Raw gas collecting system and method for internal heating type vertical furnace
By setting up a material separation tower and rising pipe in the internal heat-type upright furnace, a gas collection chamber and a coal downward movement channel are formed, and dust is collected in combination with the water spraying device, the problem of dust carrying of waste gas is solved, and efficient collection of waste gas and stable operation of the system is achieved.
Patent Information
- Application Number
- CN202510491884.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2025-07-18
AI Technical Summary
During the internal heat-type upright furnace, the waste gas carries a large amount of dust during the collection of waste gas, resulting in device blockage and increased construction costs, which is difficult to effectively solve the problem of the existing technology.
A material separation tower and an ascending pipe are installed in the internal heat-type upright furnace to form a coal downward movement channel and a gas collection chamber. The temperature of the waste gas is reduced by a water spray device and dust is collected. The negative pressure gas collection chamber and the coal downward movement channel are used to reduce the dissipation of waste gas, and the efficient collection of waste gas is achieved.
It effectively reduces the amount of dust carried by waste gas, reduces the risk of device blockage, reduces construction costs, and improves the stability and efficiency of the system.
Smart Images
Figure CN120329958A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of low-rank coal carbonization, and particularly to a raw gas collection system and method in an internally heated vertical furnace. Background Art
[0002] According to different structures and compositions, coal is divided into three categories: lignite, bituminous coal, and anthracite. Among them, bituminous coal can be divided into low-rank bituminous coal and medium-rank bituminous coal. Low-rank bituminous coal is also called sub-bituminous coal, and together with lignite, it is collectively referred to as "low-rank coal". Due to its low thermal efficiency in direct combustion and the emission of a large amount of pollutants such as dust, low-rank coal has a greater impact on the environment than other coal types. Therefore, large-scale development must first process and upgrade it. One of the most scientific and common methods is pyrolysis. Low-rank coal carbonization is a process in which coal is pyrolyzed at a relatively low temperature (500 - 700 °C) under an airtight condition. During this process, coal will decompose into solid semi-coke, liquid tar, and gaseous coal gas. Semi-coke can be used as boiler fuel and gasification raw material, containing far fewer pollutants than raw coal and having less impact on the environment.
[0003] At present, the main process equipment for low-rank coal carbonization includes internally heated vertical furnaces, externally heated vertical furnaces, Guofu furnaces, etc. Due to the characteristics of low-rank pulverized coal such as low ash, low sulfur, high volatile matter, high oil content (>10%), and poor thermal stability, the common and core problems existing in the current low-rank pulverized coal carbonization process are that a large amount of dust is carried during the derivation of raw gas in the carbonization process, and the device is blocked and difficult to operate stably for a long time.
[0004] Taking the internally heated vertical furnace as an example, its furnace top is a flat-top structure, and a gas collection umbrella is arranged in the furnace body near the top to collect raw gas. When the raw gas rises to the top of the drying section, the temperature is about 80 - 110 °C. Most of the raw gas enters the raw gas pipeline through the gas collection umbrella. However, since the coal processed by the internally heated vertical furnace is lump coal, and the gas collection umbrella is buried in the coal during production, the raw gas inevitably diffuses into the coal seam and escapes from the bin top. Therefore, a double-chamber and double-valve seal needs to be set on the bin top, resulting in a higher cloth layer on the bin top and an increase in construction costs. In addition, since the area of the gas collection umbrella is smaller than the cross-sectional area of the carbonization furnace, the speed of the raw gas entering the gas collection umbrella is relatively fast, so a large amount of dust will be carried into the raw gas pipeline. Summary of the Invention
[0005] The present invention provides an internally heated vertical furnace raw gas collection system and method. A raw gas collection system is arranged between the coal bin and the drying section of the vertical furnace. By setting a distributing tower, two coal downward movement channels are formed on both sides of the vertical furnace. At the same time, a gas collection chamber with a relatively large space and in a negative pressure state is formed at the bottom of the distributing tower, avoiding the escape of raw gas through the narrow coal downward movement channels to the coal bin above, and the raw gas will not carry a large amount of dust when entering the gas main pipe.
[0006] To achieve the above object, the present invention is implemented by the following technical solutions:
[0007] An internal-heating vertical furnace raw gas collection system. The vertical furnace is successively provided with a coal bin, a drying section, a carbonization section, a cooling section and a coke discharging section from top to bottom. The raw gas collection system is arranged between the coal bin and the drying section. The raw gas collection system includes a distributing tower, riser pipes and a gas main pipe. The distributing tower is arranged longitudinally along the vertical furnace. The distributing tower is a hollow structure composed of a conical top section, a vertical section and a conical bottom. The cross-sections of both the conical top section and the conical bottom section are cones that contract upward. The conical top section serves as the bottom of the coal bin. A coal downward movement channel is formed between the vertical section and the furnace walls on both sides. The cavity between the conical bottom section and the coal material that naturally accumulates after entering the lower drying section is the gas collection chamber. A plurality of riser pipes are arranged at the center of the top of the conical bottom section. The riser pipes are communicated with the gas main pipe arranged in the distributing tower. One end of the gas main pipe extends outside the vertical furnace and is connected to an external gas purification and treatment system.
[0008] The width of the coal downward movement channel is 600 - 800 mm.
[0009] The plurality of riser pipes are uniformly arranged longitudinally along the vertical furnace.
[0010] The riser pipe is composed of a straight pipe and a 180° elbow. The lower end of the straight pipe is communicated with the gas collection chamber. The upper section of the straight pipe is connected to one end of the 180° elbow. The other end of the 180° elbow section is connected to the gas main pipe. The gas main pipe is horizontally arranged.
[0011] A water spraying device is arranged at the inner upper part of the 180° elbow close to the gas main pipe.
[0012] The cone angle of the conical top section is ≥ 45°.
[0013] The cone angle of the conical bottom section is 40° - 50°.
[0014] A plurality of gas outlet pipes are arranged on the furnace wall of the vertical furnace outside the coal downward movement channel. The plurality of gas outlet pipes are uniformly arranged longitudinally along the vertical furnace. A gas outlet pipe is arranged at the gas outlet. The gas outlet pipe is inclined upward and outward. The gas outlet pipe is connected to an external VOCs treatment unit through a connecting pipe. A fan is arranged on the connecting pipe.
[0015] An internal-heating vertical furnace raw gas collection method includes the following processes:
[0016] 1) After the coal material is loaded into the coal bin, it moves downward through the coal downward movement channels on both sides of the distributing tower and enters the drying section. The coal material after entering the drying section naturally accumulates below the distributing tower, forming a gas collection chamber with a rhombus cross-section between it and the conical bottom section of the distributing tower.
[0017] 2) The raw gas at 500 - 600 °C produced by coal carbonization is cooled to 80 - 110 °C after heat exchange with the coal material in the drying section. After passing through the coal seam, the raw gas reaches the gas collecting chamber, and then enters the riser pipe from the top of the gas collecting chamber. The escape velocity of the raw gas when entering the riser pipe is 0.6 - 0.8 times the upward velocity of the raw gas in the furnace body.
[0018] 3) Before the raw gas enters the main gas pipe, water is sprayed into the raw gas in the riser pipe through a water spraying device to lower the temperature of the raw gas. At the same time, tar is precipitated and dust is trapped. The raw gas after water spraying and cooling enters the main gas pipe together with the mixture of tar and water vapor and is sent to the subsequent gas purification treatment system.
[0019] Under the action of the fan, a small amount of raw gas escaping into the coal downward movement channel is extracted through the gas outlet pipe arranged outside the coal downward movement channel and sent to the external VOCs treatment unit.
[0020] Compared with the prior art, the beneficial effects of the present invention are:
[0021] (1) A gas collecting chamber with a relatively large space is formed between the conical bottom section of the distributing tower and the naturally piled coal material below. The gas collecting chamber is in a negative pressure state, which is more conducive to the escape of the raw gas from the gas collecting chamber to the riser pipe. At the same time, the gas collecting chamber effectively reduces the escape velocity of the raw gas, thereby effectively reducing the amount of dust carried by the raw gas.
[0022] (2) A coal downward movement channel is formed between the vertical section of the distributing tower and the furnace wall of the vertical furnace, which not only realizes the effective connection between the coal bunker and the drying section, but also effectively avoids the escape of the raw gas into the upper coal bunker because the cross-sectional area of the coal downward movement channel is much smaller than that of the vertical furnace. Compared with the method using a double-chamber and double-valve, the investment is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is the front view of the raw gas collection system of the internal-heating vertical furnace described in the present invention ( Figure 2 view A-A in
[0024] Figure 2 is Figure 1 the side view of Figure 1 view B-B in
[0025] In the figure: 1. Coal bunker; 2. Drying section; 3. Distributing tower; 4. Coal downward movement channel; 5. Gas collecting chamber; 6. Riser pipe; 7. Main gas pipe; 8. Water spraying device; 9. Gas outlet pipe DETAILED DESCRIPTION OF THE INVENTION
[0026] The following further describes the specific embodiments of the present invention with reference to the accompanying drawings:
[0027] As shown in Figure 1 andFigure 2 As shown in the figure, for the raw gas collection system of an internally heated vertical furnace according to the present invention, a coal bunker 1, a drying section 2, a carbonization section, a cooling section, and a coke discharging section are successively arranged in the vertical furnace from top to bottom. The raw gas collection system is arranged between the coal bunker 1 and the drying section 2. The raw gas collection system includes a distributing tower 3, riser pipes 6, and a main gas pipe 7. The distributing tower 3 is arranged longitudinally along the vertical furnace. The distributing tower 3 is a hollow structure composed of a conical top section, a vertical section, and a conical bottom. The cross-sections of both the conical top section and the conical bottom section are cones that contract upward. The conical top section serves as the bottom of the coal bunker 1. A coal downward movement channel 4 is formed between the vertical section and the furnace walls on both sides. The cavity between the conical bottom section and the coal material that naturally accumulates after entering the lower drying section 2 is a gas collection chamber 5. Multiple riser pipes 6 are arranged at the center of the top of the conical bottom section. The riser pipes 6 are communicated with the main gas pipe 7 arranged in the distributing tower 3. One end of the main gas pipe 7 extends outside the vertical furnace and is connected to an external gas purification and treatment system.
[0028] The width of the coal downward movement channel (the distance between the vertical section of the distributing tower 3 and the corresponding side furnace wall of the vertical furnace) is 600 - 800 mm.
[0029] The multiple riser pipes 6 are uniformly arranged longitudinally along the vertical furnace.
[0030] The riser pipe 6 is composed of a straight pipe and a 180° elbow. The lower end of the straight pipe is communicated with the gas collection chamber 5. The upper section of the straight pipe is connected to one end of the 180° elbow. The other end of the 180° elbow section is connected to the main gas pipe 7, and the main gas pipe 7 is horizontally arranged.
[0031] A water spraying device 8 is arranged at the inner upper part of the 180° elbow close to the main gas pipe 7.
[0032] The cone angle of the conical top section is ≥ 45°.
[0033] The cone angle of the conical bottom section is 40° - 50°.
[0034] Multiple gas outlet ports are arranged on the furnace wall of the vertical furnace outside the coal downward movement channel 4. The multiple gas outlet ports are uniformly arranged longitudinally along the vertical furnace. A gas outlet pipe 9 is arranged at the gas outlet port. The gas outlet pipe 9 is inclined upward and outward. The gas outlet pipe 9 is connected to an external VOCs (volatile organic compounds) treatment unit through a connecting pipe, and a fan is arranged on the connecting pipe.
[0035] A method for collecting raw gas from an internally heated vertical furnace according to the present invention includes the following processes:
[0036] 1) After the coal material is loaded into the coal bunker 1, it moves downward through the coal downward movement channels 4 on both sides of the distributing tower 3 and enters the drying section 2. The coal material that enters the drying section 2 naturally accumulates below the distributing tower 3, and a gas collection chamber 5 with a rhombus cross-section is formed between the coal material and the conical bottom section of the distributing tower 3.
[0037] 2) The raw gas at 500 - 600 °C produced by coal carbonization is cooled to 80 - 110 °C after heat exchange with the coal charge in the drying section 2, then passes through the coal layer and reaches the gas collecting chamber 5. Then it enters the riser 6 from the top of the gas collecting chamber 5. The escape velocity of the raw gas when it enters the riser 6 is 0.6 - 0.8 times the upward velocity of the raw gas in the furnace body.
[0038] 3) Before the raw gas enters the main gas pipe 7, water is sprayed into the raw gas in the riser 6 through the water spraying device 8 to lower the temperature of the raw gas, while tar is precipitated and dust is trapped. The raw gas after temperature reduction by water spraying enters the main gas pipe 7 together with the mixture of tar and water vapor and is sent to the subsequent gas purification treatment system.
[0039] Under the action of the fan, a small amount of raw gas that escapes into the coal downward movement channel is extracted through the gas outlet pipe arranged on the outside of the coal downward movement channel and sent to the external VOCs treatment unit.
[0040] The raw gas collection system of the internal heat type vertical furnace described in the present invention is arranged in the internal heat type vertical furnace, and the involved functional parts are as follows:
[0041] Coal bunker 1, arranged at the top of the vertical furnace, for loading coal charge into the vertical furnace.
[0042] Distribution tower 3, connected to the coal bunker 1 at the top and to the drying section 2 of the vertical furnace at the bottom. It has a structure that slopes downward to both sides at the top (cone top section), which has the function of guiding the material flow; the middle part is a vertical section, used to form a long and narrow coal downward movement channel 4 on both sides of the vertical furnace; the bottom has a structure that converges upward to the center (cone bottom section), used to jointly form the gas collecting chamber 5 with the coal charge naturally accumulated below.
[0043] Coal downward movement channel 4: It is a long and narrow channel structure, and the design requirement for its width is: it is necessary to ensure that the coal charge moves downward smoothly at a set speed, and at the same time prevent the upward escape of the raw gas due to the large channel size.
[0044] Gas collecting chamber 5, having a relatively large space with a rhombus cross-section, for collecting the raw gas in the vertical furnace. After the raw gas enters the gas collecting chamber 5, the flow rate slows down, which is beneficial to removing the dust carried in it. And the inside of the gas collecting chamber 5 is in a slightly negative pressure state (generated by the gas blower on the main gas pipe), and the raw gas will preferentially enter the gas collecting chamber 5, which can effectively prevent the raw gas from diffusing into the coal bunker 1.
[0045] Riser 6, several are arranged at the top of the gas collecting chamber, used to lead the raw gas into the main gas pipe 7. A water spraying device 8 is arranged at one end of the riser 6 close to the main gas pipe.
[0046] Water spraying device 8, used to cool and cool the raw gas, trap the dust carried in it, and at the same time is beneficial to the precipitation of tar.
[0047] The gas outlet pipe 9 is used to extract a small amount of raw gas that escapes into the coal downward movement channel and send it to the external VOCs treatment unit.
[0048] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.
Claims
1. An internal-heating vertical furnace raw gas collection system. The vertical furnace is successively provided with a coal bunker, a drying section, a carbonization section, a cooling section and a coke discharging section from top to bottom. The raw gas collection system is arranged between the coal bunker and the drying section. It is characterized in that The raw gas collection system includes a distributing tower, riser pipes and a main gas pipe; the distributing tower is arranged longitudinally along the vertical furnace, and the distributing tower is a hollow structure composed of a conical top section, a vertical section and a conical bottom. The cross-sections of both the conical top section and the conical bottom section are upwardly contracting cones; the conical top section serves as the bottom of the coal bin; a coal downward movement channel is formed between the vertical section and the furnace walls on both sides; the cavity between the conical bottom section and the coal material naturally accumulated after entering the lower drying section is the gas collection chamber. A plurality of riser pipes are provided at the center of the top of the conical bottom section, and the riser pipes are communicated with the main gas pipe arranged in the distributing tower. One end of the main gas pipe extends outside the vertical furnace and is connected to an external gas purification and treatment system.
2. The internal heat type vertical furnace raw gas collection system according to claim 1, wherein The width of the coal downward movement channel is 600 - 800 mm.
3. The internal heat type vertical furnace raw gas collection system according to claim 1, characterized in that, The plurality of riser pipes are evenly arranged longitudinally along the vertical furnace.
4. The internal heat type vertical furnace raw gas collection system according to claim 1, characterized in that, The riser pipe is composed of a straight pipe and a 180° elbow. The lower end of the straight pipe is communicated with the gas collection chamber, the upper section of the straight pipe is connected to one end of the 180° elbow, and the other end of the 180° elbow section is connected to the main gas pipe. The main gas pipe is horizontally arranged.
5. The internal heat type vertical furnace raw gas collection system according to claim 4, characterized in that, A water spraying device is arranged at the inner upper part of the 180° elbow near the main gas pipe.
6. The internal heat type vertical furnace raw gas collection system according to claim 4, characterized in that The conical angle of the conical top section is ≥ 45°.
7. The internal heat type vertical furnace raw gas collection system according to claim 4, characterized in that The conical angle of the conical bottom section is 40° - 50°.
8. The internal heat type vertical furnace raw gas collection system according to claim 4, characterized in that, A plurality of gas outlet pipes are arranged on the furnace wall of the vertical furnace outside the coal downward movement channel. The plurality of gas outlet pipes are evenly arranged longitudinally along the vertical furnace. A gas outlet pipe is arranged at the gas outlet. The gas outlet pipe is inclined upward and outward. The gas outlet pipe is connected to an external VOCs treatment unit through a connecting pipe, and a fan is arranged on the connecting pipe.
9. A method for collecting raw gas from an internally heated vertical furnace based on the raw gas collection system of the internally heated vertical furnace according to any one of claims 1 to 8, characterized in that, It includes the following processes: 1) After the coal material is loaded into the coal bin, it moves downward through the coal downward movement channels on both sides of the distributing tower and enters the drying section. The coal material in the drying section naturally accumulates below the distributing tower, forming a gas collection chamber with a rhombic cross-section between it and the conical bottom section of the distributing tower; 2) The raw gas at 500 - 600 °C generated by coal dry distillation exchanges heat with the coal material in the drying section and the temperature is reduced to 80 - 110 °C. The raw gas passes through the coal seam and reaches the gas collection chamber, and then enters the riser pipe from the top of the gas collection chamber. The escape velocity of the raw gas when entering the riser pipe is 0.6 - 0.8 times the upward velocity of the raw gas in the furnace body; 3) Before the raw gas enters the main gas pipe, water is sprayed into the raw gas in the riser pipe through the water spraying device to reduce the temperature of the raw gas, and at the same time, tar is precipitated and dust is trapped. The raw gas after water spraying and cooling enters the main gas pipe together with the mixture of tar and water vapor and is sent to the subsequent gas purification and treatment system.
10. The method for collecting raw coal gas of an internally heated vertical furnace according to claim 9, characterized in that, Under the action of the fan, a small amount of raw gas escaping into the coal downward movement channel is extracted through the gas outlet pipe arranged outside the coal downward movement channel and sent to an external VOCs treatment unit.