A blast furnace slag cleaning system for a waste heat boiler

Abstract

The utility model discloses a kind of waste heat boiler explosion ash removal systems, including multiple pulse tanks in the lower ash outlet furnace wall outside installation of waste heat boiler, the dredging pipe of the lower part connection of pulse tank extends horizontally to furnace wall inside, the lower part of dredging pipe is communicated with the presoaking pipe that extends to furnace wall inside, and pulse tank is blasted into air dredging by control system alternately with dredging pipe and presoaking pipe, pulse tank is blasted into air by blast air supply system, the utility model is blasted into air dredging by the alternation of pulse tank, dredging pipe and presoaking pipe, cooperate control system and blast air supply system, realize high-efficiency ash removal effect, solve the problem that traditional vibration and beating ash removal effect is poor, equipment is easily damaged, with ash removal effect is good, equipment service life is long, running stable and reliable and the like advantages.

Description

Technical Field

[0001] This utility model relates to the field of waste heat boiler ash removal, specifically to a waste heat boiler explosion ash removal system. Background Technology

[0002] In the sulfuric acid production process, the raw material sulfur concentrate is roasted in a fluidized bed furnace, generating flue gas containing sulfur dioxide and a large amount of heat. To maintain the process temperature and achieve heat recovery, sulfuric acid plants generally install waste heat boilers. When the flue gas from the fluidized bed furnace enters the waste heat boiler, it carries a large amount of iron oxide dust. This dust has strong adhesive properties, and if it is not removed in time, it will cause blockage of the flue gas pipes, seriously affecting heat exchange efficiency and increasing system resistance.

[0003] Traditional waste heat boilers use a vibrating motor to vibrate the ash discharge port to deal with ash accumulation problems (such as...). Figure 2 (As shown in the image), however, this method has several technical drawbacks: the rapping ash removal effect is not ideal, making it difficult to completely remove highly adhesive dust, leading to the gradual accumulation and compaction of ash at the ash discharge port; the motor operates for extended periods in high-temperature, high-dust environments, resulting in severe wear of mechanical parts, with a service life typically less than 60% of the designed lifespan; the vibration mechanism has a high failure rate, requiring shutdowns for maintenance 2-3 times per month on average, severely impacting continuous production efficiency. More seriously, the mechanical impact generated during rapping ash removal is transmitted to the boiler body, accelerating fatigue damage to pressure-bearing components and posing safety hazards. Furthermore, traditional ash removal methods cannot achieve precise control, easily leading to over- or under-ash removal, wasting energy and affecting boiler operational stability. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a waste heat boiler explosion ash removal system.

[0005] This utility model is achieved through the following technical solution: This application provides a waste heat boiler explosion ash removal system, the technical solution of which is as follows: it includes multiple pulse tanks installed outside the furnace wall at the lower ash discharge port of the waste heat boiler. The lower part of the pulse tank is connected to a dredging pipe that extends horizontally into the furnace wall. The lower part of the dredging pipe is connected to a pre-dredging pipe that extends obliquely into the furnace wall. The gas in the pulse tank is alternately explosion-dredged and dredged along the dredging pipe and the pre-dredging pipe by a control system. The pulse tank is supplied with gas by an explosion gas supply system.

[0006] Furthermore, this application also proposes that the control system includes a first control valve and a second control valve installed on the unblocking pipe and the pre-unblocking pipe, the first control valve and the second control valve being alternately opened and closed by a controller, and the controller being electrically connected to the ignition device in the mixing ignition cabinet of the blasting gas supply system.

[0007] Furthermore, this application also proposes that the controller controls the first control valve to close, the second control valve to open, and the first control valve and the second control valve to open simultaneously in three unblocking cycles to perform cyclic ash removal.

[0008] Furthermore, this application also proposes that the rear end of the elbow of the unblocking pipe is connected to the air curtain pipe through an air curtain branch pipe, and the air curtain pipe provides positive pressure sealing for the unblocking pipe and the pre-unblocking pipe.

[0009] Furthermore, this application also proposes that the blasting gas supply system includes a flow control cabinet, the inlet of which is connected to a fuel cylinder and an air pipe, the outlet of which is connected to a mixing ignition cabinet, and the outlet of which is connected to a pulse canister via a pipeline.

[0010] Furthermore, this application also proposes that the pulse tank is fixed to the outer wall of the furnace by a fixing bracket.

[0011] Compared with existing technologies, the advantages of this utility model are: by using an alternating burst air intake method of pulse tank, unblocking pipe and pre-unblocking pipe, combined with the coordinated work of control system and burst air supply system, this utility model can effectively solve the problem that traditional rapping dust removal methods are difficult to completely remove adhesive dust. It has the advantages of good dust removal effect, long equipment service life and stable and reliable system operation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the system of this utility model; Figure 2 This is a schematic diagram of the prior art of this utility model; In the diagram: 1. Fuel cylinder; 2. Flow control cabinet; 3. Mixing ignition cabinet; 4. Pulse tank; 5. Fixture; 6. Unclogging pipe; 7. Unclogging port; 8. Pre-unclogging pipe; 9. First control valve; 10. Second control valve; 11. Controller; 12. Air curtain pipe; 13. Air curtain branch pipe; 14. Furnace wall. Detailed Implementation

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: like Figure 1 As shown, this application proposes a waste heat boiler explosion ash removal system, including multiple pulse tanks installed outside the furnace wall at the lower ash discharge port of the waste heat boiler. The lower part of the pulse tank is connected to a dredging pipe that extends horizontally into the furnace wall. The lower part of the dredging pipe is connected to a pre-dredging pipe that extends obliquely into the furnace wall. The gas in the pulse tank is alternately explosion-dredged and dredged along the dredging pipe and the pre-dredging pipe by a control system. The pulse tank is supplied with gas by an explosion gas supply system.

[0014] The pulse tank adopts a pressure-resistant container structure, with a preferred volume range of 50-200L and a working pressure of 0.6-1.2MPa. The pulse tank is connected to the unblocking pipe via a flange connection. The unblocking pipe is made of high-temperature resistant stainless steel and has a diameter of 50-100mm. The pre-unblocking pipe is arranged at a 30-60° angle to the horizontal plane and has a diameter of 30-80mm. The control system uses PLC or DCS control and achieves airflow switching via solenoid valves. The blasting gas supply system includes a compressed air source or a mixed gas source, with a supply pressure of 0.8-1.5MPa.

[0015] This technical solution clears the ash discharge port through alternating explosive air intake. High-pressure gas directly impacts the ash-accumulated area through the clearing pipe, while a pre-clearing pipe loosens the ash beforehand. Compared to traditional rapping motor methods, this system offers advantages such as high cleaning efficiency, long equipment lifespan, and low maintenance costs. Specifically, the pulsed airflow generates stronger impact force, effectively solving the problem of ash caking; it also avoids equipment wear caused by mechanical vibration, significantly reducing the failure rate. As a preferred implementation, the pulse frequency can be controlled at 10-20 times / minute, with each explosion lasting 0.1-0.5 seconds, and parameters can be adjusted according to the actual ash accumulation.

[0016] Furthermore, this application also proposes that a first control valve and a second control valve are installed on the unblocking pipe and the pre-unblocking pipe. The first control valve and the second control valve are alternately opened and closed by a controller, and the controller is electrically connected to the ignition device in the mixing ignition cabinet of the blasting gas supply system.

[0017] Specifically, the first and second control valves can be implemented using solenoid valves or pneumatic valves to achieve rapid opening and closing. The solenoid valves are preferably high-temperature resistant, and their operating temperature range must cover the actual operating temperature of the waste heat boiler ash discharge area. The controller can be implemented using, but is not limited to, a PLC controller or a dedicated control circuit. Its signal input is connected to the ignition signal feedback line of the mixing ignition cabinet, and its output drives the control valve via a relay module. The ignition device of the mixing ignition cabinet can be a high-voltage arc igniter or a catalytic igniter, and its feedback signal is transmitted to the controller via hardwiring or a fieldbus. As a preferred embodiment, the control valve is installed at least 300mm from the outer wall of the furnace to avoid the high-temperature radiation zone.

[0018] Therefore, this technical solution achieves precise switching of the airflow channel during the ash removal process through the linkage control of the controller and the ignition device. When the ignition device triggers the explosion, the controller synchronously receives the feedback signal and switches the control valve state according to the preset program, so that the high-pressure airflow alternately acts on the unblocking pipe and the pre-unblocking pipe. This timing control method effectively solves three technical problems existing in traditional mechanical vibration ash removal: First, the impact force generated by the directional explosion of the airflow is much greater than that of mechanical vibration, which significantly improves the removal effect on adhesive dust; second, it completely eliminates the mechanical wear of moving parts, and the reliability of the equipment is fundamentally improved; third, the response speed of the electronic control system is two orders of magnitude faster than that of the mechanical mechanism, which can achieve millisecond-level adjustment of the ash removal cycle. This solution is particularly suitable for handling the ash removal of waste heat boilers containing sticky dust such as iron oxide, as its explosion airflow can effectively peel off the ash accumulated on the pipe wall without causing impact damage to the boiler structure.

[0019] Furthermore, this application also proposes that the controller controls the first control valve to close, the second control valve to open, and the first control valve and the second control valve to open simultaneously in three unblocking cycles to perform cyclic ash removal.

[0020] Specifically, the ignition device feedback signal refers to the status signal indicating successful ignition within the mixing ignition cabinet, which is transmitted to the controller via an electrical connection. Based on this signal, the controller executes the following three clearing cycles according to a preset program: In the first cycle, the first control valve is closed and the second control valve is opened, allowing airflow only through the pre-clearing pipe; in the second cycle, the first control valve is opened and the second control valve is closed, allowing airflow only through the clearing pipe; in the third cycle, both control valves are opened simultaneously to form a parallel airflow channel. The duration of each cycle can be set to 1-3 seconds by the controller. As an implementation method, the controller can be programmed using a PLC to achieve the three-cycle cycle, with the cycle interval set to 2-5 minutes.

[0021] Therefore, this technical solution effectively solves the problem of incomplete dust removal in traditional single-mode dust removal by establishing a multi-mode cyclic dredging mechanism. The three dredging cycles correspond to different airflow paths and pressure distributions: the first cycle uses a pre-dredging pipe to initially loosen the deposited ash; the second cycle uses a dredging pipe to directionally remove the loose ash; and the third cycle uses parallel double pipes to form a high-pressure shock wave. Experimental data shows that this cyclic method can improve dust removal efficiency by more than 40% while avoiding structural damage to the pipeline caused by continuous high pressure. Compared with existing technologies, its advantage lies in the dynamic adjustment of dredging intensity through time-sequence control, which ensures both dust removal effect and extends equipment lifespan.

[0022] Furthermore, this application also proposes that the rear end of the bend of the unblocking pipe is connected to the air curtain pipe via an air curtain branch pipe, and the air curtain pipe provides positive pressure sealing for the unblocking pipe and the pre-unblocking pipe. At the same time, a check valve is installed on the air curtain branch pipe to prevent explosive gas from returning and depressurizing from the air curtain branch pipe.

[0023] Specifically, the air curtain branch pipes are made of high-temperature resistant metal tubing with a diameter ranging from 20-50mm, and are fixed to the drain pipe via flanges or welding. The air curtain pipes provide a continuous air supply. The air supply pressure is controlled within the range of 0.2-0.5MPa, and compressed air can be used.

[0024] Therefore, this technical solution, by installing an air curtain system at the bend in the unblocked pipe, utilizes a continuous positive pressure airflow to form an air curtain barrier, effectively preventing the release of internal toxic gases and avoiding dust accumulation at pipe connections. Compared with existing technologies, this design solves the problems of easy wear and frequent maintenance of traditional mechanical seals, while also preventing pipe blockage caused by dust backflow. In practical implementation, the airflow parameters of the air curtain system can be adjusted according to actual operating conditions, ensuring sealing effectiveness while reducing energy consumption.

[0025] Furthermore, this application also proposes that the blasting gas supply system includes a flow control cabinet, the inlet of which is connected to a fuel cylinder and an air pipe, the outlet of which is connected to a mixing ignition cabinet, and the outlet of which is connected to a pulse canister via a pipeline.

[0026] The flow control cabinet is used to precisely regulate the mixing ratio of fuel gas and air, where the fuel gas can be acetylene, a highly safe combustible gas. The mixing and ignition cabinet contains a mixing chamber and an ignition device. The mixing chamber ensures thorough mixing of the gases, which are then ignited by the ignition device to form a high-temperature combustion gas. Piping connections can be made using flanges or quick-connect couplings to ensure airtightness. As a preferred embodiment, the flow control cabinet can be equipped with a proportional regulating valve and a flow sensor to achieve automatic control of the mixing ratio. The mixing and ignition cabinet can be equipped with backfire prevention devices, such as flame arresters or check valves, to prevent flame backfire.

[0027] This technical solution precisely controls the gas mixing ratio through a flow control cabinet, generating stable high-temperature gas via a mixing and ignition cabinet to provide a controllable explosive gas source for the pulse canister. Compared to using compressed air directly, gas explosion has higher energy density and temperature, effectively decomposing adhering ash and slag. The centralized arrangement of the mixing and ignition cabinet facilitates maintenance and monitoring, while the automatic adjustment function of the flow control cabinet improves system reliability and response speed. Specifically, the synergistic effect of the shock wave and thermal effect generated by gas explosion solves the problem of incomplete ash removal by traditional rapping methods, while avoiding equipment wear caused by mechanical vibration.

[0028] Furthermore, this application also proposes that the pulse tank be fixed to the outer wall of the furnace by a fixing bracket.

[0029] This technical solution uses a fixing frame to stably fix the pulse canister to the outer wall of the furnace, solving the problem of vibration displacement caused by airflow impact during the blasting and ash removal process. Specifically, the rigid support provided by the fixing frame can effectively absorb the vibration energy of the pulse canister during operation, preventing the connecting pipelines from loosening or leaking due to vibration.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A waste heat boiler explosion ash removal system, characterized in that: The system includes multiple pulse tanks (4) installed outside the furnace wall (14) at the lower ash discharge port of the waste heat boiler. The lower part of the pulse tank (4) is connected to a dredging pipe (6) that extends horizontally into the furnace wall (14). The lower part of the dredging pipe (6) is connected to a pre-dredging pipe (8) that extends obliquely into the furnace wall (14). The gas in the pulse tank (4) is blasted and dredged alternately along the dredging pipe (6) and the pre-dredging pipe (8) by a control system. The pulse tank (4) is supplied with gas through a blasting gas supply system.

2. The waste heat boiler explosion ash removal system according to claim 1, characterized in that: The control system includes a first control valve (9) and a second control valve (10) installed on the unblocking pipe (6) and the pre-unblocking pipe (8). The first control valve (9) and the second control valve (10) are controlled to open and close alternately by a controller (11). The controller (11) is electrically connected to the ignition device in the mixing ignition cabinet (3) of the blasting gas supply system.

3. The waste heat boiler explosion ash removal system according to claim 2, characterized in that: The controller (11) controls the first control valve (9) to close, the second control valve (10) to open, and the first control valve (9) and the second control valve (10) to open simultaneously for three dredging cycles to circulate and dredge ash.

4. The waste heat boiler explosion ash removal system according to claim 2, characterized in that: The rear end of the bend of the unblocking pipe (6) is connected to the air curtain pipe (12) through the air curtain branch pipe (13), and the unblocking pipe (6) and the pre-unblocking pipe (8) are sealed by positive pressure through the air curtain pipe (12).

5. The waste heat boiler explosion ash removal system according to claim 1, characterized in that: The blasting gas supply system includes a flow control cabinet (2), the inlet of which is connected to a fuel cylinder (1) and an air pipe, the outlet of which is connected to a mixing ignition cabinet (3), and the outlet of which is connected to a pulse canister (4) via a pipeline.

6. The waste heat boiler explosion ash removal system according to claim 1, characterized in that: The pulse tank (4) is fixed to the outer wall of the furnace wall (14) by a fixing frame (5).

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