Patent GB-1100455-A (GB)
Title: Apparatus for cooling gases by contact with liquids
Inventor: FJALLBORG SIGNAR
IPC: F28C3/06
Filed: 1965-04-26
Abstract: 1,100,455. Automatic temperature control. SVENSKA FL€KTFABRIKEN A. B. April 26, 1965, No. 17554/65. Heading G3R. [Also in Division F4] In a heat exchanger 1 in which a hot gas is cooled by direct contact with water, the water is sprayed into the gas through nozzle assemblies 5, 6, 7, 8 which are selectively operated to regulate the quantity of water in accordance with the temperature of the cooled gas at the gas outlet 3. As shown, the water path comprises a supply conduit 9 which subdivides into two main ducts 10, 11. These in turn each subdivide into two branch ducts 12, 13 and 14, 15 respectively ending in a nozzle assembly 5, 6, 7 or 8. The main ducts 10, 11 are interconnected by a pressure balancing duct 28 and pneumatically actuated control valves 21-27 designed to open at predetermined and differing air pressures are provided in the ducts as shown. The pneumatic system is operated in accordance with electrical impulses from a device 16 which measures the cooled gas temperature at the heat exchange outlet 3. The pneumatic supply to valves 21-26 is further controlled by electromagnetic valves regulated by governing devices 29, 30 in accordance with the coolant water pressure in the ducts 10, 11 downstream of the valves 21, 22. Assuming a flow of hot gas through the heat exchanger to the outlet 3 and that no coolant water is presently being discharged by the nozzle assemblies. The sensing device 16 transmits electrical impulses through the units 17, 48 and 18 to the air line 19 of the pneumatic system which is pressurized through a line 20. The impulses effect firstly gradual opening of the valve 21 and thereafter at differing values the valves 27 and 22. As the valve 21 opens coolant water flows through the line 10 into the ducts 12, 13, whereafter until a predetermined minimum pressure sensed by the device 29 is reached, it passes to a sump via ducts 35, 37 to a sump (not shown). At the predetermined minimum water pressure in the duct 10 the device 29 operates an electromagnetic valve 31 which allows pneumatic operation of the valve 23 to direct the coolant liquid to the nozzle assembly 5. If the gas outlet temperature at 3 continues to rise the valve 21 is opened fully resulting in a rise in water pressure in the duct 10 which causes the device 29 to operate the electromagnetic valve 32 thus permitting pneumatic operation of the valve 25 and consequent flow of coolant to the nozzle assembly 6. Further increases in gas temperature at the outlet 3 cause gradual opening of the valve 27 followed by gradual opening of the valve 22 and subsequent opening of the valves 33 and 34 to permit coolant discharge through the nozzle assemblies 7 and 8 to supplement the delivery through nozzle assemblies 5, 6. Until the valve 22 is fully open, some flow takes place in the duct 28 but when the valves 21 and 22 are fully opened, no flow takes place through the valve 27 and duct 28. A drop in temperature at the gas outlet 3 causes a gradual closing of the valves 21-27 in the reverse sequence. Ducts 41-44 are provided for draining the system if required. 46 and 47 indicate means for manual operation of the pneumatic system when necessary. A predetermined maximum air pressure in the system (e.g. 1 atmosphere) is ensured by reducing valves 45. 38a and 38b are throttling valves in the liquid system to maintain a minimum pressure and 39, 40 are non-return valves. 49 is a means for measuring the quantity of coolant flowing through the inlet duct 9. The device is intended for the cooling-down of gases from an oxygen-fired converter furnace to a temperature suitable for passing them through a cleaning device.