US3433218A - Off gas firing system - Google Patents

Off gas firing system Download PDF

Info

Publication number
US3433218A
US3433218A US380139A US3433218DA US3433218A US 3433218 A US3433218 A US 3433218A US 380139 A US380139 A US 380139A US 3433218D A US3433218D A US 3433218DA US 3433218 A US3433218 A US 3433218A
Authority
US
United States
Prior art keywords
stack
bypass
exhaust
gas
duet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US380139A
Inventor
Peter Von Wiesenthal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Linde GmbH
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3433218A publication Critical patent/US3433218A/en
Assigned to FIRST PENNSYLVANIA BANK N A, A NATIONAL BANKING ASSOCIATION reassignment FIRST PENNSYLVANIA BANK N A, A NATIONAL BANKING ASSOCIATION SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SELAS CORPORATION OF AMERICA A CORP OF PA
Assigned to SELAS CORPORATION OF AMERICA A CORP. OF PA reassignment SELAS CORPORATION OF AMERICA A CORP. OF PA RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: FIRST PENNSYLVANIA BANK N.V., FOR ITSELF AND AS AGENT FOR THE PHILADELPHIA NATIONAL BANK
Assigned to LINDE AKTIENGESELLSCAFT A CORP. OF GERMANY reassignment LINDE AKTIENGESELLSCAFT A CORP. OF GERMANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SELAS CORPORATON OF AMERICA A CORP. OF PA
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D47/00—Separating dispersed particles from gases, air or vapours by liquid as separating agent
    • B01D47/02—Separating dispersed particles from gases, air or vapours by liquid as separating agent by passing the gas or air or vapour over or through a liquid bath
    • B01D47/021—Separating dispersed particles from gases, air or vapours by liquid as separating agent by passing the gas or air or vapour over or through a liquid bath by bubbling the gas through a liquid bath
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/18—Apparatus
    • C10G9/20—Tube furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/06—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases
    • F23G7/061—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating
    • F23G7/065—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating using gaseous or liquid fuel

Definitions

  • each well has a shroud projecting downward therein so that heads of water can be maintained thereacross to serve as seals against passage of either combustion gases or vented 0fl5 gas through their respective wells or exit via the stack.
  • This disclosure relates to firing carbon monoxide in lean concentrations occurring in ofi gas trom hydrocarbon catalytic cracking units.
  • the invention contemplates a stack and seal pot arrangement especially suited to this service.
  • CO-iring systems must provide not only for the condition when 0f gas is being fired but also for the condition when the COfiring unit is out of service for maintenance.
  • condtion o gas is fed to the CO-firing unit and combustion products are vented to the atmosphere via a stack.
  • the latter conditions calls for bypassing the CO-firing unit by delivering the oi gas directly to the stack.
  • the present advance accommodates both of these conditions in a particularly facile manner by integrating seal pot construction with fabrication of the stacks lower portion. More particularly wells are provded in the lower portion of the stack and a level of water is maintained in each well.
  • a shroud which conducts gas below the level of the water so that a head of water can be maintained across the two sides of the shroud. This head of water serves as a seal against passage of the gas under the shroud.
  • FIGURE I is a schematic illustration of the ofl gas i'iring system here contemplated.
  • FIGURE 11 is an enlarged elevation view in section of the 1ower portion of the stack, and taken along line 2-2 of FIGURE ]I[.
  • FIGURE 111 is taken along line 3-3 of FIGURE II.
  • the firing arrangement set forth herein is not unlike those in common use throughout the petroleum refining industry.
  • feed 1 and exhaust 2 seal pots are open and bypass seal pot 3 is closed so that 0 gas trom catalyst regenerator (not 3,433218 Patented Mar. 18, 1969 shown) is conducted via feed duct 6 to CO-iiring unit 7 wherein it is burned.
  • CO-iiring unit 7 wherein it is burned.
  • air and auxiliary uel are introduced to the burning of gas.
  • Heat is recovered from the products of C0 combustion by means of non-contact heat exchange with a process stream in tube coil 8.
  • Products of combustion exit CO-firing unit 7 via exhaust duet 9. These products pass through exhaust seal pot 2 and leave via interior 11 and top opening 12 of stack 13.
  • Exhaust 2 and bypass 3 seal pots are formed integrally with lower portion 14 of stack 13.
  • Shell 16 lined with refractory 17 cooperates with wall 18 to define exhaust well 19 and bypass well 21 each open te flow communica tion with top opening 12 via interior 11.
  • Each of the wel1s 19 and 21 are suitable for retaining pools of water 22 and 23 therein.
  • Bypass seal pot 3 is closed during normal operation. When open this seal pot allows o gas te bypass CO- firing unit 7 by fiowing via bypass duet 24, through bypass port 26, under bypass shroud 27 and into interior 11 for exit via top opening 12 of stack 13. During normal operation of the system water adrntted via line 28 forms bypass pool 23 defining level 29 which forms a lquid seal against the flow of gases under bypass shroud 27 from bypass duet 24.
  • exhaust seal pot 2 in detail, flow through exhaust duet 9 can be either from COfiring unit 7 through exhaust port 31 under exhaust shroud 32 through interior 11 and out top opening 12 of stack 13 or convcrsely from interior 11 of stack 13 under exhaust shroud 32 through exhaust duct 9 back to CO-firing unit 7.
  • Exhaust seal pot 2 is usually called upon during periods when CO- firing unit 7 is out of service to prevent back flow of off gas from interior 11 of stack 13 to CO-firing unit 7.
  • Toward this objective water is introduced via line 33 to maintain level 34 shown as a dashed line.
  • O gas generally comes from catalyst regenerators at temperatures from 800 to 1100 F. Further, carbon monoxide is quite lethal. S0 when CO-firing unit 7 is to be entered for repair werk, it is necessary that both feed duet 6 and exhaust duet 9 be positively closed. Positive closure is accomplished by means of feed 36 and exhaust '37 guillotine dampers. Feed 1 and exhaust 2 seal pots must generally be closed in order for feed 36 and exhaust 37 guillotine dampers to be moved to their closed positons.
  • a feed seal means operatively connected in the feed duet to accomplish shutting 0 flow of the 0 gas to the CO-firing unit when the CO-firing unit is not in service
  • bypass seal means operatively connected in the bypass duet for allowing the bypassing of 0 gas to the stack when the CO-firing unit is not in service and to preve1it passage of the ofl gas from the catalys t regenerator directly to the stack when the CO-firing unit is in service
  • the stack having a shell with a lower portion
  • a wal! connected across the lower portion of the shell to define an exhaust well and a bypass well each open to flow communication with the top opening and each suitable for. retaining a pool of watertherein,
  • the lower portiorr of the shell defining an exhaust port haust port and havihg an e xhaust lower er r tr t which projects below the exhaustport so that when the level of water in the exhaustwell is above the exhaust lower extenta headpf water may be maintained across the exhaust shroud;
  • bypass seal means including means for introducing water into the bypass well,l
  • bypass shroud connected-tothe shell about the bypassport and having a bypass lower extent which projects below the bypass port so that when the level of water in the bypass well is.above the bypass lower extent a head of water may bemaintained across the bypass shroud 2.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Environmental & Geological Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Incineration Of Waste (AREA)

Description

P. VON WIESENTHAL 3,433218 OFF GAS FIRING SYSTEM Sheet March 18, 1969 Filed July 5, 1964 United States Patent C) Claims ABSTRAC'I OF THE DISCLOSURE A stack and seal pot arrangement for use with a CO- fired furnace and especially suited to vent either combustion gases when the furnace is in operation or C when the furnace is shut down. Two wells are formed in the lower portion of the stack, one connected in flow series between the CO-fired unit and the stack and the other between the supply of o gas and the stack. Levels of water are maintained in each of the wells and each well has a shroud projecting downward therein so that heads of water can be maintained thereacross to serve as seals against passage of either combustion gases or vented 0fl5 gas through their respective wells or exit via the stack.
This disclosure relates to firing carbon monoxide in lean concentrations occurring in ofi gas trom hydrocarbon catalytic cracking units. The invention contemplates a stack and seal pot arrangement especially suited to this service.
Commercial CO-iring systems must provide not only for the condition when 0f gas is being fired but also for the condition when the COfiring unit is out of service for maintenance. In the former condtion o gas is fed to the CO-firing unit and combustion products are vented to the atmosphere via a stack. The latter conditions calls for bypassing the CO-firing unit by delivering the oi gas directly to the stack. The present advance accommodates both of these conditions in a particularly facile manner by integrating seal pot construction with fabrication of the stacks lower portion. More particularly wells are provded in the lower portion of the stack and a level of water is maintained in each well. Associated with each of the wells is a shroud which conducts gas below the level of the water so that a head of water can be maintained across the two sides of the shroud. This head of water serves as a seal against passage of the gas under the shroud.
The present arrangement ofiers increased safety, ruggedness, and economy over comparable systems. CO- firing systems are characterized by high temperatures and velocities as well as wide swings in operating condi tions. Seal pots receive especially sore abuse. Here the seal pots are brought into the formidable structural arrangement found at the lower portion of a stack. Housing the seal pots within the stack adds an extra measure of safety in the event of C0 leakage. Further the compatibility of stack and seal pot structures also give rise to savings.
These and other features will appear more fully from the accompanying drawing wherein:
FIGURE I is a schematic illustration of the ofl gas i'iring system here contemplated.
FIGURE 11 is an enlarged elevation view in section of the 1ower portion of the stack, and taken along line 2-2 of FIGURE ]I[.
FIGURE 111 is taken along line 3-3 of FIGURE II.
In principal, the firing arrangement set forth herein is not unlike those in common use throughout the petroleum refining industry. During normal operation feed 1 and exhaust 2 seal pots are open and bypass seal pot 3 is closed so that 0 gas trom catalyst regenerator (not 3,433218 Patented Mar. 18, 1969 shown) is conducted via feed duct 6 to CO-iiring unit 7 wherein it is burned. Usually air and auxiliary uel are introduced to the burning of gas. Heat is recovered from the products of C0 combustion by means of non-contact heat exchange with a process stream in tube coil 8. Products of combustion exit CO-firing unit 7 via exhaust duet 9. These products pass through exhaust seal pot 2 and leave via interior 11 and top opening 12 of stack 13.
When CO-firing unit 7 is out of service feed 1 and exhaust 2 seal pots are closed to prevent off gas from entering C0firing unit 7 either through feed duet 6 or through exhaust duet 9. Bypass seal pot 3 is open so that 0 gas is shunted to the atmosphere via bypass duet 24, interior 11 and top opening 12 of stack 13.
Exhaust 2 and bypass 3 seal pots are formed integrally with lower portion 14 of stack 13. Shell 16 lined with refractory 17 cooperates with wall 18 to define exhaust well 19 and bypass well 21 each open te flow communica tion with top opening 12 via interior 11. Each of the wel1s 19 and 21 are suitable for retaining pools of water 22 and 23 therein.
Bypass seal pot 3 is closed during normal operation. When open this seal pot allows o gas te bypass CO- firing unit 7 by fiowing via bypass duet 24, through bypass port 26, under bypass shroud 27 and into interior 11 for exit via top opening 12 of stack 13. During normal operation of the system water adrntted via line 28 forms bypass pool 23 defining level 29 which forms a lquid seal against the flow of gases under bypass shroud 27 from bypass duet 24.
Considering exhaust seal pot 2 in detail, flow through exhaust duet 9 can be either from COfiring unit 7 through exhaust port 31 under exhaust shroud 32 through interior 11 and out top opening 12 of stack 13 or convcrsely from interior 11 of stack 13 under exhaust shroud 32 through exhaust duct 9 back to CO-firing unit 7. Exhaust seal pot 2 is usually called upon during periods when CO- firing unit 7 is out of service to prevent back flow of off gas from interior 11 of stack 13 to CO-firing unit 7. Toward this objective water is introduced via line 33 to maintain level 34 shown as a dashed line.
O gas generally comes from catalyst regenerators at temperatures from 800 to 1100 F. Further, carbon monoxide is quite lethal. S0 when CO-firing unit 7 is to be entered for repair werk, it is necessary that both feed duet 6 and exhaust duet 9 be positively closed. Positive closure is accomplished by means of feed 36 and exhaust '37 guillotine dampers. Feed 1 and exhaust 2 seal pots must generally be closed in order for feed 36 and exhaust 37 guillotine dampers to be moved to their closed positons.
It will -be apparent to these skilled in CO-firing systems that wide devations can be made in the details of this disclosure without departing from the main theme of invention as set forth in the claims.
What is claimed is:
1. A system for iiring off gas from the catalyst regenerator of a hydrocarbon catalytic cracking unit and comprising in combination a feed duet which connects in flow series with the catalyst regenerator to receive the off gas therefrom,
a COfiring unit,
the feed duet connected in flow series with the C0- iring unit to deliver the oi gas thereto,
means operatively associated with the CO-firing unit for reeovering heat from combustion products gen erated therein,
a feed seal means operatively connected in the feed duet to accomplish shutting 0 flow of the 0 gas to the CO-firing unit when the CO-firing unit is not in service,
and to allow passage of the oi gasr the eatalyst regenerator to the CO-firing unit when the CO-firng unit is in service,
a stack with a top opening for venting gases to the atmosphere,
an exhaust duet connectng the CO-firing unit to the stack for exhausting the combustion products there to an exhaust seal means operatively connected in the exhaust duet to accom-plish shutting ofi back flow of gases from the stack to the CO-firing unit when the CO-firing unit is not in service and to allow passage of combustion products from the C-firing unit to the stack when the CO-firing unit is in service,
a bypass duet connecting the feed duet upstream of the feed seal means with the stack,
a bypass seal means operatively connected in the bypass duet for allowing the bypassing of 0 gas to the stack when the CO-firing unit is not in service and to preve1it passage of the ofl gas from the catalys t regenerator directly to the stack when the CO-firing unit is in service,
the stack having a shell with a lower portion,
a wal! connected across the lower portion of the shell to define an exhaust well and a bypass well each open to flow communication with the top opening and each suitable for. retaining a pool of watertherein,
the lower portiorr of the shell defining an exhaust port haust port and havihg an e xhaust lower er r tr t which projects below the exhaustport so that when the level of water in the exhaustwell is above the exhaust lower extenta headpf water may be maintained across the exhaust shroud;
the lowerportion of tlie shell dfining a bypass port throug h which it communicaties in flow series with the bypassduct to receive "o gas therefrom,
the bypass seal means including means for introducing water into the bypass well,l
a bypass shroud connected-tothe shell about the bypassport and having a bypass lower extent which projects below the bypass port so that when the level of water in the bypass well is.above the bypass lower extent a head of water may bemaintained across the bypass shroud 2. The systern Ofclaim 1 with a feed guillotine damper operatively connected to the feed duct downstrearn ofthe bypass duct for positively closing the feed duet,
and an exhaust guillotine damper operatively con nected to the exhaust duet for positive closure there- References"lcited UNITED STATES.PATENTS 2,971,605 2/ 1961 Frost et al.
3248,178 4/1966 H( Jskinsoti.. 3,251,656 5/1966 Edwarcls.
J()SEPH SCOVRONEK, Pfz'rndry Eiraminer.
US380139A 1964-07-03 1964-07-03 Off gas firing system Expired - Lifetime US3433218A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US38013964A 1964-07-03 1964-07-03

Publications (1)

Publication Number Publication Date
US3433218A true US3433218A (en) 1969-03-18

Family

ID=23500043

Family Applications (1)

Application Number Title Priority Date Filing Date
US380139A Expired - Lifetime US3433218A (en) 1964-07-03 1964-07-03 Off gas firing system

Country Status (1)

Country Link
US (1) US3433218A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3782302A (en) * 1972-10-12 1974-01-01 I Sigal Method of thermal purification of waste not forming a burning mixture with fuel or air separately
US3828700A (en) * 1972-04-06 1974-08-13 Speichim Process for the smokeless burning of residues, and apparatus therefor
US3917458A (en) * 1972-07-21 1975-11-04 Nicoll Jr Frank S Gas filtration system employing a filtration screen of particulate solids
FR2284090A1 (en) * 1974-09-09 1976-04-02 Zink Co John INSTALLATION FOR RECOVERING COMBUSTIBLE VAPORS FROM A BURNING TORCH
US3984196A (en) * 1974-05-28 1976-10-05 Kurt Zenkner Method and burner for combustion of waste air
US5235804A (en) * 1991-05-15 1993-08-17 United Technologies Corporation Method and system for combusting hydrocarbon fuels with low pollutant emissions by controllably extracting heat from the catalytic oxidation stage
US5318436A (en) * 1991-11-14 1994-06-07 United Technologies Corporation Low NOx combustion piloted by low NOx pilots
US5968320A (en) * 1997-02-07 1999-10-19 Stelco, Inc. Non-recovery coke oven gas combustion system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2971605A (en) * 1957-02-18 1961-02-14 Exxon Research Engineering Co Method and apparatus for flaring combustible gaseous materials
US3248178A (en) * 1964-05-06 1966-04-26 Cornell Hoskinson Mfg Waste products combustion apparatus
US3251656A (en) * 1961-07-13 1966-05-17 Moffitt Co Roy M Fume incineration system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2971605A (en) * 1957-02-18 1961-02-14 Exxon Research Engineering Co Method and apparatus for flaring combustible gaseous materials
US3251656A (en) * 1961-07-13 1966-05-17 Moffitt Co Roy M Fume incineration system
US3248178A (en) * 1964-05-06 1966-04-26 Cornell Hoskinson Mfg Waste products combustion apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3828700A (en) * 1972-04-06 1974-08-13 Speichim Process for the smokeless burning of residues, and apparatus therefor
US3917458A (en) * 1972-07-21 1975-11-04 Nicoll Jr Frank S Gas filtration system employing a filtration screen of particulate solids
US3782302A (en) * 1972-10-12 1974-01-01 I Sigal Method of thermal purification of waste not forming a burning mixture with fuel or air separately
US3984196A (en) * 1974-05-28 1976-10-05 Kurt Zenkner Method and burner for combustion of waste air
FR2284090A1 (en) * 1974-09-09 1976-04-02 Zink Co John INSTALLATION FOR RECOVERING COMBUSTIBLE VAPORS FROM A BURNING TORCH
US5235804A (en) * 1991-05-15 1993-08-17 United Technologies Corporation Method and system for combusting hydrocarbon fuels with low pollutant emissions by controllably extracting heat from the catalytic oxidation stage
US5318436A (en) * 1991-11-14 1994-06-07 United Technologies Corporation Low NOx combustion piloted by low NOx pilots
US5968320A (en) * 1997-02-07 1999-10-19 Stelco, Inc. Non-recovery coke oven gas combustion system

Similar Documents

Publication Publication Date Title
US2447306A (en) Fluid heater
US4650414A (en) Regenerative heat exchanger apparatus and method of operating the same
US3433218A (en) Off gas firing system
US3702308A (en) Process for the utilization of the energy content of the flue gas accrued in catalytic cracking plants
CN85109422A (en) The continuous annealing furnace that is used for metal strip
US3279520A (en) Off gas firing system
US2349439A (en) Contrivance for the heating of gases
CN106501015A (en) A kind of multitubular bundles integrated form radiant tube combustion experimental system and method
KR0131561B1 (en) Industrial furnace provided with rotary regenerative burner
US2514084A (en) Apparatus for supplying heated air to blast furnaces and the like
US2777428A (en) Apparatus
CN104197733B (en) Regenerative cycles device in Gas heating furnace high-temperature burns carbon distribution device and technique
US1246114A (en) Method of operating furnace and oven apparatus with recovery of heat.
US1421155A (en) Tunnel kiln
US3738795A (en) Regenerative hot blast stoves and their operation
US1911831A (en) Method of and apparatus for controlling furnaces
CN106196104B (en) Bed heat reclaiming system is catalytically decomposed in heat accumulating type
KR100541647B1 (en) Incinerator of waste
GB2068517A (en) Preventing smoke generation in coke ovens
GB1489453A (en) Protective gas plant
SU904315A1 (en) Coke dry quenching installation
JPH10168458A (en) Coke dry quenching apparatus
US3003517A (en) Stack arrangement
CN213746789U (en) High-efficient RCO heat accumulation type catalytic oxidation equipment
US1845253A (en) Hot blast stove

Legal Events

Date Code Title Description
AS Assignment

Owner name: FIRST PENNSYLVANIA BANK N A 19TH FL.CENTRE SQ WEST

Free format text: SECURITY INTEREST;ASSIGNOR:SELAS CORPORATION OF AMERICA A CORP OF PA;REEL/FRAME:003997/0981

Effective date: 19820217

AS Assignment

Owner name: SELAS CORPORATION OF AMERICA A CORP. OF PA

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:FIRST PENNSYLVANIA BANK N.V., FOR ITSELF AND AS AGENT FOR THE PHILADELPHIA NATIONAL BANK;REEL/FRAME:004096/0520

Effective date: 19821231

AS Assignment

Owner name: LINDE AKTIENGESELLSCAFT A CORP. OF GERMANY,GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SELAS CORPORATON OF AMERICA A CORP. OF PA;REEL/FRAME:004156/0552

Effective date: 19830523

Owner name: LINDE AKTIENGESELLSCAFT WIESBADEN, GERMANY A CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SELAS CORPORATON OF AMERICA A CORP. OF PA;REEL/FRAME:004156/0552

Effective date: 19830523