A cooling device and cooling method for a coal gangue sintering material vertical furnace

Abstract

The present invention discloses a cooling device and a cooling method for a coal gangue sintering material vertical furnace, comprising a vertical furnace body, the vertical furnace cooling device also comprising a receiving system, a cooling system and a discharging system arranged in sequence from top to bottom; the receiving system comprises a storage tank and a vibrating feeder; the storage tank is arranged above the vibrating feeder for feeding materials from above the vibrating feeder, and a material trough is arranged at the bottom end of the vibrating feeder; the head end of the material trough is connected to the storage tank, and the end thereof is connected to the vertical furnace body; a baffle is arranged at the end of the material trough, and the height of the baffle is 3 to 8 cm. The present invention arranges a baffle at the end of the material trough of the vibrating feeder to form a dead material layer above the material trough, thereby preventing the hot sintering material from the storage tank from causing thermal shock to the material trough, reducing aging damage to the equipment, and using the vertical furnace cooling method to solve the technical problems of high air leakage rate, high fan consumption and slow cooling speed in common on-board cooling or annular coolers.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of solid wastes, and relates to a cooling device and a cooling method for a coal gangue sintering material vertical furnace. Background Art

[0002] my country is rich in coal resources, and its energy structure is dominated by coal. The yield of coal gangue is about 5% to 20% of coal mining, so the output of coal gangue is very large. China has accumulated more than 8 billion tons of coal gangue, covering more than 110,000 hectares, with more than 1,100 coal gangue storage mountains, and the emission of coal gangue is still growing rapidly.

[0003] The large-scale production, discharge and storage of coal gangue not only bring serious environmental pollution problems, but also cause many safety hazards. The bulk disposal of coal gangue is imminent. The main components of coal gangue are SiO2 and Al2O3, which are similar to building materials. Therefore, using coal gangue as a building material (such as cement admixture) is one of the important ways to achieve large-scale disposal and application of coal gangue. If coal gangue is used to prepare cement admixtures and other building materials, it is necessary to use appropriate methods to increase its activity and reduce organic matter such as residual carbon in coal gangue. Pyrolysis is currently an effective means of activating coal gangue. Among them, the belt sintering method is an important pyrolysis activation process for coal gangue, which has the advantages of low energy consumption, high output, strong raw material adaptability, etc., and has good application prospects.

[0004] Chinese patent CN110078401B discloses a process for preparing active mixed materials by belt sintering of coal gangue. Chinese patent CN113526883A discloses a process for decarbonizing coal gangue by self-heating ultra-high material layer without fuel. Chinese patent CN113526895B discloses a method for decarbonizing coal gangue by double-layer oxygen-enriched sintering. The coal gangue belt sintering processes mentioned in the above patents all adopt belt or annular cooling methods. However, belt or annular coolers have the disadvantages of high air leakage rate, high fan consumption, slow cooling speed, and low activity caused by not complying with the cooling law of sintering materials, resulting in high energy consumption and low output. In addition, when the belt or annular cooling method is adopted, the hot sintered ore is fed into the cooler through the feeding device after crushing, resulting in a large particle size distribution of the sintered ore, small particles are filled in the middle of large particles, and the material layer has a low porosity, resulting in a poor cooling effect of the coal gangue sintering material and a low activity of the coal gangue sintering material. Summary of the invention

[0005] The gangue belt sintering process generally adopts belt or annular cooling technology, which has the problems of high air leakage rate, high fan consumption, slow cooling speed and low activity of cooled gangue sinter material. The object of the present invention is to provide a gangue sinter material vertical furnace cooling device and cooling method to improve the cooling efficiency of gangue and the activity of gangue sinter material.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a coal gangue sintering material vertical furnace cooling device, comprising a vertical furnace body, the vertical furnace cooling device also includes a material receiving system, a cooling system and a material discharging system arranged in sequence from top to bottom;

[0008] The material receiving system includes a storage tank and a vibrating feeder;

[0009] The storage tank is arranged above the vibrating feeder and is used to feed materials from above the vibrating feeder. A material trough is arranged at the bottom end of the vibrating feeder. The head end of the material trough is connected to the storage tank, and the tail end thereof is connected to the vertical furnace body.

[0010] A baffle is provided at the end of the material trough, and the height of the baffle is 3 to 8 cm.

[0011] By setting a baffle to form a dead material layer above the trough, the hot sintered material from the storage tank is prevented from thermally impacting the trough; on the other hand, the sintered material and the dead material layer on the trough rub against each other, causing mechanical loss and reducing aging damage to the equipment. If the height of the baffle exceeds 8cm, the material discharge is hindered and not smooth; if the height of the baffle is less than 3cm, a stable dead material layer with a certain thickness cannot be formed, resulting in poor protection effect.

[0012] Preferably, the height of the baffle is 3 to 5 cm.

[0013] Preferably, the cooling system adopts a graded and gradual cooling method, and the cooling system includes a primary cooling unit and a secondary cooling unit from top to bottom.

[0014] Preferably, the primary cooling unit and the secondary cooling unit both include a central hood, a cold air duct and a fan.

[0015] Furthermore, the primary cooling unit includes two groups of central hoods, which are arranged up and down in the height direction, and each group of central hoods is provided with an air outlet;

[0016] The primary cooling unit also includes two fans, which are symmetrically arranged on both sides of the vertical furnace body, each fan is connected to three cold air pipes, and an air inlet regulating valve is arranged at the connection between the fan and the three cold air pipes;

[0017] Among them, two cold air ducts are connected to the two groups of central air hoods; another cold air duct is arranged on the side of the vertical furnace body, and the side of the vertical furnace body is provided with a corresponding air outlet.

[0018] Furthermore, an inverted cone is provided between the central hood and the vertical furnace body to facilitate the collection and cooling of the gangue sintered material.

[0019] Furthermore, the central hood is fixedly mounted on the cold air duct.

[0020] Preferably, the structure of the secondary cooling unit is consistent with that of the primary cooling unit.

[0021] Preferably, the air supply system of the primary cooling unit is a dry cooling blower, which performs the first stage cooling on the incoming coal gangue sintered material, quickly cools it and forms high-temperature exhaust gas; the air supply system of the secondary cooling unit is a normal temperature blower, which performs the second stage cooling on the incoming coal gangue sintered material to form low-temperature exhaust gas.

[0022] Preferably, the discharging system comprises a disc discharging machine, which is arranged at the bottom of the vertical furnace body. The cooled coal gangue sintered material is discharged through the disc discharging machine and transported to the next process by a belt.

[0023] Preferably, the lower part of the vertical furnace body is cylindrical, and the upper part is conical; the outer shell of the furnace body is welded with steel plates, and the inner lining of the furnace body is made of refractory material.

[0024] Preferably, the vertical furnace body is fixed on the installation foundation by using a metal bracket.

[0025] Preferably, an observation hole is provided on the lower side of the vertical furnace body.

[0026] Preferably, a material level controller is provided inside the vertical furnace body for controlling the material level.

[0027] Preferably, the lower part of the vertical furnace body is provided with 2 to 3 temperature measuring points for controlling the discharge temperature.

[0028] Preferably, an exhaust port is provided at the upper portion of the vertical furnace body, and the exhaust port is connected to the dust collector through a pipeline.

[0029] The present invention also provides a vertical furnace cooling method for gangue sintering material, comprising the following steps:

[0030] S1: The hot coal gangue sintering material is unloaded from the sintering machine into the storage tank of the receiving system, and the hot sintering material is fed into the vertical furnace body through the vibrating feeder of the receiving system;

[0031] S2: The gangue sintering material is firstly rapidly cooled in the primary cooling unit, and the temperature of the gangue sintering material is lower than 400°C after the primary cooling;

[0032] S3: The gangue sintered material after being cooled in the primary cooling unit enters the secondary cooling unit. After the secondary cooling, the temperature of the gangue sintered material is lower than 50°C;

[0033] S4: After secondary cooling, the gangue sintered material enters the hopper, is discharged through the disc discharging machine, and is transported to the next process by a belt; at the same time, the hot gangue sintered material is fed into the receiving system, and this cycle is repeated to realize the continuous cooling production of the gangue sintered material.

[0034] Preferably, the sintering process of the gangue sintering material adopts any one of belt sintering, ring sintering and step sintering.

[0035] Preferably, the air supply temperature of the dry cooling blower of the primary cooling unit is 5 to 35°C; more preferably 20 to 30°C.

[0036] Compared with the prior art, the present invention has the following beneficial technical effects:

[0037] (1) The present invention provides a cooling device and method for a coal gangue sintering material vertical furnace. A baffle is provided at the end of the material trough of a vibrating feeder to form a dead material layer above the material trough, thereby preventing the hot sintering material from coming down from a storage tank from causing thermal shock to the material trough, thereby reducing aging damage to the equipment. The vertical furnace cooling method is used to solve the technical problems of high air leakage rate, high fan consumption and slow cooling speed in common on-machine cooling or annular coolers.

[0038] (2) The present invention provides a cooling device and a cooling method for a coal gangue sintering material vertical furnace. Based on the cooling principle of coal gangue sintering material, two cooling units are creatively proposed to realize step cooling, that is, in the first cooling stage, rapid cooling is performed by a dry cooling fan, which can effectively store the heat energy in the hot sintering material in the glass phase formed after rapid cooling, thereby improving its activity; at the same time, high-temperature rapid cooling can cause strong temperature-shrinkage stress to be generated inside and on the surface of the sintering material particles, increase the fine cracks in the sintering material, reduce the strength of the sintering material, improve its grindability, and reduce the cost of subsequent fine grinding to prepare mixed materials; in addition, high-temperature rapid cooling can form hot exhaust gas with a relatively high temperature, which is beneficial to the recovery and utilization of waste heat and reduces the overall process energy consumption. After high-temperature rapid cooling, normal temperature cooling can be used in the second stage to avoid the continued use of high air volume and low air temperature cooling, thereby effectively reducing the energy consumption of the cooling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of a cooling device for a gangue sintering material vertical furnace provided by the present invention;

[0040] Figure 2 The present invention is a schematic structural diagram of a vibrating feeder trough baffle in the vertical furnace cooling device.

[0041] In the figure, 1-vertical furnace body; 2-storage tank; 3-vibrating feeder; 4-material trough; 5-baffle; 6-center hood; 7-air outlet; 8-fan; 9-cold air duct; 10-air inlet regulating valve; 11-inverted cone; 12-disc discharger; 13-belt; 14-exhaust port. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0043] The following examples and comparative examples use coal gangue from a certain region, and its chemical composition is as follows:

[0044] Fe 1.32%, SiO2 51.66%, CaO 3.44%, MgO 1.67%, Al2O3 20.76%, fixed carbon 3.46%, Na2O 0.44%, K2O 0.88%.

[0045] The present invention is further described below in conjunction with specific embodiments and drawings.

[0046] Example 1

[0047] like Figures 1-2 As shown, a coal gangue sintering material vertical furnace cooling device comprises a vertical furnace body 1, and the vertical furnace cooling device also comprises a material receiving system, a cooling system and a material discharging system arranged in sequence from top to bottom;

[0048] The material receiving system includes a storage tank 2 and a vibrating feeder 3; the storage tank 2 is arranged above the vibrating feeder 3, and the storage tank 2 is used to receive high-temperature coal gangue sintering material; a material trough 4 is provided at the bottom end of the vibrating feeder 3; the head end of the material trough 4 is connected to the storage tank 2, and the end thereof is connected to the vertical furnace body 1; a baffle 5 is provided at the end of the material trough to form a dead material layer to protect the material trough, and the height of the baffle 5 is 5 cm.

[0049] The cooling system adopts a hierarchical and gradual cooling method, and the cooling system includes a primary cooling unit and a secondary cooling unit from top to bottom. The primary cooling unit includes two groups of central hoods 6, which are arranged up and down in the height direction, and each group of central hoods 6 is provided with an air outlet 7; the primary cooling unit also includes two fans 8, which are symmetrically arranged on both sides of the vertical furnace body 1, and each fan 8 is connected to three cold air pipes 9, of which two cold air pipes 9 are connected to the two groups of central hoods 6; another cold air pipe 9 is arranged on the side of the vertical furnace body 1, and the side of the vertical furnace body is provided with a corresponding air outlet 7.

[0050] In this embodiment, the central hood 6 and the cold air duct 9 are both made of wear-resistant and heat-resistant materials. Four groups of central hoods are arranged along the height direction. Each group of hood units is respectively provided with an air outlet. The central hood is fixedly installed on the cold air duct.

[0051] In this embodiment, an air inlet regulating valve 10 is provided at the connection between the fan and the three cold air pipes to facilitate the adjustment of the air supply volume of each cold air pipe 9 according to the feed rate of the sintering material.

[0052] In this embodiment, an inverted cone 11 is provided between the central hood and the vertical furnace body to facilitate the collection and cooling of the gangue sintered material.

[0053] In this embodiment, the structure of the secondary cooling unit is consistent with that of the primary cooling unit.

[0054] In this embodiment, the air supply system of the primary cooling unit is a dry cooling blower, which performs the first stage cooling on the incoming coal gangue sintered material, quickly cools it and forms high-temperature exhaust gas; the air supply system of the secondary cooling unit is a normal temperature blower, which performs the second stage cooling on the incoming coal gangue sintered material to form low-temperature exhaust gas.

[0055] In this embodiment, the discharging system includes a disc discharging machine 12, which is arranged at the bottom of the vertical furnace body 1. The cooled coal gangue sintered material is discharged through the disc discharging machine and transported to the next process by a belt 13.

[0056] In this embodiment, the lower part of the vertical furnace body 1 is cylindrical and the upper part is conical; the outer shell of the furnace body is welded by steel plates, and the inner lining of the furnace body is made of refractory materials. The vertical furnace body is fixed on the installation foundation by a metal bracket. An observation hole is provided on the lower side of the vertical furnace body. A material level controller is provided inside the vertical furnace body for controlling the material level, and 2 to 3 temperature measuring points are provided at the lower part of the vertical furnace body for controlling the discharge temperature. An exhaust port 14 is provided at the upper part of the vertical furnace body, and the exhaust port is connected to the dust collector through a pipeline.

[0057] Example 2

[0058] The present invention also provides a vertical furnace cooling method for gangue sintering material, comprising the following steps:

[0059] S1: The hot gangue sintering material is unloaded from the sintering machine into the storage tank of the receiving system, and the hot sintering material is fed into the vertical furnace body by the vibrating feeder of the receiving system;

[0060] S2: The gangue sintering material is firstly rapidly cooled in the primary cooling unit. The air supply temperature of the dry cooling blower of the primary cooling unit is 20-30°C. After the primary cooling, the temperature of the gangue sintering material is about 350°C.

[0061] S3: The gangue sintered material after being cooled in the primary cooling unit enters the secondary cooling unit. After the secondary cooling, the temperature of the gangue sintered material is about 40°C;

[0062] S4: After secondary cooling, the gangue sintered material enters the hopper, is discharged through the disc discharging machine, and is transported to the next process by a belt; at the same time, the hot gangue sintered material is fed into the receiving system, and this cycle is repeated to realize the continuous cooling production of the gangue sintered material.

[0063] Example 3

[0064] The gangue raw material is distributed through rollers in a belt sintering machine (material layer height 1000mm), and then ignited, kept warm and sintered with ventilation. Gangue with a thickness of 15-20mm is used as the base material, and the base material thickness is 20mm. The ignition time is 2min, the ignition temperature is 1100℃, the ignition negative pressure is 5KPa, the insulation temperature is 900℃, the insulation time is 5min, and the insulation negative pressure is 5KPa; the sintering negative pressure is 12KPa, and the gangue sintering material is obtained;

[0065] A vertical furnace cooling method for gangue sintering material according to the present invention;

[0066] The cooled coal gangue sintered material is crushed to -1mm by a jaw crusher and then dry-ground in a ball mill to a particle size of 600m 2 / kg, the active mixed material of coal gangue can be obtained, the burning loss is 1.21%, and the residual carbon content is 0.72%. The utilization coefficient of coal gangue sintering is 1.54t / (m 2 h), the gangue sintering material is tested according to GB / T17671-1999 and GB / T12957-2005, and the activity index is 93%.

[0067] Comparative Example 1

[0068] The gangue raw material is distributed through rollers in a belt sintering machine (material layer height 1000mm), and then ignited, kept warm and sintered with ventilation. Gangue with a thickness of 15-20mm is used as the base material, and the base material thickness is 20mm. The ignition time is 2min, the ignition temperature is 1100℃, the ignition negative pressure is 5KPa, the insulation temperature is 900℃, the insulation time is 5min, and the insulation negative pressure is 5KPa; the sintering negative pressure is 12KPa, and the gangue sintering material is obtained;

[0069] The belt sintering machine is cooled by a blast type during the cooling process. The cooling is divided into three stages. The length of the cooling stage is 5 bellows, and the blast flow rate is 3000-4000m 3 / t; cooling section 2, its length is 4 bellows, the blast flow rate is 2000~3000m 3 / t; cooling three sections, the length of which is 3 bellows, the blast flow rate is 1000~2000m 3 / t;

[0070] The cooled coal gangue sintered material is crushed to -1mm by a jaw crusher and then dry-ground in a ball mill to a particle size of 600m 2 / kg, you can get coal gangue active mixed material, the burning loss is 1.27%, and the residual carbon content is 0.78%.

[0071] The utilization coefficient of coal gangue sintering is 1.47t / (m 2 h), the gangue sintering material is tested according to GB / T17671-1999 and GB / T12957-2005, and the activity index is 87%.

[0072] Comparative Example 2

[0073] The gangue raw material is distributed through rollers in a ring sintering machine (material layer height 1000mm), then ignited, sintered by exhaust air, and cooled. Gangue of 15-20mm is used as the base material, and the base material thickness is 20mm. The ignition time is 2min, the ignition temperature is 1100℃, the ignition negative pressure is 5KPa, the insulation temperature is 900℃, the insulation time is 5min, and the insulation negative pressure is 5kPa; the sintering negative pressure is 12KPa; the cooling air volume is 2200m 3 / t, the coal gangue sintering material is obtained;

[0074] The cooled coal gangue sintered material is crushed to -1mm by a jaw crusher and then dry-ground in a ball mill to a particle size of 600m 2 / kg, you can get coal gangue active mixed material, the burning loss is 1.34%, and the residual carbon content is 0.84%.

[0075] The utilization coefficient of coal gangue sintering is 1.43t / (m 2 h), the gangue sintering material is tested according to GB / T17671-1999 and GB / T12957-2005, and the activity index is 84%.

[0076] 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 vertical furnace cooling method for gangue sintering material, characterized in that: The following steps are involved: S1: The hot coal gangue sintering material is unloaded from the sintering machine into the storage tank of the receiving system, and the hot sintering material is fed into the vertical furnace body through the vibrating feeder of the receiving system; S2: The gangue sintering material is firstly rapidly cooled in the primary cooling unit. The air supply temperature of the dry cooling blower of the primary cooling unit is 5-35°C. After the primary cooling, the temperature of the gangue sintering material is lower than 400°C. S3: The gangue sintered material after being cooled in the primary cooling unit enters the secondary cooling unit. After the secondary cooling, the temperature of the gangue sintered material is lower than 50°C; S4: After secondary cooling, the gangue sintered material enters the hopper, is discharged through the disc discharging machine, and is transported to the next process by a belt; at the same time, the hot gangue sintered material is fed into the receiving system, and the cycle is repeated to realize the continuous cooling production of the gangue sintered material; The adopted vertical furnace cooling device comprises a vertical furnace body, and the vertical furnace cooling device also comprises a receiving system, a cooling system and a discharging system arranged in sequence from top to bottom; The material receiving system includes a storage tank and a vibrating feeder; The storage tank is arranged above the vibrating feeder and is used to feed materials from above the vibrating feeder. A material trough is arranged at the bottom end of the vibrating feeder. The head end of the material trough is connected to the storage tank, and the tail end thereof is connected to the vertical furnace body. A baffle is provided at the end of the trough, and the height of the baffle is 3 to 8 cm; The air supply system of the primary cooling unit is a dry cooling blower, which performs the first stage cooling on the incoming coal gangue sintering material, quickly cools it and forms high-temperature exhaust gas; the air supply system of the secondary cooling unit is a normal temperature blower, which performs the second stage cooling on the incoming coal gangue sintering material to form low-temperature exhaust gas.

2. The method for cooling a gangue sintered material in a vertical furnace according to claim 1, characterized in that: The cooling system adopts a hierarchical and gradual cooling method, and the cooling system includes a primary cooling unit and a secondary cooling unit in sequence from top to bottom.

3. The method for cooling a gangue sintered material in a vertical furnace according to claim 1, characterized in that: The primary cooling unit and the secondary cooling unit both include a central hood, a cold air duct and a fan.

4. A vertical furnace cooling method for gangue sintering material according to claim 3, characterized in that: The primary cooling unit comprises two sets of central hoods, which are arranged vertically in the height direction, and each set of central hoods is provided with an air outlet; The primary cooling unit also includes two fans, which are symmetrically arranged on both sides of the vertical furnace body, each fan is connected to three cold air pipes, and an air inlet regulating valve is arranged at the connection between the fan and the three cold air pipes; Among them, two cold air ducts are connected to the two groups of central air hoods; another cold air duct is arranged on the side of the vertical furnace body, and the side of the vertical furnace body is provided with a corresponding air outlet.

5. A method for cooling a gangue sintered material in a vertical furnace according to claim 3 or 4, characterized in that: An inverted cone is arranged between the central hood and the vertical furnace body, so as to facilitate the collection and cooling of the gangue sintering material.

6. A method for cooling a gangue sintered material in a vertical furnace according to claim 3 or 4, characterized in that: The central hood is fixedly mounted on the cold air duct.

7. The method for cooling a gangue sintered material in a vertical furnace according to claim 1, characterized in that: The discharging system comprises a disc discharging machine, which is arranged at the bottom of the vertical furnace body. The cooled coal gangue sintered material is discharged through the disc discharging machine and transported to the next process by a belt.

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