WO2012163274A1

WO2012163274A1 - Gas-burning and electric-arc dual-heating high-efficiency silicon refining furnace and heating method thereof

Info

Publication number: WO2012163274A1
Application number: PCT/CN2012/076264
Authority: WO
Inventors: 李恒杰
Original assignee: Li Hengjie
Priority date: 2011-06-01
Filing date: 2012-05-30
Publication date: 2012-12-06
Also published as: CN102275927A

Abstract

Provided are a gas-burning and electric-arc dual-heating high-efficiency silicon refining furnace and heating method thereof. Disposed within a furnace body are two heating chambers, a first heating chamber being inside of the heat-conducting internal furnace, and a second heating chamber between the heat-conducting internal furnace and a heat insulation sleeve. The first heating chamber uses electrode heating, and the second heating chamber uses fuel-burning heating. Heat guide holes are evenly provided on the wall of the heat-conducting internal furnace. The first heating chamber communicates with the second heating chamber through the heat guide holes. First, fuel is burnt to heat up the second heating chamber, and the electrode does not operate. The heat of the second heating chamber flows into the first heating chamber through the heat guide holes. When the temperature of the first heating chamber reaches a pre-set value, the electrode starts to heat the first heating chamber. The temperature of the first heating chamber continuously increases. After the temperature reaches a pre-set value, a cycle of a thermal chemical reaction ends, the burning in the second heating chamber is reduced to maintain the temperature. Material is discharged.

Description

Gas arc double-heating high-efficiency silicon-making furnace and heating method thereof

Technical field

The invention relates to a silicon smelting furnace, and mainly relates to a gas arc double-heating heat storage waste heat exhaust gas returning environmental protection energy-saving high-efficiency silicon-making furnace and a heating method thereof.

Background technique

The traditional silicon alloy smelting furnace adopts the arc heating method alone. Since the arc heating is a point type heat release from the bottom to the top, when smelting ferrosilicon alloy, silicon alloy, 99% silicon, it is necessary to add about 1/4 ton of ingredients. Blue carbon, coking coal, arc heating method due to its arc heat generation characteristics can not be used to recover a large amount of carbon monoxide, carbon dioxide, sulfur dioxide, waste heat (about 50% of the total output heat energy) generated by the high temperature reaction process for secondary use, directly Emissions, while high energy consumption, also cause high pollution atmosphere.

Summary of the invention

The object of the present invention is to provide a gas arc double-heating heat storage waste heat exhaust gas returning environmental protection energy-saving high-efficiency silicon-making furnace and a heating method thereof, and the waste heat generated by the arc is generated by using the arc primary heating and the fuel combustion secondary heating method. After secondary combustion, the dust exhausted by the exhausted waste is treated to achieve energy saving, environmental protection and efficiency improvement, and the long-standing problems of the existing silicon-making furnace are better overcome.

The heating method for carrying out the invention is: comprising the following steps:

Two heating chambers are arranged in the furnace body, that is, the first heating chamber is inside the heat conduction furnace, the second heating chamber is between the heat conduction furnace and the outer casing, the first heating chamber is electrode heating, and the second heating chamber is fuel combustion heating;

a heat guiding hole is uniformly distributed on the wall of the heat conducting furnace, and the first heating chamber and the second heating chamber are communicated through the heat guiding hole; firstly, the fuel is heated to heat the second heating chamber, and the electrode does not work; The heat of the second heating chamber is heated into the first heating chamber through the heat guiding hole on the heat conducting furnace; when the temperature of the first heating chamber reaches the set value, the electrode starts to heat the first heating chamber;

When the temperature of the first heating chamber continues to rise to a set value, the thermochemical reaction ends one cycle, at which time the second heating chamber is reduced to a small fire and burned;

Discharge.

The silicon-making furnace structure for realizing the invention is: The silicon-making furnace comprises a secondary combustion of fuel combustion and a primary heating of the arc, and the towel:

The primary heating of the arc comprises a heat-conducting furnace, the inside of the heat-conducting furnace is a first heating chamber, a top cover is arranged on the top, a melting crucible is arranged at the bottom, and a material is placed on the crucible crucible, and the first heating chamber is provided The arc electrode for heating the material is further provided with an inclined secondary heating flame hole on the wall of the heat conducting furnace, an automatic feeding port is arranged on the top cover, and a flue is connected on the circumferential surface of the top cover, the flue One end is connected to the first heating chamber, and the other end is connected to a cyclone type oscillating waste heat recovery dust remover;

The secondary heating of the fuel comprises: providing a heat insulating sleeve on the periphery of the heat conducting furnace, the space between the heat insulating sleeve and the heat conducting furnace is a second heating chamber, and the burner is provided with a burner, the burner is The heating chamber sprays the flame, the burner is connected with the regenerator, and the top surface of the second heating chamber is provided with a heat insulation layer, the heat insulation layer is provided with a furnace surface working platform, and the second heating chamber is provided with a cleaning door. The hot smoke of the second heating chamber enters the first heating chamber through the secondary heating flame hole, and the heat of the second heating chamber is conducted to the first heating chamber through the heat conducting furnace.

The hot smoke of the first heating chamber and the second heating chamber is then discharged into the heat storage body through the hot smoke outlet of the burner, and then reburned through the hot phleb gas inlet of the burner.

The structure of the above silicon-making furnace further includes:

The burner includes a burner A and a burner B, and the heat storage body includes a heat storage body A and a heat storage body B; wherein the burner A and the burner B respectively pass through the heat storage body A, the reversing valve, and The regenerator B alternately operates, the burner A and the burner B are provided with a hot flue gas inlet and a hot flue gas outlet, and the regenerator body A and the regenerator body B are respectively provided with a hot flue gas inlet and a hot flue gas outlet, wherein the combustion The hot flue gas inlet and the hot flue gas outlet of the burner A and the burner B are respectively passed through the burner A and The hot flue gas inlet and the hot flue gas outlet of the burner B are connected to the reversing valve. The lower end of the regenerator A and the regenerator B are respectively provided with a ash outlet, and the ash outlet is provided at the ash outlet.

The burner is a nozzle, and the nozzle is provided with an igniter, a fuel inlet, a hot flue gas inlet, a hot flue gas outlet and a flange, wherein the nozzle is fixed in the regenerator A and the regenerator B through a flange, The hot flue gas outlet is in communication with the second heating chamber.

The cold working channel is arranged in the furnace working platform to cool the working surface of the working surface.

The furnace surface working platform is further provided with a second heating chamber explosion-proof door, and the second heating chamber explosion-proof door is connected to the second heating chamber.

The first heating chamber explosion-proof door is also disposed on the flue.

The lower end of the cyclone type oscillating waste heat recovery dust collector is respectively provided with a flue port and a sedimentation tank port connecting the flue and the dust removing sedimentation tank, and a dusting shower is arranged above the flue pipe, and the upper end of the precipitator is connected with dust removal The chamber is connected to the dust chamber, and a preheated air outlet is arranged in the upper part of the dust collector, and a preheated air inlet and an oscillator are arranged in the lower part of the dust remover.

The heat conducting furnace comprises a crucible crucible, a heat conducting material biliary body and a top cover, wherein the upper end of the melting crucible is connected with the heat conducting material biliary body, and the upper end of the heat conducting material biliary body is connected to the top cover through the furnace surface working platform.

The inclined secondary heating flame hole has an inclination direction which is low in the orifice of the first combustion chamber and high in the orifice of the second combustion chamber.

The upper circumferential surface of the heat conducting furnace is also provided with a manual feeding door.

The invention has the beneficial effects that the silicon-making furnace adopts secondary combustion heating technology, and adopts gas-fired heat storage double-type high-efficiency combustion while arc heating, and the waste heat generated by the electric arc furnace can save energy by more than 60% after secondary combustion, and reduce emissions. 90% of carbon monoxide and more than 60% of carbon dioxide make sulfur dioxide emissions greatly reduced, and energy saving and emission reduction effects are remarkable. The gas combustion efficiency of the invention is 99%, the primary energy and secondary energy utilization efficiency are more than 50%, the comprehensive efficiency is more than 65%, and the single thermal arc heating smelting efficiency is more than doubled. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view showing the overall appearance of the present invention.

Figure 2 is a cross-sectional view of Figure 1.

Figure 3 is a plan view of Figure 2.

Figure 4 is a plan view of Figure 1.

Figure 5 is a schematic view of the burner of Figure 1.

Figure 6 is a schematic view of the cyclone type oscillating waste heat recovery dust remover of the present invention.

Figure 7 is a schematic view of a heat storage device of the heat storage body of the present invention.

Figure 8 is a table showing the relationship between the heat storage preheating combustion air and the fuel economy ratio, wherein the numbers 10 - 70 indicate the combustion energy saving rate %, and the numbers 200 - 1400 indicate the heat storage preheating combustion air temperature. C, the curve in the figure shows the temperature curve of the flue gas discharged without heat storage.

In the figure: 1 furnace base bracket, 2 base bearing pile, 3 regenerator B, 31 solenoid valve, 32 regenerator A, 33 blower, 34 reversing valve, 35 induced draft fan, 36 exhaust pipe, 37 heat storage Body B, 4 melt crucible, 41 crucible discharge, 5 insulation sleeve, 51 dust collector fixed lifting ring, 52 connected dust chamber port, 53 preheated air outlet, 54 dusting shower, 55 connected to the sedimentation tank, 56 smoke inlet, 57 preheated air inlet, 6 secondary heating flame hole, 61 igniter, 62 fuel inlet, 63 hot flue gas inlet, 64 hot flue gas outlet, 65 flange, 7 insulation, 8 furnace surface Work platform, 9 second heating chamber explosion-proof door, 10 manual feeding door, 11 top cover, 12 first heating chamber explosion-proof door, 13 flue, 131 electric ventilation valve, 14 cold water passage, 15 second heating chamber, 16 arc Electrode, 17 first heating chamber, 18 heat conduction furnace, 19 regenerator A, 20 burner, 21 secondary combustion chamber cleaning door, 22 automatic feed port, 23 top cover ring, 24 furnace shell, 26 out Grey door, 27 hanging rings, 28 heat transfer material biliary body, 29 nozzles, 50 cyclone type oscillating heat recovery dust collector, 60 oscillator. detailed description The present invention will be further described below in conjunction with the accompanying drawings:

As shown in the figure, the furnace (circular) includes a secondary heating and a secondary heating structure, and the secondary heating is divided into arc heating and fuel (gas) combustion heating, and the first heating chamber 17 and the second heating chamber 15 are provided for this purpose. The first heating chamber 17 is heated by the arc, and the second heating chamber 15 is heated by the burner 20 (fuel/gas).

The first heating chamber 17 includes a heat conducting furnace 18, and the inside of the heat conducting furnace 18 is a first heating chamber 17, a heat conducting furnace

18 consists of a crucible crucible 4, a heat transfer material biliary body (heat transfer material including graphite carbon brick) 28 and a top cover 11, a crucible crucible 4 at the bottom, an upper end connected to the heat transfer material biliary body 28, and a heat transfer material biliary body 28 upper end The top cover 11 is connected through the furnace surface working platform 8, and the crucible discharge port 41 is arranged on the crucible crucible 4,

The top of the crucible crucible 4 is a material, and three arc electrodes 16 are uniformly distributed in the first heating chamber 17 to heat the material (see FIG. 1), and the inner wall of the heat conducting material body 28 is also provided with an inner low and an outer high inclination. The secondary heating hole 6, the inclined hole is arranged to prevent the material from entering the second heating chamber 15, the top cover 11 is provided with an automatic feeding port 22, and the circumferential surface of the top cover 11 is further provided with a flue 13 and a flue The first end is connected to the first heating chamber 17, and the other end is connected to the cyclone type oscillating waste heat recovery dust remover 50. In the flue 13, there is also a first heating chamber venting door 12 for preventing the internal pressure of the first heating chamber 17 from being excessively high. The outlet 13 is also provided with an electric ventilation valve 131. The circumferential surface of the top cover 11 is further provided with a manual feeding door 10, and on the top cover 11, there are three top lifting rings 23 for lifting the heat conducting furnace 18 (see Fig. 1). ).

The second heating chamber 15 includes a heat insulating sleeve (insulation wall) 5 on the outside of the heat conducting furnace 18, and the heat insulating sleeve 5 is made of heat insulating material including refractory bricks, and the outside of the heat insulating sleeve 5 is a furnace shell 24, separated by There is a cavity between the heat jacket 5 and the heat conducting furnace 18, and the cavity is a second heating chamber 15, and a heat storage body is arranged on the furnace body casing 24, and the burner 20 is stored in the heat storage body, and the heat storage body is stored. The heat body A and the heat storage body B are disposed on two sides of the furnace body casing 24, and the burners 20 are two-group, and the two burners 20 are respectively disposed on the heat storage body A and the heat storage body B, and the burner 20 The flame is sprayed into the second heating chamber 15, and the heat generated by the second heating chamber 15 enters the first heating chamber 17 through the heat transfer material biliary body 28, and the hot flue gas generated by the second heating chamber 15 enters through the inclined secondary heating hole 6. The first heating chamber 17 heats the material, and the hot flue gas generated by the second heating chamber 15 alternately supplies the combustion gas to the hot flue gas inlet 63 of the nozzle 29 of the burner 20 via the regenerator A and the regenerator B. The top surface of the second heating chamber 15 is provided with a heat insulating layer 7, and the insulating layer 7 is provided with workers' work. The furnace surface working platform 8, the furnace surface working platform 8 has a plurality of cold water passages 14 for cooling the furnace surface working platform 8, and the second heating chamber explosion-proof door 9 is also installed on the furnace surface working platform 8, the second heating The lower end of the chamber explosion-proof door 9 communicates with the second heating chamber 15, the upper end of which is open to the atmosphere, and three cleaning doors 21 are uniformly disposed under the second heating chamber 15.

The burner 20 (see Fig. 5) is a nozzle 29, which is composed of an igniter 61, a fuel inlet 62, a hot flue gas inlet 63, a hot flue gas outlet 64, a flange 65, a fuel inlet 62 connected to the fuel pipe, and a hot smoke. The gas inlet 63 and the hot flue gas outlet 64 are connected to the hot flue gas inlet and the hot flue gas outlet of the regenerators A, B, respectively, and the nozzle 29 is fixed to the furnace casing 24 by a flange 65.

The heat storage body heat exchange device (see Fig. 7) is composed of a solenoid valve 31, a heat storage body A (32), a blower 33, a reversing valve 34, an induced draft fan 35, a smoke exhaust pipe 36, and a heat storage body B (37); There are two burners 20, one connected to the heat storage body A and the other connected to the heat storage body B. The hot flue gas generated by the nozzle 29 enters the heat storage body A and the heat storage body through the hot flue gas outlet 64 of the nozzle 29, respectively. B, under the action of the reversing valve 34, alternately enters the hot flue gas inlet 63 to serve as a combustion-supporting energy saving function, and the regenerator body A and the regenerator body B are hung on the furnace body casing 24 through the hanging ring 27.

Cyclone type oscillating waste heat recovery dust remover 50 (see Fig. 6), the dust eliminator fixing hoist ring 51, the dust removal chamber port 52, the preheating air outlet 53, the dust blasting device 54, the sedimentation tank port 55, the tobacco inlet port 56, and the preheating The air inlet 57 is composed; the lower end of the dust remover 50 is a three-way structure, and there is a dust spray shower 54 for spraying dust to the dust, a lower end of the sedimentation tank port 55 is connected to the sedimentation tank, and a side flue port 56 is connected to the flue 13 The dust removing chamber port 52 of the upper end is connected to the dust removing chamber, and a preheating air outlet 53 connecting the heat storage body B is further disposed at the upper portion of the dust remover 50, and a preheating air inlet 57 connecting the air blower is further disposed at a lower portion of the dust remover 50. There is also an oscillator 60 for causing the dust remover 50 to generate vibration and ash, and the soot is discharged through the ash door 26 of the lower end ash outlet.

working principle:

The ore and ingredients are classified and crushed, mixed according to the ratio, delivered to the silo, and then the exhaust fan and blower of the regenerator heat exchange device (see Figure 7) are activated. At this time, the regenerator A or B in the secondary heating is first ignited. Burner A or B, when the heat storage temperature in the regenerator A or B reaches 800-1000 °C, alternately sucks and stores through the reversing valve, and exchanges heat exchange between the two heating chambers through the regenerator The exhaust fan of the device is pumped to the regenerative burner A or B for air preheating In combination with the second high temperature combustion, when the burner A is working, the burner B stores heat, and vice versa, when the burner B is working, the burner A stores heat, and the hot smoke of the second heating chamber enters through the secondary heating flame hole. The high temperature of the first heating chamber and the second heating chamber are transferred into the first heating chamber through the graphite carbon brick, so that the first heating chamber is heated to above 120 CTC, and the first batch of the silo is mixed to the first. Heating in the heating chamber, turning on the three arc electrodes in the first heating chamber, starting to generate the arc once, the mineral in the first heating chamber is heated and heated to 1600-165 CTC to melt, the thermochemical reaction ends one cycle, and the second heating The burner is reduced to a small fire and burned, and the furnace is opened to open the discharge port, and the molten high temperature solution is discharged to the outside of the furnace for cooling. Blocking the discharge port for the second round of charging and smelting. See Figure 8 for a table of the relationship between preheated air temperature and fuel economy.

The mineral material is charged into the arc once and heated. The high temperature heating of the inner tank of the inner tank produces a large amount of carbon monoxide, carbon dioxide and sulfur dioxide, which are led to the A or B burner regenerator through the heat storage device of the regenerative heat exchanger, and are alternately stored by the reversing valve. The heat is subjected to high temperature combustion above 140CTC to reduce the emission of polluted gases, and the excess waste heat smoke is finally discharged by the dust collector.

When the pressure in the first heating chamber and the second heating chamber is excessively large, the first heating chamber explosion-proof door and the second heating chamber explosion-proof door may be opened for decompression. When the combustible exhaust gas exceeds the maximum combustion amount of the secondary exhaust gas combustion chamber, the combustion window automatically opens the smoke window electric ventilation valve to start the cyclone dust collector, and the cyclone exhaust gas discharges excessive combustible gas to prevent deflagration, and the test gas is safely burned. After the range, close the smoke window electric ventilation valve and the cyclone dust collector to return to normal combustion. The working principle of the regenerative burner (as shown in Fig. 5): The normal temperature air from the blower is switched from the reversing valve to the regenerative burner B, after passing through the regenerative burner B (ceramic ball or honeycomb) When heated, the air at room temperature is heated to near the furnace temperature (usually 5CT100 °C lower than the furnace temperature) in a very short time. After the heated high temperature air enters the furnace, the smoke in the surrounding furnace is formed into a package. The oxygen is much lower than 21% of the lean oxygen-poor high-temperature gas stream, and at the same time, fuel (fuel or gas) is injected near the thin high-temperature air, and the fuel is burned in an oxygen-poor (2-20%) state; at the same time, the furnace is burned. The hot flue gas is discharged into the atmosphere through another regenerative burner A. When the high-temperature hot flue gas in the furnace passes through the regenerative burner A, the sensible heat is stored in the regenerative burner A, and then lower than The low temperature flue gas at 150 °C is discharged through the reversing valve. The reversing valve with low operating temperature switches at a certain frequency, so that two The switching period used is 30 to 200 seconds.

Claims

Rights request

1. A heating method for a gas arc double-heating high-efficiency silicon-making furnace, characterized in that the method comprises the following steps:

1) Two heating chambers are arranged in the furnace body, that is, the first heating chamber is inside the heat conduction furnace, and the second heating chamber is between the heat conduction furnace and the outer casing, the first heating chamber is electrode heating, and the second heating chamber is fuel combustion. Heating

2) a heat guiding hole is uniformly distributed on the wall of the heat conducting furnace, and the first heating chamber and the second heating chamber are communicated through the heat guiding hole;

3) First, the fuel is burned to heat the second heating chamber, at which time the electrode does not work;

4) the heat of the second heating chamber is heated into the first heating chamber through the heat guiding hole on the heat conducting furnace;

5) when the temperature of the first heating chamber reaches the set value, the electrode starts to heat the first heating chamber;

6) When the temperature of the first heating chamber continues to rise to a set value, the thermochemical reaction ends one cycle, at which time the second heating chamber is reduced to a small fire and burned;

7) Discharge.

2. A gas arc double-heating high-efficiency silicon-making furnace for realizing the heating method of claim 1, characterized in that it comprises an arc primary heating and a fuel combustion secondary heating;

The secondary heating of the fuel comprises: providing a heat insulating sleeve on the periphery of the heat conducting furnace, the space between the heat insulating sleeve and the heat conducting furnace is a second heating chamber, and the burner is provided with a burner, the burner is 2. The indoor flame is sprayed in the heating chamber, the burner is connected with the heat storage body, the heat insulation layer is arranged on the top surface of the second heating chamber, the furnace surface working platform is arranged on the heat insulation layer, and the cleaning door is arranged below the second heating chamber. The hot smoke of the second heating chamber enters the first heating chamber through the secondary heating flame hole, and the heat of the second heating chamber is conducted to the first heating chamber through the heat conducting furnace to heat;

The hot smoke of the first heating chamber and the second heating chamber is discharged into the heat storage body through the hot smoke outlet of the burner, and then burned The hot pharyngeal gas inlet is reburned.

3. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein said burner comprises a burner A and a burner B, said heat storage body comprising a heat storage body A and heat storage. Body B; wherein burner A and burner B are alternately operated via regenerator A, reversing valve and regenerator B, respectively, burner A and burner B are provided with hot flue gas inlet and hot flue gas outlet, heat storage The body A and the regenerator B are respectively provided with a hot flue gas inlet and a hot flue gas outlet, wherein the hot flue gas inlet and the hot flue gas outlet of the burner A and the burner B respectively pass through the hot smoke of the burner A and the burner B, respectively. The gas inlet and the hot flue gas outlet are connected to the reversing valve.

4. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein the burner comprises a nozzle, the nozzle is provided with an igniter, a fuel inlet, a hot flue gas inlet, a hot flue gas outlet, and a flange, wherein the hot flue gas outlet is in communication with the second heating chamber.

5. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein the furnace surface working platform is provided with a cold water passage for cooling the working surface of the furnace surface.

6. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein the furnace surface working platform further comprises a second heating chamber explosion-proof door, and the second heating chamber explosion-proof door is connected to the second Heating chamber.

7. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein the flue is further provided with a first heating chamber explosion-proof door.

8. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein the lower end of the cyclone-type oscillating waste heat recovery dust collector is provided with a flue port and a sediment connected to the flue and the dust-removing sedimentation tank, respectively. At the mouth of the pool, there is a dusting shower above the cigaretteway. The upper end of the dust collector is provided with a dust chamber connecting the dust chamber, and a preheating air outlet is arranged at the upper portion of the dust collector, and a preheating is also provided in the lower portion of the dust collector. Air inlet and oscillator.

9. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein the heat-conducting furnace comprises a crucible crucible, a heat-conducting material body and a top cover, wherein the upper end of the crucible crucible is connected to heat conduction. The material biliary body, the upper end of the heat transfer material biliary body is connected to the top cover through the working surface of the furnace surface.

10. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, characterized in that said heat-conducting furnace The circumferential surface of the section is also provided with a manual feed door.

11. The gas arc double-heating high-efficiency silicon-making furnace according to claim 2, wherein said inclined secondary heating flame hole has an inclination direction of a lower opening in the first combustion chamber, and a second combustion The chamber has a high opening.