HG/T 20534-1993 Chemical solid raw materials and fuel preparation design regulations
Some standard content:
Industry Standard of the People's Republic of China
Design regulations concerning preparationof chemical solid feed stocks and fuelsHG 20534-93
Main editor: The Second Design Institute of Ministry of Chemical Industry
Approving department: Ministry of Chemical Industry
Effective date: →October 1, 1994 Engineering Construction Investment Standards Center of Ministry of Chemical Industry
1994Beijing
1.0.1 These regulations are formulated in order to unify the content and standards of engineering design for preparation of chemical solid feed stocks and fuels, further improve the design quality and accelerate the design progress. 1.0.2 This regulation applies to the engineering design of solid fuel preparation for heating furnaces, hot blast furnaces, boilers and other kilns and furnaces, and applies to the engineering design of solid raw material preparation for coking plants using coal as raw material, and coal gasification plants using coal or coke as raw material: applies to the engineering design of chemical products such as calcium carbide, yellow phosphorus, phosphoric acid, ammonium phosphate, calcium sulfate, heavy calcium, sulfuric acid, barium salt, titanium dioxide, and lead powder produced from raw materials such as coal, coke, quicklime, phosphate rock, pyrite, cryolite, barite, salt, soda ash, and ilmenite; applies to the engineering design of chemical solid raw materials such as acetylene, acetylene black, and polyvinyl chloride produced from calcium carbide as raw material. The above-mentioned chemical solid raw material and fuel preparation processes include material size classification (screening), block material crushing, grinding, and wet material drying.
1.0.3 The industry standards related to or cited in these regulations are: HG20518-192 "Principles of Chemical Mechanized Transportation Design" and HG20532-93 "Safety and Health Regulations for Chemical Powder Engineering Design". 1.0.4 If these regulations conflict with relevant national standards, specifications, regulations or relevant regulations of superiors, they shall be implemented in accordance with relevant national standards, specifications, regulations or superior regulations. 1
Process design
2.1 General provisionswww.bzxz.net
2.1.1 The process design for the preparation of chemical solid raw materials and fuels shall be based on the type of materials, supply conditions, use, characteristics (particle size, moisture content, density, hardness, adhesion, etc.), type of chemical process equipment or combustion equipment, scale, environmental characteristics, etc., and technical and economic comparisons shall be made to ensure reliable operation, advanced technology and reasonable economy. 2.1.2· Non-ferromagnetic chemical solid raw materials and fuels must have at least one iron removal device before the processing system consisting of crushing, screening, and grinding or the processing process consisting of a single process of crushing, screening, and grinding, and generally there must be an impurity separator. 2.1.3 When there is a batching requirement, whether the batching process is carried out before the preparation process or after the preparation process should be determined after comprehensive analysis based on material characteristics, batching accuracy and other conditions.
2.1.4 The storage capacity of the buffer silo after the preparation process should not be less than the material consumption of the chemical process unit or combustion unit for 4 hours of rated load. 2.1.5 When the mud content of limestone used in the production of soda ash and calcium carbide is high, a desludging treatment device should be added before the crushing and screening process.
2.1.6 Powders below 2~～3mm in quicklime and coke used in the production of calcium carbide should be screened out and can be used in hollow electrodes when hollow electrodes are used. *2.1.7 When medium-sized nitrogen fertilizer plants use anthracite for gasification, water washing is recommended to remove pulverized coal from the coal entering the furnace.
Dry preparation process systems for chemical solid raw materials and fuels should generally be equipped with dust removal devices. 2.1.8
Dust removal devices must select appropriate dust removal systems and equipment based on the properties, temperature, humidity, dust concentration and particle size of the dust-containing gas and the requirements of the environment for purification, to ensure that the dust concentration of exhaust gas emissions meets the national environmental protection allowable emission standards. 2.1.8.2 The piping layout of the dust removal system should be as simple as possible, and a group of dust removal systems should generally not exceed 5 to 6 dust suction points.
2.1.8.3 The air duct should be arranged vertically or tilted as much as possible to avoid using horizontal pipes. The inclination angle between the inclined pipe section and the horizontal plane should not be less than 45~50°. When a horizontal pipe section must be used, the distance should be shortened as much as possible and a higher wind speed (v16m/s) should be used. At the same time, it is necessary to consider adding a cleaning hole, and the cleaning hole cover should be sealed.
2.1.8.4 In order to reduce the fluid resistance of the system, the number of bends should be reduced. The bending radius of the bend can be calculated by 1.5 to 3 times the diameter of the wind pipe. 2.1.8.5 In order to avoid sucking too much dust, the wind speed in the dust hood should be correctly selected. For extremely fine dust below 10, the wind speed can be 0.4~0.6m/s; for fine powder after grinding, the wind speed can be less than 2m/s; for dust with a larger particle size, the wind speed should not exceed 3m/s.
2.1.8.6 The dust removal equipment on the interlocking line should be started in advance, and the dust removal equipment should be stopped last after all equipment is stopped.
2.1.9 The preparation of coal powder for self-provided thermal power stations of chemical enterprises shall be carried out in accordance with the relevant provisions of the "Technical Regulations for Coal Transportation Design of Thermal Power Plants" (SDGJI) issued by the Ministry of Water Resources and Electric Power. 2.1.10 The work shift system for the preparation of chemical solid raw materials and fuels shall be implemented in accordance with the "Principles of Chemical Mechanized Transportation Design" (HG20518-92). 2.2 Crushing and screening
2.2.1 The pre-crushing of chemical solid raw materials and fuels shall adopt an open-circuit crushing process. Whether the final crushing of chemical solid raw materials and fuels adopts an open-circuit crushing process or a closed-circuit crushing process shall be determined based on the chemical process unit's requirements for the composition of the raw material and fuel particle size and the type of crushing equipment selected. See Appendix B for the classification of particle size. 2.2.2 Before entering the crushing equipment, the qualified particle size content of the material exceeds 20% of the upper limit of the crusher's discharge particle size, and its absolute value has a great impact on the crusher's production capacity, the process of pre-screening and then crushing should be adopted; for projects with smaller system capacity, no pre-screening will not cause a significant change in the crusher load, and when the material over-crushing has no effect on production, the full material crushing process should be adopted. 2.2.3 The content of unqualified pulverized coal in the raw coal entering the crushed coal pressurized gasification furnace shall not exceed 5%. In order to ensure the requirements of the coal entering the furnace, screening shall be carried out before entering the furnace, and the number of transfers of qualified coal entering the furnace after screening should not exceed 2 times. 2.2.4 When the particle size classification of coke is divided into five levels, the screening process should be configured from double-layer screen to double-layer screen; when the particle size classification is divided into four levels, the screening process should be configured from single-layer screen to double-layer screen.
2.2.5 When the screen width is greater than 1.8m and the system feed volume is greater than 70% of the actual screening capacity of a single screen, the material should be evenly added to the screen surface through the feeder.
2.2.6 When the raw coal contains a high amount of abrasives, a crushing process should be set up in the screening and crushing process. The thermal coal supplied to boilers and other combustion furnaces is allowed to be crushed without abrasives when it does not affect the crushing operation and the calorific value of the combustion furnace.
2.2.7 In the fuel coal used for chain boilers, if the content of lump coal exceeding the maximum particle size of the coal entering the furnace is less than 5% or the fuel coal is washed medium coal, a crusher may not be set up, and only a metal coal grate with a grate hole size of 50mm×50mm may be set up.
2.2.8 The final crushing of pyrite should generally adopt a closed-circuit crushing process. When a crusher with a bottom grate is used instead of a closed-circuit crushing process, the humidity and clay content of the pyrite entering the crusher should be controlled.
2.3 Grinding and Powdering
2.3.1 Whether the grinding process adopts a circular flow process or an open process should be determined according to the grindability characteristics of the material and the particle size requirements of the material after grinding. The grindability coefficient of the material is shown in Appendix C.
2.3.2 The effective volume of the feeding bin in front of the grinding equipment should be able to meet the output of the mill for more than 3 hours. The feeding bin should have a valve or be equipped with a feeder that can seal the material. The feeding device of the feeder should be closed. If the closed type is not adopted, a locking air blower should be added to the discharge chute. 2.3.3 Dry grinding should have a dust removal system to ensure that the dust content of the exhaust gas meets the national environmental protection emission standards.
2.3.4. The feeding, diluent and additive addition of the wet ball mill should all have feeding automatic control devices and automatic metering devices to achieve the indication, control, accumulation and lower limit alarm and interlocking of the material flow.
2.3.5 The capacity of the wet grinding slurry collection tank should be the output of the mill at rated output for 0.5~2 hours.
2.3.6 The pipelines, separators and dust collectors of the dry coal grinding system should be equipped with explosion-proof doors and explosion-proof membranes, and protected with inert gas, and anti-static measures should also be taken. 2.3.7 The equipment and all air ducts of the air-sweeping mill system from the mill outlet to the powder selector and the three-stage dust collector should be insulated.
2.3.8 The air ducts of the air-sweeping mill system should be equipped with regulating valves. The following valves should generally be installed for the intermediate bin system:
A control butterfly valve should be installed on the vent pipe of the hot blast furnace:
The total air volume regulating valve at the exhaust fan inlet and the outlet auxiliary blowing air distribution valve. 2.3.9 The hot blast furnace should have a secondary air system to adjust the hot air temperature. 2.3.10 Coal loading and ash removal of hot blast furnaces should be mechanized as much as possible according to the size of the scale to reduce the labor intensity of workers.
2.3.11 Effective sound insulation measures should be taken for large mills. 2.3.12 Large mills can use high-pressure lifting of the main bearing and dynamic pressure lubrication technology. Use pneumatic clutch to achieve load start-up and reduce the impact on the network. Use electric ear devices to control the material level with sound and realize automatic control of feeding. Large and small gears are lubricated by oil mist spray to improve lubrication conditions.
2.4 Drying
2.4.1 In addition to considering the contents specified in 2.1.1 of this chapter, the determination of the drying process should also be based on the state of the material before and after drying, thermal physical properties, adhesion, cohesion, charge and available heat sources. 2.4.2 The effective volume of the feeding bin of the drying equipment should be able to meet the output of the dryer for more than 3 hours. For the feeding bin fed by the elevator, it can be appropriately reduced, but it must not be less than the output of the dryer for 1 hour. The outlet of the feeding bin should be equipped with a valve and a feeding device. 2.4.3 The feeding device of the drying system should be of a closed type. If the closed type is not adopted, a lock air device should be added to the unloading chute.
2.4.4 The hot air furnace of the drying system should generally have a secondary air system to adjust the hot air temperature. 2.4.5 The rotary dryer should be operated under a slight negative pressure, and the negative pressure should generally be maintained at 50~20bPa.
2.4.6 The temperature of the gas out of the dryer should be calculated based on the gas temperature of the last stage dust collection equipment being 20℃ higher than the dew point of the gas, and should generally be controlled between 80~120℃. 2.4.7 The mixed gas velocity of the rotary dryer cylinder section should not be greater than 5m/s. When the particle size of the dried material is less than 1mm and the density is less than 2g/cm, the velocity should not be greater than 2m/S
·2.4.8 The airflow velocity in the drying tube of the airflow dryer should be twice the maximum particle settling velocity of the material, or 3m/s greater than the settling velocity of the maximum particle. 2.4.9 The airflow dryer should use unsaturated hot air as the heat carrier. When drying at high temperature, the heat source can be heated by flue gas produced by coal and other fuels: steam heating can be used for low temperature (below 160℃). When the output is small, electric heating can also be used for low temperature drying. 2.4.10 The heat source of the rotary dryer can use the flue gas of the combustion furnace with coal as the fuel as the heat carrier, or by-product furnace gas or other combustible fuels (such as natural gas, generator gas, heavy oil, etc.) as the combustion material according to actual conditions. When the inlet temperature of the dryer is less than 160℃, steam-heated hot air can also be used as the heat carrier. 6
2.4.11 The heat carrier in direct contact with the material should not react chemically with the material and should not pollute the product. If conditions permit, waste heat and waste gas should be used as much as possible. 2.4.12 Rotary dryers should be used for continuous and mass production of sulfur concentrate. When the evaporation intensity per unit volume is 15-20 kg/m2·h, the heat transfer method should generally adopt parallel flow direct heat transfer. The moisture content of sulfur concentrate entering the dryer should be controlled below 17%, and the moisture content out of the dryer should be controlled at 6%-8%. Equipment selection
3.1 General provisions
: 3.1.1 The preparation of chemical solid raw materials and fuels is a key process in the mechanized transportation system of the chemical industry. The equipment selection should be adapted to the automatic control level of the entire mechanized transportation system. It should be adapted to the scale of the factory and the level of development of contemporary science and technology. The selected equipment should be a high-quality product with superior technical performance, low energy consumption, low noise, low environmental pollution, and convenient operation and maintenance among similar products. 3.1.2 The selection of equipment for the preparation of chemical solid raw materials and fuels shall be calculated. If necessary, the actual production capacity of the equipment shall be investigated or tested before determination. The production capacity determined by design shall be consistent with the capacity of the feeding system. In any of the following cases, the production capacity determined by design shall be 1.2 times the rated capacity of the system: (1) When there is no feeding control device in the conveying system before the crushing and screening equipment; (2) When the screening equipment is installed before the crusher, and the proportion of the screened material after screening varies greatly; (3) When there is return material in the unit system of the grinding and drying device. 3.1.3 The selection principle of inventory equipment shall be in accordance with 3.0.2.5 of HG20518-92 "Principles and Regulations for the Design of Chemical Mechanized Transportation". 3.1.4 The selection principle of new products shall be in accordance with 3.0.2.4 of HG20518-92 "Principles and Regulations for the Design of Chemical Mechanized Transportation".
3.1.5 Determination of spare machines
3.1.5.1 The number of equipment should be determined based on the system capacity, work shift system, equipment load rate calculated by the number of working hours per shift, the environmental characteristics of the equipment and the material characteristics.
3.1.5.2 Equipment should be installed in any of the following situations (1) Crusher: Gasifier, coke oven and other production equipment with strong continuity or when the operation time per shift exceeds 6 hours.
(2) Screens are configured in accordance with the first crusher or when the total number of screens installed exceeds 3.
(3) According to production practice, the operating rate of medium and small grinding mills is about 75%. The actual number of units required is calculated based on the 75% operating rate.
(4) When the stability of production is affected by the equipment itself (such as long maintenance cycle, frequent replacement of wearing parts), or when the durability of the equipment is affected by material characteristics such as abrasiveness, equipment should be installed.
3.1.5.3 No need to install a crusher if any of the following conditions exist: (1) Small projects that meet the requirements of 3.1.5.2, when the system has a buffer silo that exceeds the material consumption of the chemical process unit or combustion unit for 12 hours; (2) Large mills are generally not equipped with crushers, but the working time of the mill should not exceed 8,000 hours per year.
(3) Sturdy and durable equipment such as drying equipment and jaw crushers (if necessary, two small-sized drying equipment can replace one large-sized one). (4) Small projects where the chemical process unit does not have strict requirements on raw material preparation, their crushing and screening equipment can be installed without crushers, and a bypass system can be added. 3.2 Crushing equipment
3.2.1 In addition to considering the relevant contents specified in 3.1, the selection of crushing equipment should also be based on the hardness of the material, the crushing ratio of the material and other characteristics of the material. For the hardness classification of the relevant materials, see Appendix C; for the crushing ratio of the crusher, see Appendix D. 3.2.2 Jaw crusher: This machine is suitable for coarse and medium crushing of various materials with a compressive strength of less than 250MPa. Applicable materials include pyrite, phosphate rock, barite, calcium carbide, coke, limestone, etc. Jaw crusher is not suitable for crushing flaky materials. 3.2.3 Impact crusher: This machine is suitable for crushing brittle or medium hardness materials, such as coal, coke, limestone, pyrite, etc. When the material crushing ratio is about 10, a single-rotor impact crusher should be selected; when the material crushing ratio is greater than 25, a double-rotor impact crusher should be selected. Impact crusher is not suitable for crushing plastic or viscous materials. When selecting, different types of impact crushers should be selected according to different materials. For example, MFI type impact crusher should be selected for coke crushing, and impact crusher equipped with ZGMn13 hammer plate should be selected for pyrite crushing to reduce the wear of pyrite on the crusher and reduce maintenance workload.
3.2.4 Ring hammer coal crusher: This machine is used for crushing coal, and is also suitable for crushing other materials (such as clay, etc.) with a compressive strength not exceeding 100MPa. The moisture content of the crushed material should not be greater than 8%~10% (the smaller value is taken when the discharge particle size is small). 3.2.5 Ring hammer stone crusher: It is used for crushing brittle materials with a compressive strength of less than 200MPa, such as limestone and pyrite. 3.2.6 When the crushing level of the material does not allow more than 10% of the excessive particle size, the ring hammer crusher should be used first.
3.2.7 Series crusher: This machine is suitable for crushing brittle materials such as coal, coke, limestone, pyrite, etc., and is not suitable for sticky, flaky, and fibrous materials. 3.2.8 Tooth crusher: The applicable scope of this machine is the same as 3.2.7, but it is also applicable to materials with layered and flaky structures. When used to crush materials with strong abrasiveness such as coke, the surface of the tooth roller should be welded with wear-resistant materials. 3.2.9 Hammer crusher: This machine is suitable for crushing brittle materials with medium hardness, but not suitable for crushing tough, fibrous materials, or materials mixed with strips and fibers. This machine is suitable for crushing materials with a moisture content of less than 10%. When the moisture content of the material is greater than 10%~15%, and the material output is allowed to have a certain excessive particle size (about 25%), a hammer crusher without a bottom grate should be selected. 3.2.10 Cone crusher: This machine is suitable for crushing various brittle materials with a compressive strength of less than 160MPa. This machine should not be used for wet crushing and crushing materials with high clay content and large moisture content.
3.2.11 Vibrating crushers should be used to crush sticky materials. 3.2.12 Try to use a crusher with small air volume and good sealing. For example, peripheral unloading mills are suitable for crushing pyrite.
3.2.13 Chain furnaces that use coal throwers to supply coal should use hammer crushers to crush coal. Roller or toothed roller crushers are not suitable. Chain hammer coal crushers can also be used. 3.2.14 Large coal or frozen coal should be crushed with large coal crushing devices. When receiving coal in a coal receiving pit, a bridge-type pneumatic 3. 2. 14.1
miner should be installed above the coal receiving pit;
3. 2. 14.2
crusher.
When using a dumper to unload coal, a coal crushing and cutting machine should be installed below it. When using a belt conveyor to feed coal, a large coal crusher should be installed at its head. 3.3 Screening equipment
3.3.1 In addition to considering the contents specified in 3.1, the selection of screening equipment should also be based on the screening efficiency required by the production device and the humidity of the material (dry or wet). The screening efficiency of the screening equipment is shown in Appendix E. 3.3.2 It is not advisable to use a shaking screen for materials with high abrasiveness. When using a vibrating screen, a rubber screen or a polyurethane elastic screen, or other screens with good wear resistance should be used. 3.3.3 When the surface moisture content of the material exceeds 12% and the material is required to be free of pollutants, a stainless steel screen should be used for type screening. 3.3.4. When the surface moisture content of materials exceeds 8%, or when fine screening of materials with a certain degree of viscosity is required, and the screening efficiency is required to be greater than 75%, a relaxation screen, a spiral screen or a string screen should be used for 6mm classification; if the classification particle size is above 13mm, a probability screen can be used. 3.3.5 When the material particle size classification is greater than level 2, a double-layer screen should be used. 3.3.6 Linear vibrating screens or curved screens should be used for wet screening, desludging, dehydration and demediation. 11
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