Alkali recovery boiler melt solid-state recovery negative pressure system

Abstract

This utility model discloses a negative pressure system for solid-state recovery of molten material from an alkali recovery boiler, relating to the field of alkali recovery boilers in the pulp and paper industry. It includes: a solid-state treatment component for recovering molten material from the alkali recovery boiler, a flue gas treatment component for recovering flue gas from the incineration section, and a negative pressure pulse dust collector. Both the solid-state treatment component and the flue gas treatment component are connected to the negative pressure pulse dust collector for collecting fly ash generated during the recovery process. This utility model uses the negative pressure pulse dust collector to uniformly collect fly ash generated by the solid-state treatment component and the flue gas treatment component, forming a fully closed negative pressure system. This effectively prevents dust escape, eliminates the risk of combustible dust explosions at the source, reduces equipment corrosion and occupational hazards, and achieves resource utilization of ash and slag. The two-stage slag cooling device, scraper conveyor, slag bin, and baler are directly connected to the negative pressure dust collection system to ensure the sealing of the entire molten material treatment process.

Description

Technical Field

[0001] This utility model relates to the field of alkali recovery boilers in the pulp and paper industry, specifically to a negative pressure system for solid recovery of molten material in an alkali recovery boiler. Background Technology

[0002] In industrial production processes such as pulp and paper making and viscose fiber, alkali recovery boilers serve as key energy recovery devices, undertaking important functions such as black liquor incineration, chemical recovery, and thermal energy conversion. The ash (mainly composed of inorganic salts such as Na2CO3) from the dust collector of the alkali recovery boiler is transported to the ash silo by a scraper conveyor. The boiler slag is cooled and crushed by a two-stage slag cooling device. However, the accumulation of ash at the top of the ash silo and the upper part of the cooling device has the following significant drawbacks: (1) When combustible dust reaches a certain concentration, it may cause an explosion when exposed to sparks, static electricity, or high temperature; (2) The accumulation of dust causes corrosion and wear on the equipment; (3) The dispersion of fine dust may cause occupational diseases such as silicosis and asthma. There is an urgent need for an innovative technology to reduce the accumulation of floating gas and the resulting hazards.

[0003] Therefore, it is necessary to develop a simple and easy-to-operate negative pressure system for solid recovery of alkali recovery boiler molten material to collect floating particles and dust from related equipment and recycle resources. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the aforementioned background technology and provide a simple and easy-to-operate negative pressure system for solid recovery of alkali recovery boiler molten material, which collects floating particles and dust from related equipment and achieves resource recycling.

[0005] The technical solution of this utility model is: a negative pressure system for solid recovery of molten material from an alkali recovery boiler, comprising: a solid treatment component for recovering molten material from an alkali recovery boiler, a flue gas treatment component for treating flue gas from the incineration section, and a negative pressure pulse dust collector.

[0006] The solid-state processing component and the flue gas processing component are both connected to the negative pressure pulse dust collector to collect the fly ash generated during the processing.

[0007] Preferably, the solid-state treatment component includes a two-stage slag cooling device, a slag scraper conveyor, a slag bin, and a slag baler arranged in sequence, wherein the two-stage slag cooling device, the slag scraper conveyor, the slag bin, and the slag baler are all connected to the negative pressure pulse dust collector pipeline.

[0008] Furthermore, the negative pressure pulse dust collector is equipped with a first air inlet pipe and a second air inlet pipe connected in parallel, and the two-stage slag cooling device, slag scraper conveyor, slag bin, and slag baler are all connected to the first pipe.

[0009] Furthermore, the two-stage slag cooling device includes a primary cooling device, a water-cooled scraper conveyor, and a secondary cooling device arranged sequentially, all of which are connected to the first air inlet pipe.

[0010] Furthermore, the flue gas treatment assembly includes a dust removal and conveying device, an ash silo, and an ash packaging machine arranged in sequence, wherein the ash silo and the ash packaging machine are both connected to the second air inlet pipe.

[0011] Furthermore, the ash removal and conveying device includes a dust collector for the incineration section and an ash scraper conveyor. The discharge port of the dust collector for the incineration section is connected to the inlet of the ash scraper conveyor, and the discharge port of the ash scraper conveyor is connected to the inlet of the ash silo.

[0012] Furthermore, the negative pressure pulse dust collector includes an upper chamber and a dust hopper connected vertically. The dust hopper is equipped with an air inlet pipe at the top and a weighted unloading valve at the bottom. The upper chamber is equipped with an exhaust pipe at the top to discharge the purified gas into the atmosphere, and an induced draft fan is installed on the exhaust pipe.

[0013] Furthermore, all of the intake pipes are connected to the first intake pipe and the second intake pipe.

[0014] Furthermore, the upper chamber includes a purification chamber and a filter chamber arranged vertically. The top of the filter chamber is horizontally provided with a perforated plate and the bottom of the perforated plate is correspondingly installed with a dust collection bag. The exhaust pipe is located on the purification chamber.

[0015] Furthermore, the upper housing is also equipped with a pulse jet blowing assembly for blowing dust off the dust collection bags.

[0016] Furthermore, the pulse jet assembly includes a jet pipe, an air reservoir, and a pulse jet valve. The jet pipe is disposed inside the filter chamber and corresponds to each dust collection bag. The air reservoir is disposed outside the upper housing and is connected to the jet pipe through the pulse jet valve for jetting each dust collection bag.

[0017] Furthermore, the counterweight unloading valve includes an inner channel connected to the outlet of the ash hopper and a valve shell connected to the outer wall of the inner channel. The lower end of the inner channel is provided with an oblique opening. The outer valve shell is rotatably provided with a rotating shaft near the top of the oblique opening. Both ends of the rotating shaft pass through the valve shell and a valve plate is provided at the oblique opening. One end of the rotating shaft is provided with a long rod outside the valve shell, and a counterweight is provided at the outer end of the long rod.

[0018] The beneficial effects of this utility model are as follows:

[0019] 1. By using a negative pressure pulse dust collector to collect fly ash generated by the solid processing components and flue gas processing components in a unified manner, a closed negative pressure system is formed throughout the entire process. This effectively prevents dust from escaping, eliminates the risk of combustible dust explosions at the source, reduces equipment corrosion and occupational hazards, and realizes the resource utilization of ash and slag.

[0020] 2. Directly connect the two-stage slag cooling device, scraper conveyor, slag bin and baler to the negative pressure dust removal system to ensure the sealing of the entire molten material processing process, prevent dust generation during high-temperature slag transportation, suppress dust diffusion through the negative pressure environment, and reduce the risk of equipment wear.

[0021] 3. The negative pressure pulse dust collector adopts a parallel dual-inlet pipe design (first inlet pipe and second inlet pipe) to independently handle solid melt and flue gas fly ash, avoiding cross-contamination of dust from different sources. At the same time, it optimizes airflow distribution, improves the capture efficiency of the negative pressure system for fine particles, and enhances the stability of system operation.

[0022] 4. By connecting the primary cooling device, the water-cooled scraper conveyor, and the secondary cooling device in series, dust is collected simultaneously through the negative pressure pipeline (first air inlet pipeline) during the cooling process of the molten material. This prevents the risk of dust explosion caused by temperature fluctuations in the high-temperature slag during the cooling stage and extends the service life of the equipment.

[0023] 5. The flue gas treatment component is equipped with a negative pressure pipeline (second air inlet pipeline) to specifically collect fly ash from the dust collector in the incineration section, preventing dust accumulation at the top of the ash silo and optimizing the value of resource recycling. The negative pressure system enables closed-loop treatment of fly ash from generation to packaging, reducing the probability of workers being exposed to harmful dust.

[0024] 6. The negative pressure pulse dust collector adopts an upper box and lower ash hopper structure, combined with a heavy hammer discharge valve at the bottom of the ash hopper, to achieve a balance between automatic dust discharge and equipment sealing, avoiding secondary dust caused by manual cleaning. At the same time, the induced draft fan provides stable negative pressure power to ensure the continuous and efficient operation of the system.

[0025] 7. The purification chamber and filtration chamber are set in layers, and the dust collection bag is supported by a perforated plate to achieve dual purification of gas filtration and dust settling, which extends the service life of the filter bag, reduces the frequency of pulse jet cleaning, and reduces system energy consumption.

[0026] 8. The pulse jet cleaning unit regularly cleans the dust collector bag surface to maintain the filter bag's air permeability, avoids the increase in system resistance caused by dust blockage, ensures negative pressure stability, extends equipment maintenance cycle, and improves overall dust removal efficiency.

[0027] This utility model system, through innovations such as full-process negative pressure sealing design, separate treatment by dual pipelines, and optimized pulse dust removal, systematically solves the drawbacks of existing technologies, such as dust explosion, equipment corrosion, and personal injury, while realizing the resource utilization of ash and slag. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the negative pressure system for solid-state recovery of molten material in an alkali recovery boiler according to this utility model.

[0029] Figure 2 Front view of a negative pressure pulse dust collector

[0030] Figure 3 Side view of a negative pressure pulse dust collector (upper housing without outer shell).

[0031] Figure 4 Top view of a negative pressure pulse dust collector

[0032] Figure 5 for Figure 2 Enlarged schematic diagram of the medium-heavy hammer unloading valve

[0033] Figure 6 for Figure 3 Enlarged schematic diagram of the medium-heavy hammer unloading valve

[0034] Among them: 1-Alkali recovery boiler 2-Primary cooling device 3-Water-cooled scraper conveyor 4-Secondary cooling device 5-Slag scraper conveyor 6-Slag bin 7-Slag baler 8-Dust collector for incineration section 9-Ash scraper conveyor 10-Ash bin 11-Ash baler 12-Negative pressure pulse dust collector (121-Upper box 121.1-Purification chamber 121.2-Filter chamber 122-Ash hopper 123-Inlet pipe 124-Exhaust pipe 125-Exhaust fan 126-Perforated plate 127-Dust bag 128-Jet pipe 129-Air storage tank 130-Pulse valve) 13-First inlet pipe 14-Second inlet pipe 20-Heavy hammer unloading valve (21-Inner channel 22-Outer shell 23-Valve shell 24-Valve plate 25-Long rod 26-Heavy hammer). Detailed Implementation

[0035] The embodiments of this utility model are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0036] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] like Figure 1 As shown, this utility model provides a negative pressure system for solid-state recovery of molten material from an alkali recovery boiler. It consists of three parts: a solid-state treatment component, a flue gas treatment component, and a negative pressure pulse dust collector 12, forming a fully negative pressure sealed pipeline. The solid-state treatment component is used to recover the molten material generated by the alkali recovery boiler 1, the flue gas treatment component is used to treat the flue gas generated in the incineration section, and the negative pressure pulse dust collector 12 is used to collect the fly ash generated during the processing by the solid-state treatment component and the flue gas treatment component.

[0039] The solid-state processing assembly includes a two-stage slag cooling device, a slag scraper conveyor 5, a slag bin 6, and a slag baler 7 arranged sequentially along the solid flow direction of the molten material. In a preferred embodiment, the two-stage slag cooling device includes a primary cooling device 2, a water-cooled scraper conveyor 3, and a secondary cooling device 4 arranged sequentially along the solid flow direction of the molten material. Therefore, the solid-state processing assembly includes a primary cooling device 2, a water-cooled scraper conveyor 3, a secondary cooling device 4, a slag scraper conveyor 5, a slag bin 6, and a slag baler 7 arranged sequentially along the molten material flow direction. More specifically, the outlet of the primary cooling device 2 is connected to the inlet of the water-cooled scraper conveyor 3, the outlet of the water-cooled scraper conveyor 3 is connected to the inlet of the secondary cooling device 4, the outlet of the secondary cooling device 4 is connected to the inlet of the slag scraper conveyor 5, the outlet of the slag scraper conveyor 5 is connected to the inlet of the slag bin 6, and the outlet of the slag bin 6 is connected to the inlet of the slag baler 7.

[0040] The flue gas treatment assembly includes a dust removal and conveying device, an ash silo 10, and an ash packaging machine 11 arranged sequentially along the fly ash flow direction. In a preferred embodiment, the ash removal and conveying device includes a dust collector 8 from the incineration section and an ash scraper conveyor 9. Therefore, the solid waste treatment assembly includes a dust collector 8 from the incineration section, an ash scraper conveyor 9, an ash silo 10, and an ash packaging machine 11 arranged sequentially along the fly ash flow direction. More specifically, the discharge port of the dust collector 8 from the incineration section is connected to the inlet of the ash scraper conveyor 9, the discharge port of the ash scraper conveyor 9 is connected to the inlet of the ash silo 10, and the discharge port of the ash silo 10 is connected to the inlet of the ash packaging machine 11.

[0041] The negative pressure pulse dust collector 12 is a negative pressure pulse bag dust collector. The negative pressure pulse dust collector is equipped with a first air inlet pipe 13 and a second air inlet pipe 14 connected in parallel. The internal spaces of the primary cooling device 2, the water-cooled scraper conveyor 3, the secondary cooling device 4, the slag scraper conveyor 5, the slag bin 6, and the slag baler 7, which contain solid materials, are all connected to the first air inlet pipe 13. The internal spaces of the ash bin 10 and the ash baler 11 are all connected to the second air inlet pipe 14.

[0042] In this embodiment, as Figure 2-6 As shown, the negative pressure pulse dust collector 12 has the following specific structure: it includes an upper housing 121 and a dust hopper 122 connected vertically. The dust hopper 122 has an air inlet pipe 123 at the top and a counterweight discharge valve 20 at the bottom. The upper housing 121 has an exhaust pipe 124 at the top to discharge the purified gas into the atmosphere, and an induced draft fan 125 is installed on the exhaust pipe 124. The induced draft fan 125 is used to maintain the negative pressure of the entire system. The air inlet pipes 123 are connected to the first air inlet pipe 13 and the second air inlet pipe 14, and are used to introduce fly ash generated by the solid-state treatment component and the flue gas treatment component.

[0043] The upper housing 121 has the following specific structure: it includes a purification chamber 121.1 and a filter chamber 121.2 arranged vertically inside. The top of the filter chamber 121.2 is provided with a perforated plate 126 horizontally, and a dust collection bag 127 is installed at the bottom of the perforated plate 126. The exhaust pipe 124 is arranged on the purification chamber 121.1. The upper housing 121 is also provided with a pulse jet blowing assembly for blowing dust from the dust collection bag 127.

[0044] The specific structure of the counterweight discharge valve 20 is as follows: it includes an inner channel 21 connected to the outlet of the ash hopper 122 and a valve shell 22 connected to the outer wall of the inner channel 21. A collection device can be installed at the lower end of the valve shell 22. The lower end of the inner channel 21 has an inclined opening. The outer valve shell 22 has a rotatable shaft 23 near the top of the inclined opening. Both ends of the shaft 23 pass through the valve shell 22, and a valve plate 24 is provided at the inclined opening. One end of the shaft 23 has a long rod 25 outside the valve shell 22, and a counterweight 26 is provided at the outer end of the long rod 25. Under normal conditions, if the weight of the fly ash collected in the ash hopper 122 does not reach the preset weight, the gravity of the counterweight 26 causes the valve plate 24 to fit against the inclined opening, closing the inner channel 21. Once the weight of the fly ash collected in the ash hopper 122 reaches or exceeds the preset weight, the gravity of the fly ash causes the valve plate 24 to rotate downwards, opening the inner channel 21. After the fly ash is discharged, the valve plate 24 returns to normal under the action of the counterweight 26.

[0045] The pulse jet cleaning assembly has the following structure: it includes a jet pipe 128, an air reservoir 129, and a pulse jet valve 130. The jet pipe 128 is located inside the filter chamber 121.2 and has nozzles corresponding to each dust bag 127. The air reservoir 129 is located outside the upper housing 121 and is connected to the jet pipe 128 via the pulse jet valve 130, used for jet cleaning each dust bag 129. The pulse jet cleaning principle is as follows: high-pressure air is pre-stored in the air reservoir 129. The pulse jet valve 130 opens rapidly, releasing a large amount of high-pressure gas in a very short time (pulse). The released gas forms a high-speed jet, which is guided through the jet pipe 128 to the opening of the dust bag 127, causing the dust on the surface of the dust bag 127 to fall off efficiently and into the ash hopper 122 below.

[0046] The working process of the negative pressure system for solid-state recovery of molten material from an alkali recovery boiler is as follows:

[0047] The molten material produced by the alkali recovery boiler 1 enters the primary cooling device 2 through a chute. The primary cooler 2 is a cooling device with a water-cooled jacket. Cooling water is circulated in the jacket to cool the material. The material temperature is cooled from 1000℃ to below 300℃ and then discharged from the outlet.

[0048] The water-cooled scraper conveyor 3 is a scraper conveyor with water cooling function. The water-cooled scraper conveyor 3 is subsequently connected to the secondary cooling device 4. The secondary cooling device 4 is a commonly used twin-shaft crushing and cooling device, which cools the material temperature to below 200℃ and then discharges it from the outlet.

[0049] The secondary cooling device 4 is sequentially connected to the slag scraper conveyor 5, which lifts the cooled material into the slag bin 6. The slag bin 6 then packages the material through the slag baler 7.

[0050] The dust collector 8 in the incineration section collects dust from the flue gas in the incineration section, and the ash scraper conveyor 9 transports the cooled ash to the ash silo 10. The ash silo 10 is then packaged by a packaging machine 11.

[0051] The fly ash generated by the primary cooling device 2, water-cooled scraper conveyor 3, secondary cooling device 4, slag scraper conveyor 5, slag silo 6, and slag baler 7 enters the negative pressure pulse dust collector 12 for collection via the first air inlet pipe 13. The fly ash generated by the ash silo 10 and material packaging 11 enters the negative pressure pulse dust collector 12 for collection via the second air inlet pipe 14. In this embodiment, the negative pressure pulse dust collector 12 is preferably a negative pressure pulse bag filter. Pulse bag filters have the characteristics of large gas handling capacity, good purification effect, simple structure, reliable operation, and low maintenance workload. They are suitable for the negative pressure system of solid recovery of molten material in alkali recovery boilers. The entire solid recovery system is made into a negative pressure state by the induced draft fan 125 (the negative pressure of the entire system is controlled according to the requirements). The collected dust continues to be recycled back to the ash and slag equipment for collection, thus utilizing resources.

[0052] This invention uses a negative pressure pulse dust collector to collect fly ash generated by the solid-state treatment components and the flue gas treatment components in a unified manner, forming a closed negative pressure system throughout the entire process. This effectively prevents dust from escaping, eliminates the risk of combustible dust explosions at the source, reduces equipment corrosion and occupational hazards, and realizes the resource utilization of ash and slag.

Claims

1. A negative pressure system for solid-state recovery of molten material from an alkali recovery boiler, characterized in that, include: Solid processing components for recovering alkali recovery boiler melt, flue gas treatment components for treating flue gas in the incineration section, and negative pressure pulse dust collector (12). The solid processing component and the flue gas processing component are both connected to the negative pressure pulse dust collector (12) to collect the fly ash generated during the processing.

2. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 1, characterized in that, The solid processing component includes a two-stage slag cooling device, a slag scraper conveyor (5), a slag bin (6), and a slag baler (7) arranged in sequence. The two-stage slag cooling device, the slag scraper conveyor (5), the slag bin (6), and the slag baler (7) are all connected to the negative pressure pulse dust collector (12) via pipeline.

3. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 2, characterized in that, The negative pressure pulse dust collector (12) is equipped with a first air inlet pipe (13) and a second air inlet pipe (14) connected in parallel. The two-stage slag cooling device, slag scraper conveyor (5), slag bin (6), and slag baler (7) are all connected to the first air inlet pipe (13).

4. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 3, characterized in that, The two-stage slag cooling device includes a first-stage cooling device (2), a water-cooled scraper conveyor (3), and a second-stage cooling device (4) arranged in sequence. The first-stage cooling device (2), the water-cooled scraper conveyor (3), and the second-stage cooling device (4) are all connected to the first air inlet pipe (13).

5. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 3, characterized in that, The flue gas treatment assembly includes a dust removal and conveying device, a dust hopper (10), and a dust packaging machine (11) arranged in sequence. The dust hopper (10) and the dust packaging machine (11) are both connected to the second air inlet pipe (14).

6. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 5, characterized in that, The ash removal and conveying device includes a dust collector (8) for the incineration section and an ash scraper conveyor (9). The outlet of the dust collector (8) for the incineration section is connected to the inlet of the ash scraper conveyor (9), and the outlet of the ash scraper conveyor (9) is connected to the inlet of the ash silo (10).

7. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 3, characterized in that, The negative pressure pulse dust collector (12) includes an upper box (121) and a hopper (122) connected vertically. The hopper (122) is provided with an air inlet pipe (123) at the top and a heavy hammer unloading valve (20) at the bottom. The upper box (121) is provided with an exhaust pipe (124) at the top to discharge the purified gas into the atmosphere, and an induced draft fan (125) is provided on the exhaust pipe (124).

8. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 7, characterized in that, The air intake pipes (123) are all connected to the first air intake pipe (13) and the second air intake pipe (14).

9. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 7, characterized in that, The upper housing (121) includes a purification chamber (121.1) and a filter chamber (121.2) arranged vertically. The top of the filter chamber (121.2) is horizontally provided with a perforated plate (126) and a dust removal bag (127) is installed at the bottom of the perforated plate (126). The exhaust pipe (124) is arranged on the purification chamber (121.1).

10. The alkali recovery boiler molten solid recovery negative pressure system as described in claim 9, characterized in that, The upper housing (121) is also equipped with a pulse jet blowing assembly for blowing dust off the dust collection bag (127).

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