Device of totally-closed submerged arc furnace preheating kiln and working method

Abstract

The device comprises the preheating kiln, the preheating kiln comprises a material cup, a material mixing and weighing system is installed outside the material cup, a hydraulic jack is connected to the interior of the material cup and used for controlling opening and closing of the material cup, a trouser leg stock bin is tightly connected to the inner wall of the bottom end of the material cup, and the trouser leg stock bin is connected with the trouser leg stock bin. A trouser leg stock bin is arranged in the preheating kiln, a plurality of outlets of the trouser leg stock bin are connected with preheating chambers correspondingly, the multiple preheating chambers surround the periphery of the preheating kiln at equal intervals, the top of each preheating chamber is provided with an extraction opening and a thermocouple, and the thermocouples are used for measuring the flue gas temperature of the outlets of the preheating chambers. According to the device of the totally-closed submerged arc furnace preheating kiln and the working method, raw coke oven gas generated by the submerged arc furnace can be used for preheating ore, energy needed by temperature rise of the ore in the submerged arc furnace is saved, smelting power consumption is reduced, energy is saved, production efficiency is improved, and meanwhile it can be guaranteed that smoke is sealed and does not leak.

Description

Technical Field

[0001] The present invention relates to the technical field of ore-bearing furnace smelting, and in particular to a device and a working method for a fully enclosed ore-bearing furnace preheating kiln. Background Art

[0002] Submerged arc furnaces are primarily used for the reduction and smelting of ore, primarily producing ferroalloys such as silicon-manganese, ferromanganese, ferrochrome, and ferrosilicon. They are crucial equipment in the metallurgical industry. Submerged arc furnace smelting is a highly energy-intensive industry, with energy consumption accounting for one-third of production costs. Smelting in submerged arc furnaces accounts for the largest share of electricity consumption. Therefore, reducing energy consumption during the submerged arc furnace smelting process is of great significance and urgent importance.

[0003] CO can account for 60%-80% of the flue gas from a fully enclosed submerged arc furnace, which has high physical sensible heat and chemical energy. Currently, the main energy-saving method is to recover the waste heat from the flue gas. Therefore, the existing preheating kiln for submerged arc furnaces has the following drawbacks:

[0004] Drawbacks of existing submerged arc furnace preheating kilns: Application No. 201910042986.1 discloses a raw material preheating device and method. These devices can both stably preheat raw materials to high temperatures and reduce smelting power consumption. However, due to their use of a rotating distribution device, there is a risk of CO leakage from the preheating kiln top, potentially causing safety hazards.

[0005] Therefore, in order to solve the above problems, we propose a new device and working method for preheating kiln of submerged arc furnace. Summary of the Invention

[0006] The present invention discloses a device and a working method for a fully enclosed submerged arc furnace preheating kiln, aiming to solve the technical problem of CO leakage from the top of the preheating kiln, which causes safety risks.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A fully enclosed ore-fired furnace preheating kiln device includes a preheating kiln, the preheating kiln includes a material cup, a mixing weighing system is installed on the outside of the material cup, and a hydraulic top is connected to the inside of the material cup, the hydraulic top is used to control the opening and closing of the material cup, the bottom inner wall of the material cup is tightly connected to a trouser leg material bin, and multiple outlets of the trouser leg material bin are respectively connected to preheating chambers, multiple preheating chambers are provided, and multiple preheating chambers are equidistantly around the periphery of the preheating kiln, and each preheating chamber is provided with an exhaust port on the top and a thermocouple, and the thermocouple is used to measure the outlet flue gas temperature of the preheating chamber, a gate valve is respectively provided at the outlet of each trouser leg silo, and each trouser leg silo and each preheating chamber are provided with a radar level meter, the gate valve independently controls the feed amount of the preheating chamber, and the opening and closing of the gate valve is controlled by the radar level meter, the bottom inner wall of each preheating chamber is respectively connected with a discharge pipe, the bottom of the preheating kiln is provided with an annular smoke and air channel, and the outlet of the annular smoke and air channel is provided with a hanging plate smoke hood.

[0009] The ore-heating furnace is mainly used for reducing and smelting ores, and mainly produces ferroalloys such as silicon-manganese alloy, ferromanganese, ferrochrome, and ferrosilicon. It is an important production equipment in the metallurgical industry. By setting a preheating kiln, the raw coal gas generated by the ore-heating furnace is used to burn and generate high-temperature flue gas, which is introduced into the preheating kiln to preheat the ore, saving the energy required for heating the ore in the ore-heating furnace, reducing smelting power consumption, saving energy, and improving production efficiency. During the process, the opening and closing of the material cup and the gate valve can be automatically controlled according to the signals sent by the radar level meter in the trouser leg material bin and the preheating chamber, and the material cup and the gate valve can be interlocked to ensure that the flue gas is sealed and does not leak during the feeding process. The problems existing in the existing annular smoke and air duct include: the ore in the preheating chamber can easily enter the annular smoke and air duct and cause blockage, and the ore will cause wear on the smoke hood during the falling process of the preheating chamber. By using a hanging plate smoke hood at the outlet of the annular smoke and air duct, the ore will not enter the annular flue during the falling process of the preheating chamber, and it is easy to replace if it is worn.

[0010] In a preferred embodiment, a bag dust collector is connected to one side of the preheating kiln, and the input end of the bag dust collector is connected to a plurality of air extraction ports, and the output end of the bag dust collector is connected to an induced draft fan;

[0011] The output end of the induced draft fan is connected to a first diversion pipe, and the first diversion pipe is provided with a first diversion port and a second diversion port, the first diversion port of the induced draft fan is connected to a chimney, and the second diversion port of the induced draft fan is connected to a circulating fan;

[0012] The output end of the circulating fan is tightly connected to a second diversion pipe, and the second diversion pipe is provided with a third diversion port and a fourth diversion port, and the third diversion port and the fourth diversion port of the circulating fan are simultaneously connected to a hot air furnace;

[0013] One end of the hot blast furnace is connected to a combustion-supporting blower, and the other end of the hot blast furnace is connected to an annular smoke and air channel. A combustion zone and a mixing zone are provided in the hot blast furnace, and a castable is laid inside the hot blast furnace;

[0014] The fourth diversion port of the circulating fan is connected to the combustion zone, the third diversion port is connected to the mixing zone, and the third diversion port and the fourth diversion port are respectively provided with pneumatic regulating valves, each of the pneumatic regulating valves is used to adjust the flue gas flow of the third diversion port and the fourth diversion port respectively, the flue gas flow adjustment range of the third diversion port is set at 0-100%, and the flue gas flow adjustment range of the fourth diversion port is set at 0-50%.

[0015] The problems existing in the existing hot blast furnaces include: low-temperature, low-oxygen circulating flue gas increases the total volume of the mixed gas in the hot blast furnace, dilutes the oxygen concentration in the mixed gas, prolongs the combustion time of the raw coal gas in the blast furnace, reduces the combustion intensity, and causes the maximum combustion temperature to drop. The flame is diffusely distributed, achieving spatial combustion and improving the uniformity of the furnace temperature. However, the existing circulating flue gas is not diverted and transported to the hot blast furnace, so that excessive circulating flue gas leads to too low oxygen concentration, which is not conducive to the stable combustion of the hot blast furnace. In the present invention, a hot blast furnace is provided. Since the circulating air volume accounts for 60%-80% of the total flue gas volume, the circulating flue gas volume is large, and the low-temperature and low-oxygen circulating flue gas will change the temperature and oxygen concentration distribution of the combustion zone, thereby affecting the stability of combustion. Excessive circulating flue gas will cause problems such as incomplete combustion or flameout. Therefore, the circulating flue gas is divided into two streams, which enter the combustion zone and the mixing zone of the hot blast furnace respectively. The flow rate of circulating flue gas into the combustion zone is small, and the flow rate into the mixing zone is large. Reasonable distribution can ensure the stability of raw gas combustion. In addition, since the calorific value of the raw gas of the blast furnace is high, a part of the low-temperature circulating flue gas is mixed in the combustion zone, which can reduce the combustion flue gas temperature on the one hand, and protect the castable inside the furnace on the other hand. At the same time, by mixing the low-temperature circulating flue gas in the mixing zone, the purpose of ensuring the uniformity of the flue gas temperature can also be achieved.

[0016] A method for operating a fully enclosed submerged arc furnace preheating kiln device comprises the following specific steps:

[0017] S1: Ore and coke enter the preheating kiln according to a certain mass ratio;

[0018] S2: The raw gas produced by the ore-fired furnace enters the hot blast furnace;

[0019] S3: The combustion-supporting fan provides the air required for combustion in the hot air furnace;

[0020] S4: The flue gas generated by the combustion of raw gas is mixed with the recycled flue gas to form high-temperature flue gas;

[0021] S5: Strictly control the O2 concentration in the high-temperature flue gas by adjusting the combustion-supporting air volume to prevent the coke from burning during the heating process;

[0022] S6: High-temperature flue gas enters the preheating kiln through the annular flue gas channel;

[0023] S7: High-temperature flue gas exchanges heat with the material in countercurrent in the preheating kiln;

[0024] S8: Reduce the flue gas temperature at the top outlet of the preheating kiln to 100-250°C and let it flow out from the exhaust port at the top of the preheating chamber;

[0025] S9: The outflowing flue gas is dust-removed by the bag filter and then pressurized by the induced draft fan;

[0026] S10: The flue gas pressurized by the induced draft fan is divided into two streams, one of which enters the chimney, and the other is pressurized by the circulating fan and enters the hot air furnace;

[0027] In S4, the flue gas generated by the combustion of the raw gas is mixed with the recycled flue gas to form a high-temperature flue gas reaching 650-800°C;

[0028] The induced draft fan, combustion-supporting fan and circulation fan are all frequency-controlled, and the air volume of the circulation fan accounts for 60%-80% of the air volume at the outlet of the induced draft fan;

[0029] In the above S10, the flue gas at the outlet of the circulating fan is divided into two streams. By adjusting two pneumatic regulating valves, the ratio of the flue gas entering the combustion zone and the mixing zone is adjusted to adjust the flue gas temperature entering the preheating kiln.

[0030] As can be seen from the above, a device for preheating a fully enclosed ore-fired furnace comprises a preheating kiln, the preheating kiln comprises a material cup, a mixing weighing system is installed on the outside of the material cup, and a hydraulic top is connected to the inside of the material cup, the hydraulic top is used to control the opening and closing of the material cup, the inner wall of the bottom end of the material cup is tightly connected to a trouser leg material bin, and a plurality of outlets of the trouser leg material bin are respectively connected to preheating chambers, a plurality of preheating chambers are provided, and the plurality of preheating chambers are equidistantly around the periphery of the preheating kiln, and a pump is respectively provided on the top of each preheating chamber. The air inlet and thermocouple are used to measure the outlet flue gas temperature of the preheating chamber. A gate valve is provided at the outlet of each trouser leg silo, and a radar level meter is provided in each trouser leg silo and each preheating chamber. The gate valve independently controls the feed amount of the preheating chamber, and the opening and closing of the gate valve is controlled by the radar level meter. The bottom inner wall of each preheating chamber is connected to a feed pipe. The bottom of the preheating kiln is provided with an annular smoke and air channel, and the outlet of the annular smoke and air channel is provided with a hanging plate smoke hood. The device and working method of the fully enclosed submerged arc furnace preheating kiln provided by the present invention can utilize the raw gas generated by the submerged arc furnace to burn and generate high-temperature flue gas, which is introduced into the preheating kiln to preheat the ore, saving the energy required to heat the ore in the submerged arc furnace, reducing the power consumption of smelting, saving energy, and improving production efficiency. At the same time, it can also ensure that the flue gas is sealed and does not leak. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the overall structure of a fully enclosed submerged arc furnace preheating kiln device proposed by the present invention.

[0032] Figure 2 This is a schematic diagram of the overall structure of a preheating kiln for a fully enclosed submerged arc furnace preheating kiln device proposed by the present invention.

[0033] Figure 3 The invention proposes a device for preheating a fully enclosed ore-fired furnace. Figure 2 Enlarged view of position A in the middle.

[0034] Figure 4 This is a top view of a preheating kiln of a fully enclosed submerged arc furnace preheating kiln device proposed by the present invention.

[0035] Figure 5 This is a specific flow chart of the working method of a fully enclosed submerged arc furnace preheating kiln device proposed by the present invention.

[0036] In the figure: 1. Preheating kiln; 2. Bag filter; 3. Induced draft fan; 4. First diversion pipe; 401. First diversion port; 402. Second diversion port; 5. Chimney; 6. Circulation fan; 7. Second diversion pipe; 701. Third diversion port; 702. Fourth diversion port; 8. Pneumatic control valve; 9. Hot blast furnace; 901. Mixing zone; 902. Combustion zone; 10. Combustion-supporting fan; 101. Material cup; 102. Hydraulic top; 103. Trouser leg material silo; 104. Gate valve; 105. Exhaust port; 106. Thermocouple; 107. Preheating chamber; 108. Annular smoke and air duct; 109. Radar level meter; 110. Feed pipe; 111. Hanging plate type smoke hood. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0038] The present invention discloses a device and a working method for a fully enclosed submerged arc furnace preheating kiln, which are mainly used in the smelting of ferromanganese alloys.

[0039] Reference Figure 1-Figure 4, a device for a fully enclosed ore-heating furnace preheating kiln, comprising a preheating kiln 1, the preheating kiln 1 comprising a material cup 101, a material mixing and weighing system being installed on the outside of the material cup 101, and a hydraulic top 102 being connected to the inside of the material cup 101, the hydraulic top 102 being used to control the opening and closing of the material cup 101, the inner wall of the bottom end of the material cup 101 being tightly connected to a trouser leg material bin 103, and a plurality of outlets of the trouser leg material bin 103 being respectively connected to a preheating chamber 107, nine preheating chambers 107 are provided, and the nine preheating chambers 107 are equidistantly surrounding the periphery of the preheating kiln 1, an exhaust port 105 and a thermocouple 106 being respectively provided at the top of each preheating chamber 107, and the thermocouple 106 being used to measure the outlet flue gas temperature of the preheating chamber 107, and a gate valve 1 being respectively provided at the outlet of each trouser leg material bin 103 04, and each trouser leg silo 103 and each preheating chamber 107 are provided with a radar level meter 109, the gate valve 104 independently controls the feed amount of the preheating chamber 107, and the opening and closing of the gate valve 104 is controlled by the radar level meter 109, and the bottom inner wall of each preheating chamber 107 is respectively connected with a discharge pipe 110, and the bottom of the preheating kiln 1 is provided with an annular smoke and wind channel 108, and the outlet of the annular smoke and wind channel 108 is provided with a hanging plate type smoke hood 111. The submerged arc furnace is mainly used for reducing and smelting ores, and mainly produces silicon-manganese alloys, ferromanganese, ferrochrome, ferrosilicon and other ferroalloys. It is an important production equipment in the metallurgical industry. By providing a preheating kiln 1, the raw coal gas generated by the submerged arc furnace is used to burn and generate high-temperature flue gas, which is introduced into the preheating kiln 1 to preheat the ore, saving the submerged arc furnace. The energy required for heating the ore in the furnace reduces the power consumption of smelting, saves energy and improves production efficiency. In detail, the ore and coke enter the material cup 101 on the top of the preheating kiln 1 through the mixing weighing system, wherein the hydraulic top 102 is used to control the opening and closing of the material cup 101. By opening the hydraulic top 102, the material can pass through the material cup 101 smoothly and be transferred to the trouser leg silo 103 for diversion. Among them, the gate valve 104 is used to control multiple outlets of the trouser leg silo 103 respectively to realize the feeding of a specific preheating chamber 107. In this process, based on the setting of the material cup 101 and the gate valve 104, double sealing can be achieved. At the same time, since the trouser leg silo 103 and the preheating chamber 107 are both provided with a radar level meter 109, the radar level meter 109 can measure the level of the material in the trouser leg silo 103. The material level and the material level in each preheating chamber 107 are monitored, and according to the signals sent by the trouser leg silo 103 and the radar level meter 109 in the preheating chamber 107, the opening and closing of the material cup 101 and the gate valve 104 can be automatically controlled to realize the interlocking of the material cup 101 and the gate valve 104, thereby ensuring that the flue gas is sealed and does not leak during the feeding process. In addition, in the nine preheating chambers 107 arranged in the preheating kiln 1, an exhaust port 105 and a thermocouple 106 are provided on the top of each preheating chamber 107. The outlet flue gas temperature can be measured by the thermocouple 106 to realize the temperature control during the subsequent flue gas utilization. The setting of the annular smoke and air channel 108 can make the flue gas re-enter the preheating kiln 1 through the smoke and air channel 108, so as to realize countercurrent heat exchange between the flue gas and the material.At the same time, the outlet of the annular smoke and air channel 108 adopts a hanging type smoke cover 111, so that the ore will not enter the annular smoke and air channel 108 during the falling process of the preheating chamber, and it is easy to replace if it is worn.

[0040] Reference Figure 1 In a preferred embodiment, a bag dust collector 2 is connected to one side of the preheating kiln 1, and the input end of the bag dust collector 2 is respectively connected to multiple exhaust ports 105, and the output end of the bag dust collector 2 is connected to an induced draft fan 3.

[0041] Reference Figure 1 In a preferred embodiment, the output end of the induced draft fan 3 is connected to a first diversion pipe 4, and the first diversion pipe is provided with a first diversion port 401 and a second diversion port 402, the first diversion port 401 of the induced draft fan 3 is connected to a chimney 5, and the second diversion port 402 of the induced draft fan 3 is connected to a circulating fan 6.

[0042] Reference Figure 1 In a preferred embodiment, the output end of the circulating fan 6 is tightly connected to the second diversion pipe 7, and the second diversion pipe 7 is provided with a third diversion port 701 and a fourth diversion port 702, and the third diversion port 701 and the fourth diversion port 702 of the circulating fan 6 are simultaneously connected to the hot air furnace 9.

[0043] Reference Figure 1 In a preferred embodiment, one end of the hot blast furnace 9 is connected to a combustion-supporting blower 10, and the other end of the hot blast furnace 9 is connected to an annular smoke and wind channel 108. A combustion zone 902 and a mixing zone 901 are also provided in the hot blast furnace 9, and a castable is laid inside the furnace of the hot blast furnace 9.

[0044] Reference Figure 1In a preferred embodiment, the fourth branch port 702 of the circulating fan 6 is connected to the combustion zone 902, the third branch port 701 is connected to the mixing zone 901, and the third branch port 701 and the fourth branch port 702 are respectively provided with a pneumatic regulating valve 8, each pneumatic regulating valve 8 is used to adjust the flue gas flow of the third branch port 701 and the fourth branch port 702, respectively. The flue gas flow adjustment range of the third branch port 701 is set at 0-100%, and the flue gas flow adjustment range of the fourth branch port 702 is set at 0-50%. The flue gas pressurized by the induced draft fan 3 passes through the circulating fan 6. After the machine 6, the circulating flue gas is divided into two streams by the second diversion pipe 7, and enters the combustion zone 902 and the mixing zone 901 of the hot blast furnace 9 respectively. The flow rate of the circulating flue gas into the combustion zone 902 is relatively small, and the flow rate into the mixing zone 901 is relatively large. Reasonable distribution can ensure the stability of the raw gas combustion. In addition, due to the high calorific value of the raw gas of the blast furnace, the combustion temperature is relatively high>2000℃. Therefore, by mixing a part of the low-temperature circulating flue gas in the combustion zone 902, its main purpose is to protect the refractory material. At the same time, by mixing the low-temperature circulating flue gas in the mixing zone, the purpose of ensuring the uniformity of the flue gas temperature can also be achieved.

[0045] Reference Figure 5 In a preferred embodiment, a method for operating a fully enclosed submerged arc furnace preheating kiln device comprises the following specific steps:

[0046] S1: Manganese ore and coke enter the preheating kiln 1 in a mass ratio of 80:20;

[0047] S2: The raw coal gas produced by the ore-fired furnace enters the hot blast furnace 9;

[0048] S3: The combustion-supporting blower 10 provides the air required for combustion in the hot blast furnace 9;

[0049] S4: The flue gas generated by the combustion of raw gas is mixed with the recycled flue gas to form high-temperature flue gas;

[0050] S5: Strictly control the O2 concentration in the high-temperature flue gas by adjusting the combustion-supporting air volume to prevent the coke from burning during the heating process;

[0051] S6: The high-temperature flue gas enters the preheating kiln 1 through the annular flue gas channel 108;

[0052] S7: The high-temperature flue gas exchanges heat with the material in countercurrent in the preheating kiln 1;

[0053] S8: Lowering the flue gas temperature at the top outlet of the preheating kiln 1 to 100-250°C and allowing it to flow out from the exhaust port 105 at the top of the preheating chamber 107;

[0054] S9: The outgoing flue gas is dust-removed by the bag filter 2 and then pressurized by the induced draft fan 3;

[0055] S10: The flue gas pressurized by the induced draft fan 3 is divided into two streams, one of which enters the chimney 5, and the other is pressurized by the circulating fan 6 and enters the hot blast furnace 9.

[0056] Reference Figure 5 In a preferred embodiment, in S4, the high-temperature flue gas formed by mixing the flue gas generated by the combustion of the raw gas with the recycled flue gas reaches 650-800°C.

[0057] Reference Figure 5 In a preferred embodiment, the induced draft fan 3, the combustion-supporting fan 10 and the circulation fan 6 are all controlled by variable frequency, and the air volume of the circulation fan 6 accounts for 60%-80% of the outlet air volume of the induced draft fan 3.

[0058] Reference Figure 5 In a preferred embodiment, in S10, the flue gas at the outlet of the circulating fan 6 is divided into two streams, and the ratio of the flue gas entering the combustion zone 902 and the mixing zone 901 is adjusted by adjusting the two pneumatic regulating valves 8 to adjust the flue gas temperature entering the preheating kiln 1.

[0059] Working Principle: The submerged arc furnace is mainly used for reducing and smelting ores, and mainly produces ferroalloys such as silicon-manganese alloy, ferromanganese, ferrochrome, and ferrosilicon. It is an important production equipment in the metallurgical industry. By setting up a preheating kiln 1, the raw gas generated by the submerged arc furnace is used to burn and generate high-temperature flue gas, which is introduced into the preheating kiln 1 to preheat the ore, saving the energy required for heating the ore in the submerged arc furnace, reducing the power consumption of smelting, saving energy, and improving production efficiency. In detail, the ore and coke enter the material cup 101 on the top of the preheating kiln 1 through the mixing and weighing system. The hydraulic top 102 is used to control the opening and closing of the material cup 101. By opening the hydraulic top 102, the material can pass through the material cup 101 smoothly and be transferred to the trouser leg silo 103 for diversion. The gate valve 104 is used to control the outlet of the trouser leg silo 103 respectively to realize the feeding of the specific preheating chamber 107. In this process, based on the setting of the material cup 101 and the gate valve 104, double sealing can be achieved. At the same time, since each trouser leg silo 103 and each preheating chamber 107 are provided with a radar level meter 109, the radar The material level meter 109 can monitor the material level in the trouser leg silo 103 and the material level in each preheating chamber 107. According to the signal sent by the radar material level meter 109 in the trouser leg silo 103 and the preheating chamber 107, the opening and closing of the material cup 101 and the gate valve 104 can be automatically controlled to realize the interlocking of the material cup 101 and the gate valve 104, thereby ensuring that the smoke is sealed and does not leak during the feeding process. In addition, in the nine preheating chambers 107 set in the preheating kiln 1, each preheating chamber 107 is provided with an exhaust port 1 at the top. 05 and a thermocouple 106, through which the outlet flue gas temperature can be measured to achieve temperature control during subsequent flue gas utilization, and the setting of the annular flue gas channel 108 can allow the flue gas to pass through the flue gas channel 108 and re-enter the preheating kiln 1 to achieve countercurrent heat exchange between the flue gas and the material. The temperature of the material entering the preheating kiln 1 is room temperature, and the temperature of the material leaving the preheating kiln 1 is 400-500°C; the temperature of the flue gas entering the preheating kiln 1 is 650-800°C, and the temperature of the flue gas leaving the preheating kiln 1 is 100-250°C.

[0060] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A device for preheating a fully enclosed ore-fired furnace, comprising a preheating kiln (1), characterized in that: The preheating kiln (1) comprises a material cup (101), a material mixing and weighing system is installed on the outside of the material cup (101), and a hydraulic top (102) is connected to the inside of the material cup (101), and the hydraulic top (102) is used to control the opening and closing of the material cup (101). The inner wall of the bottom end of the material cup (101) is tightly connected to a trouser leg material bin (103), and multiple outlets of the trouser leg material bin (103) are respectively connected to preheating chambers (107). There are multiple preheating chambers (107), and the multiple preheating chambers (107) are equidistantly arranged around the periphery of the preheating kiln (1), and the top of each preheating chamber (107) is respectively provided with an exhaust port (105) and a thermocouple (106), and the thermocouple (10 6) For measuring the outlet flue gas temperature of the preheating chamber (107), a gate valve (104) is provided at the outlet of each trouser leg silo (103), and a radar level meter (109) is provided in each trouser leg silo (103) and each preheating chamber (107). The gate valve (104) independently controls the feed amount of the preheating chamber (107), and the opening and closing of the gate valve (104) is controlled by the radar level meter (109). A discharge pipe (110) is connected to the inner wall of the bottom end of each preheating chamber (107). An annular smoke and air channel (108) is provided at the bottom of the preheating kiln (1), and a hanging plate type smoke hood (111) is provided at the outlet of the annular smoke and air channel (108).

2. The device for preheating a fully enclosed submerged arc furnace according to claim 1, characterized in that: A bag dust collector (2) is connected to one side of the preheating kiln (1), and the input end of the bag dust collector (2) is respectively connected to a plurality of air extraction ports (105), and the output end of the bag dust collector (2) is connected to an induced draft fan (3).

3. The device for preheating a fully enclosed submerged arc furnace according to claim 2, characterized in that: The output end of the induced draft fan (3) is connected to a first diversion pipe (4), and the first diversion pipe is provided with a first diversion port (401) and a second diversion port (402); the first diversion port (401) of the induced draft fan (3) is connected to a chimney (5), and the second diversion port (402) of the induced draft fan (3) is connected to a circulating fan (6).

4. The device for preheating a fully enclosed submerged arc furnace according to claim 3, characterized in that: The output end of the circulating fan (6) is tightly connected to a second diversion pipe (7), and the second diversion pipe (7) is provided with a third diversion port (701) and a fourth diversion port (702). The third diversion port (701) and the fourth diversion port (702) of the circulating fan (6) are simultaneously connected to a hot air furnace (9).

5. The device for preheating a fully enclosed submerged arc furnace according to claim 4, characterized in that: One end of the hot blast furnace (9) is connected to a combustion-supporting blower (10), and the other end of the hot blast furnace (9) is connected to an annular smoke and air channel (108). A combustion zone (902) and a mixing zone (901) are simultaneously provided in the hot blast furnace (9), and a casting material is laid inside the furnace of the hot blast furnace (9).

6. The device for preheating a fully enclosed submerged arc furnace according to claim 5, characterized in that: The fourth diversion port (702) of the circulating fan (6) is connected to the combustion zone (902), and the third diversion port (701) is connected to the mixing zone (901). The third diversion port (701) and the fourth diversion port (702) are respectively provided with a pneumatic regulating valve (8). Each of the pneumatic regulating valves (8) is used to regulate the flue gas flow of the third diversion port (701) and the fourth diversion port (702). The flue gas flow regulation range of the third diversion port (701) is set at 0-100%, and the flue gas flow regulation range of the fourth diversion port (702) is set at 0-50%.

7. A method for operating a fully enclosed preheating kiln for a submerged arc furnace, applied to the fully enclosed preheating kiln for a submerged arc furnace as claimed in claim 6, characterized in that: The specific steps include: S1: Ore and coke enter the preheating kiln (1) according to a certain mass ratio; S2: The raw gas produced by the ore-fired furnace enters the hot blast furnace (9); S3: The combustion-supporting blower (10) provides the air required for combustion in the hot air furnace (9); S4: The flue gas generated by the combustion of raw gas is mixed with the recycled flue gas to form high-temperature flue gas; S5: Strictly control the O2 concentration in the high-temperature flue gas by adjusting the combustion-supporting air volume to prevent the coke from burning during the heating process; S6: The high-temperature flue gas enters the preheating kiln (1) through the annular flue gas channel (108); S7: The high-temperature flue gas exchanges heat with the material in a countercurrent manner in the preheating kiln (1); S8: Lowering the temperature of the flue gas at the top outlet of the preheating kiln (1) to 100-250°C and allowing the flue gas to flow out from the exhaust port (105) at the top of the preheating chamber (107); S9: The outflowing flue gas is dust-removed by the bag filter (2) and then pressurized by the induced draft fan (3); S10: The flue gas pressurized by the induced draft fan (3) is divided into two streams, one of which enters the chimney (5), and the other is pressurized by the circulating fan (6) and enters the hot air furnace (9).

8. The method for operating a fully enclosed submerged arc furnace preheating kiln according to claim 7, characterized in that: In the above-mentioned S4, the high-temperature flue gas formed by mixing the flue gas generated by the combustion of the raw gas with the recycled flue gas reaches 650-800°C.

9. The method for operating a fully enclosed submerged arc furnace preheating kiln according to claim 7, characterized in that: The induced draft fan (3), the combustion-supporting fan (10) and the circulating fan (6) all adopt frequency conversion control, and the air volume of the circulating fan (6) accounts for 60%-80% of the air volume at the outlet of the induced draft fan (3).

10. The method for operating a fully enclosed submerged arc furnace preheating kiln according to claim 7, characterized in that: In the above S10, the flue gas at the outlet of the circulating fan (6) is divided into two streams. By adjusting the two pneumatic regulating valves (8), the ratio of the flue gas entering the combustion zone (902) and the mixing zone (901) is adjusted to adjust the flue gas temperature entering the preheating kiln (1).

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