Efficient heat energy recovery process for flue gas filtration for caustic-burned magnesia powder furnace

Abstract

The invention discloses an efficient heat energy recovery process for filtering flue gas for a caustic-burned magnesia powder furnace kiln, which comprises the following steps: A, dust removal: flue gas enters dust removal equipment through a gas inlet pipe, and the dust removal equipment is an electric dust remover or a cloth bag filter so as to remove solid particles in the flue gas, reduce the emission concentration and protect the atmospheric environment; and B, desulfurization: carrying out desulfurization treatment on sulfur dioxide in the flue gas through a desulfurization technology. The flue gas is subjected to dust removal, desulfurization and denitration treatment in advance, the content of solid particles, the content of sulfur and the content of nitrate in the flue gas can be effectively reduced, so that the sanitation of the surrounding environment is guaranteed, meanwhile, the treated flue gas is conveyed into the cooling mechanism, high-temperature flue gas can be cooled, and in the process, the flue gas can be cooled, so that the environment is protected. And the heat of the flue gas can be transferred into the water body, so that people can conveniently use hot water, the purpose of recycling the heat is achieved, and the national energy-saving and emission-reducing requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of light-burned magnesium production, and in particular to a heat energy efficient recovery process for flue gas filtration in a light-burned magnesium powder furnace. Background Art

[0002] Light-burned magnesium powder is a powdery material obtained by crushing light-burned magnesium. Light-burned magnesium is obtained by calcining magnesite, brucite and magnesium hydroxide extracted from seawater or brine at about 800-1000℃ to decompose and discharge CO2 or H2O. It is widely used in building materials, chemical industry, metallurgy, medicine and other fields. It is an ideal material for producing fireproof boards, lightweight partition boards, magnesium sulfate, papermaking, desulfurization process, steel plant protection and splashing slag, etc. Light-burned magnesium powder needs to use kilns in the production process. Kilns are a kind of kilns. According to the type of calcined materials, they can be divided into ceramic kilns, cement kilns, glass kilns, enamel kilns, etc. The former can be divided into continuous kilns (tunnel kilns), semi-continuous kilns and intermittent kilns according to the operation method, and can be divided into flame kilns and electric kilns according to the heat source. According to the heat source facing the blank, it can be divided into open flame kiln, muffle flame kiln and semi-muffle flame kiln. According to the blank carrier, it can be divided into kiln car kiln, push plate kiln, roller bottom kiln (roller kiln), conveyor belt kiln, walking beam kiln and air cushion kiln, etc. According to the number of channels, it can be divided into single channel kiln, double channel kiln and multi-channel kiln. Generally, large kilns are fueled by heavy oil, light diesel oil or coal gas, natural gas. The kiln is usually composed of four parts: kiln chamber, combustion equipment, ventilation equipment and conveying equipment. Electric kilns mostly use electric furnace wire, silicon carbon rod or molybdenum disilicide as heating elements. They have a relatively simple structure and are easy to operate. In the process of preparing light-burned magnesium powder in the kiln, a large amount of high-temperature flue gas will be generated, which not only increases environmental pollution, but also causes heat energy loss, which does not meet the national energy conservation and emission reduction needs. Summary of the invention

[0003] The object of the present invention is to provide a high-efficiency heat recovery process for flue gas filtration in a light-burned magnesium powder furnace to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a process for efficiently recovering heat energy for flue gas filtration in a light-burned magnesium powder furnace, comprising the following steps: A. Dust removal: The flue gas enters the dust removal equipment through the air intake pipe. The dust removal equipment is an electrostatic precipitator or a bag filter to remove solid particles in the flue gas, reduce emission concentration, and protect the atmospheric environment; B. Desulfurization: Desulfurize the sulfur dioxide in the flue gas through desulfurization technology; C. Denitrification: Denitrification of nitrogen oxides in flue gas is carried out through denitrification technology; D. Flue gas cooling: The flue gas treated in the above steps is transported to the cooling mechanism through the cooling pipeline for cooling; E. Waste heat recovery: discharge the water heated by flue gas so that people can use hot water; F. Chimney emission: The flue gas after cooling is discharged into the atmosphere from the exhaust pipe, and the emission concentration must be lower than the statutory emission standard.

[0005] Preferably, the desulfurization technology includes wet desulfurization and dry desulfurization, and the wet desulfurization is a limestone-gypsum desulfurization method.

[0006] Preferably, the denitrification technology includes selective catalytic reduction and selective non-catalytic reduction.

[0007] Preferably, other treatments are also included: the flue gas discharged from some light-burned magnesium powder furnaces needs to undergo defluorination and demercuration treatment steps to reduce the emission of fluoride and mercury pollutants, and the defluorination treatment adopts an adsorption method or a crystallization method, and the mercury removal treatment adopts an activated carbon adsorption method or a chemical precipitation method.

[0008] Preferably, it also includes a power generation mechanism, which is arranged between the air intake pipe and the dust removal equipment. The power generation mechanism includes a spoiler arranged above the rotor. The rotor is arranged inside the protective cover. A stator is arranged inside the protective cover and at a corresponding position of the rotor. The stator is connected to an external battery through a wire, and the protective cover is arranged in a cooling water tank, and the spoiler is located 3-5 cm above the water body of the cooling water tank.

[0009] Preferably, the cooling mechanism comprises a water tank, which is provided with a water inlet, a water outlet and a heat conducting coil, one end of the heat conducting coil is connected to the cooling pipe, and the other end of the heat conducting coil is connected to the exhaust pipe.

[0010] Preferably, a circulation pump is provided at the exhaust pipe, and a sensor for detecting the flue gas standard is provided inside the circulation pump. When the flue gas detection does not meet the standard, step A is repeated through the first outlet pipe of the circulation pump. When the flue gas detection meets the standard, it is directly discharged from the second outlet pipe of the circulation pump.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention performs dust removal, desulfurization and denitrification treatment on the flue gas in advance, which can effectively reduce the content of solid particles, sulfur content and nitrate content in the flue gas, thereby ensuring the hygiene of the surrounding environment. At the same time, the flue gas after the above treatment is transported to the cooling mechanism, and the high-temperature flue gas can be cooled. In this process, the heat of the flue gas can be transferred to the water body, so that people can use hot water conveniently, achieve the purpose of heat recycling, and meet the national energy conservation and emission reduction requirements.

[0012] 2. The present invention can further reduce the content of fluoride and mercury in the flue gas discharged from the light-burned magnesium powder furnace through fluorine removal and mercury removal treatment, and a power generation mechanism is added between the air intake pipe and the dust removal equipment. The air blows the spoiler to rotate, and the spoiler drives the rotor to rotate, and generates electrical energy with the cooperation of the stator, and stores the electrical energy in the battery, which can achieve the purpose of self-generation, thereby further improving the utilization rate of the flue gas. DETAILED DESCRIPTION

[0013] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0014] A highly efficient heat recovery process for flue gas filtration in a light-burned magnesium powder furnace comprises the following steps: A. Dust removal: Flue gas enters the dust removal equipment through the air intake pipe. The dust removal equipment is an electrostatic precipitator or a bag filter to remove solid particles in the flue gas, reduce emission concentration, and protect the atmospheric environment. Dust removal equipment is the first step in flue gas treatment and is crucial to the subsequent treatment process; B. Desulfurization: Desulfurize the sulfur dioxide in the flue gas through desulfurization technology; C. Denitrification: Denitrification of nitrogen oxides in flue gas is carried out through denitrification technology; D. Flue gas cooling: The flue gas treated in the above steps is transported to the cooling mechanism through the cooling pipeline for cooling; E. Waste heat recovery: discharge the water heated by flue gas so that people can use hot water; F. Chimney emission: The flue gas after cooling is discharged into the atmosphere from the exhaust pipe, and the emission concentration must be lower than the statutory emission standard.

[0015] Pre-treatment of flue gas with dust removal, desulfurization and denitrification can effectively reduce the content of solid particles, sulfur and nitrogen in the flue gas, thereby ensuring the hygiene of the surrounding environment. At the same time, the flue gas after the above treatment is transported to the cooling mechanism to cool the high-temperature flue gas. In this process, the heat of the flue gas can be transferred to the water body, which can facilitate people's use of hot water and achieve the purpose of heat recycling, which is in line with the national energy conservation and emission reduction needs.

[0016] Desulfurization technologies include wet desulfurization and dry desulfurization, and wet desulfurization is a limestone-gypsum desulfurization method. Denitrification technologies include selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR). SCR technology has high denitrification efficiency, but a large investment cost. SNCR technology has a low investment cost, but a relatively low denitrification efficiency. Other treatments are also included: the flue gas discharged from some light-burned magnesium powder furnaces must also undergo defluorination and demercury treatment steps to reduce the emission of fluoride and mercury pollutants. The defluorination treatment adopts an adsorption method or a crystallization method, and the mercury removal treatment adopts an activated carbon adsorption method or a chemical precipitation method. A power generation mechanism is also included. The power generation mechanism is arranged between the air intake pipe and the dust removal equipment. The power generation mechanism includes a spoiler arranged above the rotor, and the rotor is arranged inside the protective cover. A stator is arranged on the inner side of the protective cover and at a corresponding position of the rotor. The stator is connected to an external battery through a wire, and the protective cover is arranged in a cooling water tank. and the spoiler is located 3-5cm above the water in the cooling water tank. The cooling mechanism includes a water storage tank, which is provided with a water inlet, a water outlet and a heat transfer coil. One end of the heat transfer coil is connected to the cooling pipe, and the other end of the heat transfer coil is connected to the exhaust pipe. A circulating pump is provided at the exhaust pipe. A sensor for detecting the flue gas standard is provided inside the circulating pump. When the flue gas detection does not meet the standard, step A is repeated through the first outlet pipe of the circulating pump. When the flue gas detection meets the standard, it is directly discharged from the second outlet pipe of the circulating pump. The content of fluoride and mercury in the flue gas discharged from the light-burned magnesium powder furnace can be further reduced by defluorination and demercuration treatment. A power generation mechanism is added between the air inlet pipe and the dust removal equipment. The air blows the spoiler to rotate, and the spoiler drives the rotor to rotate, and generates electrical energy with the cooperation of the stator, and stores the electrical energy in the battery, which can achieve the purpose of self-generation, thereby further improving the utilization rate of the flue gas.

[0017] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly efficient heat recovery process for flue gas filtration in a light-burned magnesium powder furnace, characterized in that: The following steps are involved: A. Dust removal: The flue gas enters the dust removal equipment through the air intake pipe. The dust removal equipment is an electrostatic precipitator or a bag filter to remove solid particles in the flue gas, reduce emission concentration, and protect the atmospheric environment; B. Desulfurization: Desulfurize the sulfur dioxide in the flue gas through desulfurization technology; C. Denitrification: Denitrification of nitrogen oxides in flue gas is carried out through denitrification technology; D. Flue gas cooling: The flue gas treated in the above steps is transported to the cooling mechanism through the cooling pipeline for cooling; E. Waste heat recovery: discharge the water heated by flue gas so that people can use hot water; F. Chimney emission: The flue gas after cooling is discharged into the atmosphere from the exhaust pipe, and the emission concentration must be lower than the statutory emission standard.

2. The high-efficiency heat recovery process for flue gas filtration of a light-burned magnesium powder furnace according to claim 1, characterized in that: Desulfurization technologies include wet desulfurization and dry desulfurization, and wet desulfurization is a limestone-gypsum desulfurization method.

3. The high-efficiency heat recovery process for flue gas filtration of a light-burned magnesium powder furnace according to claim 1, characterized in that: Denitrification technologies include selective catalytic reduction and selective non-catalytic reduction.

4. The high-efficiency heat recovery process for flue gas filtration of a light-burned magnesium powder furnace according to claim 1, characterized in that: Other treatments are also included: the flue gas emitted by some light-burned magnesium powder furnaces must also undergo defluorination and demercuration treatment steps to reduce the emission of fluoride and mercury pollutants. The defluorination treatment adopts adsorption or crystallization method, and the mercury removal treatment adopts activated carbon adsorption method or chemical precipitation method.

5. The high-efficiency heat recovery process for flue gas filtration of a light-burned magnesium powder furnace according to claim 1, characterized in that: It also includes a power generation mechanism, which is arranged between the air intake pipe and the dust removal equipment. The power generation mechanism includes a spoiler arranged above the rotor. The rotor is arranged inside the protective cover. A stator is arranged inside the protective cover and at a corresponding position of the rotor. The stator is connected to an external battery through a wire. The protective cover is arranged in a cooling water tank, and the spoiler is located 3-5 cm above the water body of the cooling water tank.

6. The high-efficiency heat recovery process for flue gas filtration of a light-burned magnesium powder furnace according to claim 1, characterized in that: The cooling mechanism comprises a water storage tank, which is provided with a water inlet, a water outlet and a heat conducting coil, one end of the heat conducting coil is connected to the cooling pipe, and the other end of the heat conducting coil is connected to the exhaust pipe.

7. The high-efficiency heat recovery process for flue gas filtration of a light-burned magnesium powder furnace according to claim 1, characterized in that: A circulation pump is provided at the exhaust pipe, and a sensor for detecting the flue gas standard is provided inside the circulation pump. When the flue gas detection does not meet the standard, step A is repeated through the first outlet pipe of the circulation pump. When the flue gas detection meets the standard, it is directly discharged from the second outlet pipe of the circulation pump.