Oxygen thermal method calcium carbide process equipped with hearth pressure regulating system

Abstract

The invention discloses an oxygen thermal method calcium carbide process equipped with a hearth pressure regulating system. Comprising an oxygen supply system, an oxygen pressure reducing valve, a high-pressure centrifugal fan, a fan ball valve, an oxygen flow meter, a fan flow meter, a gas mixing tank, a gas mixing tank pressure gauge, four mixed gas outlet valves, four mixed gas flow meters, a material height measuring device, a calcium carbide furnace plate type continuous feeding system, a calcium carbide furnace body reaction area and four oxygen inlet points. The calcium carbide furnace body comprises a melting area, a reaction area and melting area connecting device, four temperature measuring points, two pressure measuring points, a reserved observation hole, an air outlet, a cyclone dust collector, a tubular heat exchanger, an outlet end centrifugal fan, a flue gas analyzer, an ignition device, a casting material layer and a heat preservation layer. A plate-type continuous feeding system is arranged on the furnace top and matched with a material height measuring device, and the change of the material height is monitored in real time to add coke and calcium oxide. The calcium carbide furnace gas inlet system is arranged at the bottom of the reaction area, and four gas inlets are uniformly and annularly injected. The high-temperature flue gas outlet end of the calcium carbide furnace is connected with a cyclone dust removal device and connected with an outlet end centrifugal fan and a flue gas analyzer after dust removal and cooling, the change conditions of all temperature measurement points and a pressure gauge are observed, and the pressure in a hearth is accurately regulated and controlled by adjusting a tail end fan. The calcium carbide furnace body is formed by physically splicing a reaction area and a melting area connecting device, and calcium carbide flows out from the bottom after the connecting device is opened. The pressure in the oxygen thermal method calcium carbide furnace can be accurately regulated and controlled, and the economical efficiency and safety of the process are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of calcium carbide production equipment and process, in particular to an oxygen-thermal method for producing calcium carbide process equipped with a hearth pressure regulating system. BACKGROUND

[0002] Calcium carbide (CaC2) is commonly known as calcium carbide, which is an important chemical raw material connecting the organic and inorganic worlds. The energy structure of "rich in coal and poor in oil" in China determines that the coal-based calcium carbide is the mainstream process of calcium carbide production in China.

[0003] For a long time, the electric heating method for producing calcium carbide is used in industry, and the raw material is a mixture of blocky calcium oxide and blocky coke (5-30mm), which is introduced into the hearth from the top of the calcium carbide furnace. The electric arc heat and the Joule heat generated when the electric current passes through the conductive material (coke) are used to supply the raw material to be heated to above 2000℃, so as to synthesize molten calcium carbide which is discharged from the bottom of the furnace. The high-temperature CO generated during the production process is discharged from the upper part of the furnace body through the gaps of the blocky material, which is not reasonably utilized due to the difficulty in control. After cooling and crushing, it is packaged as finished product. The whole process involves the calcination of limestone into calcium oxide, the preparation of coke from coal, and the high energy consumption process of coal-fired power generation (the thermal efficiency of coal-fired power generation is less than 40%) to supply heat to the electrode.

[0004] Based on the defects of the traditional electric heating method for producing calcium carbide, the oxygen-thermal method for producing calcium carbide process is proposed. The main difference between the two processes is that the heat supply method is changed from electric heat supply to coke and oxygen combustion heat supply. The existing oxygen-thermal method for producing calcium carbide furnace types include fixed bed, gas flow bed, composite bed and slurry bubble bed, etc. The existing researches are directed to the material contact sites in the hearth and the heat exchange characteristics of the natural upward flow of gas and the natural downward movement of solid, ignoring the problems of pressure imbalance and temperature imbalance caused by uneven gas flow distribution in the furnace under high temperature atmosphere. Specifically, due to the participation of a large amount of oxygen in the oxygen-thermal process, and a large amount of high-temperature CO2 and CO will be generated in the coke combustion and calcium carbide synthesis reaction, the temperature rise will cause the formation of positive pressure in the hearth, and the gas is difficult to be discharged naturally upward, which causes the pressure in the furnace to be unable to be reasonably controlled, and further affects the temperature in the furnace. And the research shows that in the oxygen-thermal method for producing calcium carbide process, the pressure and temperature of the reaction stage will seriously affect the synthesis process of CaC2, further affecting the content of effective components in the produced calcium carbide, and in serious cases, there is a risk of oxygen concentration distribution and oxygen explosion. Ultimately, the economy and safety of the oxygen-thermal method for producing calcium carbide are reduced. SUMMARY

[0005] In order to solve the defect that the pressure in the hearth of the oxygen-thermal method for producing calcium carbide process cannot be reasonably controlled, the purpose of the present application is to provide an oxygen-thermal method for producing calcium carbide process equipped with a hearth pressure regulating system.

[0006] In order to achieve the above object, the present application adopts the following technical scheme: An oxygen hot method of producing calcium carbide with a hearth pressure regulating system, comprising an oxygen supply system 1, an oxygen pressure reducing valve 2, a high-pressure centrifugal fan 3, a fan ball valve 4, an oxygen flowmeter 5, a fan flowmeter 6, a gas mixing tank 7, a gas mixing tank pressure gauge 8, four mixed gas outlet valves 9, four mixed gas flowmeters 10, a material height measuring device 11, a calcium carbide furnace plate type continuous feeding system 12, a calcium carbide furnace body reaction zone 13, four oxygen inlet points 14, a calcium carbide furnace body melting zone 15, a reaction zone and melting zone connecting device 16, a temperature measuring point I 17, a pressure measuring point I 18, a temperature measuring point II 19, a temperature measuring point III 20, a temperature measuring point IV 21, a pressure measuring hole II 22, a reserved observation hole 23, an air outlet 24, a cyclone dust collector 25, a tubular heat exchanger 26, an outlet end centrifugal fan 27, a flue gas analyzer 28, an ignition device 29, a casting material layer 30, and a heat preservation layer 31.

[0007] The outlet of the oxygen supply system 1 is connected to the oxygen pressure reducing valve 2, and the outlet of the high-pressure centrifugal fan 3 is connected to the fan ball valve 4. Oxygen passes through the oxygen flowmeter 5, and air passes through the fan flowmeter 6 to enter the gas mixing tank 7 for mixing.

[0008] The top of the gas mixing tank 7 is connected to the gas mixing tank pressure gauge 8, and a row of evenly arranged four gas outlet holes on the side of the gas mixing tank 7 are controlled by the four mixed gas outlet valves 9. The mixed gas flow is controlled by the four mixed gas flowmeters 10 and enters the calcium carbide furnace body reaction zone 13 through the four oxygen inlet points 14 evenly distributed around the calcium carbide furnace.

[0009] The oxygen hot method calcium carbide furnace is composed of the calcium carbide furnace plate type continuous feeding system 12, the calcium carbide furnace body reaction zone 13, the reaction zone and melting zone connecting device 16, and the calcium carbide furnace body melting zone 15. The material height measuring device 11 is connected to the calcium carbide furnace plate type continuous feeding system 12 to control the height of the material added to the calcium carbide furnace, ensuring continuous feeding operation.

[0010] The reaction raw materials, coke and calcium oxide, are filled into the calcium carbide furnace body reaction zone 13 and the calcium carbide furnace body melting zone 15 before reaction, and the two are connected through the reaction zone and melting zone connecting device 16. In order to avoid the phenomenon of excessive bed resistance of stacked materials leading to difficulty in adjusting the furnace pressure, the first batch of stacked materials does not exceed half of the height of the hearth, and subsequent materials can be added according to the reaction situation through the calcium carbide furnace plate type continuous feeding system 12.

[0011] The side of the calcium carbide furnace is arranged from low to high with the temperature measuring point I 17, the pressure measuring point I 18, the temperature measuring point II 19, the temperature measuring point III 20, the temperature measuring point IV 21, the pressure measuring hole II 22, the reserved observation hole 23, and the air outlet 24. The pressure, temperature, and progress of the overall calcium carbide synthesis reaction are monitored.

[0012] The high-temperature tail gas of the gas outlet 24 is firstly dedusted by a cyclone dust collector 25, and then cooled by a tubular heat exchanger 26, so as to effectively control the smooth discharge of the tail gas. The tail gas is sent into a flue gas analyzer 28 for component analysis after being cooled to a temperature lower than 60 DEG C.

[0013] The oxygen-heating calcium carbide furnace is ignited by an ignition device 29 through an ignition hole reserved in a melting zone 15 of the furnace body, and the whole furnace body is composed of a cast layer 30 and an insulation layer 31.

[0014] The furnace pressure of the oxygen-heating calcium carbide furnace is regulated by the outlet end centrifugal fan 27 and a pressure measuring point I 18 and a pressure measuring hole II 22 on the side of the reaction zone 13 of the furnace body.

[0015] Compared with the existing oxygen-heating method, the present application has the following advantages.

[0016] The present application is an oxygen-heating calcium carbide process equipped with a furnace pressure regulating system, and a gas mixing system is designed to adjust the oxygen concentration according to the reaction, reasonably save the oxygen consumption and improve the economy of the oxygen-heating calcium carbide process.

[0017] The present application is an oxygen-heating calcium carbide process equipped with a furnace pressure regulating system, and a gas mixing system is designed to adjust the oxygen concentration according to the reaction, reasonably save the oxygen consumption and improve the economy of the oxygen-heating calcium carbide process.

[0018] The present application is an oxygen-heating calcium carbide process equipped with a furnace pressure regulating system, and a gas mixing system is designed to adjust the oxygen concentration according to the reaction, reasonably save the oxygen consumption and improve the economy of the oxygen-heating calcium carbide process.

[0019] The present application is an oxygen-heating calcium carbide process equipped with a furnace pressure regulating system, and a gas mixing system is designed to adjust the oxygen concentration according to the reaction, reasonably save the oxygen consumption and improve the economy of the oxygen-heating calcium carbide process. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The present application is an oxygen-heating calcium carbide process equipped with a furnace pressure regulating system, and a gas mixing system is designed to adjust the oxygen concentration according to the reaction, reasonably save the oxygen consumption and improve the economy of the oxygen-heating calcium carbide process.

[0021] Figure 2 The present application is an oxygen-heating calcium carbide process equipped with a furnace pressure regulating system, and a gas mixing system is designed to adjust the oxygen concentration according to the reaction, reasonably save the oxygen consumption and improve the economy of the oxygen-heating calcium carbide process. DETAILED DESCRIPTION

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "top," "bottom," "one side," "the other side," "front," "rear," "middle part," "inner," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The present invention will now be described in further detail with reference to the accompanying drawings.

[0025] like Figure 1 Figure 2 As shown, this invention provides an oxythermal calcium carbide production process equipped with a furnace pressure regulation system, including an oxygen supply system 1, an oxygen pressure reducing valve 2, a high-pressure centrifugal fan 3, a fan ball valve 4, an oxygen flow meter 5, a fan flow meter 6, a mixing tank 7, a mixing tank pressure gauge 8, four mixed gas outlet valves 9, four mixed gas flow meters 10, a material height measuring device 11, a calcium carbide furnace plate-type continuous feeding system 12, a calcium carbide furnace reaction zone 13, four oxygen inlet points 14, a calcium carbide furnace melting zone 15, a connection device between the reaction zone and the melting zone 16, a temperature measuring point I 17, a pressure measuring point I 18, a temperature measuring point II 19, a temperature measuring point III 20, a temperature measuring point IV 21, a pressure measuring hole II 22, a reserved observation hole 23, a gas outlet 24, a cyclone dust collector 25, a tubular heat exchanger 26, an outlet-end centrifugal fan 27, a flue gas analyzer 28, an ignition device 29, a casting material layer 30, and an insulation layer 31.

[0026] The top of the gas mixing tank 7 is connected with a gas mixing tank pressure gauge 8. A row of four evenly opened gas outlets is arranged on the side of the gas mixing tank 7, and the four gas outlets are controlled by four mixed gas outlet valves 9. The mixed gas flow is controlled by four mixed gas flow meters 10, and the four oxygen inlets 14 are evenly distributed around the calcium carbide furnace to enter the reaction zone 13 of the calcium carbide furnace body.

[0027] The oxygen-heating method calcium carbide furnace is composed of a calcium carbide furnace plate-type continuous feeding system 12, a calcium carbide furnace body reaction zone 13, a reaction zone and melting zone connecting device 16, and a calcium carbide furnace body melting zone 15. The material height measuring device 11 is connected with the calcium carbide furnace plate-type continuous feeding system 12 to control the height of the material added into the calcium carbide furnace and ensure continuous feeding operation.

[0028] The reaction raw materials coke and calcium oxide are filled into the calcium carbide furnace body reaction zone 13 and the calcium carbide furnace body melting zone 15 before reaction, and the two are connected through the reaction zone and melting zone connecting device 16. In order to avoid the phenomenon that the bed resistance of the stacked material parameters is too large, causing the furnace pressure to be difficult to adjust, the first batch of stacked materials does not exceed half of the height of the furnace chamber, and subsequent materials can be supplemented according to the reaction situation through the calcium carbide furnace plate-type continuous feeding system 12.

[0029] The side of the calcium carbide furnace is arranged from low to high with a temperature measuring point I 17, a pressure measuring point I 18, a temperature measuring point II 19, a temperature measuring point III 20, a temperature measuring point IV 21, a pressure measuring hole II 22, a reserved observation hole 23, and a gas outlet 24. The pressure, temperature and reaction situation of the overall calcium carbide synthesis reaction are monitored.

[0030] The high-temperature tail gas of the gas outlet 24 is first dedusted by a cyclone dust collector 25, and then cooled by a tubular heat exchanger 26. In order to effectively control the smooth discharge of the tail gas, the outlet end centrifugal fan 27 is connected to the reduced temperature section (temperature lower than 60℃), and the outlet flue gas is sent into the flue gas analyzer 28 for composition analysis.

[0031] The oxygen-heating method calcium carbide furnace is ignited by an ignition device 29 through the ignition hole reserved in the calcium carbide furnace body melting zone 15. The whole furnace body is composed of a cast layer 30 and an insulation layer 31.

[0032] The pressure in the oxygen-heating method calcium carbide furnace is regulated by the outlet end centrifugal fan 27 and the pressure measuring point I 18 and the pressure measuring hole II 22 on the side of the calcium carbide furnace body reaction zone 13.

[0033] In the above embodiments, in order to concentrate heat, the furnace body is selected as a high and thin container (the height-diameter ratio is between 10-16), the furnace body is cast by steel sintered silicon carbide castable, the outer layer is added with perlite light insulation layer, in order to ensure that the high-temperature flue gas is smoothly discharged and the atmosphere in the furnace is uniformly distributed during the reaction, the furnace is always in a micro-negative pressure condition (-0.5 KPa or so), the oxygen concentration is pure oxygen at the beginning, and air mixing is carried out when the subsequent reaction reaches the peak value, the safety is ensured while the economy is improved, the highest operating temperature in the furnace is 1800-2600℃, the purity of calcium carbide reaches an excellent level (CaC2≥80%), the operating conditions in the furnace can be accurately controlled according to the flue gas composition and the temperature and pressure at each position in the furnace, and the economy and safety are high.

[0034] Before the reaction starts, thermocouples and pressure gauges are installed on the temperature measuring points 17, pressure measuring points 18, temperature measuring points 19, temperature measuring points 20, temperature measuring points 21 and pressure holes 22 from low to high on the side of the calcium carbide furnace, the reaction zone 13 of the calcium carbide furnace body is connected to the melting zone 15 of the calcium carbide furnace body through the reaction zone and melting zone connecting device 16, and the reactant material block coke and calcium oxide are stacked to half the height of the spliced furnace body before the reaction according to the molar ratio of 1:11 (CaO:C), and the remaining materials are loaded into the calcium carbide furnace plate type continuous feeding system 12 and connected to the furnace body. In order to make the reaction proceed quickly, the oxygen supply system 1 supplies pure oxygen gas alone at the beginning, the pure oxygen gas enters the gas mixing tank 7 through the oxygen pressure reducing valve 2, and enters the furnace through four mixed gas outlet valves 9 and four mixed gas flow meters 10 according to a certain flow rate through four oxygen inlet points 14. The outlet end centrifugal fan 27 and the pressure measuring points 18 and pressure holes 22 on the side of the calcium carbide furnace body reaction zone 13 are used to control the micro-negative pressure in the furnace, and the ignition device 29 is used for ignition and combustion. The high-temperature tail gas cyclone dust collector 25 of the gas outlet 24 is used for dust removal, the tubular heat exchanger 26 is used for cooling and heat exchange, the outlet flue gas is sent into the flue gas analyzer 28 for composition analysis, and the pressure gauge and the temperature gauge are used for dynamic adjustment according to the readings, and the heat supply efficiency is improved.

[0035] The existing research on the oxygen-thermal method for producing calcium carbide mainly focuses on the heat transfer process of the high-temperature CO2 produced by the combustion of heating coke at the bottom of the furnace under normal pressure, and the basic properties of the material (particle size, ratio, characteristics of carbon materials and calcium materials), ignoring the influence of the pressure in the furnace on the entire calcium carbide synthesis reaction process. The uneven distribution of airflow in the furnace and the local overheating of temperature caused by the uncontrollable pressure in the furnace.

[0036] In a preferred embodiment, the theoretical conditions of the oxygen thermal method calcium carbide production are CaO:O2:C=1:4:11 (mole ratio), and the gas mixing system 7 can adjust the oxygen concentration according to the reaction degree, so that all the coke is completely burned into CO2, the oxygen consumption is saved, the ratio is controlled to be CaO:O2:C=1:2:6, the energy utilization rate of the oxygen thermal method is improved, and the economy is improved.

[0037] In a preferred embodiment, the material height measuring device 11 is matched with the calcium carbide furnace plate type continuous feeding system 12, and the reserved observation hole 23 is matched with the material height measuring device 11 to monitor the change of the material height in real time, so that the effect of material replenishment is achieved, and the continuous production of calcium carbide is realized.

[0038] In a preferred embodiment, the calcium carbide furnace plate type continuous feeding system 12, the calcium carbide furnace body reaction zone 13 and the calcium carbide furnace body melting zone 15 are all cast by steel jade silicon carbide castable, and the outer layer is added with a perlite light weight insulation layer.

[0039] In a preferred embodiment, the calcium carbide furnace plate type continuous feeding system 12, the calcium carbide furnace body reaction zone 13 and the calcium carbide furnace body melting zone 15 are connected in a physical splicing manner by the reaction zone and the melting zone connecting device 16, so that if local damage occurs in the hearth, the design is convenient for maintenance based on the light weight insulation material.

[0040] In a preferred embodiment, the calcium carbide furnace plate type continuous feeding system 12, the calcium carbide furnace body reaction zone 13 and the calcium carbide furnace body melting zone 15 are connected in a physical splicing manner by the reaction zone and the melting zone connecting device 16, so that if local damage occurs in the hearth, the design is convenient for maintenance based on the light weight insulation layer 31.

[0041] In a preferred embodiment, the four oxygen inlet points 14 are uniformly surrounded by the calcium carbide furnace wall and sprayed into the calcium carbide furnace body reaction zone 14, so as to ensure the initial uniform distribution of oxygen in the hearth.

[0042] In a preferred embodiment, the calcium carbide furnace wall is designed from low to high, and the temperature measuring point I 17, the pressure measuring point I 18, the temperature measuring point II 19, the temperature measuring point III 20, the temperature measuring point IV 21, the pressure measuring hole II 22 and the reserved observation hole 23 are arranged to monitor the pressure, temperature and reaction of the whole calcium carbide synthesis reaction process. In an absolutely closed environment, the temperature and pressure changes in the hearth can be effectively monitored, the concentration changes of various gas components in the tail gas analyzer 28 can be effectively monitored, and the precision control of the tail gas outlet end centrifugal fan 27 can effectively adjust the pressure in the furnace to improve the safety of the oxygen thermal method calcium carbide production process.

[0043] It will be obvious to a person skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments and can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims to the identity of the reference signs therein.

[0044] Furthermore, it should be understood that although the description is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A thermo-oxygenated calcium carbide production process equipped with a furnace pressure regulating system, characterized in that: It includes an air-oxygen mixed gas intake system, a continuous plate feeding system for the calcium carbide furnace, the calcium carbide furnace body, a temperature and pressure measurement system for the calcium carbide furnace, a flue gas analyzer, and a centrifugal fan at the outlet.

2. The continuous feeding system for the calcium carbide furnace plate is located at the top of the furnace and is equipped with a material height measuring device to monitor changes in material height in real time, achieving the effect of replenishing material when needed and realizing continuous production of calcium carbide. The furnace body consists of a reaction zone and a melting zone, which are physically connected by a connection device. Molten or semi-solid calcium carbide can be obtained by opening the connection device.

3. The oxygen-thermal calcium carbide production process equipped with a furnace pressure regulating system according to claim 1, characterized in that: Four oxygen inlet points are uniformly injected into the reaction zone of the calcium carbide furnace body through a circumferential cut from the furnace wall, and are equipped with a gas mixing system and independent control valves.

4. The oxygen-thermal calcium carbide production process equipped with a furnace pressure regulating system according to claim 1, characterized in that: The material height monitoring device is installed at the second sealing layer of the plate feeding device.

5. The oxygen-thermal calcium carbide production process equipped with a furnace pressure regulating system according to claim 1, characterized in that: The three parts of the calcium carbide furnace—the charging zone, the reaction zone, and the melting zone—are assembled using a physical connection method. All parts are cast from corundum silicon carbide castable, and the outer insulation layer is a perlite layer.

6. The oxygen-thermal calcium carbide production process equipped with a furnace pressure regulating system according to claim 1, characterized in that: One pressure gauge is located at the bottom of the reaction zone, and another is located at the gas outlet. All temperature measuring points are equidistant from each other and are positioned at the center of the furnace.

7. The oxygen-thermal calcium carbide production process equipped with a furnace pressure regulating system according to claim 1, characterized in that: A cyclone dust collector is connected to the high-temperature flue gas outlet of the calcium carbide furnace. The cyclone dust collector is connected to a tubular heat exchanger. The tubular heat exchanger is connected to a centrifugal fan at the outlet. The centrifugal fan at the outlet is connected to a flue gas analyzer.

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