Sludge low-temperature drying circulating air system

Abstract

The utility model relates to the technical field of sludge treatment and disposal, in particular to a sludge low-temperature drying circulating air system which comprises a circulating air system and a circulating water system. According to the sludge low-temperature drying machine, the sludge in the sludge low-temperature drying machine is dried through the circulating air system, the heat exchanger is arranged on the air return pipeline of the circulating air system, and water in the circulating pipeline can be heated through return air in the air return pipeline through the heat exchanger, so that the heat of the return air is further utilized; the PAM dissolving tank can be heated in winter, the PAM dissolving efficiency can be effectively guaranteed, and a positive effect is achieved on stable operation of production. According to the utility model, on one hand, the return air heat can be further utilized, the heat utilization efficiency is improved, and on the other hand, the PAM solvent tank can be heated, so that the stable dissolution of PAM is ensured, and a positive role is played in ensuring the stable operation of production.

Description

Technical Field

[0001] This utility model relates to the field of sludge treatment and disposal technology, specifically to a sludge low-temperature drying circulating air system. Background Technology

[0002] Flocculants, such as PAM, are used in wastewater treatment. Flocculants can flocculate and settle the remaining sludge, which helps to further dewater the sludge and facilitates its treatment and disposal.

[0003] In the process of using PAM, the existing commercially available PAM is generally in powder form. During use, it needs to be dissolved in a dissolving tank to form a PAM solution, and then pumped to the sludge conditioning tank, etc. However, in actual production, PAM dissolution requires a certain temperature. At low temperatures, the PAM dissolution efficiency is slow. On the one hand, incomplete dissolution may cause blockage of the pipeline, and on the other hand, it also affects the addition of the reagent and the flocculation efficiency of the sludge.

[0004] Therefore, in winter when the temperature is low, it is often necessary to heat the PAM dissolving tank to ensure the dissolution efficiency of PAM. In actual production, electric heating is often used, which increases energy consumption and poses certain safety hazards. Therefore, this utility model is based on the sludge low-temperature drying circulating air system. By modifying it, the PAM dissolving tank is heated through the return air duct, which realizes further comprehensive utilization of heat while ensuring the dissolution efficiency of PAM, and plays a positive role in ensuring the stable operation of production. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of the existing technology by providing a low-temperature sludge drying circulating air system, which can heat the PAM dissolving tank in winter.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a sludge low-temperature drying circulating air system, including a sludge low-temperature dryer, wherein a heat exchanger is installed on the return air duct of the sludge low-temperature dryer, and the return air in the return air duct exchanges heat with the circulating medium in the circulating duct through the heat exchanger, and the circulating duct is connected to the jacket outside the PAM dissolving tank.

[0007] Furthermore, the return air duct is connected to the evaporator, and the return air in the return air duct is connected to the condenser after passing through the evaporator. The return air in the condenser is returned to the sludge low-temperature dryer by the circulating fan to complete the cycle.

[0008] Furthermore, a dust collector is installed on the return air duct at the rear end of the sludge low-temperature dryer.

[0009] Furthermore, the refrigerant in the evaporator is connected to the compressor after heat exchange, and the refrigerant is connected to the condenser after passing through the compressor. The condensing medium in the condenser is returned to the evaporator through the expansion valve after heat exchange, completing the cycle.

[0010] Furthermore, the return air duct includes a first return air duct and a second return air duct, which are located at the rear end of the dust collector; control valves are installed on both the first and second return air ducts, and a heat exchanger is installed on the second return air duct, which is located at the rear end of the control valve. The second return air duct exchanges heat with the circulating duct through the heat exchanger.

[0011] Furthermore, the dissolving tank includes a tank body, a jacket is disposed outside the tank body, a circulating medium inlet is disposed at the bottom of the jacket, and a circulating medium outlet is disposed at the top of the jacket. The circulating medium inlet and the circulating medium outlet are respectively connected to a circulating pipeline. The circulating medium in the circulating pipeline is heated by a heat exchanger, and then transported to the jacket by a circulating pump. After passing through the jacket, it returns to the heat exchanger to complete the circulation.

[0012] Furthermore, a spiral guide plate is provided in the jacket.

[0013] The beneficial effects of this utility model are: on the one hand, it can further utilize the heat of the return air and improve the heat utilization efficiency; on the other hand, it can also heat the PAM solvent tank, ensuring the stable dissolution of PAM, which plays a positive role in ensuring stable production operation. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall process of this utility model;

[0015] Figure 2 This utility model relates to a schematic diagram of a dissolving tank structure.

[0016] The names corresponding to each mark in the diagram:

[0017] 1. First return air duct; 2. Second return air duct; 3. Dissolving tank; 31. Tank body; 32. Jacket; 321. Circulating medium inlet; 322. Circulating medium outlet; 323. Spiral guide plate. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0019] Embodiments of this utility model:

[0020] like Figure 1-2 As shown, the circulating air system in this embodiment includes a compressor. The compressor outputs a high-temperature, high-pressure gaseous refrigerant, which is then transported to a condenser. In the condenser, the refrigerant undergoes heat exchange and releases heat, condensing into a low-temperature, high-pressure liquid refrigerant. This low-temperature, high-pressure liquid refrigerant is then transported to an evaporator via an expansion valve. In the evaporator, it vaporizes into a low-temperature, low-pressure gaseous refrigerant, absorbing heat during the transformation process. The resulting low-temperature, low-pressure gaseous refrigerant returns to the compressor and is transformed back into a high-temperature, high-pressure gaseous refrigerant, completing the cycle. In this embodiment, the refrigerant can be R-410A, etc.

[0021] The return air from the sludge low-temperature dryer, after being dusted by an industrial dust collector, is transported to the evaporator through the first return air duct 1 and / or the second return air duct 2. In the evaporator, the aforementioned cold medium absorbs heat, and the water vapor in the return air condenses to form condensate, which is discharged from the evaporator, forming a low-temperature dry circulating air. This circulating air passes through a condenser, where it exchanges heat with the high-temperature, high-pressure cold medium output by the compressor. While heating the circulating air, it also absorbs heat from the cold medium. The resulting high-temperature dry circulating air is then transported to the sludge low-temperature dryer by a circulating fan to complete the cycle. In this embodiment, the sludge low-temperature dryer can be a low-temperature belt sludge dryer, etc.

[0022] In this embodiment, during normal use, the return air from the sludge low-temperature dryer returns to the evaporator via the first return air duct 1. During winter use, the return air can be fully or partially returned to the evaporator via the second return air duct 2. In this embodiment, control valves are installed on the first return air duct 1 and the second return air duct 2 respectively. With the help of flow meters, the distribution and control of the return air volume in the first return air duct 1 and the second return air duct 2 can be realized.

[0023] A heat exchanger is installed on the second return air duct 2, and the return air in the second return air duct 2 exchanges heat with the circulating medium in the circulation duct. The circulating medium in the circulation duct is transported to the dissolving tank 3. A jacket 32 ​​is installed outside the tank body 31 of the dissolving tank 3. A circulation medium inlet 321 is installed at the bottom of the jacket 32, and a circulation medium outlet 322 is installed above the jacket 32. A spiral guide plate 323 is installed in the jacket 32. In this embodiment, the circulating medium can be water, which is transported by a circulation pump. A filter is installed on the circulation duct at the front end of the circulation pump. A thermometer is installed in the dissolving tank 3, which can be used to regulate the temperature in the dissolving tank 3. A stirrer is also installed in the dissolving tank 3, with a feed inlet above it and a discharge outlet below it. The discharge outlet is connected to a discharge pipe, and a delivery pump and a control valve are installed on the discharge pipe. In this embodiment, each flow meter, control valve, temperature sensor, etc. can be connected to a field PLC for control. An insulation layer can be installed on the outside of each pipe and the jacket.

[0024] The principle of this utility model is as follows:

[0025] During use, this invention can heat the dissolving tank 3 when the temperature is low in winter, thereby facilitating the dissolution of PAM.

[0026] When the temperature is low in winter, open the control valve on the second return air duct 2 so that part or all of the return air returns to the evaporator through the second return air duct 2. At this time, the return air exchanges heat with the circulating medium in the heat exchanger. The circulating medium after heat exchange can heat the dissolution tank 3, thereby ensuring the temperature in the dissolution tank 3 and facilitating the dissolution of PAM.

[0027] During on-site control, if the circulating water volume remains constant, the distribution of air volume in the first return air duct 1 and the second return air duct 2 can be adjusted to control the temperature in the dissolving tank 3. During the process, the temperature in the dissolving tank 3 can be controlled within a certain range, which facilitates the dissolution of PAM, realizes the comprehensive utilization of energy, and helps industrial production.

[0028] This utility model relates to compressors, condensers, evaporators, sludge low-temperature dryers, dust collectors, heat exchangers, etc., which are existing and mature equipment; the temperature control involved is a simple PLC control; the equipment and principles involved are not difficult to understand by those skilled in the art, so they will not be described in detail.

Claims

1. A low temperature drying air recirculation system for sludge, characterized by: The system includes a sludge low-temperature dryer, wherein a heat exchanger is installed on the return air duct of the sludge low-temperature dryer, and the return air in the return air duct exchanges heat with the circulating medium in the circulation duct through the heat exchanger. The circulation duct is connected to the jacket outside the PAM dissolving tank.

2. A circulating air system for low temperature drying of sludge according to claim 1, characterized in that: The return air duct is connected to the evaporator. The return air in the return air duct passes through the evaporator and then connects to the condenser. The return air in the condenser is returned to the sludge low-temperature dryer by the circulating fan, completing the cycle.

3. A circulating air system for low temperature drying of sludge according to claim 2, characterized in that: A dust collector is installed on the return air duct at the rear end of the sludge low-temperature dryer.

4. The low-temperature sludge drying and circulating air system according to claim 2, characterized in that: The refrigerant in the evaporator is connected to the compressor after heat exchange, and then connected to the condenser after passing through the compressor. The condensing medium in the condenser is returned to the evaporator through the expansion valve after heat exchange, completing the cycle.

5. A sludge low-temperature drying circulating air system according to claim 3, characterized in that: The return air duct includes a first return air duct and a second return air duct, which are located at the rear end of the dust collector. Control valves are installed on both the first and second return air ducts. A heat exchanger is installed on the second return air duct, which is located at the rear end of the control valve. The second return air duct exchanges heat with the circulating duct through the heat exchanger.

6. A circulating air system for low temperature drying of sludge according to claim 5, characterized in that: The dissolving tank includes a tank body, a jacket is disposed outside the tank body, a circulating medium inlet is disposed at the bottom of the jacket, and a circulating medium outlet is disposed at the top of the jacket. The circulating medium inlet and the circulating medium outlet are respectively connected to a circulating pipeline. The circulating medium in the circulating pipeline is heated by a heat exchanger, and then transported to the jacket by a circulating pump. After passing through the jacket, it returns to the heat exchanger to complete the circulation.

7. A circulating air system for low temperature drying of sludge according to claim 6, characterized in that: The jacket is equipped with a spiral guide plate.

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