Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/12—Casings; Linings; Walls; Roofs incorporating cooling arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D9/00—Cooling of furnaces or of charges therein
  • F27D2009/0002—Cooling of furnaces
  • F27D2009/0005—Cooling of furnaces the cooling medium being a gas
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D9/00—Cooling of furnaces or of charges therein

Definitions

• the invention relates to metallurgy and to the field of processing of solid industrial and household waste. They can also be used in the energy sector for burning or gasifying coal with a high ash content on a layer of molten slag.
• the high temperature in the working space of the melting chambers makes it necessary to protect the walls of their metal casing with refractory lining.
• the refractory lining is gradually destroyed (worn out) as a result of exposure to high temperature, chemical corrosion and mechanical erosion of the refractory material. Therefore, the melting chamber cannot operate continuously, and is periodically stopped for cold repair of the lining. This reduces productivity and affects the technical and economic performance of the melting chamber.
• the period of continuous operation of the melting chamber can be significantly increased by providing the conditions for the formation of a skull (refractory conglomerate consisting of sintered charge materials, refractory lining, slag, dust, etc.) on the inner surface of the walls of the metal body of the melting chamber
• steam "plugs" may be formed that impair the cooling of the casing and lead to the destruction of the casing wall;
• a known method of cooling the case of the melting unit includes the supply of liquid metal coolant - sodium to the body of the melting chamber, made in the form of a double-walled metal shell with a sealed cavity, cooling the liquid metal coolant with a cold gaseous coolant passing through a heat exchanger.
• Cold gaseous coolant is fed into the cavity formed by the outer wall of the casing of the melting chamber, and the outer shell of the heat exchanger, located directly on the casing of the melting chamber, and containing at the ends of the pipe for supplying cold and selection of the heated gaseous coolant.
• the cold gaseous heat carrier is swirled in the cavity of the heat exchanger and is fed first to the parts of the heat exchanger adjacent to the sections of the casing of the melting chamber with the highest thermal loads, and then to the parts of the heat exchanger adjacent to the sections of the casing of the melting chamber with lower thermal loads.
• the known melting unit comprises a melting chamber with a metal body made in the form of a double-walled metal shell with an airtight cavity filled with a liquid metal coolant - sodium, a heat exchanger for cooling the liquid metal coolant with a gaseous coolant, a refractory lining of the molten metal bath, a loading device, a heating device, and melting charge for metal and slag, removal and purification of furnace gases and utilization of their heat.
• a heat exchanger for cooling the liquid metal coolant with a gaseous coolant is located directly on the body of the melting chamber, its outer shell is located at a distance of 50-300 mm in diameter from the outer wall of the melting chamber and is made in the form of a sealed metal cylinder or part thereof with pipes for supplying cold and selection of heated gaseous coolant covering the melting chamber.
• the outer wall of the chamber serves as the inner shell of the heat exchanger, while curved copper strips are fixed at a distance of 3-300 mm from each other in the cavity between the outer wall of the melting chamber and the outer shell of the heat exchanger on the outer wall of the melting chamber.
• the known method of cooling the casing of the melting unit and the unit for its implementation “have the following disadvantages: - there is a supercooling of the lower part of the bath of the metal melt, the formation of a layer of solidified metal on the refractory lining of the metal bath, a decrease in the volume of the metal bath, difficulties in opening the metal gap when the metal is drained from the melting chamber due to intensive cooling of the entire inner wall of the body of the melting chamber with a liquid metal coolant;
• the task of the invention is to increase the efficiency of the method and the melting unit for its implementation.
• the technical result of the method of cooling the casing of the melting unit and the melting unit for its implementation is to increase productivity and efficiency due to:
• the liquid metal coolant is cooled the upper part of the sealed cavity formed by a double-walled metal shell the melting chamber, by feeding a liquid metal coolant into a cavity covering the free space, the slag bath and the upper part of the lined metal bath, and the lower part of the sealed cavity formed by the double-walled metal shell of the body, separated from the upper part and covering the lower part of the lined metal bath, is cooled only gaseous coolant supplied through nozzles placed on the side surface of the outer wall of the heat exchanger, heated gaseous the heat carrier is taken from the heat exchanger through nozzles located on the side surface of the outer wall of the heat exchanger, the temperature of the liquid metal coolant is
• the gaseous coolant is fed into the cavity formed by the outer wall of the housing of the melting chamber and the outer wall of the heat exchanger.
• the temperature of the liquid metal coolant is maintained within 450-500 ° C.
• Sodium can be used as a liquid metal coolant.
• Lead may be used as the liquid metal coolant.
• a liquid metal coolant a lead-bismuth alloy can be used.
• Air can be used as the gaseous heat carrier.
• Nitrogen can be used as the gaseous heat carrier.
• the gaseous heat carrier heated in the heat exchanger is used for injecting injectors into the melt located in the melting chamber of finely divided charge materials and dust trapped by gas cleaning.
• the gaseous coolant heated in the heat exchanger is mixed with the gases having a temperature of 1600-1800 ° C leaving the melting chamber or charge heater.
• the air heated in the heat exchanger is used for afterburning CO and H 2 present in the composition of the gas mixture leaving the melting chamber or heater.
• a melting unit containing a melting chamber with a metal casing in the form of a double-walled metal shell with a sealed cavity filled with a liquid metal coolant, a heat exchanger for cooling the liquid metal coolant with a gaseous coolant, a refractory lining molten metal baths, charge loading, heating and melting devices, separate outlets for metal and slag, removal and purification of furnace gases and utilization of their heat
• the upper part of the sealed cavity formed by the double-walled metal shell of the melting chamber body and filled with a liquid metal coolant in the area of free space, the slag bath and the upper part of the metal bath is separated by a partition from the bottom of the same cavity, filled with gaseous heat
• the outer wall of the lower part of the double-walled metal shell of the melting chamber housing has openings for supplying and selecting gaseous heat carrier from the secondary cooling system of the liquid metal coolant, pipes for supplying cold gaseous coolant to
• the diameter of the holes in the lower part of the outer wall of the metal shell of the housing may be 30-50 mm.
• the holes in the lower part of the outer wall of the metal shell of the housing can be located at a distance of 150-200 mm from each other.
• the cavity in the housing of the melting chamber for the liquid metal coolant may be filled with sodium.
• the cavity for the liquid metal coolant in the housing of the melting chamber may be filled with lead.
• the cavity for the liquid metal coolant in the body of the melting chamber may be filled with a lead-bismuth alloy.
• Combined fuel and oxygen tuyeres are located in the side and end walls of the body of the melting chamber.
• Holes for the release of metal and slag are located in the end walls of the body of the melting chamber.
• curved strips of aluminum or aluminum alloy are fixed at a distance from each other on the outer wall of the melting chamber.
• the cooling of the upper part of the sealed cavity formed by the double-walled metal shell of the body of the melting chamber is carried out by feeding a liquid metal coolant into the cavity, covering the free space, the slag bath and the upper part of the lined metal bath, which provides intensive heat removal only from that part internal working walls of the case, which are subjected to the greatest thermal loads, and guarantees the formation of garnishes on them soot.
• the skull protects the internal working walls of the housing and reduces the heat loss of the chamber, ensuring the efficiency of the method.
• the lower part of the sealed cavity formed by a double-walled metal shell of the housing and separated from its upper part, covering the lower part of the lined metal bath, is cooled only by gaseous heat carrier.
• the heat from the lower part of the metal bath is less intensively removed, the metal in it does not cool down, the difficulties with opening the metal notch and draining the metal from the melting chamber are excluded, the lining service life is increased, a long continuous process of melting and processing of various charge materials is carried out without stopping the melting unit, those. achieved increased productivity of the method and efficiency.
• the supply of cold gaseous coolant into the cavity formed by the outer wall of the melting chamber body and the outer wall of the heat exchanger, and the selection of heated gaseous coolant from the cavity through the nozzles located on the side surface of the outer wall of the heat exchanger, allows you to free the end walls of the melting chamber and place combined fuel and oxygen burners in them lances to ensure a more uniform and faster melting of the charge, and tap holes for the release of metal and slag, which increases production telnost and economical fashion.
• Adjusting the flow rate of gaseous cold coolant passing through the heat exchanger allows you to save energy by reducing the flow of gaseous coolant while lowering the temperature of the liquid metal coolant to 450 ° C and lower, and to avoid destruction of the skull or reducing the thickness of its layer, and increasing the consumption of gaseous coolant with increasing temperature up to 500 ° C.
• sodium as a liquid metal coolant allows intensive heat removal from the cooled internal surfaces of the melting chamber.
• Sodium has high thermal conductivity and heat capacity, low melting point and high boiling point (900 ° C). But the use of sodium requires a high culture and technological discipline of production and careful maintenance of the cooling system.
• lead as a liquid metal coolant greatly simplifies the transportation of the coolant, simplifies and facilitates the maintenance of the cooling system of the melting unit, does not require a very high technological discipline and production culture.
• lead has lower thermal conductivity and heat capacity, and a higher melting point than sodium.
• lead-bismuth alloy as a liquid metal coolant allows you to realize the same advantages as when using lead, and has the same disadvantages as using lead.
• the lead-bismuth alloy has a lower melting point, which is more convenient than when using lead.
• nitrogen as a gaseous coolant can reduce the fire hazard of the cooling system of the melting chamber case during the initial cooling of the case with sodium, since in case of leakage from the cooling cavity it will not be oxidized in a nitrogen atmosphere.
• a partition separates the upper part of the sealed cavity formed by the double-walled metal shell of the melting chamber body and filled with liquid metal coolant in the free space region, the slag bath and the upper part of the metal bath, and the lower part of the same cavity filled with gaseous coolant in the lower part of the lined metal bathtubs, allows to increase productivity and profitability.
• the supply of gaseous coolant into the cavity of the lower part of the double-walled shell of the housing of the melting chamber allows less intensive cooling of the refractory lining of the metal bath, to increase the service life of the lining, without overcooling the metal in the bath.
• the location of the nozzles for supplying a cold gaseous coolant to a heat exchanger located on the body of the melting chamber for cooling the liquid metal coolant and selecting from it a heated gaseous coolant on the side the surface of the outer wall of the heat exchanger allows you to free the end walls of the melting chamber and place the combined fuel-oxygen burner-tuyeres and slots for the release of metal and slag.
• the installation of the temperature recording liquid metal coolant device in the upper part of the housing of the melting chamber, in the cavity of the body filled with liquid metal coolant, allows you to register the highest temperature of the liquid metal coolant (450-500 ° C) in the melting chamber. This temperature determines the required flow rate of the cold gaseous heat carrier in the heat exchanger for cooling the liquid metal coolant.
• the connection of the recording device with the automatic process control system or the operator of the melting chamber allows you to quickly adjust the flow of cold gaseous coolant in the heat exchanger. Regulation of the flow of gaseous coolant depending on the maximum temperature of the liquid metal coolant allows to reduce energy consumption and increase the stability of the skull layer on the wall of the melting chamber.
• the location of the holes (let) for the release of metal and slag in the end walls of the melting chamber allows you to separate the flows of metal and slag, improve the organization of production, increase the productivity of the melting unit.
• FIG. 1 shows a longitudinal section of a melting unit with a heat exchanger assembly.
• FIG. 2 is a cross-sectional view of a melting unit with a heat exchanger assembly.
• FIG. 3 shows a top view of a melting unit with a heat exchanger assembly.
• the method of cooling the case of the melting unit includes supplying an intermediate liquid metal coolant to the upper part of the sealed cavity 10 formed by a double-walled metal shell of the body of the melting chamber 20 with the outer wall 8 and the inner wall 9.
• the liquid metal coolant is fed into the cavity 10, which covers the free space 3, the slag bath 2 and the upper part of the lined metal bath 1 of the melting chamber 20.
• the intermediate liquid metal coolant is cooled in a heat exchanger 21, azmeschennom directly on the housing of the melting chamber 20, cold coolant gas.
• the lower part of the sealed cavity formed by the double-walled metal shell of the casing of the melting chamber 20, covering the lower part 7 of the metal bath 1, is cooled only with cold gaseous coolant.
• Cold gaseous heat carrier is fed into the cavity 7, formed by the outer wall 8 of the housing of the melting chamber 20 and the outer wall 4 of the heat exchanger 21, through a pipe 17 located on the side surface of the outer wall 4 of the heat exchanger 21.
• the heated gaseous heat carrier is taken from the heat exchanger 21 through the pipe 18 located on the side surface of the outer wall 4 of the heat exchanger 21.
• the temperature of the liquid metal coolant is maintained within 450-500 ° C, automatically or manually changing the flow rate of cold gaseous heat transfer fluid passing through the heat exchanger 21, depending on the readings of the device 12, fixing the temperature of the liquid metal coolant in the upper part 10 of the cavity of the housing of the melting chamber 20.
• Sodium, lead, or a lead-bismuth alloy can be used as the liquid metal coolant.
• Air or nitrogen may be used as the gaseous heat carrier.
• the gaseous coolant heated in the heat exchanger 21 is used for injection by injectors (not shown in the figures) into the melt in the melting chamber 20, finely divided charge materials and dust captured by gas cleaning (not shown in the figures).
• the gaseous heat carrier heated in the heat exchanger 21 is mixed with the gases having a temperature of 1600-1800 ° C leaving the melting chamber 20 or the charge heater, reducing the temperature of the exhaust gases and reducing the buildup of dust on the walls of the recovery boiler (not shown in the figures), in which the gases are used to generate steam.
• the air heated in the heat exchanger is used for afterburning of CO and H 2 present in the composition of the gas mixture leaving the melting chamber or heater, increasing the degree of utilization of the heat produced in the melting chamber 20.
• the melting unit for implementing the method comprises a melting chamber 20 with a metal body made in the cooling zone in the form of a double-walled metal shell, a heat exchanger 21 for cooling the primary liquid metal coolant, covering the body of the melting chamber 20, charging, heating and melting devices of the charge (not shown in the figures) , removal, purification of gases leaving the melting chamber and utilization of their heat (not shown in the figures).
• the body of the melting chamber 20 is made in the form of a double-walled (wall 8, 9) metal shell.
• the upper part of the sealed cavity formed by the double-walled metal shell 10 is filled with a liquid metal coolant and covers only the free space 3, the slag bath 2 and the upper part of the metal bath 1 of the melting chamber 20.
• the lower part of the cavity 7 formed by the double-walled metal shell of the melting chamber 20 is separated from the upper part 10 of the cavity by a partition 19.
• the outer wall of the lower part of the double-walled metal shell of the casing of the melting chamber has holes with a diameter of 30-50 cm (in Fig.
• a device 12 In the upper part of the casing of the melting chamber 20 and in the upper cavity of the casing filled with the liquid metal coolant, a device 12 is detected that records the temperature of the liquid metal coolant associated with an automatic process control system or the operator of the melting chamber that adjusts the flow rate of the gaseous coolant in the heat exchanger.
• the cavity in the housing of the melting chamber for the liquid metal coolant is filled with sodium or lead or a lead-bismuth alloy.
• Combined fuel-oxygen burner tuyeres 1 1 are located in the side and end walls of the housing of the melting chamber 20.
• the hole 5 for the release of metal and the hole 14 for the release of slag, the groove 6 for draining the metal and the groove 15 for draining the slag are located in the end walls of the housing of the melting chamber 20.
• a bath of molten molten metal 1 is lined with refractory bricks 16, for example, fused periclase bricks.
• the method of cooling the housing of the melting unit and the unit for its implementation are as follows.
• the housing of the melting chamber 20 is heated by turning on the combined fuel-oxygen burner tuyeres 11 for reduced power.
• the walls 8, 9 of the case are heated to a temperature of 200-250 ° C, the liquid metal coolant is heated in a reserve tank with a special heating system and the liquid metal coolant is pumped into the upper part of the cavity 10 between the walls 8, 9 of the case the melting chamber 20.
• the power introduced into the melting chamber 20 by the combined lance burners 11 is increased, and cold gaseous heat carrier is supplied to the heat exchanger 21 for cooling the liquid metal coolant.
• a fusible metal mixture for example, cast iron shavings
• the metal bath 1 is filled with molten metal to protect the refractory lining 16 from the aggressive effects of molten slag.
• the exhaust gases (not shown conventionally) start loading the standard batch at the required speed, and the melting chamber 20 then operates continuously.
• the slag bath 2 open the slag notch 14, and over the slurry 15, the excess amount of slag is poured into the slag ladle or into the slag granulation unit.
• the slag discharge rate is maintained such that during continuous or periodic loading of the charge, the level of slag melt in the melting chamber changes insignificantly or remains constant.
• the metal melt accumulating in the metal bath 1 is periodically drained from the melting chamber 20 through a metal groove 5 along the lined groove 6 into the casting ladle so that the level of the metal melt does not decrease by more than 150-250 mm.
• the proposed invention makes it possible to carry out a long continuous process of melting and processing various charge materials without stopping the melting chamber for repairing the lining, and to reduce operating costs when using the melting chamber.
• Patent RU 2067273 "Method for cooling a melting furnace and a melting furnace for its implementation.”
• Patent RU2383837 “Method for cooling the body of the melting unit and the melting unit for its implementation.”

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Vertical, Hearth, Or Arc Furnaces (AREA)
• Manufacture And Refinement Of Metals (AREA)

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• 2013
  • 2013-02-21 EP EP13876077.2A patent/EP2960608A4/de not_active Withdrawn
  • 2013-02-21 WO PCT/RU2013/000138 patent/WO2014129921A1/ru active Application Filing
  • 2013-02-21 RU RU2014129686A patent/RU2617071C2/ru not_active IP Right Cessation

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