

Another car can pass from cylinder G to cylinder H by opening valve VH, passing car and closing VG. Y

Another car can pass from cylinder F to cylindvii G by opening valve VF, passing car and closing Similarly, a car can pass from cylinder E to cylinder F by opening valve VE, passing car and closing VE.

Each time after car has passed from one cylinder to another, the valve that was open to allow the passing of the car is again closed.

During all of the previous operations, cars of material to be processed have been dehydrated in cylinders C and D.

Now D has been completely dehydrated ready o0 for subsequent operation in cylinder E.

In order to move car in process from cylinder D containing vapors into cylinder E containing some liquid solvent, valves V-S and VV-9 are iirst closed on cylinder D and valve V-Sa is opened u to equalize pressures in cylinders E and D by permitting solvent to ilow from E to D. 'Ihe valve VD between cylinders E and D is then opened and the car in cylinder D moved to cylinder E, after which valves VD and V-Ss are closed and the 70 process of solvent extraction is continued in cylinder E.

We now have cylinder D partly full of liquid solvent. This may be removed by leaving valve VV--l closed and applying vapor pressure tov 75 cylinder D through valve V--9I from pump VP and discharging the solvent remaining in cylinder D out of the bottom valve V-92 into the piping leading to the evaporator, thus leaving cylinder D empty. When the liquid has been removed, valve V-92 is closed, as is also V9I. Valve VV-9 is then opened, allowing the pressure to be reduced in cylinder D by means of vacuum pump P-l, bringing it to the same pressure as cylinder C.

The car of material in process in cylinder C can l0 now be moved to cylinder D by opening valve VC, after which VC is closed. Later valve V--9 is opened to continue the dehydration.

Valve VV--I 0 on cylinder C is then closed; also. valve V-I0 if vapors have been used for dehydra.- l5 tion.

In order to move car of material to be processed from cylinder B to cylinder C, valves V-Ii and VV-H on cylinder B will be closed, and vent valve VV-I IA opened until the pressure has been 20 reduce to atmospheric. Valve V-Ilh is then opened to equalize the pressure in the two cylinders B and C. Valves VV-I lA and V--IDl are then closed, and valve VB, between cylinders C and B, is opened, and the car is allowed to pass 25 from cylinder B into cylinder C, after'which valve VB is closed.

Valve VV-i on cylinder C is then opened and the process of dehydration continued. and later valve V-IU is opened to continued dehydration 30 with vapors.

Valve VV-ll and valve V-II being closed, valve V--Ii is then opened to bring the pressure up in cylinder B to that in cylinder A, and valve VA between cylinders A and B is then opened 35 and vthe car is allowed to pass from cylinder A to cylirder B, after which valve VA is closed. Valve VV-I I is then opened and the material in cylinder B is processed.

Valves V-I2 and VV-I2 on cylinder A are 49 now closed and vent valve VV-I 2A opened, allowing the pressure to be reduced in cylinder A'to atmospheric. Valve VV-l2A is closed. Valve VA-I is then opened and a new carload of` material to be processed enters cylinder A, after 4 which VA-l is closed. `Valve V-l-2 is thenopened, admitting steam into cylinder A. Valve VV-I2 is also opened, and the process of the extraction continued.

The sequence of operation of the electrically .E0 operated controls in the cycle described is diagrarrmatleally shown in Fig. 2.

The number of cylinders in each particular operation is so arranged that when the time cycle is completed on cylinder A, cylinder M will .3.) be ready for its next cycle of operation and the car can be removed from M in the manner described above and the whole process of moving a car from one cylinder section to another repeated, and so on indenitely.

Any number of cylinders can be used in any particular part of the operation, all depending upon the time necessary for the operation to be performed.

'Ihe size of the cylinders, valves, interconnect- C5 ing piping, etc. can be made of any convenient size for a denite amount of material to be processed in a given time.

Returning now to the car which was removed from extractor M at the beginning of the cycle of operations just described, this car will be moved onto a transfer table, carried across t'o a track extending over a dump, moved into position over the dump, inverted by an unloader of the usual type and the extracted chips there- 'i5 vals the operation of said above named means.

in contained discharged into a bln from -which they may-be fed into the furnaces of the plant. The car is then sent to a second transfer table on which it is shunted across to the track leading into extractor A and placed under hoppers from which the fresh wood supply, in the form of chips, is discharged into the car. The car is then ready to be introduced into extractor A at the proper point in the cycle.

As will be seen, the time during which any car may remain in any one of the nextractora: is limited, by the continuous nature of the process, to the same period, no matter what process may be carried on in the extractor. Hence, necessary `variations in the periods of time to which the chips must be subjected inthe difierent operations is permitted by increasing or decreasing the number of extractors in the group of extractors in which the same operation takes place. Thus, in the process outlined, two extractors each were used for turpentine distillation, dehydration and solvent recovery, respectively; while six extractors were used for rosin extraction. By changing the number ot extractors in these groups, the entire apparatus and method may be made exceedingly ilexible, so that any desired processing treatment can be given.

What I claim and desire to protect by Letters Patent is:

l. Apparatus for the continuous extraction of resinous wood comprising a horizontal chamber of` greatlength in relation to its cross-sectional area., means for dividing said chamber into a plurality of isolated small chambers, means for `introducing and removing uid agents into and from each small chamber so formed, means for passing resinous wood through each of said small chambers in sequence, and master-control means adapted to effect automatically in predetermined sequence and at predetermined inter- 2. Apparatus for the continuous extraction of resinous wood comprising' a horizontal chamber o-I great length in relationvto its cross-sectional area',v means for dividing said chamber into a plurality of isolated small chambersm'eans for introducing and removing iluid agents into and from each small chamber so formed, rails laid the length of said large chamber, cars travelling on said rails and adapted to carry resinous wood, said cars being perforated for the passage of uids therethrough, means for moving said cars hrough each of said small chambers in sequence, and master-control means adapted to' etlect automatically in predetermined sequence and at predetermined intervals the operation of said above named means.

3. Apparatus for the continuous extraction of resinous wood comprising a horizontal chamber lof great length in relation to its cross-sectional (area, gate valves for dividing said chamber into a plurality of isolated small chambers, means for operating said gate valves, means for equalizing the pressure conditions in adjacent small chambers, means for introducing and removing iluid agents into and from each small chamber, rails laid the length of said large chamber, cars travelling on said rails and adapted to carry resinous wood, said cars being perforated for the passage of fluids therethrough, and means for moving said cars through each of said small chambers in sequence.

4. Apparatus for the continuous extraction of resinous wood comprising a horizontal chamber of great length in relation to its cross-sectional area, gate valves for dividing said chamber into a plurality of isolated small chambers, means for operating said gate valves, means for equalizing the pressure conditions in adj-scent small chambers, means 'for introducing and removing fluid agents into and from each small chamber, rails laid the length of Asaid large chamber, cars travelling on. said rails and adapted to carry" resinous wood, said cars being perforated ior the passage of iluids therethrough, means for moving said cars through eachof said small chambers in sequence, and master-control means adapted to effect automatically in predetermined sequence and at predetermined intervals the operation of said above named means.

5. Apparatus for the continuous extraction of resinous wood comprising a horizontal chamber of great lengthin relation `to its cross-sectional area, means for dividing said chamber into a plurality/ of isolated small chambers, means for introducing and removing fluid agents into and from each small chamber so formed, rails laid the length of said large chamber, cars travelling on said rails and adapted to carry resinous wood, said cars being perforated for the passage of iluids therethrough, means for moving said cars through each of said small chambers in sequence, and means positioned between said cars and the walls of said chambers and adapted to-prevent anyiluid introduced into said chambers from passing from inlet to outlet thereof between the cars and chamber walls. l

6. Apparatus for the continuous extraction of resinous wood comprising a horizontal chamber of great length in relation to its cross-sectional area, means for dividing said chamber into a plurality of isolated small chambers, means for introducing and removing fluid agents into and from each small chamber so formed, rails laid the length of said large chamber, cars travelling on said rails and adapted to carry resinous wood,

said cars being perforated for the e of fluids therethrough, a gear rack carried by each of said cars, pinions positioned in eachof said small chambers and engaging ,'said gear racks, and driving means for said pinions, whereby the said cars may be movedfrom chamber to .Je

chamber.

GEORGE E. BAKER.

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