Suspended-state and hot-state gas-solid reaction device

Abstract

The utility model discloses a suspended-state and hot-state gas-solid reaction device which comprises a spiral material conveying machine, a material preheating furnace, a reaction furnace, a gas preheating furnace, a furnace tube and a gas distribution system, the furnace tube is of an integrated structure, a necking opening used for accelerating gas is formed in the furnace tube, the furnace tube is divided into an upper reaction area and a lower gas preheating area, and an upper connector and a lower connector are arranged at the two ends of the furnace tube respectively. A feeding sleeve of the spiral conveying machine penetrates through the material preheating furnace and is connected with an upper joint, and a first air outlet is formed in the upper joint; the reaction furnace and the gas preheating furnace are vertically arranged, the reaction furnace is positioned at the upper part of the gas preheating furnace, and the furnace tube is arranged in the reaction furnace and the gas preheating furnace; an observation window is arranged on the reaction furnace and is used for observing the suspension state of the solid particles; the gas distribution system is connected with the lower joint; the lower end of the lower connector is connected with a material receiving bin, and a second air outlet is formed in the material receiving bin. According to the utility model, preheating of materials and gas can be realized, and a better material state observation effect can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a gas -solid reaction device, concretely relates to a gas -solid reaction device under hot state makes solid powder material present suspended state, is used for researching the mechanism of gas -solid chemical reaction and the process parameter of powder material heat treatment. BACKGROUND

[0002] Solid particle suspension calcination technology has the advantages of high mass transfer and heat transfer efficiency, and is widely used in calcination decomposition (such as decomposition of carbonates in cement raw materials), oxidation (such as solid fuel combustion), reduction (such as reduction of iron oxide to low valence iron in clay decolorization), gas-solid catalysis (such as catalytic denitration) and other fields. In the process of new technology development and optimization, the reaction mechanism and heat treatment process need to be further studied.

[0003] Currently, when studying the gas-solid reaction mechanism and powder heat treatment process, thermal analysis method or self-made reaction furnace is generally used for experiment. Thermal analysis method is to measure the mass and heat release / absorption of solid during heating process by using thermal analyzer. In this method, the solid material is in a stacked state. The heat transfer and mass transfer efficiency between the gas and solid phases in this state is low. However, most chemical reactions under hot state have high reaction rates. Therefore, the experimental results have limited reference significance for suspended state reactions.

[0004] The existing self-made reaction furnace has problems such as uncertain suspension state due to invisible material state, no preheating of material and gas, limited suspension state and residence time adjustment means, etc. It is difficult to accurately reflect the gas-solid flow, heat transfer, mass transfer and chemical reaction process in the suspended state gas-solid reaction process. CN114657369A discloses an experimental type of suspended state mineral phase conversion device. The reaction zone is in a high temperature zone, and the material and gas have no preheating stage. The material and gas are in the heating stage at the initial stage, and the reaction time is not the real reaction time. In addition, a quartz glass plate is provided at the top of the settling chamber as an observation window. The viewing angle is limited, and the side viewing angle cannot be observed. At the same time, the reaction zone is separated from the observation window by a settling zone, which leads to poor observation effect and cannot guarantee that the material is in a real suspended state. Based on the above reasons, the experimental data obtained by using the device cannot truly reflect the relationship between process parameters (such as temperature, reaction time, gas-solid ratio, etc.) and reaction rate. UTILITY MODEL CONTENT

[0005] The utility model aims to provide a suspended state hot gas-solid reaction device with better material state observation effect and preheating of material and gas.

[0006] Technical Solution: This utility model discloses a suspended hot gas-solid reaction device, comprising a screw conveyor, a material preheating furnace, a reaction furnace, a gas preheating furnace, a furnace tube, and a gas distribution system. The furnace tube is an integral structure with a constriction for accelerating gas, dividing the furnace tube into an upper reaction zone and a lower gas preheating zone. An upper connector and a lower connector are respectively provided at both ends of the furnace tube. The feeding sleeve of the screw conveyor passes through the material preheating furnace and connects to the upper connector, which has a first gas outlet. The reaction furnace and the gas preheating furnace are arranged vertically, with the reaction furnace located above the gas preheating furnace. The furnace tube is located inside both the reaction furnace and the gas preheating furnace. An observation window is provided on the reaction furnace for observing the suspension state of solid particles. The gas distribution system is connected to the lower connector. A receiving hopper is connected to the lower end of the lower connector, and a second gas outlet is provided on the receiving hopper.

[0007] Furthermore, the screw conveyor is driven by a variable frequency speed-regulating motor to achieve feeding speed adjustment; a first air inlet is provided on the feeding sleeve in front of the hopper interface for introducing inert protective gas to prevent hot gas from backflowing into the hopper; the hopper has a sealing cover.

[0008] Furthermore, both the reactor and the gas preheater are left-right opening structures, mounted on the main frame via transverse slide rails, allowing the left and right furnace bodies to move left and right on the transverse slide rails.

[0009] Furthermore, the upper connector is equipped with a temperature measuring port and an air intake port. The temperature measuring port and the air intake port are respectively fixed with a thermocouple and an air intake rod by a compression fitting assembly. The insertion depth of the thermocouple and the air intake rod is adjustable. A dust filter is provided at the front end of the air intake rod.

[0010] Furthermore, a manual feeding valve is provided on the upper connector for conveying materials that do not require preheating.

[0011] Furthermore, the upper and lower joints are fixedly connected to the furnace tubes via flanges and sealing gaskets; cooling water circulation chambers are provided outside the upper and lower joints to allow cooling water to flow in and prevent high temperature damage to the sealing gaskets.

[0012] Furthermore, a cooling water circulation chamber is provided on the outer wall of the receiving hopper to allow cooling water to be introduced to cool the hot materials that have completed the reaction.

[0013] Furthermore, the gas distribution system includes a mixing tank, which is connected to multiple inlet pipes and one outlet pipe. Each of the multiple inlet pipes is equipped with a mass flow meter; the outlet pipe is used to input the mixed gas into the furnace tube.

[0014] Furthermore, the upper connector is connected to the feeding sleeve via a flexible connection.

[0015] The experimental parameters of this invention are flexible and controllable, which is reflected in the following aspects:

[0016] The material preheating furnace, reaction furnace, and gas preheating furnace are all independently temperature controlled. After the reaction is completed, the furnace bodies of the reaction furnace and gas preheating furnace can be opened to both sides immediately to stop heating immediately. The feeding motor has a variable frequency speed control to control the feeding amount. The gas distribution system consists of multiple mass flow meters, and the composition and flow rate of the experimental gas can be precisely controlled. While keeping the outer diameter and height of the furnace tube unchanged, the furnace tube narrowing and reaction zone size can be designed and processed as needed to achieve a more ideal material suspension effect.

[0017] Beneficial effects: Compared with the prior art, this utility model has the following advantages:

[0018] (1) Visualization of material state: The heated gas is accelerated in the constriction, and the high-speed airflow from the constriction can suspend solid particles in the gas-solid reaction zone, ensuring that the material is in an effective suspension state. At the same time, for some chemical reactions with flames, color changes, or changes in solid morphology (such as combustion reactions, oxidation and reduction reactions, gasification reactions, etc.), the dynamics of the chemical reaction can be observed in real time.

[0019] (2) The materials and gases have sufficient time to be preheated before they meet, so that the reaction can start directly when the materials and the reaction gas meet, thus shielding the influence of the heating process of the materials and gases.

[0020] In summary, this invention provides a more reliable research device for studying the mechanism of suspended gas-solid reactions and optimizing the process parameters of powder heat treatment. Attached Figure Description

[0021] Fig. 1 This is a schematic diagram of the structure of the suspended hot gas-solid reaction device provided in this embodiment of the utility model;

[0022] Fig. 2 This is a schematic diagram of the furnace tube structure in an embodiment of this utility model. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] Appendix Figs. 1-2 The accompanying figure labels are as follows:

[0025] 1. Motor; 2. First air inlet; 3. Feeding sleeve; 4. Hopper; 5. Material preheating furnace; 6. Flexible connection; 7. Upper connector; 8. Thermocouple; 9. Air intake rod; 10. First air outlet; 11. Manual feeding valve; 12. First cooling water outlet; 13. First cooling water inlet; 14. Main frame; 15. Dust filter; 16. Horizontal slide rail; 17. Reactor; 18. Observation window; 19. Gas preheating furnace; 20. Furnace tube; 201. Reaction zone; 202. Narrowing; 203. Gas preheating zone; 21. Lower connector; 22. Second air outlet; 23. Second cooling water inlet; 24. Receiving hopper; 25. Second cooling water outlet; 26. Second air inlet; 27. Third air outlet; 28. Mixing tank; 29. ​​Mass flow meter; 30. Third air inlet; 31. Control panel; 32. Display panel.

[0026] like Fig. 1 and Fig. 2 As shown, this utility model embodiment provides a suspended hot gas-solid reaction device, including a screw conveyor, a material preheating furnace 5, a reaction furnace 17, a gas preheating furnace 19, a furnace tube 20, and a gas distribution system.

[0027] The feeding sleeve 3 of the screw conveyor passes through the material preheating furnace 5, thereby enabling the material preheating furnace 5 to heat the material. The screw conveyor is driven by a variable frequency speed-regulating motor 1 to achieve adjustable feeding speed. A first air inlet 2 is provided on the feeding sleeve 3 in front of the hopper 4 interface, used to introduce inert protective gas during the experiment to prevent hot air from the material preheating furnace 5 from backflowing into the hopper 4 and causing safety issues. The hopper 4 has a sealed cover to isolate the influence of outside air during the experiment. For ease of maintenance and cleaning, the material preheating furnace 5 can be designed with an opening structure at the top and bottom, and the motor 1, feeding screw, feeding sleeve 3, and hopper 4 are all designed to be detachable.

[0028] The reactor 17 and the gas preheater 19 are arranged vertically, with the reactor 17 on top and the gas preheater 19 on the bottom. Both the reactor 17 and the gas preheater 19 are left-right opening structures, and are mounted on the main frame 14 via transverse slide rails 16, allowing the left and right furnace bodies to move left and right on the transverse slide rails 16.

[0029] The furnace tube 20 is installed inside the reactor 17 and the gas preheating furnace 19. The furnace tube 20 is an integrated high-temperature resistant quartz furnace tube. On the one hand, quartz glass is an inert material and does not affect the chemical reaction; on the other hand, the surface of quartz glass is smooth, and the material is not easy to stick to the wall or agglomerate.

[0030] The furnace tube 20 is equipped with a constriction 202 for accelerating the gas, dividing the furnace tube 20 into an upper reaction zone 201 and a lower gas preheating zone 203. The incoming gas is heated in the gas preheating zone 203, and the heated gas is accelerated in the constriction 202. The high-speed gas flow exiting the constriction 202 can suspend solid particles in the reaction zone 201. The reactor 17 is equipped with an observation window 18 for observing the suspension state of the solid particles. The observation window 18 is made of high-temperature resistant quartz glass.

[0031] The upper end of the furnace tube 20 is fixed to the upper connector 7 via a flange and sealing gasket. The upper connector 7 is fixed to the main frame 14 with screws and nuts. A stainless steel flexible connector 6 is provided on the upper connector 7 for connection with the feeding sleeve 3. The upper connector 7 also has a temperature measuring port and a gas sampling port. The temperature measuring port and the gas sampling port are respectively fixed to a thermocouple 8 and a gas sampling rod 9 via compression fittings. The insertion depth of the thermocouple 8 and the gas sampling rod 9 is adjustable, used for temperature measurement and gas sampling at different heights in the reaction zone 201 (the rear end can be connected to a flue gas analyzer for online analysis of flue gas components, or the flue gas can be sampled and analyzed by instruments such as GC and GC-MASS). A dust filter 15, made of high-temperature resistant porous ceramic or high-temperature resistant quartz wool, is provided at the front end of the gas sampling rod 9. In addition, the upper connector 7 also has a first gas outlet 10 and a manual feeding valve 11. For materials that do not require preheating, feeding can be done through the manual feeding valve 11.

[0032] To prevent high temperature from damaging the sealing gasket, a cooling water circulation chamber is provided outside the upper connector 7. Cooling water enters from the first cooling water inlet 13 and flows out from the first cooling water outlet 12.

[0033] The lower end of the furnace tube 20 is fixed to a lower connector 21 via a flange and a sealing gasket. The lower connector 21 is secured to the main frame 14 with screws and nuts. A receiving hopper 24 is connected to the lower end of the lower connector 21. The receiving hopper 24 has a second air outlet 22 for discharging excess waste gas. A cooling water circulation chamber is provided on the outer wall of the receiving hopper 24. Cooling water enters through a second cooling water inlet 23 and exits through a second cooling water outlet 25, used to cool the hot materials that have completed the reaction. The lower connector 21 also has a second air inlet 26, through which the mixed gas from the gas distribution system enters the furnace tube 20. The upper connector 7, furnace tube 20, lower connector 21, and receiving hopper 24 are all detachable structures for easy maintenance and cleaning.

[0034] The gas distribution system includes multiple third air inlets 30, a multi-channel mass flow meter 29, a mixing tank 28, and a third air outlet 27. The third air outlet 27 is connected to the second air inlet 26 via a gas pipe, and the third air outlet 27 is connected to a gas cylinder for gas supply.

[0035] The main frame 14 is also equipped with a control panel 31 and a display panel 32. The control panel 31 integrates the control functions of the feed motor speed, the temperature and heating rate of the three heating furnaces, and the flow rate of the mass flow meter. The display panel 32 displays the feed motor speed, the controlled temperature and real-time temperature of the three heating furnaces, and the controlled flow rate and real-time flow rate of the mass flow meter. The heating temperature range of the material preheating furnace 5 is room temperature to 1000℃, and the heating temperature range of the reaction furnace 17 and the gas preheating furnace 19 is room temperature to 1200℃. The three reaction furnaces are all independently temperature controlled, and the heating rate is 0 to 10℃ / min.

[0036] To make the technical solution of this utility model clearer, the following describes in detail the clay decolorization experiment conducted using this device (Decolorization principle: Clay contains a certain amount of Fe2O3, so its color is reddish. After the Fe2O3 is reduced to black Fe3O4 by CO in hot flue gas, the clay color turns gray, thus achieving clay decolorization).

[0037] After the material is processed using standard laboratory methods (grinding and sieving), 300g is placed in silo 4 and sealed with a lid. The temperature of material preheating furnace 5 is set to 680℃, gas preheating furnace 19 to 800℃, and reaction furnace 17 to 800℃. The heating rate is 10℃ / min, and the holding time is 10h. After the material preheating furnace 5, reaction furnace 17 and gas preheating furnace 19 reach the set temperature, open the cooling water of the upper connector 7 and the receiving hopper 24; connect the gas cylinder to the third air inlet 30, close the second air outlet 22, and turn on the four-way mass flow meter 29. The flow rates of the four-way mass flow meter 29 are 200 mL / min for oxygen, 2 L / min for carbon dioxide, 500 mL / min for carbon monoxide and 7.5 L / min for nitrogen (corresponding to the concentration composition of the mixed gas as 2% oxygen + 3% CO + 20% carbon dioxide); after the four-way gas is mixed in the mixing tank 28, it leaves the gas distribution system from the third air outlet 27, and then enters the lower connector 21 and furnace tube 20 from the second air inlet 26. The reaction gas is heated in the gas preheating zone 203 and then enters the reaction zone 201 through the constriction 202; nitrogen protective gas is introduced from the first air inlet 2, and the motor 1 is turned on and the motor speed is controlled to make the feeding rate reach 5 g / min. Timing begins when material is observed falling into reaction zone 201. After 30 seconds, motor 1 is shut off, and the furnace bodies of reactor 17 and gas preheating furnace 19 are quickly opened to both sides. Then, all mass flow meters 29 are shut off. At this point, without the buoyancy and drag of the gas, the material falls under its own gravity and is rapidly cooled in the receiving hopper 24. After 5 minutes, the receiving hopper 24 is removed, and the reacted material is taken out for subsequent experimental analysis. This completes one experiment. Comparative experiments with different gas compositions can be conducted by changing the gas composition.

Claims

1. A suspended hot gas-solid reaction device, characterized in that, The system includes a screw conveyor, a material preheating furnace (5), a reaction furnace (17), a gas preheating furnace (19), a furnace tube (20), and a gas distribution system. The furnace tube (20) is an integral structure with a constriction (202) inside for accelerating the gas, dividing the furnace tube (20) into an upper reaction zone (201) and a lower gas preheating zone (203). The furnace tube (20) has an upper connector (7) and a lower connector (21) at both ends. The feeding sleeve (3) of the screw conveyor passes through the material preheating furnace (5) and connects to the upper connector (7). The connector (7) is provided with a first gas outlet (10); the reactor (17) and the gas preheater (19) are arranged vertically, with the reactor (17) located above the gas preheater (19), and the furnace tube (20) is arranged inside the reactor (17) and the gas preheater (19); the reactor (17) is provided with an observation window (18) for observing the suspension state of solid particles; the gas distribution system is connected to the lower connector (21); the lower end of the lower connector (21) is connected to a receiving bin (24), and the receiving bin (24) is provided with a second gas outlet (22).

2. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The screw conveyor is driven by a variable frequency speed-regulating motor (1) to realize the adjustment of feeding speed; a first air inlet (2) is provided on the feeding sleeve (3) in front of the interface of the hopper (4) for introducing inert protective gas to prevent hot gas from backflowing into the hopper (4); the hopper (4) has a sealing cover.

3. The suspended hot gas-solid reaction device according to claim 1, characterized in that, Both the reactor (17) and the gas preheater (19) are left-right opening structures, and are installed on the main frame (14) via a transverse slide rail (16). The left and right furnace bodies can move left and right on the transverse slide rail (16).

4. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The upper connector (7) is provided with a temperature measuring port and an air intake port. The temperature measuring port and the air intake port are respectively fixed with a thermocouple (8) and an air intake rod (9) by a compression fitting assembly. The insertion depth of the thermocouple (8) and the air intake rod (9) is adjustable. A dust filter (15) is provided at the front end of the air intake rod (9).

5. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The upper connector (7) is equipped with a manual feeding valve (11) for conveying materials that do not require preheating.

6. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The upper and lower joints are fixedly connected to the furnace tube (20) through flanges and sealing gaskets; cooling water circulation chambers are provided outside the upper and lower joints to allow cooling water to be introduced to prevent high temperature damage to the sealing gaskets.

7. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The outer wall of the receiving hopper (24) is provided with a cooling water circulation chamber for introducing cooling water to cool the hot materials that have completed the reaction.

8. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The gas distribution system includes a mixing tank (28), which is connected to multiple inlet pipes and one outlet pipe. Each of the multiple inlet pipes is equipped with a mass flow meter (29). The outlet pipe is used to input the mixed gas into the furnace tube (20).

9. The suspended hot gas-solid reaction device according to claim 1, characterized in that, The upper connector (7) is connected to the feeding sleeve (3) via a flexible connection (6).

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