Calcination energy-saving device

Abstract

The invention discloses a calcining energy-saving device, and relates to the field of metallurgical energy conservation and comprehensive utilization of heat energy. The device solves the problems of high loss on ignition of ores, equipment corrosion, low heat energy recovery efficiency and the like in yellow phosphorus smelting through the integrated design of calcining, neutralizing and waste heat recovery. The core structure of the device comprises a material distribution section, a calcination section, a cooling section, a discharging section and a waste heat recovery system, uniform heat supply is achieved through an inverted-V-shaped hot air groove, crushing of mineral powder pellets is avoided through a triangular material distribution plate, calcium oxide generated through calcination is used for neutralizing acidic substances in tail gas, and equipment corrosion is solved from the source; heat energy is recycled through the waste heat boiler in a stepped mode, and the heat efficiency is improved to 80% or above. The production cost of yellow phosphorus per ton can be reduced, the economic benefit of the smelting industry is improved, the method is suitable for phosphorus chemical industry and metallurgical industry, and energy conservation, emission reduction and efficient utilization of resources are promoted.

Description

Technical Field

[0001] The present invention belongs to the field of metallurgical energy conservation and comprehensive utilization of thermal energy, and specifically relates to calcination process optimization of phosphate rock and ore powder pellets, high-temperature flue gas waste heat recovery and yellow phosphorus tail gas resource optimization utilization technology. Background Art

[0002] Industry status and resource challenges my country, the world's largest producer of yellow phosphorus (accounting for 70% of global output), currently sells approximately 80,000 tons annually. With the expanding use of phosphoric acid in new energy vehicle batteries, demand for yellow phosphorus continues to grow, driving up phosphate rock prices and highlighting resource scarcity. In recent years, the grade of phosphate rock entering the furnace has dropped from 27% (P2O5) to 23%, requiring 11 tons of ore to produce each ton of yellow phosphorus. At the same time, ore loss on ignition has increased from 5% to a maximum of 9%, significantly increasing smelting costs. Data shows that reducing loss on ignition by 1% per ton of yellow phosphorus saves 400 kWh of electricity and 130 kg of coke. Reducing loss on ignition by 6% through the calcination process can reduce smelting costs by 1,300 yuan per 11 tons of ore. For an annual production of 800,000 tons of yellow phosphorus, calcining 30% of the ore can save 312 million yuan per year.

[0003] Utilization of yellow phosphorus tail gas and environmental protection pain points During the yellow phosphorus smelting process, each ton of yellow phosphorus produces 2700 Nm³ of tail gas (mainly CO, P2O 5、 H2S, impurities, and a calorific value of 2700 kcal) are high-quality fuels. However, the P2O5 and H2S in the exhaust gas react with water to form phosphoric acid and hydrosulfuric acid, which are severely corrosive to metal equipment. Traditional heat pipe boilers, while using corrosion-resistant stainless steel, still face problems such as corrosion and leakage of steel pipes, the need to replace the entire heating surface within two years, and the need for alkaline water cleaning and maintenance. This results in low heat recovery efficiency and significant safety risks.

[0004] Defects of existing calcination and drying technology - Rotary kiln dryer: Traditional equipment with a diameter of 2.2m can achieve a 7% crushing rate for phosphate rock (damage caused by tumbling during drying). Based on the current ore price of 850 yuan / ton, calcining 30% of the 8.8 million tons of ore required for an annual production of 800,000 tons of yellow phosphorus can save 1.848 billion yuan / year in damage losses.

[0005] - Traditional smelting furnaces: Rotary kilns have problems such as low thermal efficiency (<50%), uneven combustion (local high / low temperatures), and difficulty in meeting environmental emission standards, and cannot meet current energy-saving and environmental protection requirements.

[0006] Core content of the invention

[0007] - Integrated calcination-neutralization-waste heat recovery: Utilizes the combustion of yellow phosphorus tail gas to generate high temperatures above 900°C to calcine phosphate rock. More than 70% of the calcium carbonate and magnesium carbonate in the ore are calcined to produce calcium oxide and magnesium oxide, which neutralize the phosphoric acid and hydrosulfuric acid produced by the tail gas combustion, solving equipment corrosion problems at the source.

[0008] - Damage-free drying process: Drying, calcining and cooling are achieved by lowering the material's own weight, avoiding the ore from being broken by the rotary kiln, and reducing the ore breakage rate to 0.

[0009] - Efficient cascade utilization of thermal energy: After calcination, the high-temperature ore is cooled to below 120°C by cold air in the cooling section. The cooled hot air is then sent to the waste heat boiler to generate steam (or directly to the hot air furnace), increasing the thermal efficiency to over 80%. The flue gas is cooled to below 150°C after drying the ore, and can meet emission standards.

[0010] Key structure and process advantages - Uniform heating and calcination at the bottom of the smelting section: hot air is in full contact with the material, and the temperature is precisely controlled, solving the problem of local temperature deviation in traditional furnaces and ensuring consistent calcination quality.

[0011] - Diversified heat recovery: Cooled hot air can be fed into waste heat boilers for power generation or reused in hot blast furnaces. Taking a medium-temperature, medium-pressure boiler as an example, if 30% of yellow phosphorus production capacity is covered by this technology, the annual power generation could reach 1.6 billion kWh, with an economic benefit of 800 million yuan.

[0012] Implementation Effect and Application Prospects

[0013] - The production cost of yellow phosphorus per ton is reduced by RMB 1,300, resulting in an annual saving of RMB 312 million (30% calcination); - The ore breakage rate dropped from 7% to 0, saving 1.848 billion yuan annually; - The annual revenue from exhaust gas heat recovery power generation is RMB 800 million, with significant comprehensive benefits.

[0014] Environmental protection and process advantages

[0015] - Flue gas emission temperature is less than 150°C, acidic substances are neutralized, and environmental protection standards are met; - Thermal efficiency has increased from less than 50% to over 80%, with huge annual energy-saving potential. This technology can be applied to calcium carbonate smelting, steel, chemical and other industries, promoting the upgrading of smelting technology.

[0016] Comparison with existing technology Technical indicators of the present invention compared with rotary kiln Thermal efficiency above 80%: <50% Ore breakage rate 0%: 7% Environmental protection standard flue gas temperature <150℃ Dust in the flue gas requires additional treatment in conclusion The present invention breaks through the technical bottlenecks of heat recovery and equipment corrosion in yellow phosphorus smelting through the integrated design of "calcination-neutralization-waste heat recovery". It has the multiple advantages of energy saving, cost reduction and environmental protection. It can replace traditional equipment such as rotary kilns, and has broad application prospects in the phosphorus chemical and metallurgical industries. It provides core technical support for energy conservation and emission reduction in the national smelting field.

[0017] Key solution goals Reduce the loss on ignition and breakage rate of calcined ore, recover heat energy for heating and power generation, recover waste heat to reduce heat loss, and use calcium oxide produced by calcination to neutralize the phosphoric acid in the yellow phosphorus tail gas to avoid corrosion of the boiler when burning the yellow phosphorus tail gas to generate electricity and heat. The function of each structure of calcination energy-saving device

[0018] - Distribution section: The ore is distributed in different areas through several distributors to prevent the separation of large and small particles due to free rolling and falling, ensuring that the material distribution in the drying room is uniform and the height is consistent, and the wind resistance of the material is consistent everywhere.

[0019] - Calcination section: The hot air trough adopts an inverted V-shaped structure to ensure that the material descends evenly and smoothly. The bottom of the hot air trough is open, which can maximize the contact area between the hot air and the material, and there is no dead angle between the hot air and the material.

[0020] - Cooling section: The discharge hopper and discharge pipe are combined to discharge materials in different areas, ensuring uniform distribution of materials in the cooling chamber. At the same time, it ensures the isolation of calcination hot air and cooling air, ensuring that the materials are cooled to below 120℃.

[0021] - Discharging section: The discharging structure of the boom and swing plate is adopted to maximize the bottom discharging area, ensure full contact between the material and the cooling air, ensure that the material in the cooling chamber descends evenly, and the material and the cooling air are evenly mixed. The boom and swing plate are a pendulum structure, which can ensure the efficient and stable operation of the device.

[0022] - Fabric umbrella: makes the material and cooling air mix more evenly, enhances the mixing effect of material and cooling air, and improves cooling efficiency.

[0023] - Add a waste heat boiler to the waste heat recovery system to use the heated cooling air to generate steam to meet production needs. The heated cooling air does not contain acidic substances, which avoids boiler corrosion.

[0024] - The increased flue gas must pass through the material layer of calcined ore (the material layer contains a large amount of calcium oxide) to neutralize the acidic substances in the flue gas. The calcined material layer is used to eliminate corrosive substances to prevent corrosion of the boiler. This not only increases the steam production of the waste heat boiler, but also solves the problem of boiler corrosion caused by the combustion of yellow phosphorus tail gas. The increased flue gas volume can ensure that the waste heat boiler generates more steam for production and power generation.

[0025] - Triangular distribution plate: Located at the top of the calcining chamber, it acts as a partial pressure on the low-strength phosphate rock powder balls to prevent them from piling up too high and crushing the balls at the bottom. The addition of the triangular distribution plate ensures that the balls change position when falling, which increases the heat exchange efficiency between the hot air and the balls.

[0026] A calcination energy-saving device, characterized in that it includes a material distribution section 1, a calcination section 2, a cooling section 3, a material discharge section 4, a waste heat recovery system 5, a hot air furnace system 6, a furnace body 101, and materials 102; The distribution section 1 includes a feed box 15, a discharge pipe 14, a distributor 13, a distributor 12, and a distribution port 11. The feed box 15 is fixed to the top of the furnace body 101. The bottom of the feed box 15 is connected to the discharge pipe 14, the distributor 13, and the distributor 12 in sequence. Each distributor 12 is provided with (1-4) distribution ports 11 at the bottom. The multiple distributors 12 are all arranged on the same horizontal plane, and a hot air channel is left between each distribution port (11); The calcining section 2 includes a calcining chamber 22, an inverted V-shaped hot air groove 21, a hot air header 23, a hot air inlet 24, and a hot air outlet 25. The calcining chamber 22 is located in the upper half of the furnace body 101. The bottom of the calcining chamber 22 is installed with horizontally arranged inverted V-shaped hot air grooves 21 (there is a material and hot air channel between each hot air groove (21) and is fixed on the furnace body 101. One end of the hot air groove 21 is closed and the other end is connected to the hot air header 23. The hot air header 23 is provided with a hot air inlet 24, and the upper part of the calcining chamber 22 is provided with a hot air outlet 25; The cooling section 3 includes a cooling chamber 31, a lower hopper 33, a lower feeding pipe 32, an air outlet 34, and a discharge port 42 which also serves as a cooling air inlet. The cooling chamber 31 is located at the lower part of the furnace body 101, below the hot air trough 21, and the lower hopper 33 is arranged horizontally. The lower hoppers 33 are arranged horizontally and connected and fixed to each other. The external lower hopper 33 is fixed on the furnace body 101, and the lower part of the lower hopper 33 is connected to the discharge pipe 32. The upper part of the cooling chamber 31 is provided with an air outlet 34, and the discharge port 42 which also serves as a cooling air inlet is provided in the discharge section 4; The discharging section 4 includes a discharging chute 43, a discharging port 42 which also serves as a cooling air inlet, a cloth umbrella 44, a shaking plate 41, a suspension rod 45, a connecting rod 46, a movable crank arm 47 and a reducer 48. The discharging chute 43 is located at the bottom of the cooling chamber 31 (closely arranged and connected and fixed on the furnace body 101 on the same horizontal plane). The discharging chute 43 is provided with a discharging port 42 which also serves as a cooling air inlet. A shaking plate 41 is installed below (movably fixed by the suspension rod 45 and can be moved laterally, with a gap between it and the discharging port); the shaking plate 41 is connected to the movable crank arm 47 through the connecting rod 46, and the movable crank arm 47 is fixed on the reducer 48 (the reducer is fixed on the furnace body 101). The cloth umbrella 44 is fixed on the center line of the discharging chute 43, and a material descending channel is left between it and the discharging chute to facilitate the passage of materials and cooling air. The cloth umbrella 44 is fixed on the furnace body 101. The furnace body 101 is provided with calcined material 102. The waste heat recovery system 5 includes a suction fan 51, an induced draft pipe 52, and an air outlet pipe 53. One end of the induced draft pipe 52 is connected to the air outlet 34, and the other end is connected to the air inlet of the induced draft fan 51. The air outlet of the induced draft fan 51 is connected to the air inlet of the hot air furnace 61 through the air outlet pipe 53. The hot blast furnace system 6 includes a hot blast furnace 61, a high-temperature air duct 62, a suction fan 63, and a suction duct 64. The air inlet of the hot blast furnace 61 and the air outlet of the induced draft fan 51 are connected through the air outlet duct 53. The air outlet of the hot blast furnace 61 is connected to the hot air inlet 24 through the high-temperature air duct 62. The air inlet of the suction fan 63 is connected to the hot air outlet 25 through the suction duct 64.

[0027] 2. The device according to claim 1, further comprising a waste heat boiler 7, wherein the air inlet of the waste heat boiler 7 is connected to the air outlet of the induced draft fan 51, and the air outlet of the waste heat boiler 7 is connected to the air inlet of the hot air furnace 61 through the air outlet pipe 53.

[0028] 3. The device according to claim 1 is characterized in that it further includes a flue gas system 8, wherein the flue gas system 8 includes a flue gas trough 81, a flue gas header 82, a flue gas outlet 83 and a regulating valve 84, the flue gas trough 81 is installed between the hot air trough 21 and the lower hopper 33, the flue gas trough 81 is arranged horizontally, and a material channel is left between each flue gas trough 81 and the hot air trough 21 and the lower hopper 33, and is fixed on the furnace body 101; one end of the flue gas trough 81 is closed and the other end is connected to the flue gas header 82, a flue gas outlet 83 is provided on the flue gas header 82, the flue gas outlet 83 is connected to the inlet of the regulating valve 84 through a pipeline, the outlet of the regulating valve 84 and the air outlet (34) are connected to the induced draft pipe 52 through a pipeline, so that the flue gas and the heated cooling wind can enter the induced draft fan 51 together.

[0029] 4. The device according to claim 1 is characterized in that it further comprises a triangular cloth plate 9, which is installed below the cloth opening 11. The triangular cloth plates 9 are arranged in multiple rows and staggered, and a material channel is left between each cloth plate (9). The triangular cloth plates 9 are fixed on the furnace body 101. The addition of the triangular cloth plates 9 can play a role in stratification and pressure distribution for low-strength materials, prevent material damage, and can change position when the material descends, thereby improving the contact efficiency between the hot air and the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 AA cross-sectional view of the calcination energy-saving device Figure 2 BB cross-sectional view of the calcination energy-saving device Figure 3 Main view of the flue gas trough of the calcination energy-saving device Figure 4 Side view of the flue gas trough of the calcination energy-saving device Figure 5 Main view of the distribution plate of the calcination energy-saving device Figure 6 Side view of the distribution plate of the calcination energy-saving device Reference numerals

[0031] Feeding section 1 (feeding port 11, feeder 12, distributor 13, discharge pipe 14, feed box 15); Calcination section 2 (hot air trough 21, calcination chamber 22, hot air header 23, hot air inlet 24, hot air outlet 25); Cooling section 3 (cooling chamber 31, discharge pipe 32, discharge hopper 33, air outlet 34, discharge port 42 also serving as cooling air inlet); Discharging section 4 (shaking plate 41, discharging port 42, discharging chute 43, cloth umbrella 44, hanging rod 45, connecting rod 46, movable crank arm 47, speed reducer 48); Waste heat recovery system 5 (induced draft fan 51, induced draft duct 52, air outlet duct 53); Hot air furnace system 6 (hot air furnace 61, high temperature air duct 62, suction fan 63, suction pipe 64); Waste heat boiler 7; Flue gas system 8 (flue gas trough 81, flue gas header 82, flue gas outlet 83, regulating valve 84); Triangular distribution plate 9, furnace body 101, material 102; DETAILED DESCRIPTION

[0032] Feeding section 1: The feed box 15 is fixed on the top of the furnace body 101, and the lower part is connected to the discharge pipe 14. The lower part of the discharge pipe 14 is connected to the distributor 13 and the distributor 12 in sequence. Each distributor 12 is provided with (1-4) distribution ports 11 at the bottom, and multiple distributors 12 are distributed on the same horizontal plane.

[0033] Calcination Section 2: Horizontally arranged inverted V-shaped hot air ducts 21 are provided at the bottom of the calcination chamber 22 (a lower material channel is left between each hot air duct and is fixed to the furnace body 101). One end of the hot air duct 21 is closed and the other end is connected to a hot air header 23. A hot air inlet 24 is provided on the hot air header 23, and a hot air outlet 25 is provided at the top of the calcination chamber 22. Cooling section 3: The cooling chamber 31 is located at the lower part of the furnace body 101 and below the hot air slot 21. The lower hopper 33 is arranged horizontally. The lower hoppers 33 are arranged horizontally and connected and fixed to each other. The external lower hopper 33 is fixed on the furnace body 101. The lower part of the lower hopper 33 is connected to the lower pipe 32. An air outlet 34 is provided at the upper part of the cooling chamber 31. A discharge port 42 is provided in the discharge section 4, which also serves as a cooling air inlet.

[0034] Discharge section 4: A discharge chute 43 is located at the bottom of the cooling chamber 31 (closely arranged and connected to the furnace body 101 on the same horizontal plane). The discharge chute 43 has a discharge port 42 that also serves as a cooling air inlet. A sway plate 41 is mounted below (movably fixed by a suspension rod 45 and capable of horizontal movement, with a gap between it and the discharge port). The sway plate 41 is connected to a movable crank arm 47 via a connecting rod 46. The movable crank arm 47 is fixed to a reducer 48 (the reducer is fixed to the furnace body 101). A material distribution umbrella 44 is fixed to the centerline of the discharge chute 43. A material channel is left between the distribution umbrella and the discharge chute to facilitate material discharge and the passage of cooling air. The umbrella is also fixed to the furnace body 101. Waste heat recovery system 5: One end of the induced draft duct 52 is connected to the air outlet 34 , and the other end is connected to the air inlet of the induced draft fan 51 . The air outlet of the induced draft fan 51 is connected to the air inlet of the hot air furnace 61 through the air outlet duct 53 .

[0035] Waste heat boiler 7: The air inlet of the waste heat boiler 7 is connected to the air outlet of the induced draft fan 51, and the air outlet of the waste heat boiler 7 is connected to the air inlet of the hot air furnace 61 through the air outlet pipe 53.

[0036] Flue gas system 8: The flue gas trough 81 is installed between the hot air trough 21 and the discharge hopper 33. The flue gas troughs are arranged horizontally. There is a discharge channel between each flue gas trough and the hot air trough 33 and the discharge hopper 33. The flue gas troughs are fixed to the furnace body 101). One end of the flue gas trough 81 is closed and the other end is connected to the flue gas header 82. The flue gas header 82 is provided with a flue gas outlet 83. The flue gas outlet 83 is connected to the inlet of the regulating valve 84 through a pipeline. The outlet of the regulating valve 84 and the air outlet 34 are connected to the induced draft pipe 52 through a pipeline, so that the flue gas and the heated cooling air can enter the induced draft fan 51 together.

[0037] Triangular distribution plates 9: The triangular distribution plates 9 are installed below the distribution port 11 . The triangular distribution plates 9 are arranged in multiple rows and staggered. Material descending channels are left between each distribution plate 9 and are fixed to the furnace body 101 .

Claims

1. A calcination energy-saving device, characterized in that: It includes a material distribution section (1), a calcining section (2), a cooling section (3), a material discharging section (4), a waste heat recovery system (5), a hot air furnace system (6), a furnace body (101), and materials (102); The distribution section (1) includes a feed box (15), a discharge pipe (14), a distributor (13), a distributor (12), and a distribution port (11). The feed box (15) is fixed to the top of the furnace body (101). The bottom of the feed box (15) is connected to the discharge pipe (14), the distributor (13), and the distributor (12) in sequence. Each distributor (12) is provided with (1-4) distribution ports (11) at the bottom. The multiple distributors (12) are all distributed on the same horizontal plane, and a hot air channel is left between each distribution port (11). The calcining section (2) includes a calcining chamber (22), an inverted V-shaped hot air trough (21), a hot air header (23), a hot air inlet (24), and a hot air outlet (25). The calcining chamber (22) is located in the upper half of the furnace body (101). Horizontally arranged inverted V-shaped hot air troughs (21) are installed at the bottom of the calcining chamber (22) (a material hot air channel is left between each hot air trough (21) and is fixed on the furnace body 101). One end of the hot air trough (21) is closed and the other end is connected to the hot air header (23). A hot air inlet (24) is provided on the hot air header (23), and a hot air outlet (25) is provided at the upper part of the calcining chamber (22); The cooling section (3) includes a cooling chamber (31), a lower hopper (33), a lower feeding pipe (32), an air outlet (34), and a discharge port (42) which also serves as a cooling air inlet. The cooling chamber (31) is located at the lower part of the furnace body (101), below the hot air trough (21), and the lower hopper (33) is arranged horizontally. The lower hoppers (33) are arranged horizontally and connected and fixed to each other. The external lower hopper (33) is fixed on the furnace body (101), and the lower part of the lower hopper (33) is connected to the discharge pipe (32). The upper part of the cooling chamber (31) is provided with an air outlet (34), and the discharge port (42) which also serves as a cooling air inlet is provided in the discharge section (4); The discharging section (4) includes a discharging trough (43), a discharging port (42) also serving as a cooling air inlet, a cloth umbrella (44), a shaking plate (41), a suspension rod (45), a connecting rod (46), a movable crank arm (47) and a speed reducer (48). The discharging trough (43) is located at the bottom of the cooling chamber (31) (closely arranged and connected to the furnace body (101) on the same horizontal plane). The discharging trough (43) is provided with a discharging port (42) also serving as a cooling air inlet. A shaking plate (41) is installed below (movably connected to the cooling air inlet through the suspension rod (45)). The swing plate (41) is connected to the movable crank arm (47) through the connecting rod (46), and the movable crank arm (47) is fixed on the reducer (48) (the reducer is fixed on the furnace body 101). The material distribution umbrella (44) is fixed on the center line of the discharge chute (43), and a material descending channel is left between the material distribution umbrella and the discharge chute to facilitate the passage of materials and cooling air, and is fixed on the furnace body (101); the furnace body (101) is provided with calcined materials (102); The waste heat recovery system (5) includes a suction fan (51), an induced draft pipe (52), and an air outlet pipe (53); one end of the induced draft pipe (52) is connected to the air outlet (34), and the other end is connected to the air inlet of the induced draft fan (51); the air outlet of the induced draft fan (51) is connected to the air inlet of the hot air furnace (61) through the air outlet pipe (53); The hot blast furnace system (6) comprises a hot blast furnace (61), a high-temperature air duct (62), a suction fan (63), and a suction duct (64). The air inlet of the hot blast furnace (61) and the air outlet of the induced draft fan (51) are connected via the air outlet duct (53). The air outlet of the hot blast furnace (61) is connected to the hot blast inlet (24) via the high-temperature air duct (62). The air inlet of the suction fan (63) is connected to the hot blast outlet (25) via the suction duct (64).

2. The calcination energy-saving device according to claim 1, characterized in that: It also includes a waste heat boiler (7), wherein the air inlet of the waste heat boiler (7) is connected to the air outlet of the induced draft fan (51), and the air outlet of the waste heat boiler (7) is connected to the air inlet of the hot blast furnace (61) through an air outlet pipe (53).

3. The calcination energy-saving device according to claim 1, characterized in that: The invention also includes a flue gas system (8), wherein the flue gas system (8) includes a flue gas trough (81), a flue gas header (82), a flue gas outlet (83) and a regulating valve (84). The flue gas trough (81) is installed between the hot air trough (21) and the lower hopper (33). The multiple flue gas troughs (81) are arranged horizontally. A material channel is left between each flue gas trough (81) and the hot air trough (21) and the lower hopper (33). The flue gas trough (81) is fixed on the furnace body (101). One end of the flue gas trough (81) is closed and the other end is connected to the flue gas header (82). A flue gas outlet (83) is provided on the flue gas header (82). The flue gas outlet (83) is connected to the inlet of the regulating valve (84) through a pipeline. The outlet of the regulating valve (84) and the air outlet (34) are connected to the induced draft pipe (52) through a pipeline, so that the flue gas and the heated cooling wind can enter the induced draft fan (51) together.

4. The calcination energy-saving device according to claim 1, characterized in that: The invention also includes a triangular cloth plate (9), which is installed in an inverted V shape below the cloth opening (11). The triangular cloth plates (9) are arranged in multiple rows and staggered. A material channel is left between each cloth plate (9) to facilitate material discharge and hot air passing through. The triangular cloth plates (9) are fixed to the furnace body (101). The addition of the triangular cloth plates (9) can play a role in layering and pressure distribution for materials with low strength, thereby preventing material damage. The materials can change position when they are lowered, thereby improving the contact efficiency between the hot air and the materials.

Images