A device for environmental protection treatment and waste heat recycling of grain drying exhaust gas

Abstract

The application discloses a kind of environmental protection treatment and waste heat recycling device of grain drying exhaust gas, it is related to grain drying environmental protection energy-saving technical field, including waste gas collection, water mist spray dust removal, cyclone adsorption depth dust removal, heat pump heat recovery, heat energy circulation transport and automatic control component, each component seal communication forms integrated system.The application realizes waste gas deep purification by double dust removal, and low-grade waste heat is recycled by heat pump and is used for grain drying, with dust removal efficient, waste heat recovery rate is high, compact structure, stable operation, energy saving and environmental protection and the like advantages, it is suitable for all kinds of grain drying equipment matching use, effectively solve the problem such as dust removal of traditional technology not up to standard, waste heat waste, system poor stability etc..

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental protection and energy conservation in grain drying, and particularly relates to an integrated device for multi-stage purification of dust-containing exhaust gas generated during the grain drying process and recycling of low-grade waste heat in the exhaust gas. It is especially suitable for the exhaust gas treatment and heat energy recycling system supporting various grain drying towers and grain dryers, and can achieve the dual goals of environmentally compliant discharge of exhaust gas and efficient recycling of waste heat. Background Art

[0002] Grain drying is a key process in the grain storage and processing links. A large amount of exhaust gas containing dust, debris, water vapor, and relatively high temperature is generated during the drying process. Currently, the following technical defects generally exist in the conventional treatment methods in the industry: First, the dust removal method is single, mostly using gravity sedimentation or simple filtration, with insufficient capture ability for fine dust, and it is difficult to meet the current atmospheric pollutant emission standards; Second, the high-temperature exhaust gas is directly discharged externally, and a large amount of recoverable waste heat contained therein is not utilized, resulting in energy waste and relatively high overall energy consumption of the drying system; Third, the dust removal equipment and the waste heat recovery equipment are arranged independently of each other. The system pipeline is complex, the air flow resistance is large, and the operation stability is poor, and the coordinated and efficient operation of dust removal and waste heat recovery cannot be achieved; Fourth, the water vapor in the exhaust gas easily enters the heat exchange equipment, causing condensation and corrosion, reducing the service life of the equipment, and increasing the maintenance cost.

[0003] Based on the above problems, there is an urgent need in this field for a grain drying exhaust gas treatment device with a compact structure, stable operation, high dust removal efficiency, high waste heat recovery rate, and capable of integrated coordinated operation. Summary of the Invention

[0004] Object of the Invention Aiming at the problems existing in the existing grain drying exhaust gas treatment technology, such as incomplete dust removal, serious waste heat, low system integration, and insufficient operation stability, the present invention provides a device for environmentally friendly treatment and waste heat recovery and utilization of grain drying exhaust gas. Through a multi-stage dust removal structure, deep purification of the exhaust gas is achieved, and the low-grade waste heat in the exhaust gas is recovered by a heat pump system and circulated to the drying equipment, achieving the comprehensive effects of dust removal compliance, waste heat reuse, energy consumption reduction, and stable operation. Technical Solution

[0005] A device for environmentally friendly treatment and waste heat recovery and utilization of grain drying exhaust gas includes an exhaust gas collection component, a water mist spray dust removal component, a cyclone adsorption deep dust removal component, a heat pump heat energy recovery component, a heat energy circulation and transportation component, and an automatic control component; each component is sequentially connected through a sealed pipeline to form a continuous and through exhaust gas treatment and heat energy circulation system.

[0006] The exhaust gas collection assembly includes an exhaust gas collection hood, a guide pipe, and an exhaust fan, which is used to stably introduce the exhaust gas discharged from the grain dryer into the treatment system, ensuring uniform airflow, no short circuits, and no leaks.

[0007] The water mist spray dust removal component includes a spray tower, a circulating water tank, a spray power unit, and an atomizing nozzle assembly. The tower body is arranged from top to bottom with an air distribution structure, a spray area, and a water collection area, so that the exhaust gas and the spray liquid can fully contact each other, achieving preliminary dust collection and exhaust gas cooling. The circulating water tank is equipped with a filter structure and a water quality monitoring device, which can realize automatic purification of circulating water and automatic water replenishment and sewage discharge, ensuring long-term stable operation.

[0008] The cyclone adsorption deep dust removal component includes a cyclone tower, a cyclone guide structure, an adsorption water tank, a dust settling structure, and a demisting structure. The cyclone guide structure causes the exhaust gas to form a rotating airflow, which separates the residual dust to the wall surface and falls into the adsorption water tank for collection under centrifugal force. The top demisting structure can effectively remove water droplets carried in the exhaust gas, preventing water vapor from entering the subsequent heat pump system and causing impact.

[0009] The heat pump heat recovery component includes an evaporator, a compressor, a condenser heat exchanger, and a throttling device. It uses an environmentally friendly refrigerant to form a heat pump cycle. The evaporator absorbs low-grade heat energy from the purified waste gas. After the compressor raises the temperature, the heat energy is released by the condenser heat exchanger, realizing waste heat recovery and heating reuse.

[0010] The heat energy circulation and conveying components include heat exchange pipes, air supply devices, and waste heat stabilization devices; the heat exchange pipes are equipped with external insulation structures to reduce heat loss during the conveying process; the waste heat stabilization devices can stabilize the output hot air temperature and ensure stable grain drying conditions.

[0011] The automatic control components include a controller and multiple sets of sensors, which can monitor operating parameters such as temperature, pressure, flow rate, and water quality in real time, and automatically adjust the operating status of the induced draft fan, spray system, heat pump, and air supply device to achieve fully automatic control and abnormal protection. Beneficial effects

[0012] The beneficial effects of this invention are as follows: First, it adopts a dual dust removal mode that combines water mist spraying and cyclone adsorption, which has a high efficiency in capturing both coarse and fine dust particles, and the exhaust gas purification effect is significant, which can meet the environmental protection emission requirements. Second, by recovering low-grade waste heat from the exhaust gas through a heat pump system, the heat energy that was originally directly emitted can be reused for grain drying, which greatly reduces the overall energy consumption of the system. Third, the integrated sealed connection of each functional component results in a compact structure, small footprint, smooth airflow, and low operating resistance, solving the problem of poor stability caused by the dispersed layout of traditional equipment. Fourth, it is equipped with demisting, heat preservation, flow stabilization, automatic sewage discharge and automatic control structures, which makes the equipment highly reliable, easy to maintain and long-lasting. Fifth, there is no secondary pollution throughout the process, and water and heat energy are recycled, which meets the requirements of green, low-carbon and environmental protection. Attached Figure Description Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0013] Figure label: 1-Exhaust gas collection hood, 2-Guide pipe, 3-Exhaust fan, 4-Spray tower body, 5-Circulating water tank, 6-Spray power unit, 7-Atomizing nozzle assembly, 8-Gas distribution structure, 9-Water collection area, 10-Swirl tower body, 11-Swirl guide structure, 12-Adsorption water tank, 13-Dust sedimentation structure, 14-Dual-mode drain valve, 15-Evaporator, 16-Compression device, 17-Condensation heat exchange device, 18-Throttling device, 19-Heat exchange pipe, 20-Air supply device, 21-Grain drying equipment, 22-Controller, 23-Temperature sensor, 24-Pressure sensor, 25-Flow sensor, 26-Filter structure, 27-Water quality monitoring device, 28-Waste heat stabilization device, 29-Demisting structure, 30-Insulation structure. Detailed Implementation Example 1: Small-scale grain drying equipment The exhaust gas enters the spray tower through the collection hood and guide pipe, where it comes into contact with the atomized spray liquid to complete the primary dust removal. Then it enters the cyclone tower, where deep dust removal and dehydration are achieved under the action of cyclone. The purified exhaust gas enters the evaporator, and the heat pump system recovers the waste heat and sends it to the drying equipment through the insulated pipe. The control system automatically adjusts the operating parameters to ensure that the device works stably and efficiently.

[0014] Example 2: Supporting equipment for large-scale grain drying production line The appropriate specifications of spray towers and cyclone towers are matched according to the air volume to be processed. High-power heat pump modules are used to improve the waste heat recovery capacity. Combined with waste heat stabilization devices, the output temperature is kept stable, which can meet the continuous operation requirements of large-scale drying equipment. The long-term operation has significant energy-saving and environmental protection effects.

Claims

1. A device for environmentally friendly treatment and waste heat recovery of grain drying exhaust gas, characterized in that, The system comprises, in a sealed and interconnected manner, a waste gas collection component, a water mist spray dust removal component, a cyclone adsorption deep dust removal component, a heat pump heat energy recovery component, a heat energy circulation and transportation component, and an automatic control component. The waste gas collection component includes a waste gas collection hood, a guide pipe, and an exhaust fan. The water mist spray dust removal component includes a spray tower, a circulating water tank, a spray power unit, and an atomizing nozzle assembly. The spray tower contains an air distribution structure, a spray area, and a water collection area. The circulating water tank contains a filtration structure and a water quality monitoring device. The cyclone adsorption deep dust removal component includes a cyclone tower, a cyclone guide structure, an adsorption water tank, a dust sedimentation structure, and a demisting structure. The heat pump heat energy recovery component includes an evaporator, a compression device, a condensation heat exchange device, and a throttling device, and uses an environmentally friendly refrigerant to form a circulation system. The heat energy circulation and transportation component includes a heat exchange pipe, an air supply device, and a waste heat stabilization device. The heat exchange pipe is externally insulated. The automatic control component includes a controller and temperature, pressure, flow, and water quality sensors, each electrically connected to an actuator.

2. The apparatus according to claim 1, characterized in that, The atomizing nozzle assembly can form micron-sized atomized droplets, and the spray pressure and airflow velocity inside the tower can be adjusted according to the operating conditions, resulting in high dust removal efficiency.

3. The apparatus according to claim 1, characterized in that, The swirling flow guiding structure is arranged at an angle, and the water level in the adsorption water tank is kept submerged below the swirling flow guiding structure to improve the dust separation effect.

4. The apparatus according to claim 1, characterized in that, The heat pump heat recovery component can efficiently recover low-grade heat energy from exhaust gas, and the throttling device automatically adjusts the refrigerant circulation state.

5. The apparatus according to claim 1, characterized in that, The automatic control component can achieve fully automatic operation, parameter monitoring, abnormal alarm and automatic protection shutdown.

6. The apparatus according to any one of claims 1-5, characterized in that, It has high overall dust removal efficiency and significant waste heat recovery effect, which can meet the requirements of environmental protection emission and energy conservation and consumption reduction of grain drying exhaust gas.

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