A structure of a secondary cooler for a molten solid recovery of an alkali recovery boiler

Abstract

The utility model discloses a kind of alkali recovery boiler melt solid-state recovery secondary cooler structures, including cylinder and feeding device.Cylinder includes inner cylinder, outer cylinder and the cavity of cooling water filled between inner cylinder and outer cylinder;Feeding device one end is communicated with alkali recovery boiler primary cooler outlet end, other end is communicated with the one end of inner cylinder;The other end of inner cylinder is communicated with transition part, cylinder is rotationally connected with transition part, and exhaust port and discharge port are equipped on transition part;Transition part one end face is connected with swivel joint, and water inlet pipe and water outlet pipe are equipped on swivel joint;When driving device connected with cylinder drives cylinder rotation, inner cylinder inner wall continuous spiral blade constantly revolves and pushes solid-state object in cylinder along the axial direction of cylinder moves;The utility model high-temperature solid-state object is not directly contacted with cooling water, high-temperature solid-state object-water explosion noise pollution and security risk cannot appear, cooling process does not generate a large amount of water vapor, the utility model cooling water can be recycled, and then avoid double waste of water resource and heat energy.

Description

Technical Field

[0001] This utility model belongs to the field of incineration high-temperature product cooling, specifically relating to a structure of a solid-state recovery secondary cooler for alkali recovery boiler molten material. Background Technology

[0002] In the alkali recovery process of the pulp and paper industry, the molten material produced by the combustion of the alkali recovery boiler (referred to as "alkali furnace" or "black liquor furnace") needs to be recovered and reused. The main components of the molten material are sodium carbonate, sodium sulfide, etc. In the traditional process, the molten material flows out from the bottom chute of the furnace and is directly mixed with dilute white liquor for recycling. The resulting green liquor enters the causticization section. The causticization section is an important process in the chemical or alkali production industry, used to produce caustic alkali. Specifically, it refers to the conversion of sodium carbonate and other substances into sodium hydroxide (NaOH) through a chemical reaction for recovery. The causticization section realizes the recycling of alkali in the entire papermaking process.

[0003] The recovery and recycling of molten material is a crucial part of alkali recovery processes, and resource recycling is fundamental to the economical and long-term operation of the entire system. In existing recovery processes, the high-temperature molten material is directly cooled by contact with water, causing localized explosions and noise pollution. It also generates large amounts of water vapor locally and rapidly, resulting in the waste of heat energy and some water resources. Therefore, there is an urgent need to develop a cooling mechanism to address the problems of localized explosions and low energy and resource utilization caused by direct contact cooling of high-temperature molten material with water. Summary of the Invention

[0004] The purpose of this invention is to provide a structure for a secondary cooler for solid recovery of molten material in an alkali recovery boiler, in order to solve the problem of localized explosions and noise pollution caused by direct contact between solid salt generated during combustion and water in an alkali recovery boiler, thereby reducing the waste of heat energy and water resources.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A secondary cooler structure for solid-state recovery of molten material in an alkali recovery boiler is disclosed. The feeding device of the secondary cooler is connected to the outlet end of the primary cooler of the alkali recovery boiler. The secondary cooler also includes a cylinder, which comprises an outer cylinder and an inner cylinder. A sealed interlayer cavity is formed between the outer wall of the inner cylinder and the inner wall of the outer cylinder, and the interlayer cavity is filled with cooling water. One end of the feeding device is connected to the outlet of the primary cooler, and the other end of the feeding device is connected to one end of the inner cylinder. The other end of the inner cylinder is connected to a transition section, and the cylinder is rotatably connected to the transition section. The transition section is provided with an exhaust port and a discharge port. A rotary joint is connected to the end face of the transition section, and the rotary joint is provided with an inlet pipe and an outlet pipe. The inner wall of the inner cylinder is provided with continuous spiral blades, and the cylinder is connected to a driving device. When the driving device operates and drives the cylinder to rotate, the spiral blades on the inner wall of the inner cylinder continuously rotate, lifting the high-temperature solid material upward and then throwing it downward and backward. The spiral blades push the solid material in the cylinder to move along the axis of the cylinder.

[0007] Furthermore, the feeding device includes a funnel section at the top and a connecting section below the funnel section. The top of the funnel section is connected to the outlet of the primary cooling device. The outlet of the feeding device is located at the end of the connecting section facing the cylinder. A support frame is provided on the bottom surface of the connecting section. The support frame is fixed on the channel steel frame or the ground.

[0008] Furthermore, the inner cylinder is a cylindrical spiral conveying mechanism with spiral blades on the inner wall. One end of the inner cylinder is connected to the inside of the feeding device. The high-temperature solid material enters from the top of the feeding device and falls into the inner cylinder of the cylinder from the outlet of the feeding device. The cylinder rotates around its own central axis under the drive of the driving device.

[0009] Furthermore, the outlet end of the feeding device is connected to the inner cylinder through a pipe, and the feeding device is rotatably connected to the inner cylinder. When the driving device is working, it drives the cylinder to rotate relative to the feeding device.

[0010] Furthermore, the drive device includes a motor, which is mounted on a channel steel frame on one side via a motor base. A chain drive mechanism is provided on the surface of the outer cylinder. The chain drive mechanism includes a drive sprocket, a driven sprocket, and a chain. The drive sprocket is mounted on the output shaft of the motor. When the motor is running, the output shaft drives the drive sprocket to rotate. The driven sprocket is mounted on the cylinder body. The chain is looped around the drive sprocket and the driven sprocket. The output shaft of the motor is connected to the drive sprocket. The drive sprocket drives the driven sprocket through the chain. The driven sprocket is connected to the cylinder body. The power of the motor is transmitted to the cylinder body through the chain drive, realizing the rotation of the cylinder body driven by the motor.

[0011] Furthermore, a grooved ring is provided near each end of the outer cylinder, and a support is provided below each ring. Each support has two supporting rollers. When the driving device drives the cylinder to rotate, the surface of the groove bottom of the ring rolls against the surface of the two supporting rollers.

[0012] Furthermore, the outlet of the inner cylinder is connected to the transition section, which is a sealed shell welded to the channel steel frame. The cylinder body is rotatably connected to the transition section. When the driving device drives the cylinder body to rotate, the solid material is discharged from the inner cylinder to the transition section and discharged through the lower outlet of the transition section. The upper part of the transition section is provided with an exhaust port, and the hot air in the inner cylinder is drawn out by the suction fan through the exhaust port.

[0013] Furthermore, the stationary end of the rotary joint is connected to the inlet pipe and the outlet pipe, the rotating end of the rotary joint is connected to the end face of the transition section, the inlet pipe and the outlet pipe of the rotating end of the rotary joint extend into the interior of the transition section and communicate with the ends of the interlayer cavity of the outer cylinder and the inner cylinder, and the inlet pipe and the outlet pipe of the rotating end of the rotary joint are rotatably connected to the transition section.

[0014] The beneficial effects of this utility model are:

[0015] 1. In the prior art, the direct contact cooling of high-temperature molten material with water can cause local explosions and noise pollution. This invention improves the cooling method of solid salt generated by combustion in alkali recovery boilers. This invention can avoid direct contact between the high-temperature material generated by combustion in alkali recovery boilers and water, thereby avoiding local explosions and noise pollution, and reducing the waste of heat energy and water resources.

[0016] 2. This utility model avoids resource waste and low energy utilization. In the prior art, the high-temperature molten material is directly cooled by contacting water, and the water absorbs heat and generates a large amount of water vapor, resulting in a double waste of water resources and heat energy. This utility model does not involve direct contact between the high-temperature molten material and the cooling water, and the cooling process no longer generates a large amount of water vapor. In addition, the cooling water of this utility model can be recycled, which can avoid the double waste of water resources and heat energy.

[0017] 3. In this invention, the high-temperature molten material does not come into direct contact with the cooling water, thus avoiding noise pollution and safety hazards caused by molten material-water explosion.

[0018] 4. After the heat exchange is completed, the temperature of the high-temperature solid material in the inner cylinder decreases and the temperature of the water increases. The heated water can be used for boiler feedwater circulation, thus recovering the waste heat of the solid salt and increasing the energy utilization rate.

[0019] 5. The cylinder uses a suction system to draw in cold air, which absorbs fine dust while maintaining a negative pressure inside the cylinder to prevent dust from being stirred up on site. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the internal cross-section of the present invention.

[0021] Figure 2 This is a schematic diagram of the appearance of this utility model.

[0022] Figure 3This is a top view of the appearance of this utility model.

[0023] Figure 4 This is a schematic diagram of the drive device and chain transmission mechanism of this utility model.

[0024] Figure 5 This is a schematic diagram of the rotary joint of this utility model.

[0025] In the diagram: 1. Feeding device; 1-1. Funnel section; 1-2. Connecting section; 1-3. Support frame; 2. Cylinder; 2-1. Outer cylinder; 2-2. Inner cylinder; 3. Channel steel frame; 4. Drive device; 5. Ring; 6. Support roller; 7. Chain drive mechanism; 8. Transition section; 9. Exhaust port; 10. Discharge port; 11. Rotary joint; 12. Water inlet pipe; 13. Water outlet pipe. Detailed Implementation

[0026] To make the purpose, technical solution and advantages of this utility model clearer, the present utility model will be further described below with reference to the accompanying drawings.

[0027] like Figure 1 As shown, the structure of the secondary cooler for solid-state recovery of molten material in the alkali recovery boiler of this utility model includes a feeding device 1 and a cylinder 2.

[0028] The alkali recovery boiler has a complete set of molten solid recovery process equipment. The high-temperature solid material from the primary cooling unit enters the secondary cooler through the feed device 1 of the secondary cooler for further cooling.

[0029] The high-temperature molten material discharged from the alkali recovery boiler first enters the primary cooler. After being cooled and reduced in temperature in the primary cooler, it is no longer in a molten state and is discharged from the primary cooler in solid form. The solid material discharged from the primary cooler then enters the secondary cooler for further cooling before being recycled. Figure 1 , Figure 2 and Figure 3 As shown, Figure 1 for Figure 2 A partial cross-sectional view shows that the feeding device 1 includes a funnel section 1-1 at the top and a connecting section 1-2 below the funnel section. The funnel section 1-1 and the connecting section 1-2 are integrally formed and connected. The inlet of the feeding device 1 is located at the top of the funnel section 1-1, and the outlet of the feeding device 1 is located at one end face of the connecting section 1-2 facing the cylinder 2. A vertical rod-shaped support frame 1-3 can be provided on the bottom surface of the connecting section 1-2. The top surface of the support frame 1-3 is connected to the bottom surface of the connecting section 1-2. A channel steel frame 3 is provided on the ground below the cylinder 2. The bottom surface of the support frame 1-3 is welded to the channel steel frame 3, and the support frame 1-3 provides support for the feeding device 1. Depending on the actual situation, one or more support frames 1-3 can be provided on the bottom surface of the connecting section 1-2.

[0030] The cylinder 2 includes an outer cylinder 2-1 and an inner cylinder 2-2. One end of the feeding device 1 is connected to the outlet of the primary cooling device, and the other end of the feeding device 1 is connected to the inner cylinder 2-2, so that the high-temperature solid material coming out of the primary cooling device can enter the inner cylinder 2-2 along the feeding device 1.

[0031] The inner cylinder 2-2 is cylindrical and is a spiral conveying mechanism with spiral blades on its inner wall. The cylinder 2 can rotate around its central axis. The outlet end of the feeding device 1 is connected to the inner cylinder 2-2 through a pipe. The pipe and the inner cylinder 2-2 are movably connected by a rotary bearing, which enables the rotational connection between the feeding device 1 and the inner cylinder 2-2. When the drive device 4 is working, it drives the cylinder 2 to rotate relative to the feeding device 1.

[0032] The inner wall of the inner cylinder 2-2 is welded with continuous spiral blades, forming a spiral conveying structure. When the cylinder 2 rotates, the spiral blades on the inner wall of the inner cylinder 2-2 continuously lift the high-temperature solid material upwards and then throw it downwards and backwards. The spiral blades push the material to move axially, and the direction of material movement is determined by both the spiral blades' rotation direction and the cylinder 2's rotation direction. To prevent the high-temperature solid material from adhering to the spiral blades, Teflon can be sprayed onto the spiral blades or a self-cleaning scraper can be added.

[0033] The outer cylinder 2-1 is cylindrical and located outside the inner cylinder 2-2. The outer cylinder 2-1 and inner cylinder 2-2 are welded together as a single unit, forming cylinder 2. A sealed interlayer cavity exists between the inner wall of the outer cylinder 2-1 and the outer wall of the inner cylinder 2-2. This cavity is filled with cooling water, which indirectly cools the high-temperature solid material inside the inner cylinder. The outer cylinder 2-1 is slightly shorter than the inner cylinder 2-2. The high-temperature solid product is cooled by a two-stage cooler without direct contact with water. This cooling process recovers heat energy while cooling the solid product, avoiding explosion hazards and reducing resource waste.

[0034] The cylinder 2 rotates synchronously under the drive of the drive device 4, which can be a motor.

[0035] like Figure 3 and 4 As shown, a grooved ring 5 is provided near each end of the outer cylinder. The ring 5 fits around the outer surface of the outer cylinder 2-1, and the groove is circumferentially arranged on the outer surface of the ring 5. Below each ring 5 is a support, and each support has two supporting rollers 6. The ends of the rollers 6 are located within the grooves of the ring 5. When the driving device 4 drives the cylinder 2 to rotate, the cylinder 2 rotates relative to the rollers 6, and the surface of the bottom of the groove of the ring 5 rolls against the surfaces of the two supporting rollers 6. The supporting rollers 6 support the cylinder 2 and limit the rotation of the cylinder through the groove walls. Multiple grooved rings 5 ​​and corresponding supports and supporting rollers can be evenly spaced along the length of the cylinder 2, according to its length.

[0036] likeFigure 3 and Figure 4 As shown, a channel steel frame 3 is located on the ground below the cylinder 2. The drive device 4, i.e., the motor, is mounted on the channel steel frame 3 on one side via a motor base. A chain drive mechanism 7 is provided on the surface of the outer cylinder. The chain drive mechanism 7 includes a drive sprocket, a driven sprocket, and a chain. The drive sprocket is mounted on the output shaft of the motor. When the motor runs, the output shaft drives the drive sprocket to rotate. The driven sprocket is mounted on the cylinder 2, and its centerline is parallel to the axis of the cylinder 2. The chain is looped around the drive sprocket and the driven sprocket. The output shaft of the motor is connected to the drive sprocket, which drives the driven sprocket through the chain. The driven sprocket is connected to the cylinder 2, thus the power of the motor is transmitted to the cylinder 2 through the chain drive, realizing the rotation of the cylinder 2 driven by the motor.

[0037] The high-temperature solid product enters the inner cylinder 2-2 from the secondary cooler feed device via the chain drive mechanism 7. The inner cylinder 2-2 rotates continuously under the drive of the motor, so that the high-temperature solid product is continuously transported from the feed device to the discharge port.

[0038] One end of the cylinder 2 is connected to the feeding device 1, and the other end of the cylinder 2 is connected to the transition section 8. The outlet of the inner cylinder 2-2 is connected to the transition section 8. The transition section 8 is a sealed shell welded to the channel steel frame (3). The cylinder 2 and the transition section 8 are rotatably connected, and the cylinder 2 can rotate around the transition section 8. Specifically, one end of the cylinder 2 extends into the transition section 8, and the two are connected by bearings and mechanical seal. The cylinder 2 rotates relative to the transition section 8 through the rotating bearing. The cooled solid material flows into the transition section 8 from the outlet of the inner cylinder 2.

[0039] The top surface of the transition section 8 is provided with an exhaust vent 9, and the bottom surface of the transition section 8 is provided with a discharge port 10.

[0040] An exhaust duct is installed at exhaust outlet 9, and an extraction fan is connected to the exhaust duct. The extraction fan will draw away the hot air. The extraction fan can accelerate the air flow in the inner cylinder 2-2 by drawing in air, which helps to improve the cooling efficiency. At the same time, the extraction fan can keep the solid material of the secondary cooler in a negative pressure state during transportation to prevent the leakage of fine dust. The end of the extraction fan can be connected to a dust collector through a pipe. The dust collector is used to capture particulate matter in the gas discharged from the extraction fan.

[0041] After cooling, the solid material is discharged from the discharge port 10 and enters the next process. The discharge port 10 is equipped with valves and other control devices to control the discharge speed and flow rate of the solid material.

[0042] One side of the transition section 8 communicates with the inner cylinder 2-2, and the opposite side of the transition section 8 is connected to a rotary joint 11. The rotary joint 11 is a general-purpose multi-channel rotary joint. The rotary joint 11, such as a siphon-type or mechanically sealed type, is installed on the side of the transition section 8. Figure 5As shown, the stationary end of the rotary joint 11 is connected to the inlet pipe 12 and the outlet pipe 13, while the rotating end of the rotary joint 11 is connected to the end face of the transition section 8. The inlet and outlet pipes of the rotating end of the rotary joint 11 extend into the interior of the transition section 8 and are welded to the ends of the interlayer cavities of the outer cylinder 2-1 and the inner cylinder 2-2. The inlet and outlet pipes of the rotating end of the rotary joint 11 are connected to the bearings of the transition section 8, with a mechanical seal. The inlet and outlet pipes of the stationary end of the rotary joint 11 can be fixed to the frame or foundation by a bracket. As the rotating end of the rotary joint 11 rotates, cooling water enters from the inlet pipe 12 and flows along the interlayer between the outer and inner cylinders to the other end. In a preferred embodiment, a spiral guide can be provided on the outer wall of the inner cylinder to enhance heat exchange. After heat exchange is completed, hot water is discharged from the outlet pipe 13. In practical applications, the outlet pipe is connected to a water pump. The transition section 8 and the rotary joint 11 are connected by a flange or quick-release clamp for easy maintenance.

[0043] The circulating cooling water flows into the interlayer between the outer and inner cylinders of the cylinder from the cooling water inlet. After exchanging heat with the inner cylinder wall, it flows out from the cooling water outlet.

[0044] Summary of the working process of this utility model:

[0045] Solid salt (<300℃) from the primary cooler enters the secondary cooler through the feeding device. The secondary cooler consists of an inner cylinder and an outer cylinder with uniformly arranged spiral blades that rotate continuously. The spiral blades on the inner cylinder wall lift the solid salt upwards as they rotate, then throw it downwards and backwards, propelling the solid salt continuously from the feeding device end to the discharge end. Cooling circulating water introduced from the cooling water inlet is introduced into the interlayer between the inner and outer cylinders to exchange heat and cool the solid salt. Simultaneously, a suction fan draws in hot air to convect and cool the solid salt, ensuring that the temperature of the solid salt discharged from the discharge port is <80℃.

[0046] In the description of this utility model, it should be understood that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

Claims

1. A structure for a solid-state recovery secondary cooler for alkali recovery boiler molten material, characterized in that: The inlet of the feeding device (1) of the secondary cooler is connected to the outlet of the primary cooler of the alkali recovery boiler. The secondary cooler also includes a cylinder (2), which includes an outer cylinder (2-1) and an inner cylinder (2-2). A sealed interlayer cavity is formed between the outer wall of the inner cylinder and the inner wall of the outer cylinder, and the interlayer cavity is filled with cooling water. The inlet of the feeding device (1) is connected to the outlet of the primary cooler, and the outlet is connected to one end of the inner cylinder (2-2). The other end of the inner cylinder (2-2) is connected to the transition section (8). The transition section (8) is rotatably connected to the transition section (8), which is provided with an exhaust port (9) and a discharge port (10). One end face of the transition section (8) is connected to a rotary joint (11), which is provided with an inlet pipe and an outlet pipe. The inner wall of the inner cylinder is provided with continuous spiral blades, and the cylinder (2) is connected to a drive device (4). When the drive device (4) works and drives the cylinder (2) to rotate, the spiral blades on the inner wall of the inner cylinder push the solid material in the cylinder (2) to move backward along the axis of the cylinder (2) under continuous rotation.

2. The structure of a secondary cooler for solid-state recovery of molten material in an alkali recovery boiler according to claim 1, characterized in that: The feeding device (1) includes a funnel part (1-1) located at the top and a connecting part (1-2) located below the funnel part. The top of the funnel part (1-1) is connected to the outlet of the primary cooling device. The outlet of the feeding device (1) is located at one end of the connecting part (1-2) facing the cylinder (2). The bottom surface of the connecting part (1-2) is provided with a support frame (1-3). The support frame (1-3) is fixed on the channel steel frame (3) or on the ground.

3. The structure of a secondary cooler for solid-state recovery of molten material from an alkali recovery boiler according to claim 1, characterized in that: The inner cylinder is a cylindrical spiral conveying mechanism with spiral blades on the inner wall. One end of the inner cylinder is connected to the inside of the feeding device (1). The high-temperature solid material enters the feeding device (1) from the funnel (1-1) and then falls into the inner cylinder (2-2) from the outlet of the feeding device (1). The cylinder (2) rotates around its own center line under the drive of the driving device (4).

4. The structure of a secondary cooler for solid-state recovery of molten material from an alkali recovery boiler according to claim 1, characterized in that: The outlet end of the feeding device (1) is connected to the inner cylinder (2-2) through a pipe. The feeding device (1) is rotatably connected to the inner cylinder (2-2). When the driving device (4) is working, it drives the cylinder (2) to rotate relative to the feeding device (1).

5. The structure of a secondary cooler for solid-state recovery of molten material in an alkali recovery boiler according to claim 1, characterized in that: The drive device (4) includes a motor, which is mounted on a channel steel frame (3) on one side via a motor base. A chain drive mechanism (7) is provided on the surface of the outer cylinder. The chain drive mechanism (7) includes a drive sprocket, a driven sprocket, and a chain. The drive sprocket is mounted on the output shaft of the motor. When the motor is running, the output shaft drives the drive sprocket to rotate. The driven sprocket is mounted on the cylinder (2). The chain is sleeved on the drive sprocket and the driven sprocket. The output shaft of the motor is connected to the drive sprocket. The drive sprocket drives the driven sprocket through the chain. The driven sprocket is connected to the cylinder (2). The power of the motor is transmitted to the cylinder (2) through the chain drive, thereby realizing the rotation of the cylinder (2) driven by the motor.

6. The structure of a secondary cooler for solid-state recovery of molten material from an alkali recovery boiler according to claim 1, characterized in that: The outer cylinder is provided with a grooved ring (5) at each end. There is a support under each ring (5), and each support has two support rollers (6). When the driving device (4) drives the cylinder (2) to rotate, the surface of the groove bottom of the ring (5) rolls against the surface of the two support rollers (6).

7. The structure of a secondary cooler for solid-state recovery of molten material in an alkali recovery boiler according to claim 1, characterized in that: The outlet of the inner cylinder (2-2) is connected to the transition section (8). The transition section (8) is a sealed cover shell welded to the channel steel frame (3). The cylinder (2) is rotatably connected to the transition section (8). When the driving device (4) drives the cylinder (2) to rotate, the solid material is discharged from the inner cylinder to the transition section (8) and discharged through the lower outlet (10) of the transition section (8). The upper part of the transition section (8) is provided with an exhaust port (9). The hot air in the inner cylinder is sucked out by the suction fan through the exhaust port (9).

8. The structure of a secondary cooler for solid-state recovery of molten material from an alkali recovery boiler according to claim 1, characterized in that: The stationary end of the rotary joint (11) is connected to the inlet pipe (12) and the outlet pipe (13). The rotating end of the rotary joint (11) is connected to the end face of the transition part (8). The inlet pipe and outlet pipe of the rotating end of the rotary joint (11) extend into the interior of the transition part (8) and communicate with the ends of the interlayer cavity of the outer cylinder (2-1) and the inner cylinder (2-2). The inlet pipe and outlet pipe of the rotating end of the rotary joint (11) are rotatably connected to the transition part (8).

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