Device for pushing materials into furnace and reaction furnace gas washing and purifying system

Abstract

The invention belongs to the field of gas washing and purifying treatment equipment, and particularly relates to a device for pushing materials into a furnace and a reaction furnace gas washing and purifying system. The upper end of the shell is provided with a washing liquid inlet, the lower end of the shell is provided with a washing liquid outlet, the rear end of the shell is provided with a gas inlet used for being connected with a gas guide pipe of a reaction furnace, and the front end of the shell is provided with a material pushing and feeding mechanism; the material pushing and furnace entering mechanism comprises a transmission shaft and a shaftless spiral blade which is in transmission connection with the transmission shaft, the shaftless spiral blade extends in the front-back direction and is matched with the inner wall of the gas guide pipe, and the shaftless spiral blade is rotationally pushed towards the reaction furnace, scrapes off wall-adhering materials on the inner wall of the gas guide pipe and pushes the materials back into the reaction furnace; and the hollow structure of the shaftless spiral blade forms a gas channel for gas of the reaction furnace to flow to the washing liquid inlet. The internal materials can be cleaned in all directions, the risk that the materials are brought out of the gas guide pipe by return stroke operation is avoided, and meanwhile gas circulation of the gas guide pipe is considered.

Description

Technical Field

[0001] This invention belongs to the field of gas scrubbing and purification equipment, specifically relating to a feeding device and a gas scrubbing and purification system for a reactor. Background Technology

[0002] The production of important chemical gases such as AHF (anhydrous hydrogen fluoride) involves first calcining powdered raw materials at high temperatures in a rotary kiln to generate AHF gas and solid salts. The kiln operates under negative pressure, and the AHF gas carries a large amount of dust upon discharge. This dust is then further purified through washing to obtain the desired product. In this process, the gas generated in the kiln is introduced into a washing device via a gas pipe. The gas and washing liquid come into countercurrent contact to achieve cooling and purification. The high-temperature gas generated in the kiln carries a large amount of dust, which adheres to the inner wall of the gas pipe. As the amount of adhered material increases, it can adversely affect gas transmission through the gas pipe and process safety.

[0003] Chinese utility model patent CN201386023Y, authorized on January 20, 2010, discloses a gas outlet scrubbing device for an AHF or SiF4 rotary reactor. The gas outlet pipe of the AHF or SiF4 rotary reactor is connected to a vertical gas guide pipe via a bend and expansion joint. A four-way pipe is connected to the upper part of the vertical gas guide pipe. The lower opening of the four-way pipe is connected to the vertical gas guide pipe, and the upper opening is connected to a sulfuric acid spraying device. One side of the horizontal opening is connected to a horizontal gas guide pipe, and the other side is covered by a blind flange. The horizontal gas guide pipe is connected to a scrubbing tower. During operation, when the dust-laden gas generated in the AHF or SiF4 rotary reactor passes through the sulfuric acid spraying device, most of the dust is washed away by the sulfuric acid. Simultaneously, the sulfuric acid sprayed by the sulfuric acid spraying device leaves its mark along the inner wall of the vertical gas guide pipe, flushing away the dust inside the vertical gas guide pipe.

[0004] The aforementioned device cannot clean the material adhering to the inner wall of the horizontal gas guide pipe. Furthermore, in situations where sulfuric acid spray washing is unsuitable, existing technology typically uses a pusher to push the material back into the reactor to clean the material adhering to the inner wall of the gas guide pipe. This achieves both the cleaning of the material adhering to the inner wall and its reuse in the reaction, preventing the material from being carried into the next process and causing adverse effects.

[0005] Traditional pusher-feeding devices use a screw and slide mechanism to drive the pusher and pusher head into the gas duct. Driven by a motor, the material adhering to the furnace wall is pushed back into the furnace by the crescent-shaped pusher head. This device has several problems: the material adhering to the furnace wall inside the gas duct is circumferentially distributed, and the crescent-shaped pusher head has a small pushing area, failing to achieve thorough cleaning. Furthermore, because the pusher head moves continuously back and forth, it scrapes off material adhering to the top and side walls of the gas duct during the pushing stroke. During the return stroke, this fallen material is pulled back and moved outside the furnace, unable to be promptly fed into the furnace for high-temperature processing. This material falls into the next process, increasing the solids content and disrupting normal production. Summary of the Invention

[0006] The purpose of this invention is to provide a feeding device for a furnace, which solves the problem that existing devices do not thoroughly clean the inner wall of the gas guide pipe and will bring the falling material out of the furnace.

[0007] The second objective of this invention is to provide a reactor gas scrubbing and purification system that solves the problem of poor cleaning effect of existing systems on the wall-adhering materials on the inner wall of the reactor gas duct.

[0008] To achieve the above objectives, the technical solution of the present invention for the feeding device is as follows: A material feeding device includes a housing with a washing liquid inlet at the upper end, a washing liquid outlet at the lower end, a gas inlet at the rear end for connection to a gas duct of a reactor, and a material feeding mechanism at the front end. The material feeding mechanism includes a drive shaft and shaftless spiral blades driven by the drive shaft. The shaftless spiral blades extend in a front-rear direction and are adapted to the inner wall of the gas duct. The shaftless spiral blades rotate and advance towards the reactor, scraping off the wall-adhering material of the gas duct and pushing it back into the reactor. The hollow structure of the shaftless spiral blades forms a gas channel for the gas in the reactor to flow to the washing liquid inlet.

[0009] This invention is an improved version, employing a shaftless spiral covering the entire inner wall of the gas guide pipe to continuously propel the material, achieving 360° all-around cleaning of the internal material. This avoids the risk of material being carried out of the gas guide pipe during the return operation, significantly saving on costs. The shaftless spiral has a hollow internal structure, matching the gas flow rate within the gas guide pipe to ensure the normal operation of the reactor's gas scrubbing and purification function.

[0010] Preferably, a protective sleeve corresponding to the washing liquid inlet is fitted around the outer periphery of the drive shaft. The front end of the protective sleeve is connected to the housing, and the rear end is rotary sealed with the drive shaft.

[0011] More preferably, the rotary seal includes a sealing plug connected between the protective sleeve and the drive shaft, the sealing plug being fixedly connected to the protective sleeve.

[0012] Preferably, the front end of the drive shaft extends out of the housing, and a leak-proof sealing structure is provided on the housing at the front end of the drive shaft.

[0013] Preferably, the washing liquid inlet and the washing liquid outlet are arranged correspondingly in the vertical direction.

[0014] The technical solution of the reactor gas scrubbing and purification system of the present invention is as follows: A reactor gas scrubbing and purification system includes a scrubbing device, a reactor, and a feeding device connecting the scrubbing device and the reactor. The feeding device includes a shell, the upper end of which is connected to the scrubbing device through a scrubbing liquid inlet, the lower end of which has a scrubbing liquid outlet, the rear end of which is connected to the gas guide pipe of the reactor, and the front end of which has a feeding mechanism. The feeding mechanism includes a drive shaft and shaftless spiral blades driven by the drive shaft. The shaftless spiral blades extend in the front-back direction and are adapted to the inner wall of the gas guide pipe. The shaftless spiral blades rotate and advance towards the reactor, scraping off the wall-adhering material of the gas guide pipe and pushing it back into the reactor. The hollow structure of the shaftless spiral blades forms a gas channel for the gas from the reactor to flow to the scrubbing liquid inlet.

[0015] The reactor gas scrubbing and purification system of the present invention, through the use of the above-mentioned pusher feeding device, pushes the material that has not been sufficiently high-temperature treated on the inner wall of the gas guide pipe back into the reactor. The pushing range covers the entire inner wall surface, resulting in good cleaning effect and eliminating the problem of material carrying back. This not only achieves full utilization of the material but also avoids the impact of the material sticking to the wall on the next process, which helps to improve the economy and rationality of the entire system operation and ensures production stability and product quality.

[0016] Preferably, a protective sleeve corresponding to the washing liquid inlet is fitted around the outer periphery of the drive shaft. The front end of the protective sleeve is connected to the housing, and the rear end is rotary sealed with the drive shaft.

[0017] More preferably, the rotary seal includes a sealing plug connected between the protective sleeve and the drive shaft, the sealing plug being fixedly connected to the protective sleeve.

[0018] Preferably, the front end of the drive shaft extends out of the housing, and a leak-proof sealing structure is provided on the housing at the front end of the drive shaft.

[0019] Preferably, the washing liquid inlet and the washing liquid outlet are arranged correspondingly in the vertical direction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the reactor gas scrubbing and purification system of the present invention; Figure 2 for Figure 1 Enlarged view of point D in the middle; Among them, 1-air guide pipe; 2-four-way valve; 3-flange end plate; 4-motor; 5-drive shaft; 6-shaftless spiral blade; 7-gas passage; 8-packing seal; 9-protective sleeve; 10-sealing plug; 11-threaded hole. Detailed Implementation

[0021] Preferred embodiments of the feeding device and the gas scrubbing and purification system of the present invention are described below: In view of the problems existing in the screw-driven linear reciprocating pusher-crescent-shaped pusher head structure, this invention proposes a novel material feeding device. It utilizes a drive shaft and a shaftless spiral structure to ensure that the material feeding range covers the entire inner wall of the gas guide pipe. When the material on the inner wall is scraped off, there is no problem of the fallen material being carried out of the gas guide pipe in the reverse direction. Moreover, the central cavity of the shaftless spiral does not affect the gas conveying in the reactor. A single device integrates multiple functions such as material feeding, preventing reverse material carrying, and gas conveying, ensuring the normal production of important chemical gases.

[0022] Since the washing process can cause washing liquid to scour and corrode the drive shaft, this invention also designs a protective sleeve to prevent the washing liquid from scouring, corroding and stressing the drive shaft.

[0023] A rotary seal was designed for the protective sleeve and drive shaft to prevent the drive shaft from coming into contact with gas and liquid, thus extending the service life of the drive shaft.

[0024] The reactor gas scrubbing and purification system utilizing the aforementioned feeding device makes the entire production process smoother and safer. Material adhering to the walls of the gas guide pipe is fully pushed back into the furnace for reaction, improving raw material utilization and preventing adverse effects from material entering the next process. Simultaneously, the device features high transmission efficiency, low energy consumption, and good stability, significantly reducing the workload for workers.

[0025] The preferred embodiments described above will be illustrated below with specific examples.

[0026] Example 1 The structural schematic diagram of the reactor gas scrubbing and purification system in this embodiment is shown below. Figure 1 As shown, it includes a reactor, a gas guide pipe 1, a feeding device and a washing device.

[0027] Inside the reactor, powdered materials generate high-temperature gas under high-temperature conditions. After being washed and purified in a washing device, a gaseous product that meets the requirements is obtained.

[0028] The gas guide pipe 1 is connected to the upper end of the reactor and is used to guide the high-temperature gas generated by the reactor into the scrubbing device for scrubbing treatment. Port A of the gas guide pipe 1 forms a gas inlet or a solid material inlet. The diameter of the gas guide pipe 1 can be determined based on the generated gas flow rate and gas volume, and according to engineering calculations, to ensure negative pressure operation inside the furnace and timely discharge of the generated gas.

[0029] The washing device is connected upstream of the gas inlet pipe 1. The washing device contains washing liquid, which flows in a convective manner with the high-temperature gas generated by the reactor. The washing liquid flows downwards, while the high-temperature gas flows upwards. After sufficient convective mass transfer, the gas generated by the reactor is washed and purified. The washing device is a mature piece of equipment in this field, such as a washing tower structure.

[0030] The feeding device is connected between the gas pipe 1 and the washing device. It includes a four-way valve 2 and a feeding mechanism. The four-way valve 2 acts as a shell, realizes the transition connection between the gas pipe 1 and the washing device, and provides a flow channel for the reaction gas and washing liquid. The feeding mechanism is installed on the four-way valve 2 and pushes the adhering material on the inner wall of the gas pipe 1 back into the reaction furnace.

[0031] The four-way connector 2 has four ports. The upper port B is used to connect to the washing device and serves as both the washing liquid inlet and the gas outlet. The lower port C serves as the washing liquid outlet. The right port is connected and fixed to the gas guide pipe 1 via a flange. The left port is connected to the flange end plate 3. The upper port B and the lower port C are positioned correspondingly in the vertical direction, and the washing liquid flowing down from the upper port B flows directly out from the lower port C.

[0032] The feeding mechanism is installed at the left inlet of the four-way valve 2, and includes a motor 4, a drive shaft 5 connected to the motor 4, and a shaftless spiral blade 6 connected to the drive shaft 5. The shaftless spiral blade 6 is arranged in the left-right direction (i.e., the front-back direction), and there is a gap between the shaftless spiral blade 6 and the inner wall of the gas guide pipe 1 to avoid contact with the gas guide pipe 1 during rotation. The length of the shaftless spiral blade 6 is adapted to the length range of the gas guide pipe 1 to comprehensively scrape and clean the material adhering to the inner wall of the gas guide pipe 1. The feeding direction after the shaftless spiral blade 6 rotates (… Figure 1 (The direction of the middle arrow) is towards the reactor to push the material adhering to the wall and the material falling from the top back into the reactor.

[0033] The shaftless helical blades 6 and their pitch determine the conveying capacity of the shaftless helical screw, which should be greater than the amount of solid material carried out by the generated gas from the reactor. Continuous operation of the shaftless helical screw can promptly clean up materials adhering to the walls, ensuring timely discharge of the generated gas. Simultaneously, the hollow structure of the shaftless helical blades 6 provides more space within the gas guide pipe 1 for easy exhaust, ensuring the gas flow rate of the gas guide pipe 1. This hollow structure forms the gas channel 7 for the reactor gas to flow to the washing liquid inlet.

[0034] The drive shaft 5 extends in the front-to-back direction, with its front end extending beyond the flange end plate 3 and connected to the motor 4, and its rear end welded to the shaftless helical blade 6. A front seal is provided at the front end of the drive shaft 5 at the flange end plate 3 to prevent leakage of gas, liquid, etc. in the system. The front seal can be a packing seal 8. The connection position between the shaftless helical blade 6 and the drive shaft 5 is located behind the washing liquid inlet. A protective sleeve 9 is installed between this connection position and the flange end plate 3, surrounding the corresponding part of the drive shaft 5. The length of the protective sleeve 9 covers the size range of the washing liquid inlet to prevent the washing liquid flowing down from the washing liquid inlet from causing erosion corrosion and stress impact on the drive shaft 5.

[0035] The front end of the protective sleeve 9 is fixed to the flange end plate 3, and the connection can be achieved by welding or other means. There is a gap between the protective sleeve 9 and the drive shaft 5. The rear end of the protective sleeve 9 is rotary sealed with the drive shaft 5 to form the rear seal D of the drive shaft 5, which prevents gas and liquid from entering the interior of the protective sleeve 9 and causing corrosion to the drive shaft 5, thus affecting the service life of the drive shaft 5.

[0036] like Figure 2 As shown, the rotary seal D includes an annular sealing plug 10 disposed between the protective sleeve 9 and the drive shaft 5. The sealing plug 10 is provided with threaded holes 11 around its perimeter. The protective sleeve 9 is also provided with threaded holes at corresponding positions. The protective sleeve 9 and the sealing plug 10 are reinforced by passing screws through the threaded holes on the protective sleeve 9 and the sealing plug 10.

[0037] Taking AHF gas as an example, the raw material in the reactor is powder, which is calcined at high temperature to generate gaseous AHF and powdered granular salt. The gas generated in the reactor is discharged through the gas outlet. During the discharge process, it carries a large amount of dust, causing blockage of the gas duct. After a certain period of time, the blockage will create positive pressure inside the furnace, causing gas leakage, which is extremely dangerous. After the gas duct is blocked, in order to ensure the normal operation of the system, the entire system must be shut down for cleaning, resulting in a low start-up rate, and the thorough cleaning of the gas duct is also quite difficult.

[0038] The working process of the above-mentioned reactor gas scrubbing and purification system is as follows: The gas generated by the reactor enters the gas guide pipe 1 through port A. As the gas rises, it forms convection with the scrubbing liquid entering through port B at the top of the four-way connector 2, resulting in cooling, scrubbing, and absorption processes, thereby achieving gas purification and recovery of process components. Simultaneously, some powdery material will deposit inside the gas guide pipe 1 as the process progresses. This powdery material adheres to the inside of the gas guide pipe 1 and is distributed in a circumferential shape. This material has not undergone sufficient high-temperature treatment and needs to be pushed into the furnace for further processing.

[0039] The shaftless spiral at the end of drive shaft 5 rotates and propels the material via an external drive. It can cover the entire inner wall of the gas guide pipe 1, cleaning the material adhering to the wall from all angles. The washed wet material and liquid enter the next process through the lower port C of the four-way connector 2. The above-mentioned feeding device operates continuously, ensuring timely removal of fine dust carried by the gas continuously generated in the reactor. The gas is discharged after washing and purification.

[0040] The use of a shaftless screw provides a set flow rate for gas flow, successfully solving the problem of the small pushing range of traditional pushers. On the other hand, it also avoids the risk of material carrying during the return stroke of traditional pushers, enabling all-round cleaning of the inner wall of the gas guide pipe 1, and timely pushing the cleaned material into the reactor for subsequent heating treatment, thereby improving the gas purification efficiency and the recovery ratio of process components in the entire process.

[0041] Example 2 The feeding device in this embodiment is connected between the gas duct of the reactor and the washing device. It includes a four-way valve and a feeding mechanism. The four-way valve acts as a shell, realizes the transition connection between the gas duct of the reactor and the washing device, and provides a flow channel for the reactor gas and washing liquid. The feeding mechanism is installed on the four-way valve and pushes the adhesive material on the inner wall of the gas duct back into the reactor.

[0042] The four-way valve has four ports. The upper port is used to connect to the washing device and serves as both the washing liquid inlet and the gas outlet. The lower port is the washing liquid outlet. The right port is connected and fixed to the gas guide pipe via a flange. The left port is connected to the flange end plate. The upper and lower ports are positioned correspondingly in the vertical direction, and the washing liquid flowing down from the upper port flows directly out from the lower port.

[0043] The feeding mechanism is installed at the left inlet of the four-way valve and includes a motor, a drive shaft connected to the motor, and shaftless spiral blades connected to the drive shaft. The shaftless spiral blades are arranged in a left-right direction (i.e., a front-back direction), with a gap between them and the inner wall of the gas guide pipe to prevent them from contacting the gas guide pipe during rotation. The length of the shaftless spiral blades is adapted to the length range of the gas guide pipe to scrape and clean the material adhering to the inner wall of the gas guide pipe. After rotation, the feeding direction of the shaftless spiral blades faces the reactor to push the adhering material and the scraped material back into the reactor. The hollow structure of the shaftless spiral blades ensures the gas flow rate of the gas guide pipe.

[0044] The drive shaft extends in the front-to-back direction, with its front end protruding beyond the flange end plate and connected to the motor, and its rear end welded to the shaftless helical blades. A front seal is installed at the front end of the drive shaft near the flange end plate to prevent leakage of gas, liquid, etc. from the system; the front seal can be a packing seal. The connection point between the shaftless helical blades and the drive shaft is located behind the washing liquid inlet. A protective sleeve surrounding the corresponding part of the drive shaft is installed between this connection point and the flange end plate. The length of the protective sleeve covers the size range of the washing liquid inlet to prevent the washing liquid flowing down from the inlet from causing erosion corrosion and stress impact on the drive shaft.

[0045] The front end of the protective sleeve is fixed to the flange end plate and can be fixedly connected by welding or other methods. There is a gap between the protective sleeve and the drive shaft. The rear end of the protective sleeve and the drive shaft form a rotary seal, creating a rear seal for the drive shaft. This prevents gas and liquid from entering the protective sleeve and corroding the drive shaft, thus affecting its service life. The rotary seal includes an annular sealing plug positioned between the protective sleeve and the drive shaft. The sealing plug has threaded holes around its circumference, and screws are used to reinforce the connection between the protective sleeve and the sealing plug.

[0046] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pusher device for pushing material into a furnace, characterized in that The shell is provided with a washing liquid inlet at the upper end, a washing liquid outlet at the lower end, a gas inlet for connecting with the gas guide pipe of the reaction furnace at the rear end, and a pushing mechanism for pushing the material into the furnace at the front end.

2. The push-through furnace apparatus of claim 1 wherein, The transmission shaft is provided with a protective sleeve pipe corresponding to the washing liquid inlet, the front end of the protective sleeve pipe is connected to the shell, and the rear end is rotationally sealed with the transmission shaft.

3. The push-through furnace apparatus of claim 2 wherein, The rotation seal includes a sealing plug connected between the protective sleeve pipe and the transmission shaft, and the sealing plug is fixedly connected to the protective sleeve pipe.

4. A push-furnace device according to claim 1 or 2 or 3, characterized in that The front end of the transmission shaft extends out of the shell, and a sealing structure for preventing leakage is arranged on the shell at the front end of the transmission shaft.

5. The push-through furnace apparatus of claim 1 wherein, The washing liquid inlet and the washing liquid outlet are arranged correspondingly in the up-down direction.

6. A reaction furnace gas scrubbing purification system characterized by comprising: The shell is provided with a washing liquid inlet at the upper end, a washing liquid outlet at the lower end, a gas inlet for connecting with the gas guide pipe of the reaction furnace at the rear end, and a pushing mechanism for pushing the material into the furnace at the front end.

7. The reaction furnace gas scrubbing purification system according to claim 6, wherein The transmission shaft is provided with a protective sleeve pipe corresponding to the washing liquid inlet, the front end of the protective sleeve pipe is connected to the shell, and the rear end is rotationally sealed with the transmission shaft.

8. The reaction furnace gas scrubbing purification system according to claim 7, wherein The rotation seal includes a sealing plug connected between the protective sleeve pipe and the transmission shaft, and the sealing plug is fixedly connected to the protective sleeve pipe.

9. The reaction furnace gas scrubbing purification system as claimed in claim 6 or 7 or 8, wherein, The front end of the transmission shaft extends out of the shell, and a sealing structure for preventing leakage is arranged on the shell at the front end of the transmission shaft.

10. The reaction furnace gas scrubbing purification system according to claim 9, wherein The washing liquid inlet and the washing liquid outlet are arranged correspondingly in the up-down direction.

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