VOC Waste Gas Treatment and Waste Heat Utilization Energy Saving System for Furniture Factory

Abstract

The present invention discloses a special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories, which includes a spraying device, a concentration device, an incineration device and a gasifier. The waste gas discharge pipe of the painting workshop is connected to the air inlet of the spraying device. The air outlet of the spraying device is connected to the waste gas inlet of the concentration device through a conveying pipeline. The concentrated outlet of the concentration device is divided into two branch pipelines after passing through a first heat exchanger through a conveying pipeline. The first branch pipeline is connected to the air inlet of the gasifier, and the second branch pipeline is connected to the air inlet of the incineration device. The biomass gas outlet of the gasifier is connected to the air inlet of the incineration device through a conveying pipeline after passing through a second heat exchanger. The advantages of the present invention are as follows: The organic waste gas is subjected to multi-stage treatment and the waste heat of the waste gas is recycled, and no pollution is caused to the environment; in this way, the gas treatment volume can be reduced, the fuel consumption can be reduced, the cost can be saved, and almost zero emission of VOC waste gas can be achieved.

Description

[Technical field]

[0001] The invention relates to the technical field of VOC waste gas treatment, in particular to a VOC waste gas treatment and waste heat utilization energy-saving system dedicated to a furniture factory. [Background technology]

[0002] The painting process is widely used in machinery, electrical equipment, home appliances, automobiles, ships, furniture and other industries, especially in the furniture industry. The raw material of painting, paint, is composed of non-volatile matter and volatile matter. The non-volatile matter includes film-forming substances and auxiliary film-forming substances; the volatile matter refers to solvents and diluents (mainly xylene). The organic gas in the exhaust gas of painting comes from the volatilization of solvents and diluents. The organic solvent will not adhere to the surface of the painted object with the paint. It will be released to form organic waste gas (VOC) during the painting and drying and curing process. Generally, the amount of xylene waste gas volatilized in the painting process accounts for about 30% of the diluent usage, and another 70% volatilizes in the drying process. The two-phase suspension formed after the atomization of the paint and solvent in the painting and coating operation escapes into the surrounding air, which will seriously pollute the air.

[0003] At present, the industry mainly adopts condensation method, adsorption-vacuum desorption and absorption method, combustion method, membrane separation and other treatment methods. The existing organic waste gas treatment methods are single, and either the treatment effect is very poor, or it needs to consume most of the energy, and the treatment cost is relatively high. [Summary of the invention]

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned existing technologies and to provide a special VOC waste gas treatment and waste heat utilization energy-saving system that can completely eliminate the volatile organic compound (VOC) gas emission pollution emitted by the spray workshop of a furniture factory, and is energy-efficient, efficient and more environmentally friendly.

[0005] In order to achieve the above-mentioned purpose, the present invention is implemented as follows: a VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories includes a spray device, a concentration device, an incineration device and a gasifier. The waste gas emission pipe of the paint shop is connected to the air inlet of the spray device, and the air outlet of the spray device is connected to the waste gas inlet of the concentration device through a conveying pipeline. The concentration outlet of the concentration device is divided into two branch pipelines after passing through a first heat exchanger through a conveying pipeline. The first branch pipeline is connected to the air inlet of the gasifier, and the second branch pipeline is connected to the air inlet of the incineration device; the biomass gas outlet of the gasifier is connected to the air inlet of the incineration device after passing through the second heat exchanger through a conveying pipeline, and the biomass gas is introduced into the combustion chamber of the incineration device for high-temperature combustion.

[0006] The flue gas exhaust pipe of the incineration device is connected to the waste heat boiler after heat exchange through the first heat exchanger, the second heat exchanger and the third heat exchanger in sequence. The exhaust port of the waste heat boiler is connected to the chimney, and the clean gas after high-temperature combustion treatment is discharged at low temperature, which can effectively reduce thermal pollution.

[0007] The spray device includes a spray tower and a sedimentation tank. The spray tower is arranged below the sedimentation tank. An outlet is arranged at the bottom of the sedimentation tank and connected to the inlet of a first spiral conveying mechanism. The outlet of the first spiral conveying mechanism is connected to the feed port of a first drying device. The discharge port of the first drying device is connected to a vacuum drying device through a second spiral conveying mechanism. The discharge port of the vacuum drying device is connected to a mixing bin through a conveying pipe. The paint sludge dried by the vacuum drying device is evenly mixed with biomass scraps in the mixing bin and then transported to the bin for storage for input into a gasification furnace to generate biomass gas.

[0008] The bottom of the sedimentation tank is funnel-shaped to facilitate sedimentation and discharge.

[0009] A stirrer is arranged in the mixing bin to fully and evenly mix the paint sludge and the biomass scraps.

[0010] The mixing bin is connected to the material bin through a material conveying pipe and a hoist, and the material bin is connected to the feed port of the gasifier.

[0011] The first drying device comprises a drying chamber and a plurality of hoods arranged at the bottom of the drying chamber, and the hoods are provided with air outlets; the chimney is connected to the air inlet of the drying chamber through a conveying pipe, and the air inlet is communicated with the hoods.

[0012] The air outlet of the first drying device is connected to the air inlet of the mixer through a conveying pipeline, and the air outlet of the mixer is connected to the air inlet of the gasifier.

[0013] The gas outlet of the vacuum drying device is connected to the mixer through a conveying pipeline, and the waste gas generated by vacuum drying is mixed with other waste gases through the mixer and then introduced into the gasifier for producing biomass fuel gas.

[0014] A filter is arranged between the spraying device and the concentrating device to filter out moisture in the organic waste gas after the spraying treatment, so as to prevent the moisture contained therein from reducing the concentrating effect of the concentrating device.

[0015] The concentration device comprises at least two adsorption and desorption chambers, which are arranged side by side. The adsorption and desorption chambers comprise a purified gas discharge port, a desorption and concentration outlet, a desorption air inlet and an organic waste gas inlet.

[0016] The purification discharge port is connected to the exhaust pipe, and the exhaust pipe is connected to the exhaust chimney to discharge the purified waste gas. A valve is set on the purification discharge port; the desorption concentration outlet is connected to the concentration outlet pipe to discharge the high-concentration VOC concentrated waste gas after desorption, and all or part of it is introduced into the incineration device for combustion and decomposition after the first heat exchange preheating to about 400°C to generate heat energy; part of it is introduced into the gasification furnace for producing biomass gas for combustion; a valve is set on the desorption concentration outlet. The desorption air inlet is connected to the intake pipe, and a valve is set on the desorption air inlet. A fan is installed on the inlet of the intake pipe, and the cold air is preheated to about 150°C through the third heat exchanger and then enters the adsorption and desorption chamber to desorb the adsorption material and desorb the VOC gas adsorbed by the adsorption material. The organic waste gas inlet is connected to the outlet of the filter, and a valve is set at the organic waste gas inlet.

[0017] The adsorption and desorption chamber is filled with adsorption material, and an air inlet cavity is arranged at the bottom thereof. The air inlet cavity is communicated with the desorption air inlet and the organic waste gas inlet respectively.

[0018] The adsorption material is activated carbon particles with a particle size of 8-12 mm, which has good adsorption performance and will not cause clogging, etc. In order to improve the adsorption efficiency, a perforated plate with several through holes (air inlets) is installed on the upper part of the air inlet cavity to make the air intake more uniform and improve the adsorption and analysis effects.

[0019] In order to further prevent the adsorption material from clogging the air inlet, an air outlet hood is provided at the outlet end of each air inlet, and an air outlet is provided at the side end of the air outlet hood to communicate with the air inlet, which can effectively prevent the adsorption material particles from clogging the air inlet.

[0020] Compared with the prior art, the advantages and beneficial technical effects of the present invention are as follows: the organic waste gas (VOC) generated by the furniture factory is comprehensively treated and the waste heat of the waste gas is recycled, so that no pollution is caused to the environment; this not only makes the VOC waste gas treatment efficiency meet national standards, but also reduces fuel consumption, saves costs, and almost achieves zero VOC waste gas emissions.

Brief Description of the Drawings

[0021] Figure 1 This is a system structure diagram of the VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories of the present invention;

[0022] Figure 2 This is a system structure block diagram of the VOC waste gas treatment and waste heat utilization energy-saving system concentration device for furniture factories of the present invention. [Specific implementation method]

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories, such as Figure 1 As shown, it includes a spray device, a concentration device 5, an incineration device 6 and a gasifier 16. The exhaust gas discharge pipe of the paint shop 1 is connected to the air inlet of the spray device, and the air outlet of the spray device can be connected to the exhaust gas inlet of the concentration device 5 through a conveying pipeline. The concentration outlet of the concentration device 5 is divided into two branch pipelines after passing through the first heat exchanger 7 through the conveying pipeline. The first branch pipeline is connected to the air inlet of the gasifier 16 through the mixer 17, and the second branch pipeline is connected to the air inlet of the incineration device 6. The biomass gas outlet of the gasifier 16 produces a biomass gas of about 80°C, which is preheated to 260°C through the second heat exchanger 8 through the conveying pipeline and connected to the air inlet of the incineration device 6, and the biomass gas is introduced into the combustion chamber of the incineration device 6 for high-temperature combustion. The flue gas discharge pipe of the incineration device 6 is connected to the waste heat boiler 10 after heat exchange through the first heat exchanger 7, the second heat exchanger 8 and the third heat exchanger 9 in sequence. The discharge port of the waste heat boiler 10 is connected to the chimney 11, and the final flue gas is discharged at low temperature, which can effectively reduce thermal pollution. The initial flue gas temperature discharged by the incineration device 6 reaches 850°C. After heat exchange through the first heat exchanger 7, the temperature drops to 400°C. After heat exchange through the second heat exchanger 8, the temperature drops to 280°C. After heat exchange through the third heat exchanger 9, the temperature drops to 200°C. Then, it is introduced into the waste heat boiler 10 for steam generation. The flue gas temperature drops to less than 100°C and can be directly discharged into the air, avoiding thermal pollution. The concentrated VOC gas from the concentration device 5 is preheated to about 400°C after being heated by the first heat exchanger 7, and then introduced into the combustion chamber and gasification furnace 16 of the incineration device 6 for combustion and gasification, which can make the combustion more complete and easy to ignite.

[0025] The spraying device includes a spray tower 3 and a sedimentation tank 2. The spray tower 3 is arranged below the sedimentation tank 2. The bottom of the sedimentation tank 2 is funnel-shaped to facilitate sedimentation and discharge. The sedimentation tank 2 is connected to the spray tower 3 with a reflux branch pipe. A water pump is arranged on the reflux branch pipe to return the spray liquid in the sedimentation tank 2 to the spray tower 3 for use, so as to achieve the purpose of recycling, save water, and reduce the cost of wastewater treatment. The bottom of the sedimentation tank 2 is provided with an outlet connected to the inlet of the first spiral conveying mechanism 19. The outlet of the first spiral conveying mechanism 19 is connected to the feed port of the first drying device 13. The discharge port of the first drying device 13 is connected to the vacuum drying device 14 through the second spiral conveying mechanism. The discharge port of the vacuum drying device 14 is connected to the mixing bin 15 through a conveying pipe. The paint sludge dried by the vacuum drying device 14 is evenly mixed with the biomass scraps in the mixing bin 15, and then transported to the bin 18 for storage for input into the gasification furnace 16 to generate biomass gas. A stirrer is arranged in the mixing bin 15 to mix the paint sludge and the biomass scraps evenly. The mixing bin 15 is connected to the bin 18 through a conveying pipe and a hoist, and the bin 18 is connected to the feed port of the gasifier 16. The bin 18 is used to store biomass raw materials. The first drying device 14 includes a drying chamber and a plurality of hoods arranged at the bottom of the drying chamber, and an air outlet is arranged on the hood; the chimney 11 is connected to the air inlet of the drying chamber through a conveying pipe, and the air inlet is connected to the hood, and the exhaust flue gas overflows through the hood outlet to heat the paint sludge with a moisture content of 80-90% to achieve the purpose of drying. After being dried by the first drying device 14, the moisture content of the paint sludge is reduced to 30-40%, and then it is input into the vacuum drying device 14 to continue vacuum drying to below 20%. The gas outlet of the first drying device 14 is connected to the gas inlet of the mixer 17 through a conveying pipeline, and the gas outlet of the mixer 17 is connected to the gas inlet of the gasifier 16. The tail gas generated after drying is mixed with other gases containing organic waste gas through the mixer 17 and then introduced into the gasifier 16 for producing biomass gas. At the same time, VOC gas is completely removed, which can achieve complete waste heat utilization and zero emission of VOC waste gas, and can maximize the recycling of waste heat to achieve the purpose of effective energy saving. The gas outlet of the vacuum drying device 14 is connected to the mixer 17 through a conveying pipeline, and the waste gas generated by vacuum drying is mixed with other waste gas through the mixer 17 and then introduced into the gasifier 16 for producing biomass gas. The vacuum drying device 14 may include a vacuum box, and the semi-dried paint sludge is placed in the vacuum box and vacuum dried to further reduce the moisture content of the paint sludge. A pressure relief valve is arranged on the chimney 11 to discharge excess flue gas into the atmosphere at a regular time to prevent the system pressure from being too high.

[0026] A filter 4 is provided between the spray device and the concentrator 5 to filter out moisture in the organic waste gas after the spray treatment to prevent the moisture contained therein from reducing the concentrating effect of the concentrator. The filter 4 may be filled with a hygroscopic material to absorb moisture in the organic waste gas passing through, and dry organic waste gas is discharged.

[0027] The concentrating device 5 is as follows Figure 2 As shown, it includes at least two adsorption and desorption chambers, the two adsorption and desorption chambers are arranged side by side, and the adsorption and desorption chambers include a purification discharge port, a desorption and concentration outlet, a desorption air inlet and an organic waste gas inlet. The purification discharge port is connected to the exhaust pipe 56, and the exhaust pipe 56 is connected to the exhaust chimney to discharge the purified waste gas. A valve (the sixth valve H or the seventh valve G) is set on the purification discharge port. The desorption and concentration outlet is connected to the concentration outlet pipe 55, and the high-concentration Voc concentrated waste gas after desorption is discharged. After being preheated to about 400°C by the first heat exchange 7, all or part of it is introduced into the incineration device 6 for combustion and degradation to generate heat energy; a part is introduced into the gasification furnace 16 to generate biomass fuel gas for combustion. Valves (the fifth valve E and the sixth valve F) are set on the desorption and concentration outlet. The desorption air inlet is connected to the air intake pipe, and valves (the first valve A and the fourth valve D) are set on the desorption air inlet. A fan is installed on the inlet of the air inlet pipe. After the cold air is preheated to about 150°C by the third heat exchanger 9, it enters the adsorption and desorption chamber to desorb the adsorbent material and desorb the VOC gas adsorbed by the adsorbent material. Among them, the desorption air volume is 1 / 20-1 / 10 of the organic waste gas volume, which can effectively increase the VOC gas concentration and improve the treatment efficiency. The organic waste gas inlet is connected to the outlet of the filter 4, and a valve (a second valve B and a third valve C) is set at the organic waste gas inlet 54. The adsorption and desorption chamber is filled with spherical adsorbent material, and an air inlet cavity is set at its bottom. The air inlet cavity is connected to the desorption air inlet and the organic waste gas inlet respectively. The adsorbent material is activated carbon particles with a particle size of 8-12mm and good adsorption performance. The particles can roll up and down under the action of airflow, which increases the adsorption and desorption surface area, and can further even the airflow without causing blockage and other phenomena. In order to improve the adsorption efficiency, a perforated plate with a plurality of through holes (air inlet) is installed on the upper part of the air inlet cavity to make the air intake more uniform and improve the adsorption and analysis effects. In order to further prevent the adsorption material from clogging the air inlet, an air outlet hood 53 is provided at the outlet end of each air inlet. The side end of the air outlet hood is provided with an air outlet connected to the air inlet, which can effectively prevent the adsorption material particles from clogging the air inlet.

[0028] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the existing technology should be within the scope of protection determined by the claims.

Claims

1. A special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories, characterized in that, it includes a spraying device, a concentration device, an incineration device and a gasifier. The waste gas discharge pipe of the spraying workshop is connected to the air inlet of the spraying device. The air outlet of the spraying device is connected to the waste gas inlet of the concentration device through a conveying pipeline. The concentration device includes at least two adsorption and desorption chambers. The adsorption and desorption chamber includes a purification and discharge port, a desorption and concentration outlet, a desorption air inlet and an organic waste gas inlet. The desorption and concentration outlet of the concentration device is divided into two branch pipelines after passing through the first heat exchanger through a conveying pipeline. The first branch pipeline is connected to the air inlet of the gasifier, and the second branch pipeline is connected to the air inlet of the incineration device; the biomass gas outlet of the gasifier is connected to the air inlet of the incineration device through a conveying pipeline after passing through the second heat exchanger. The flue gas discharge pipe of the incineration device is connected to the waste heat boiler after exchanging heat through the first heat exchanger, the second heat exchanger and the third heat exchanger in sequence. The discharge port of the waste heat boiler is connected to the chimney. The initial flue gas discharged from the incineration device is exchanged heat through the first heat exchanger until the temperature drops to 400 °C, then through the second heat exchanger until the temperature drops to 280 °C, and then through the third heat exchanger until the temperature drops to 200 °C, and then introduced into the waste heat boiler to generate steam. The concentrated VOC gas discharged from the concentration device is heated through the first heat exchanger and then respectively introduced into the combustion chamber of the incineration device and the gasifier for combustion and gasification. The desorption air inlet of the concentration device is connected to an air inlet pipe, and a fan is installed at the inlet of the air inlet pipe. After preheating the cold air through the third heat exchanger, it enters the adsorption and desorption chamber to desorb the adsorption material.

2. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories according to claim 1, characterized in that, the spraying device includes a spraying tower and a sedimentation tank. The spraying tower is arranged above the sedimentation tank. The bottom of the sedimentation tank is provided with an outlet connected to the inlet of the first screw conveyor. The outlet of the first screw conveyor is connected to the feed inlet of the first drying device. The discharge outlet of the first drying device is connected to the vacuum drying device through the second screw conveyor; the discharge outlet of the vacuum drying device is connected to the mixing bin through a conveying pipe; the mixing bin is connected to the storage bin through a feeding pipe and a hoist, and the storage bin is connected to the feed inlet of the gasifier.

3. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories according to claim 2, characterized in that, the bottom of the sedimentation tank is funnel-shaped; a stirrer is arranged in the mixing bin.

4. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories according to claim 3, characterized in that, the first drying device includes a drying chamber and a plurality of air caps arranged at the bottom of the drying chamber. The air caps are provided with air outlets; the chimney is connected to the air inlet of the drying chamber through a conveying pipe, and the air inlet is communicated with the air caps.

5. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories according to claim 4, characterized in that, The air outlet of the first drying device is connected to the air inlet of the mixer through a conveying pipeline, and the air outlet of the mixer is connected to the air inlet of the gasifier.

6. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories as described in claim 5, characterized in that, the air outlet of the vacuum drying device is connected to the mixer through a conveying pipeline.

7. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories as described in claim 1, characterized in that, a filter is provided between the spraying device and the concentration device.

8. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories as described in claim 1, characterized in that, the two adsorption and desorption chambers are arranged side by side.

9. The special VOC waste gas treatment and waste heat utilization energy-saving system for furniture factories as described in claim 1, characterized in that, spherical adsorption materials are placed in the adsorption and desorption chamber, and an air inlet is provided at the bottom thereof, and the air inlet communicates with the desorption air inlet and the organic waste gas inlet respectively; an air outlet hood is provided at the outlet end of each air inlet, and an air outlet is provided at the side end of the air outlet hood and communicates with the air inlet.

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