US3741713A - Purge gas admission control for flare system - Google Patents

Purge gas admission control for flare system Download PDF

Info

Publication number
US3741713A
US3741713A US00233536A US3741713DA US3741713A US 3741713 A US3741713 A US 3741713A US 00233536 A US00233536 A US 00233536A US 3741713D A US3741713D A US 3741713DA US 3741713 A US3741713 A US 3741713A
Authority
US
United States
Prior art keywords
flare
stack
temperature
temperature sensing
purge gas
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
US00233536A
Other languages
English (en)
Inventor
R Reed
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.)
KGI Inc
Original Assignee
John Zink Co
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 John Zink Co filed Critical John Zink Co
Application granted granted Critical
Publication of US3741713A publication Critical patent/US3741713A/en
Assigned to KOCH ENGINEERING COMPANY, INC. reassignment KOCH ENGINEERING COMPANY, INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: JOHN ZINK COMPANY
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F23G7/08—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases using flares, e.g. in stacks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G2208/00—Safety aspects
    • F23G2208/10—Preventing or abating fire or explosion, e.g. by purging

Definitions

  • ABSTRACT This invention describes a system for controlling the rate of flow of purge gas through a flare stack system as a function of the temperature of the gases inside of the flare stack.
  • the second factor is temperature change within the system due either tometeorological conditions or due to the flaring of waste gases at significant temperature level.
  • the system volume is approximately 2,400 cubic feet. Assuming such a volume is filled with flare gases at 250 F. during a flaring period, when the discharge of hot gases is stopped, the system would cool to ambient temperature in about minutes.
  • the volume of gases within the flare stack at atmospheric pressure would decrease proportionately to the absolute temperature, to approximately 1,700 cubic feet.
  • air will be drawn into the stack in the amount of 2,400 minus 1,700 or approximately 700 cubic feet. This would cause an air penetration down the stack of approximately 150 feet. Since this column of air would travel for a period of 15 minutes it corresponds to a velocity of 0.15 feet per second.
  • a thirty inch stack would require about 700 cubic feet of purge gas, or to provide a margin of safety, approximately 800 cubic feet, each 15 minutes.
  • the hourly volume would be about 3,200 SCFH.
  • a nominal flow velocity of about 0.03 feet per second is adequate to ensure that air is kept out of the stack at all times.
  • This invention provides means to switch from the large to the small rate of flow of purge gas. A saving of approximately 80 percent in the cost of gas during the 95 percent of the time that the flare system is'ambient. In terms of conventional cost of the purge gas, this would mean savings of $1.00 per hour or more in the cost of the purge gas.
  • the invention further provides thermostatic means for determining the temperature in the flare stack and controlling the flow of purge gas in accordance with the temperature. When the temperature is above ambient, the flow rate is increased. When the temperature again drops back to ambient, the flow rate is decreased.
  • FIG. 1 illustrates a preferred embodiment of the invention.
  • FIGS. 2 and 3 show alternate embodiments.
  • FIGS. 4 and 5 indicate the manner in which the temperature sensing element can be installed in the flare stack.
  • FIGS. 6 and 7 illustrate alternate methods of installation of the temperature sensor.
  • a flow duct through which the flare gases flow to a stack or a flare stack, per se, is indicated by numeral l0 and the direction of flow of the flare gases by the arrow 12. Any form of stack, not shown in these views, may be used such as shown in U. S. Pat. Nos. 2,779,399 and 3,134,424.
  • a temperature sensor 14 is v inserted through the wall of the duct, which can be a pipe leading to the vertical stack, or can be the stack itself. Assuming that the temperature sensor 14 is a thermocouple, this is then connected by leads 13 to a relay 16 with operating coil 17 and relay switch 18.
  • a power supply 20 is provided which is connected to a solenoid coil 22 of a valve 24 through the relay switch 18.
  • relay switch 18 closes, the power is applied to the solenoid coil 22, which opens the valve 24 and allows purge gas flow from supply line 26 through pipe 27, through valve 24 and pipe 32 into the duct 10, which is downstream from the temperature sensor 14 to prevent a counter cooling effect of the purge gas.
  • Purge gas' is also continuously supplied through pipe 26 to pipe 28 through valve or metering means 30 at the minimum flow requirement, e.g. 0.03 feet per second.
  • the flow rate through pipe 27 is set byconventional means such as valve or orifice, to the maximum flow rate desired, less that being supplied by pipe 28. For example, 0.15
  • FIG. 2 illustrates a variation of the system of FIG. 1 in which a capillary system is used for the temperature measuring and actuating system.
  • Capillary systems are available on the market as operating control systems, and generally involve' a bulb 42 filled with suitable liquid such as mercury, glycol, oil, etc. When the bulb is heated the liquid expands and creates a pressure in the valve control box 40. This pressure is sufflcient to operate the valve and open it. When the temperature drops, the pressure in the capillary system falls, and the valve is allowed to close, shutting off the flow of extra purge gas.
  • FIG. 3 illustrates a second variation of FIG. 1 in which the temperature sensing element is a bimetallic switch 46.
  • FIGS. 1, 2 and 3 the sensing element is shown as being inserted through the sidewall of the duct.
  • FIGS. 4 and 5 illustrate a specific means to accomplish this.
  • the instrument may be a part of a section of vertical stack section 58 joined by welding or by flanges 59 and 60 into the duct or stack.
  • a shielding area comprised of a set of two or more concentric tubes 62, 64 and 66 which are coaxial with the shell and retained to the wall 58 by bracket means 65 and 67.
  • An opening 68' is provided through the wall 58 and through the pipes 64 so that the temperature sensor 14 can be inserted from the outside.
  • a mounting nipple 61 is provided to come niently support the sensing element. This can be either a thermometer of the bimetallic-type, thermocouple, capillary device, or other similar means.
  • FIGS. 4 and 5 represent a modified velocity thermocouple and provides a sensitive installation which is in direct contact with the gases inside of the stack. It is possible as shown in FIG. 6, as is well known, to insert a thermometer well through the sidewall of the stack into which the temperature sensor 46 is inserted. This provides protection for the temperature sensor. Another method is illustrated in FIG. 7
  • the temperature sensor 46 is mounted on the outside wall of the stack or duct 10 and thus is protected from the corrosive gases inside the stack.
  • sample valves chosen for sizes of stack and flow rates of purge gas, etc. which were given above, are only by way of example and any desired temperature settings can be chosen for the control of the high and low flow rates of the purge gases.
  • Purge gases are preferably that gas or mixture of gases which cannot reach dewpoint at any ambient temperature.
  • flare stack system includes the 5 waste gas supply conduit or duct and a flare stack receiving such waste gas.
  • thermosensor means in the flare stack sys tem to determine the temperature of the gases therein; b. means to flow purge gas through said system downstream of said temperature sensing means;
  • c. means responsive to said temperature sensing means for controlling the rate of flow of said purge gas, between at least a low and a high rate of flow as a function of said temperature.
  • thermocouple means thermocouple means, and including relay means controlled by said thermocouple means.
  • the flare system as in claim 1 including short cylindrical pipe means supported axially in said stack, and means to position said temperature sensor inside said pipe means.
  • thermowell which passes through the sidewall of said stack.
  • a flare system of claim 1 the further improvement of means surrounding said temperature sensing 0 device to avoid heat loss therefrom by radiation to cooler duct walls.

Landscapes

  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Incineration Of Waste (AREA)
  • Gas Burners (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Treating Waste Gases (AREA)
  • Chimneys And Flues (AREA)
US00233536A 1972-03-10 1972-03-10 Purge gas admission control for flare system Expired - Lifetime US3741713A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US23353672A 1972-03-10 1972-03-10

Publications (1)

Publication Number Publication Date
US3741713A true US3741713A (en) 1973-06-26

Family

ID=22877642

Family Applications (1)

Application Number Title Priority Date Filing Date
US00233536A Expired - Lifetime US3741713A (en) 1972-03-10 1972-03-10 Purge gas admission control for flare system

Country Status (6)

Country Link
US (1) US3741713A (enrdf_load_stackoverflow)
JP (1) JPS5215135B2 (enrdf_load_stackoverflow)
CA (1) CA968952A (enrdf_load_stackoverflow)
FR (1) FR2176375A5 (enrdf_load_stackoverflow)
GB (1) GB1413046A (enrdf_load_stackoverflow)
IT (1) IT979762B (enrdf_load_stackoverflow)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838974A (en) * 1972-07-24 1974-10-01 Midland Ross Corp Rich fume incinerator
US3872666A (en) * 1972-10-04 1975-03-25 Questor Corp Method, system and apparatus for controlling temperatures of exhaust gases in emission control systems
US3898317A (en) * 1972-07-24 1975-08-05 Midland Ross Corp Method for incinerating flue gases
US3914088A (en) * 1974-10-24 1975-10-21 Roberts Appliance Corp Gordon Apparatus for, and method of, oxidizing a gaseous mixture containing a combustible component
US3915620A (en) * 1974-09-09 1975-10-28 Zink Co John Flare system vapor recovery
DE2537351A1 (de) * 1974-08-30 1976-03-11 Zink Co John Steuersystem fuer fackelanlagen zum abfackeln von abgasen
DE2365819A1 (de) * 1973-10-12 1976-07-22 Zink Co John Spuelverfahren fuer eine brenneranordnung
US3994663A (en) * 1975-11-28 1976-11-30 John Zink Company Method and apparatus to prevent air flow inversion in flare stacks
US4015927A (en) * 1973-11-08 1977-04-05 Aero-Dyne Manufacturing, Inc. Automatic high-low burner operation
DE2351418C3 (de) 1973-10-12 1977-12-01 Ausscheidung in: 23 65 819 John Zink Co, Tulsa, OkIa. (V.StA.) Vorrichtung zur Verbrennung von veränderlichen Abgasmengen
US4120638A (en) * 1977-07-15 1978-10-17 Combustion Unlimited Incorporated Ignition system for flares
FR2398260A1 (fr) * 1977-07-21 1979-02-16 Zink Co John Joint moleculaire, notamment pour torches de brulage de gaz residuaires
US4265611A (en) * 1979-03-15 1981-05-05 John Zink Company Control system for purge gas to flare
US4559006A (en) * 1984-06-22 1985-12-17 Mcgill Incorporated Purging process
US4634369A (en) * 1984-06-22 1987-01-06 Mcgill Incorporated Purging process
US5829964A (en) * 1997-06-16 1998-11-03 Pegasus International Inc. Flare line gas purge system
DE102009017025B3 (de) * 2009-04-14 2010-09-16 EVZA Energie- und Verwertungszentrale GmbH, Anhalt Verfahren zur verbesserten Abtrennung von Quecksilber aus Rauchgasen, insbesondere aus Rauchgasen fossil gefeuerter Kraftwerke, Kohle- oder Müllverbrennungsanlagen

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54121099A (en) * 1978-03-13 1979-09-19 Sanyo Electric Co Ltd Method and device for fault display of apparatus
JPS62169240A (ja) * 1986-01-22 1987-07-25 Fujitsu Ltd 異常情報表示方式
JP4887236B2 (ja) * 2007-08-08 2012-02-29 日立マクセル株式会社 磁気テープ用リール、それを用いたテープカートリッジ、当該テープカートリッジに情報を記録再生するための記録再生装置、およびその情報記録再生方法、並びに位置決め機構

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2779399A (en) * 1952-02-29 1957-01-29 Zink Co John Flare stack gas burner
US3658482A (en) * 1970-09-08 1972-04-25 College Research Corp Afterburner
US3667408A (en) * 1970-08-04 1972-06-06 Polymer Corp Flare stack

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2779399A (en) * 1952-02-29 1957-01-29 Zink Co John Flare stack gas burner
US3667408A (en) * 1970-08-04 1972-06-06 Polymer Corp Flare stack
US3658482A (en) * 1970-09-08 1972-04-25 College Research Corp Afterburner

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3898317A (en) * 1972-07-24 1975-08-05 Midland Ross Corp Method for incinerating flue gases
US3838974A (en) * 1972-07-24 1974-10-01 Midland Ross Corp Rich fume incinerator
US3872666A (en) * 1972-10-04 1975-03-25 Questor Corp Method, system and apparatus for controlling temperatures of exhaust gases in emission control systems
DE2351418C3 (de) 1973-10-12 1977-12-01 Ausscheidung in: 23 65 819 John Zink Co, Tulsa, OkIa. (V.StA.) Vorrichtung zur Verbrennung von veränderlichen Abgasmengen
DE2365819A1 (de) * 1973-10-12 1976-07-22 Zink Co John Spuelverfahren fuer eine brenneranordnung
US4015927A (en) * 1973-11-08 1977-04-05 Aero-Dyne Manufacturing, Inc. Automatic high-low burner operation
DE2537351A1 (de) * 1974-08-30 1976-03-11 Zink Co John Steuersystem fuer fackelanlagen zum abfackeln von abgasen
US3915620A (en) * 1974-09-09 1975-10-28 Zink Co John Flare system vapor recovery
US3914088A (en) * 1974-10-24 1975-10-21 Roberts Appliance Corp Gordon Apparatus for, and method of, oxidizing a gaseous mixture containing a combustible component
US3994663A (en) * 1975-11-28 1976-11-30 John Zink Company Method and apparatus to prevent air flow inversion in flare stacks
US4120638A (en) * 1977-07-15 1978-10-17 Combustion Unlimited Incorporated Ignition system for flares
FR2398260A1 (fr) * 1977-07-21 1979-02-16 Zink Co John Joint moleculaire, notamment pour torches de brulage de gaz residuaires
US4265611A (en) * 1979-03-15 1981-05-05 John Zink Company Control system for purge gas to flare
US4559006A (en) * 1984-06-22 1985-12-17 Mcgill Incorporated Purging process
WO1986000392A1 (en) * 1984-06-22 1986-01-16 Mcgill Incorporated Purging process
US4634369A (en) * 1984-06-22 1987-01-06 Mcgill Incorporated Purging process
US5829964A (en) * 1997-06-16 1998-11-03 Pegasus International Inc. Flare line gas purge system
DE102009017025B3 (de) * 2009-04-14 2010-09-16 EVZA Energie- und Verwertungszentrale GmbH, Anhalt Verfahren zur verbesserten Abtrennung von Quecksilber aus Rauchgasen, insbesondere aus Rauchgasen fossil gefeuerter Kraftwerke, Kohle- oder Müllverbrennungsanlagen

Also Published As

Publication number Publication date
GB1413046A (en) 1975-11-05
FR2176375A5 (enrdf_load_stackoverflow) 1973-10-26
JPS5215135B2 (enrdf_load_stackoverflow) 1977-04-27
IT979762B (it) 1974-09-30
JPS48101633A (enrdf_load_stackoverflow) 1973-12-21
CA968952A (en) 1975-06-10
DE2311857B2 (de) 1976-04-29
DE2311857A1 (de) 1973-09-13

Similar Documents

Publication Publication Date Title
US3741713A (en) Purge gas admission control for flare system
US4101257A (en) Pilot gas conservation system for flare stacks
US3901643A (en) Temperature-pressure activated purge gas flow system for flares
US4708636A (en) Flow sensor furnace control
US4139339A (en) Flare gas stack with purge control
US2335471A (en) Fluid fuel burner control system
US4856982A (en) Apparatus for exhausting combustion gases from a gas water heater
US2216809A (en) Heater and thermo control therefor
US2417049A (en) Control system
US5636598A (en) Induced draft combustion water heater
US3308871A (en) Pilot burner means or the like
US2130491A (en) Draft control system
US3994663A (en) Method and apparatus to prevent air flow inversion in flare stacks
US2457378A (en) Gas control valve
US3344835A (en) Pilotless automatic ignition apparatus
US2585882A (en) Danger detecting means for gas distributing systems
US1689935A (en) Water heater
US2502345A (en) Heater
US1905414A (en) Pilot light controlled safety valve
US3042110A (en) Top surface burner for gas range
US1975656A (en) Valve mechanism
US2295455A (en) Control system
US3354931A (en) Carbon dioxide detecting safety device for apparatus operating through catalysis of gaseous hydrocarbons
US2098912A (en) Control device for heating systems
US2722945A (en) Safety devices for gas systems

Legal Events

Date Code Title Description
AS Assignment

Owner name: KOCH ENGINEERING COMPANY, INC., KANSAS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:JOHN ZINK COMPANY;REEL/FRAME:005249/0775

Effective date: 19891004