US3175340A

US3175340A - Method and apparatus for gas scrubbing

Info

Publication number: US3175340A
Application number: US853032A
Authority: US
Inventors: Hertha M Schulze
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-11-16
Filing date: 1959-11-16
Publication date: 1965-03-30
Anticipated expiration: 1982-03-30

Description

March 30, 1965 w. cs. A. SCHULZE METHOD AND APPARATUS FOR GAS SGRUBBING 4 Sheets-Sheet 1 Filed Nov. 16, 1959 INVENTOR W/LL/AM 6/]. 50/0115 BY ATTORNEY March 30, 1965 w. G- 'A. SCHULZE 3,175,340

METHOD AND APPARATUS FOR GAS SCRUBBING Filed Nov. 16, 1959 4 Sheets-Sheet 2 INV EN TOR W/AL/AM ,4. sci/M25 March 30, 1965 w, e. A. SCHULZE METHOD AND APPARATUS FOR GAS SCRUBBING 4 Sheets-Sheet 3 Filed Nov. 16

INVENTOR March 30, 1965 w. G. A. SCHULZE METHOD AND APPARATUS FOR GAS SCRUBBING 4 Sheets-Sheet 4 Filed Nov. 16

INVENTOR W/LL/AM G A. SCHULZE United States Patent 3,175,34a Mn'rrron AND arrannrus non GAS SCRUBETNG William G. A. Schulze, 814 Rosewood Court, Gntario, Calif; Hertha M. Schulze, exeeutrin of said William G. A. Schuize, deceased Filed Nov. 16, 1959, Ser. No. 853,032 11 Blaims. (Ci. 55-86) This invention relates to an improved method and apparatus for recovering light oil vapors from gaseous mixtures, particularly from coke oven gases.

Coke oven gases from coke ovens are treated to recover valuable products. Among the constituents of the gases are ammonia and light oil.

The light oii referred to generally comprises about 1% of the composition of coke oven gases. The constituents of the light oil comprise principally the benzenering aromatic hydrocarbons, i.e., benzene, toluene, xylene, and their homologs. The industry uses the term benzol to collectively define these principal constituents of the light oil. Usually, from 55 to 70 percent of the crude light oil will be represented by the benzol fraction.

Prior to the removal of light oil from the gases, the ammonia is scrubbed from the gases in absorbing systems by contacting the gases with an acid liquor spray whereby the ammonia is selectively absorbed therein and recovered as an a. monium salt. In my copending application U.S. Serial No. 811,326 filed May 6, 1959 there is described a novel method and apparatus for accomplishing the efficient removal of ammonia from coke oven gases. After removal of ammonia, the light oil is selectively recovered by scrubbing the gases with a petroleum base wash oil which has a higher distiiiation range of temperatures than the light oil. The wash oils generally in use are the petroleum oils such as gas oil, straw oil, and spindle oil. Tar oils have also been used.

The light oil is conventionally recovered by passing the coke oven gases through a series of light oil washers or scrubbers where it comes into intimate contact with the wash oil which absorbs the light oil vapors. The light oil washers or scrubbers are referred to as benzol washers in the industry. Similarly the Wash oil, which has absorbed light oil, is referred to as benzolized wash oil and the wash oil, which has been stripped of light oil in the wash oil still, is referred to as debenzolized wash oil.

The benzol washers are usually two cylindrical towers up to 100 feet high, packed with wooden hurdles or steel turnings. Debenzolized wash oil is sprayed onto the top of the packing in the second tower and drips down eX- posing a large oil covered area to the ascending gases where absorption of the light oil vapors in the gases occurs. The direction of the wash oil is counter current to the gas flow. The gas enters the first tower below the packing, moves upward, leaves the top of the first tower, enters the bottom of the second tower, moves upward and out the top through a mist eliminator. During the passage of the gas through the towers it meets with wash oil and gives up the light oil vapors to the wash oil. The wash oil from the bottom of the second tower is pumped through a high head centrifugal pump to the sprays on the first tower. The benzolized wash oil obtained from the first tower is passed to a wash oil still. In the still, the light oil is stripped from the wash oil. The light oil obtained is further processed. The debenzolized wash oil is recirculated back to the benzol washers. The coke oven gases minus the light oil are pumped to consumers.

The above described system has been satisfactory. However, it possesses serious disadvantages in that the packing becomes plugged with muck and naphthalene. Cleaning with steam or hot tar becomes less effective the Fates-tied Mar. 39, 1965 longer the unit is in operation. Consequently, the pressure differentials between gas inlets and outlets rises creating increasing power demands to pump the gases through the washers. Efiiciency of the light oil recovery system drops thereby causing yield losses. The packing must be replaced when this occurs and involves an expensive and ditficult operation.

To avoid the above disadvantages, spray type benzol washers were developed with open spray compartments. In order to obtain enough contact area between the gases and the wash oil, the washers are usually feet or higher with at least four spray sections each. With two washers in series there is a total of eight spray sections. To recirculate the wash oil through these 8 spray sections, 7 high head centrifugal pumps are used in addition to the eighth high head pump which pumps the benzolized wash oil to the wash oil still. However, even this development has disadvantages. In order to have adequate contact between the free falling wash oil droplets and the ascending gas, too large a contact space and too many compartments are required. All the sprayheaders are within the tower and are surrounded by gas and oil.v

Access to them is not possible for unplugging, maintenance, or adjustment unless the complete unit is taken.

out of service. The use of seven high head centrifugal pumps for recirculation and transfer of wash oil from.

the second tower to the first is a needless waste of power and creates extra maintenance problems.

A more eflicient method and less complicated system which is easier to operate and requires less maintenance, therefore, is a desideraturn of the industry.

This invention provides an improved, novel method and apparatus for absorbing light oils from coke oven gases in a fast and efficient manner.

In accordance with this invention, light oil is absorbed from coke oven gases in a novel cylindrical, vertical benzol absorber vessel which comprises a gas scrubbing chamber in the upper portion of the vessel, an annular gas introducing device surrounding the periphery of the scrubbing chamber, and a plurality of gas inlets communicating between the gas scrubbing chamber and the gas introducing device. The vessel is also provided with a distributor at the top of the scrubbing chamber for the introduction of the wash oil into the gas scrubbing chamber.

In the operation of the absorber, coke oven gases are introduced tangentially into the scrubbing chamber from the annular gas introducing device as a plurality of gaseous streams through the plurality of gas inlets at the periphery of the scrubbing chamber. The introduced plurality of gaseous streams form a whirling cyclone of gas within the scrubbing chamber. Simultaneously, debenzolized wash oil is introduced through the distributor at the top of the absorber vessel. The Wash oil issuing from the distributor contacts the whirling cyclone of gas and in the resultant violent mixing absorbs light oil therefrom. The wash oil containing absorbed light oil falls into a wash oil bath maintained in the bottom of the vessel. A portion of the wash oil is recirculated to the distributor and a portion is removed from the absorber and sent to a still for recovery of the light oil therefrom.

The coke oven gases are introduced into the scrubbing chamber in a tangential, horizontal direction at the periphery thereof. This is accomplished by providing an annular circular gas duct around the scrubbing chamber. The inner wall of the duct contains a plurality of slotted or circular openings through which the gas passes and enters into the scrubbing chamber. In order to introduce the gas tangentially, the openings may be disposed angularly through the inner duct wall. Thus, the piurality of openings may be circular in form, all of which point in the same angular direction horizontally into the scrubbing chamber. A plurality of vertical slots are preferred, however, with vanes which guide and deflect the gas through the slots in a tangential direction. Provision is made to make the openings adjustable in size to enable the regulation of the flow of gases therethrough. Furthermore, the adjustable opening arrangement permits the gases to enter the scrubbing chamber at the highest possible pressure regardless of the rate of operation. Thus, when the gas volume and pressure, are high, the openings can be set wide open, Whereas when gas volume and pressure are low during reduced operations, the openings can be set partly open.

The scrubbing chamber is provided at the top with a central gas outlet. The whirling cyclone of gas, created by introducing the gas tangentially through the plurality of openings, moves rapidly towards the center of the scrubbing chamber. The gas is directed upward and out through the gas outlet by a guide come the apex of which isdisposed near the gas outlet. The cone extends into a portion of the scrubbing area.

The wash oil is introduced into the scrubbing chamber through a distributor disposed at the top of the scrubbing chamber. The distributor provides for the introduction of the wash oil as a plurality of sprays into the scrubbing chamber. This is accomplished by providing a series of nozzles disposedin a horizontal, concentric arrangement at the top of the scrubbing chamber. The spray nozzles may be arranged to spray in any direction from the concentric arrangement and good absorption will result since the violent motion of the gas produces excellent mixing of gas and oil. However, in order to prevent too much oil from being carried out with the gas as mist, it is preferred to arrange the sprays nearest the central gas outlet to point countercurrent to the direction of gas flow to knock down excessive oil carry over.

Within the central gas outlet there is provided a larger capacity spray nozzle which gives a whirling motion to a coarser spray opposite in direction to the cyclone of gas passing through the outlet. This will also reduce the oil'carryover in the gases.

The intimate contact of gas and wash oil during the cyclone action achieves a high degree of light oil absorption. The Wash oil, after absorbing the light oil, falls into the lower portion of the vessel wherein a wash oil bath is maintained. The slightly benzolized wash oil overflows into an overflow pipe at the center of the bath and is recirculated to the wash oil distributor and is sprayed into the scrubbling chamber through an outer series of spray nozzles. Arrangement is made to withdraw benzolized wash oil from the bath which is saturated with light oil.

The benzolized wash oil is treated to strip the light oil therefrom and the debenzolized wash oil is returned to the benzol wash vessel.

For a clearer understanding and advantages of the invention, the following description and drawings will illustrate the preferred embodiments.

Referring to the drawings:

FIGURE 1 is a vertical sectional elevation of a benzol washer vessel;

FIGURE 2 is a top View of the benzol washer vessel of FIGURE 1 with a portion of the top of the vessel broken away to show the arrangement of the spray nozzles and the gas duct. The distributor system above the top of the vessel has been omitted for purposes of clarity;

FIGURE 3 is a vertical sectional elevation of another embodiment of this invention showing two benzol washer vessels in combination;

FIGURE 4 is a top view of the vessels shown in FIG- URE 3 with portions thereof broken away for clarity;

FIGURE 5 is adetailed view of a portion of the inner wall of the gas duct in the absorber, showing the gas introducing slots;

FIGURE 6 is a top sectional view of the benzol washer vessel of FIGURE 1 taken along line 6-6;

FIGURE 7 is a detailed view, with parts broken away for clarity, of the inner wall of the gas duct in the benzol washer vessel, showing the gas introducing slots and portions of the adjustable quarter panels.

Referring now to FIGURE 1, there is illustrated a single benzol washer system comprising vessel 2%, which comprises a gas introducing duct 24, and a wash oil distributor 45). The vessel 20 is comprised of a vertical cylindrical portion 21, bottom 22 and false bottom 6%. Contiguous with the cylindrical wall 21 is a lower slanting wall 27 of the gas introducing duct 24. The gas introducing duct 24 contains outer wall 26 contiguous with wall 27 and top 23 of the vessel. The duct contains an inner wall 30 which is comprised of a plurality of elongated slots 31. The wall 30 contains guide vanes 28 which deflect and guide the gas into the slots during its passage thorugh the duct. Provision is made to adjust the size of the slot openings 31. This is accomplished by providing a second series of vertical elongated slots substantially similar in size to slots 31. The slots 32 are contained on four

curved quarter panels

33, 33a, 33b, 33c, (FIGURE 6) all of which are adjustable circumferentially along the inner wall 30. The

quarter panels

33, 33a, 33b, 33c, contain a series of guide vanes 2% next to slots 32 which extend in the scrubbing chamber 34 for the purpose of guiding the gas into the scrubbing area substantially tangentially. As is shown in FIGURE 7, the opening of the slots 31 may be made larger or smaller by adjusting the

quarter panels

33, 33a, 33b, and 33c counterclockwise or clockwise along the inner wall 3%. The slot 32 thereby is placed in position across the slot 31 producing a larger or smaller opening communicating between the area in duct 24 and the scrubbing chamber 34. The gas duct inner wall 39 contains bolts such as 35. The quarter panel 33 contains horizontal adjusting slots such as 36, and is secured after adjustment by a washer 37 and nut 33. Similarly the other quarter panels are adjustablev The gas passes from the duct 24 through each series of

slots

31 and 32 and enters the scrubbing chamber 3 tangentially as shown in FIGURES 2, 5 and 6. A cyclone of whirling gas is created which moves rapidly towards the center of the scrubbing chamber. A series of concentric baffles 42 are arranged extending a few inches down from the top 23 of the vessel. These bafiles prevent the whirling cyclone of gas from leaving the scrubbing chamber area and going above the nozzles 41. The whirling gas is directed upwardly and into the gas outlet 3% by a guide cone 50 which contains an upwardly extending conical surface 51 and a downwardly extending conical surface 52. This type of guide cone prevents undesirable gas currents below it and gives a streamlined cyclone pattern to the gas flow. The guide cone is supported by supports 53 disposed on a submerged central oil outlet 70.

The whirling gas as it passes through the scrubbing chamber meets, penetrates, and mixes violently with Wash oil being sprayed from a plurality of spray nozzles 41 arranged in a series of concentric rings A, B, C, D, E and F. The wash oil is supplied to all of the nozzles 41 through the distributor system 40. Circular feed header pipe 58 supplies wash oil to the nozzles in rings A and B through lines 60 and 61 respectively. Circular feed header pipe 59 supplies wash oil to the nozzles in rings C, D, E and F through

lines

62, 63, 64 and 65 respectively. Circular feed header pipe 58 also supplies wash oil to the nozzle 67 located in the gas outlet 39 through line 66. Line 57 supplies debenzolized wash oil from the debenzolizing still (not shown) to header 58. Header 59 is supplied with recirculated wash oil from recycle line 75.

The gases from which the light oil has been absorbed pass out of the benzol washer through the gas outlet 39 to a conventional mist eliminator (not shown). A minor amount of wash oil is carried out with the exhaust gases and is removed in the mist eliminator.

The wash oil which passes through the scrubbing chamber and absorbs light oil from the gases falls into a wash oil bath 76 at the bottom of the vessel. The wash oil is drawn into the submerged central oil outlet 7% and is pumped through outlet line 71 containing valve 73 by pump 74 to a recycle line 75 containing valve 77. Another portion of wash oil in bath 76 is removed through another outlet line 89 containing valve 81 by pump 82 through line 84 containing valve 83 to the debenzolizing still (not shown) for processing.

A level control valve arrangement 96 and 91 is provided to control the amount of wash oil leaving the vessel. The level of the bath 76 is always maintained above the outlet 70.

A typical operation of the single benzol washer 20 will be described with reference to FIGURES 1, 2, and 6. Coke oven gases are pumped into the gas introducing duct 24 through inlet line 25. As the gas passes through the duct it is deflected into the slots 31 by guide vanes 28. The gas then passes through slots 32 and is guided tangentially into the scrubbing chamber 34 by guide vanes 29 thereby creating a cyclone of whirling gas which rapidly moves towards the center of the chamber. The cyclone of gas is directed upward and into the gas outlet 39 by the guide cone 50.

The whirling cyclone of gas as it passes through the scrubbing chamber meets, penetrates, and mixes violently with the wash oil being sprayed from the plurality of nozzles 41. The sprays may be set to spray in any direction and good absorption will result. However, to obtain the maximum efiiciency, the arrangement shown in the FIGURE 2 is preferred. As shown the nozzles 41 are arranged in 6 concentric spray rings A, B, C, D, E and F. More or less rings may be used depending on the capacity of the washer. The nozzles in the outer ring E are pointed in the direction of the gas cyclone in a slightly inward and slightly downward angle to the tangent of the circle of the ring. The force of the plurality of sprays in ring F tends to increase the velocity of the gas cyclone in the circular outer area of the scrubbing chamber 34. The nozzles in rings E and C located closer to the center are arranged to point directly against the motion of the gas cyclone in a true tangent to the circle of the ring and in a slightly downward angle. The nozzles in rings D and B are set in the same direction as those in ring F again pointing slightly inward and slightly downward from the tangent in the same direction as the gas cyclone and once again increasing its velocity. The nozzles in ring A adjacent to the outlet pipe 39 point in a true tangent against the gas cyclone just before the whirling gases leave the outlet. Since the total number of nozzles in rings B, D and F is greater than the total number of nozzles in rings A, C and E, the spray capacity of the nozzles in rings A, C and E is increased by using larger nozzles. However, the increase should be limited so that the total spray capacity of the nozzles in rings A, C and E remains somewhat somewhat below the total spray capacity of the nozzlers in rings B, D and F. The purpose of keeping the total spray capacity of the counter current nozzles somewhat below the cocurrent nozzles is to increase the force of the gas cyclone rather than to slow it down.

The force of the cyclone of gas meeting the wash oil sprays from the plurality of nozzles results in the collision of multitudes of tiny spray droplets. Since this takes place in a relatively small confined area, the ultimate in mixing and contact of gas and wash oil occurs with a resultant excellent absorption of the light oil vapors from the gas.

The wash oil supplied to the nozzles comprises two sources. Debenzolized wash oil from the Wash oil still is pumped through line 57 into heater 58 which supplies the nozzles in rings A and B and nozzle 57 in the gas outlet 39. The debenzolized wash oil issuing from the nozzles in rings A and B sprays the gas as it is about to enter the gas outlet 39. Nozzle 67 sprays a somewhat larger volume of wash oil with a whirling motion in a direction opposite to the whirling motion of the gas. A suitable type of whirling spray nozzle is shown in Patent No. 1,101,264 to Eneas. The wash oil from the above sprays is only slightly benzolized after mixing with the gas since not much light oil vapor is left in the gas at that point. This portion of wash oil drops into the bath '76 near the center where it is withdrawn immediately with wash oil already in the bath into the submerged central oil outlet 7% and recirculated by the high volume, low head, variable speed pump '74 through

lines

71 and 75 to header line 5@.

The header 59 supplies the spray nozzles in rings C, D, E and Fwith the recirculated wash oil. The sprays from these nozzles upon mixing with the gas absorb a gerater amount of light oil at this point since the entering gas contains a greater amount of light oil. The wash oil is thereby substantially benzolized and drops into bath 76 in the outer areas and it is eventually withdrawn by pump S2 through outlet line 8% and pumped to the debenzolizing still through line 84 The benzolized wash oil flow through line 84 is regulated by the movement of a conventional level control,

valve 90 which is operated by compressed air from a conventional level control regulator 91. In this manner, the amount of wash oil within the washer is controlled and the level of the bath 7 6 is kept above the submerged central oil outlet Referring now to FIGURES 3 and 4, there is shown another embodiment of this invention comprising two benzol washers in series. Both washers I and II are substantially identical to the one shown in FIGURES l and 2. However, in the embodiment where two washers are used in series the number of spray nozzle rings may be reduced in each washer. Of course, this would be governed by the desired capacity of the system. Thus washer I as shown contains spray nozzle rings G, H, J and K. The nozzles in ring G nearest to the gas duct are pointed in a slightly inward angle in the direction of the gas cyclone. The nozzles in ring H are pointed directly against the motion of the gas cyclone in a true tangent to the circle of the ring. The nozzles in ring I are the same as those in ring G. The nozzles in ring K are located around the outlet pipe and point in a true tangent against the motion of the gas cyclone just before the whirling gases leave the outlet. Similarly, washer ll contains spray nozzle rings L, M, N and O.

The washers I and H are arranged in series whereby the coke oven gases pass through washers I and TI respectively. The wash oil passes through washer II first and subsequently through washer l.

The operation of the process using two benzol washers is as follows. The debenzolized wash oil from the wash oil still (not shown) is pumped through line 1% into header 58a which supplies wash oil to the spray nozzles in ring 0 and to the spray nozzle 67a in the gas outlet pipe 3%.

The debenzolized wash oil from ring 0 after having sprayed the exiting gas is only slightly benzolized since not much light oil vapor was left in the gas coming from washer 1 through line 161 and the gas duct 24a. This slightly benzolized oil drops into bath a near the center where it is drawn immediately together with wash oil from the bath into the central submerged wash oil outlet 70a. The high volume, low head, variable speed recirculation pump 74a pumps the wash oil through lines 71a and 75a to header 5% which in turn supplies the spray nozzles in rings N, M, and L. The same amount of wash oil which enters benzol washer ll, plus a small amount of absorbed light oil (about 1% of the volume) must be transferred to benzol washer I or benzol washer II would fill up. This is accomplished by letting a controlled amount of wash oil pass through line 162 to n 77? A 0,1 t

header 50 which feeds the spray nozzles on ring K and spray nozzle 67 in benzol washer l.

The wash oil flow through line 102 is regulated by the movement of a conventional level control valve 103 which is operated by compressed air from a conventional level control regulator 104. If the oil level in benzol washer II rises, valve 103 will open more and it the level drops the valve will move towards a more closed position. In this manner the oil level in washer II is kept constant. A similar control mechanism 105 and 106 controls the level of oil in washer I.

The spray nozzles in rings G, H, and J of washer I are supplied with wash oil similarly as rings L, M and N in washer II through the

recirculation system

70, 71, 7d, 75 and 50.

The benzolized wash oil from washer I is withdrawn through line 107 and pumped by pump 110 through line 109 to the wash oil still (not shown). The valves of line 1.08 remain closed when both washers are in operation.

The gas flow through the two benzol washers is as follows: The gas enters Washer I through line 25, passes follows: The gas enters washer I through line 25, passes through the gas introducing duct 24- and into the scrubbing chamber 34. The gas after giving up a portion of its light oil content to the wash oil passes through outlet 39 into line 101 and is introduced through line 25a into the gas introducing duct 24a of washer II. On its passage through washer II, the gas gives up its last traces of light oil and passes out through outlet line 3% into a conventional mist eliminator ill. The small amount of wash oil carried over with the gas is returned through line 113 into bath 76a and the gases are passed through line M2 to booster turbines which pump it to consumers.

As stated the valve in line 108 remains closed when the two benzol washers are operated together. However, the system is designed to operate either washer I or II singly. Thus when it is desired to operate washer I alone,

valves

116, 117, 1.20 and 121 remain closed while valves 115, 118 and 119 remain open. Similarly, washer II may be operated alone by closing

valves

115, 117, 118 and 119 while valves 116, 120 and 121 remain open. When the washers are operated alone, provision is made to bypass the gases through the washer which is not in operation.

The benzol washer systems described above all contain drain valves such as 92, 122 and 123 which are opened periodically to allow accumulated water to drain out. The false bottom 69 is slanted downwardly for this purpose so that the small amount of water which accumulates in bath 76 will eventually collect in the area of the drain valves.

A typical operating example for absorption of light oil from coke oven gas in a benzol washer system as shown in FIGURES 3 and 4 is as follows:

Coal carbonized (Proportion for two benzol washers in series) 3,300 NT/day. Gas produced per ton of coal (approx.) 11,000 cu. ft.

' Gas flow through benzol washers 1,500,000 cu. ft./ hr.

Light oil yield per ton of coal (approx) 3.5 gal/NT coal. Light oil product in washers 500 gaL/ hr. Gas temperature (inlet and outlet) 30 C. Wash oil temperature 3132 C.

(Nora-Wash oil temperature is kept one to two degrees higher than gas temperature to avoid condensation of water vapor from gas.)

Gal/hr.

Recirculation capacity of pumps 74 and 74a 210,000 Debenzolized wash oil pumped through line 100 to spray header 58a a 27,500

Light oil absorbed in ii unit +200 Partially benzolized wash oil pumped through line 102, to spray header 5% 27,700

Capacity of pump 7 3a 210,000

Partially benzolized wash oil to I unit 27,700 Partially benzolized wash oil recirculated through spray header 59a 182,300 Partially benzolized wash oil recirculated through spray header 59 210,000 Light oil absorbed in I unit 300 Partially benzolized wash oil pumped through line 102 to spray header 58 27,700 Benzolized wash oil pumped through line 109 to wash oil still 28,000

While there has been shown and described hereinabove the present preferred embodiments of this invention, it is to be understood that the invention is not limited thereto and that various changes, alterations, and modifications can be made thereto by those skilled in the art without departing from the spirit and scope thereof as defined in the appended claims.

What is claimed is:

l. A process of absorbing light oil from coke oven gas and the like comprising introducing a plurality of separate coke oven gas streams contemporaneously and tangentially into the outer periphery of a substantially unobstructed scrubbing zone through a plurality of gas inlets disposed about the said periphery of said zone and forming a whirling cyclone of gas within said zone from said streams, distributing unobstructedly wash oil into said zone from the upper area thereof, effecting a violent mixing and penetration of said whirling cyclone of gas with said wash oil and simultaneously increasing the velocity of said whirling cyclone of gas, whereby said wash oil absorbs light oil from said gas and falls into a bath of wash oil maintained below said scrubbing zone, withdrawing scrubbed gas from the upper portion of said zone, withdrawing benzolized wash oil from said bath, and withdrawing slightly benzolized wash oil from said bath and recirculating it through said scrubbing zone.

2. The process of claim 1 wherein said whirling cyclone of gas is guided to a gas outlet in the upper central portion of said zone.

3. A process of absorbing light oil from coke oven gas or the like comprising introducing said gas into an annular gas space surrounding a substantially unobstructed scrubbing zone, passing said gas from said gas space into the outer periphery of said sc ubbing zone and while passing said gas from said gas space into said scrubbing zone simultaneously dividing said gas into a plurality of tangentially entering gas streams and forming a whirling cyclone of gas from said gas streams within said zone, guiding said cyclone of gas towards the upper central portion of said zone, distributing wash oil as a plurality of unobstructed sprays into said zone from the upper area thereof, eifecting a violent mixing and penetration of said whirling cyclone of gas with said plurality of sprays and simultaneously increasing the velocity of said whirling cyclone of gas, whereby said wash oil absorbs light oil from said gas and falls into a bath of wash oil maintained below said scrubbing zone, withdrawing scrubbed gas from the upper central portion of said zone, withdrawing benzolized wash oil from said bath, and withdrawing slightly benzolized wash oil from said bath and recirculating it through said scrubbing zone.

4. The process of claim 3 wherein some of said sprays are directed in the same direction as the flow of said whirling cyclone of gas while the remainder of said sprays are directed against the flow of said whirling cyclone of gas.

5. Apparatus for absorbing light oil from coke oven gas or the like by scrubbing said gas with a wash oil, comprising a vertical cylindrical vessel, an annular gas introducing device in the upper portion of said vessel, a gas scrubbing chamber surrounded by said annular device, the inner wall of said annular device containing a plurality of angularly disposed gas inlets adapted to intro duce gas tangentially into the outer periphery of said" scrubbing chamber whereby a whirling cyclone of gas is formed therein means for adjusting the size of the openings of said gas inlets, a wash oil distributor at the top of said vessel above said scrubbing chamber adapted to introduce wash oil into said scrubbing chamber as a plurality of concentrically arranged sprays, a gas outlet in the upper central portion of said scrubbing chamber, a gas guide cone the apex of which is adjacent to and aligned with said gas outlet, 21 Wash oil reservoir below said scrubbing chamber, means for Withdrawing benzelized wash oil from said reservoir and means for withdrawing slightly benzolized wash oil from said reservoir and recirculating it to said wash oil distributor.

6. Apparatus for absorbing light oil from coke oven gas or the like comprising a vertical vessel, an annular gas introducing duct in the upper portion of said vessel, a gas scrubbing chamber surrounded by said annular duct, the inner wall of said annular duct containing a plurality of gas slots with guide vanes extending into said gas duct, adjustable panels adjacent to said inner wall and containing a plurality of gas slots with guide vanes extending into said scrubbing chamber, said slots on said inner wall and on said adjustable panels adapted to adjust the rate of flow of gas from said gas duct to said scrubbing chamber, whereby said gas is introduced tangentially into the outer periphery of said chamber and thereby form a whirling cyclone of gas therein, a liquor distributor at the top of said vessel including a plurality of spray nozzles arranged in horizontal concentric rings adapted to spray wash oil into said chamber countercurrent and cocurrent to the flow of gas in said cyclone, means to supply wash oil to said nozzles, a gas outlet at the upper central portion of said chamber, a gas guide cone the apex of which is adjacent to and aligned with said gas outlet, said gas guide cone being adapted to guide said cyclone of gas towards said gas outlet, a wash oil reservoir below said scrubbing chamber, means to withdraw and recirculate to said distributor slightly benzolized wash oil from said reservoir, and means to withdraw benzolized wash oil from said reservoir.

7. The apparatus of claim 6 wherein said gas outlet contains a spray nozzle therein adapted to spray wash oil with a whirling motion opposite to the flow of said cyclone of gas.

8. The apparatus of claim 6 wherein at least two of said vessels are arranged in series, means to pass coke oven gas to the first of said vessels and subsequently to the other vessel in said series, means to supply debenzolized wash oil to the last vessel in said series, means to pass wash oil from said last vessel through said series of vessels countercurrent to the flow of gas therethrough, means to withdraw benzolized wash oil from the first of said vessels, and means to withdraw scrubbed gas from the last of said vessels.

9. Apparatus for absw g light oil from coke oven gas or the like by scrun r g said gas with a wash oil comprising a vertical cylindrical vessel provided with a gas scrubbing chamber, an annular gas introducing means disposed in the upper portion of said vessel adjacent to said chamber, said annular introducing means being provided with an inner wall containing a plurality of gas inlets adapted to introduce gas tangentially into the outer periphery of said scrubbing chamber whereby a whirling cyclone of gas is formed therein, a Wash oil distributing means located at the top of said vessel and above said scrubbing chamber, said wash oil distributing means including spray mean arranged at predetermined positions with respect to the path of flow of the whirling cyclone of gas in said chamber and adapted to increase the velocity of the whirling cyclone of gas simultaneously with spraying wash oil into said chamber, said saray means including at one ring of nozzles arranged to direct wash oil in a direction opposite to the path of flow of said whirling cyclone of gas and at least one ring of nozzles arranged to direct wash oil in the same direction as the path of iiow of said whirling cyclone of gas, a gas outlet means in the upper portion of said scrubbing chamber and collection means disposed below said scrubbing chamber for receiving the wash oil discharged into said vessel and the light oil absorbed from the treated coke oven gas.

10. Apparatus as set forth in claim 9 including means for adjusting the size of the gas inlets.

11. Apparatus as set forth in claim 9 including cone means disposed in said chamber for guiding the cyclone of gas towards the gas outlet means.

gas

Reterences Cited by the Examiner UNITED STATES PATENTS 385,037 6/88 Ash 183-87 981,098 1/11 McCaskell 261-791 1,078,848 10/13 Gray et al. 261-791 1,504,386 8/24 Senseman 183-30 1,783,813 12/30 Schneible -238 2,050,797 8/36 Kerschbaum et al. 183-30 2,250,757 7/41 Fisher 261-79 X 2,698,672 1/55 Burnside et al 183-30 X 2,753,949 7/56 Manuel 55-94 2,856,171 10/58 Otto 182-2 X 2,969,851 1/61 Preeman 55-238 2,976,949 3/61 Murphy et al. 261- X HARRY B. THORNTON, Primary Examiner.

REUBEN FRIEDMAN, WALTER BERLOWTTZ, WES- LEY S. COLE, HERBERT L. MARTIN, Examiners.

Claims

1. A PROCESS OF ABSORBING LIGHT OIL FROM COKE OVEN GAS AND THE LIKE COMPRISING INTRODUCING A PLURALITY OF SEPARATE COKE OVEN GAS STREAMS CONTEMPORANEOUSLY AND TANGENTIALLY INTO THE OUTER PERIPHERY OF A SUBSTANTIALLY UNOBSTRUCTED SCRUBBING ZONE THROUGH A PLURALITY OF GAS INLETS DISPOSED ABOUT THE SAID PERIPHERY OF SAID ZONE AND FORMING A WHIRLING CYCLONE OF GAS WITHIN SAID ZONE FROM SAID STREAMS DISTRIBUTING UNOBSTRUCTEDLY WASH OIL INTO SAID ZONE FROM THE UPPER AREA THEREOF, EFFECTING A VOILENT MIXING AND PENETRATION OF SAID WHIRLING CYCLONE OF GAS WITH SAID WASH OIL AND SIMULTANEOUSLY INCREASING THE VELOCITY OF SAID WHIRLING CYCLONE OF GAS, WHEREBY SAID WASH OIL ABRORBS LIGHT OIL FROM SAID GAS AND FALLS INTO A BATH OF WASH OIL MAINTAINED BELOW SAID SCRUBBING ZONE, WITHDRAWING SCRUBBED GAS FROM THE UPPER PORTION OF SAID ZONE, WITHDRAWING BENZOLIZED WASH OIL FROM SAID BATH, AND WITHDRAWING SLIGHTLY BENZOLIZED WASH OIL FROM SAID BATH AND RECIRCULATING IT THROUGH SAID SRUBBING ZONE.