Wastewater cooling temperature control system and method for pulping and papermaking

Abstract

The invention discloses a pulping and papermaking wastewater cooling temperature control system and method, and belongs to the technical field of pulping and papermaking industrial wastewater treatment. Comprising a temperature regulation and control module, a constant temperature tank, a heat exchanger, a first water pump and a second water pump which are communicated between a primary sedimentation tank and an anaerobic section inlet through pipelines, an industrial exchange water outlet in the heat exchanger is connected to an industrial water pipeline mechanism through a pipeline, and an industrial exchange water inlet in the heat exchanger is connected with a third water pump through a pipeline. The temperature control module comprises a temperature detection module capable of monitoring the pipeline and wastewater in the constant-temperature pool in real time and a plurality of electric control valve modules connected to the pipeline, and the electric control valve modules, the temperature detection module, the first water pump, the second water pump and the third water pump are electrically connected. According to the waste water cooling temperature control system and method for pulping and papermaking, the problems that an existing traditional waste water cooling method is low in cooling efficiency and inaccurate in temperature control, and heat recycling cannot be achieved are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment in the pulping and papermaking industry, and in particular relates to a wastewater cooling temperature control system and method for pulping and papermaking. Background Art

[0002] In the pulp and paper production process, the uninterrupted production mode throughout the year leads to continuous wastewater discharge. The wastewater temperature is significantly affected by seasonal changes. The high temperature in summer makes the average temperature of the wastewater in the primary sedimentation tank 1 reach 45°C. The subsequent anaerobic biological treatment section has strict requirements on the wastewater temperature. Anaerobic biological treatment can be carried out at medium temperature (35°C-38°C) or high temperature (52°C-55°C). Because in the anaerobic biological treatment process, it is necessary to consider the impact of various factors on methanogens, because methanogens are most active and have the best treatment effect in two temperature ranges (i.e., 35°C-38°C and 52°C-55°C).

[0003] However, the current traditional wastewater cooling methods have problems such as low cooling efficiency, inaccurate temperature control, and inability to achieve heat recovery and utilization, and cannot effectively solve the problem of high temperature of pulp and paper wastewater in summer. Therefore, there is an urgent need for an efficient, accurate, and energy-saving pulp and paper wastewater cooling temperature control system and method to ensure the treatment efficiency of wastewater generated by pulp and paper in summer. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a wastewater cooling temperature control system and method for pulping and papermaking, which solves the problems of low cooling efficiency, inaccurate temperature control and inability to achieve heat recovery and utilization in the current traditional wastewater cooling method.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a wastewater cooling temperature control system for pulping and papermaking, comprising a temperature control module, a constant temperature tank, a heat exchanger, a first water pump, and a second water pump connected between a primary sedimentation tank and an anaerobic section inlet through a pipeline; The wastewater inlet on the heat exchanger is connected to the outlet of the first water pump through a pipeline, the water inlet on the first water pump is connected to the primary sedimentation tank through a pipeline, the wastewater outlet on the heat exchanger is connected to the constant temperature tank through a pipeline, the water inlet on the second water pump is connected to the constant temperature tank through a pipeline, and the water outlet on the second water pump is connected to the inlet of the anaerobic section through a pipeline; The industrial exchange water outlet on the heat exchanger is connected to the industrial water pipeline mechanism through a pipeline, and the industrial exchange water inlet on the heat exchanger is connected to a third water pump through a pipeline; The temperature control module includes a temperature detection module that can monitor the pipeline and the wastewater in the constant temperature pool in real time, and a plurality of electric regulating valve modules connected to the pipeline. The electric regulating valve module, the temperature detection module, the first water pump, the second water pump, and the third water pump are electrically connected.

[0006] Optionally, the electric regulating valve module includes a first electric regulating valve disposed between the first water pump and the heat exchanger, and a second electric regulating valve connected to the industrial exchange water inlet.

[0007] Optionally, the industrial water pipeline mechanism includes a main water pipe connected to the industrial exchange water outlet and a plurality of secondary water pipes connected to the main water pipe, and each of the secondary water pipes is provided with a solenoid valve.

[0008] Optionally, the temperature detection module includes a first temperature sensor arranged at the industrial exchange water inlet, a second temperature sensor arranged at the industrial exchange water outlet, and a third temperature sensor arranged in the constant temperature pool.

[0009] Optionally, the first water pump and the second water pump are variable frequency pumps.

[0010] Optionally, the exterior of the constant temperature pool is coated with a thermal insulation layer.

[0011] Optionally, the length of the pipeline between the constant temperature pool and the inlet of the anaerobic section is less than m, and the outer periphery of this section of the pipeline is coated with thermal insulation cotton.

[0012] A method for cooling and controlling the temperature of wastewater for pulping and papermaking, using the aforementioned temperature control system for cooling and controlling the wastewater for pulping and papermaking, comprises the following steps: Step 1: connect the industrial exchange water inlet on the heat exchanger to the industrial water with constant temperature and pressure, open the first electric regulating valve, the second electric regulating valve, and the first water pump, close the second water pump, and open at least one of the solenoid valves; Step 2: pumping the wastewater in the primary settling tank into the heat exchanger by the first water pump, and monitoring the temperature of the wastewater in the pipeline and the constant temperature tank in real time by the first temperature sensor, the second temperature sensor and the third temperature sensor; Step three, comparing the wastewater temperature detected by the third temperature sensor with the temperature range (35℃-38℃); when the temperature in the constant temperature water pool is in the temperature range (35℃-38℃), the second water pump is started; when the temperature in the constant temperature water pool is not in the temperature range (35℃-38℃), the second water pump is turned off, and the flow rate and flow rate of wastewater and industrial water in the heat exchanger are increased or decreased through the first water pump, the first electric regulating valve, the third water pump, and the second electric regulating valve until the temperature in the constant temperature water pool is in the temperature range (35℃-38℃).

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) This system uses the first water pump to transport the wastewater in the primary sedimentation tank to the heat exchanger and the constant temperature tank, and the second water pump transports the wastewater to the inlet of the anaerobic section, forming a rapid water cycle and improving cooling efficiency. At the same time, the heat exchanger can transfer waste heat to industrial water to recover heat and reduce the heating energy consumption of other processes. The temperature detection module monitors the real-time temperature of the wastewater at different nodes in real time. Once the temperature fluctuates, the electric control valve module can respond quickly with the first water pump, the second water pump, and the third water pump, thereby accurately controlling the flow rate and flow, coordinating with heat exchange, and accurately regulating the wastewater temperature to provide the anaerobic section with wastewater with a stable water temperature; (2) The wastewater temperature is monitored in real time by the first temperature sensor, the second temperature sensor, and the third temperature sensor located at different nodes, and the temperature in the constant temperature water pool is compared with the optimal temperature range for microbial activity (35°C-38°C). If it is not within this range, the water pump and the electric regulating valve are precisely adjusted to change the flow rate and flow velocity of the wastewater and industrial water in the heat exchanger until the appropriate temperature is reached, ensuring that the temperature of the wastewater entering the anaerobic section is stable in the optimal range, thereby improving the wastewater treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0015] Figure 1 It is a structural schematic diagram of a temperature control system for cooling wastewater for pulping and papermaking in a preferred embodiment of the present invention; Among them, 1. primary sedimentation tank; 2. anaerobic section inlet; 3. constant temperature tank; 4. heat exchanger; 5. first water pump; 6. second water pump; 7. third water pump; 8. first electric regulating valve; 9. second electric regulating valve; 10. main water pipe; 11. auxiliary water pipe; 12. solenoid valve. DETAILED DESCRIPTION

[0016] The present invention will now be further described in detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0017] It should be noted that if there are directional indications (such as up, down, bottom, top, etc.) involved in this embodiment, the directional indication is only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Embodiment 1

[0018] like Figure 1 As shown, a wastewater cooling temperature control system for pulping and papermaking includes a temperature control module, a constant temperature pool 3, a heat exchanger 4, a first water pump 5, and a second water pump 6 connected between a primary sedimentation tank 1 and an anaerobic section inlet 2 through a pipeline; the wastewater inlet on the heat exchanger 4 is connected to the outlet of the first water pump 5 through a pipeline, the inlet on the first water pump 5 is connected to the primary sedimentation tank 1 through a pipeline, the wastewater outlet on the heat exchanger 4 is connected to the constant temperature pool 3 through a pipeline, the inlet on the second water pump 6 is connected to the constant temperature pool 3 through a pipeline, and the outlet on the second water pump 6 is connected to the anaerobic section inlet 2 through a pipeline. The system quickly introduces the wastewater in the primary sedimentation tank 1 into the heat exchanger 4 through the first water pump 5. The heat exchanger 4 is an existing technology. After heat exchange, the wastewater can be quickly discharged into the constant temperature pool 3, and then transported to the anaerobic section inlet 2 in time through the second water pump 6. This fast water circulation path is combined with the efficient heat conduction performance of the heat exchanger 4, which greatly improves the cooling efficiency.

[0019] Furthermore, the industrial exchange water outlet on the heat exchanger 4 is connected to the industrial water pipeline mechanism through a pipeline, and the industrial exchange water inlet on the heat exchanger 4 is connected to the third water pump 7 through a pipeline. That is, the industrial exchange water outlet of the heat exchanger 4 is connected to the industrial water pipeline mechanism, and the industrial exchange water inlet introduces water flow through the third water pump 7. The heat exchanger 4 can transfer the heat in the wastewater to the industrial water during operation, thereby realizing the effective recovery and utilization of the wastewater heat, and reducing the energy consumption of heating water in other process links of the factory.

[0020] Furthermore, the temperature control module includes a temperature detection module capable of real-time monitoring of wastewater in the pipeline and the constant temperature pool 3, and a plurality of electric regulating valve modules connected to the pipeline, and the electric regulating valve module, the temperature detection module, the first water pump 5, the second water pump 6, and the third water pump 7 are electrically connected. Specifically, the temperature detection module is distributed in the pipeline and the constant temperature pool 3, and can obtain the temperature data of the wastewater at each key node in real time. Once the temperature fluctuates, the electric regulating valve module and the first water pump 5, the second water pump 6, and the third water pump 7 can respond quickly, accurately control the flow rate and flow of wastewater and industrial water in the pipeline and the heat exchanger 4, and cooperate with the heat exchange effect of the heat exchanger 4 to stabilize the wastewater temperature in an appropriate range, thereby realizing accurate control of the wastewater temperature and providing wastewater with a stable water temperature for the anaerobic section.

[0021] Specifically, the electric regulating valve module includes a first electric regulating valve 8 disposed between the first water pump 5 and the heat exchanger 4 , and a second electric regulating valve 9 connected to the industrial exchange water inlet.

[0022] The above, such as Figure 1 As shown, the industrial water pipeline mechanism includes a main water pipe 10 connected to the industrial exchange outlet and a plurality of auxiliary water pipes 11 connected to the main water pipe 10. Each auxiliary water pipe 11 is provided with a solenoid valve 12. The auxiliary water pipe 11 can be connected to the industrial equipment. When the industrial equipment needs industrial water with a certain amount of heat, the solenoid valve 12 on the corresponding auxiliary water pipe 11 can be selectively opened according to demand to realize heat recovery of wastewater in summer.

[0023] The above, such as Figure 1 As shown, the temperature detection module includes a first temperature sensor arranged at the industrial exchange water inlet, a second temperature sensor arranged at the industrial exchange water outlet and a third temperature sensor arranged in the constant temperature pool 3. The first temperature sensor can monitor the temperature of the wastewater before entering the heat exchanger 4, the second temperature sensor can detect the temperature of the wastewater after coming out of the heat exchanger 4, and the third temperature sensor can monitor the temperature of the wastewater in the constant temperature pool 3. By comparing the difference between the monitoring data of the first temperature sensor and the second temperature sensor, the heat exchange efficiency of the heat exchanger can be fed back, and the temperature data fed back by the third temperature sensor can be used to feedback whether the wastewater in the constant temperature pool 3 meets the temperature requirements of biological treatment.

[0024] In this embodiment, the first water pump 5 and the second water pump 6 are variable frequency pumps, which are conventional technologies.

[0025] Furthermore, the outside of the constant temperature pool 3 is coated with an insulation layer, the length of the pipe between the constant temperature pool 3 and the anaerobic section inlet 2 is less than 2m, and the outer periphery of this section of the pipe is coated with insulation cotton to prevent the wastewater in the constant temperature pool 3 from dropping too much in temperature before entering the anaerobic section inlet 2. Embodiment 2

[0026] like Figure 1 As shown, based on the first embodiment, a method for cooling temperature control of wastewater for pulping and papermaking adopts the above-mentioned temperature control system for cooling temperature control of wastewater for pulping and papermaking, comprising the following steps: Step 1: connect the industrial exchange water inlet on the heat exchanger 4 with industrial water of constant temperature and pressure, open the first electric regulating valve, the second electric regulating valve 9, the first water pump 5, close the second water pump 6, and open at least one of the solenoid valves 12; Step 2: The wastewater in the primary settling tank 1 is pumped into the heat exchanger 4 by the first water pump 5, and the temperature of the wastewater in the pipeline and the constant temperature tank 3 is monitored in real time by the first temperature sensor, the second temperature sensor and the third temperature sensor; Step three, compare the wastewater temperature detected by the third temperature sensor with the temperature range (35℃-38℃); when the temperature in the constant temperature water pool is in the temperature range (35℃-38℃), the second water pump 6 is started; when the temperature in the constant temperature water pool is not in the temperature range (35℃-38℃), the second water pump 6 is turned off, and the flow rate and flow rate of wastewater and industrial water in the heat exchanger 4 are increased or decreased through the first water pump 5, the first electric regulating valve, the third water pump 7, and the second electric regulating valve 9 until the temperature in the constant temperature water pool is in the temperature range (35℃-38℃).

[0027] Working principle: The system quickly introduces the wastewater in the primary sedimentation tank 1 into the heat exchanger 4 through the first water pump 5, and quickly discharges it into the constant temperature tank 3 after heat exchange, and then promptly transports it to the anaerobic section inlet 2 through the second water pump 6. This fast water circulation path is combined with the efficient heat conduction performance of the heat exchanger 4, which greatly improves the cooling efficiency. At the same time, the industrial exchange outlet of the heat exchanger 4 is connected to the industrial water pipeline mechanism, and the industrial exchange inlet is introduced into the water flow through the third water pump 7. The heat exchanger 4 can transfer the heat in the wastewater to the industrial water during operation, thereby realizing the effective recovery and utilization of the wastewater heat and reducing the energy consumption of heating water in other process links of the factory. The temperature detection modules are distributed in the pipeline and the constant temperature pool 3, and can obtain the temperature data of the wastewater at each key node in real time. Once the temperature fluctuates, the electric regulating valve module and the first water pump 5, the second water pump 6, and the third water pump 7 can respond quickly, accurately control the flow rate and flow of wastewater and industrial water in the pipeline and the heat exchanger 4, and cooperate with the heat exchange function of the heat exchanger 4 to stabilize the wastewater temperature within a suitable range, thereby achieving accurate control of the wastewater temperature and providing wastewater with stable water temperature for the anaerobic section.

[0028] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A wastewater cooling temperature control system for pulping and papermaking, characterized in that: It comprises a temperature control module, a constant temperature tank (3), a heat exchanger (4), a first water pump (5), and a second water pump (6) which are connected between a primary sedimentation tank (1) and an anaerobic section inlet (2) through a pipeline; The wastewater inlet on the heat exchanger (4) is connected to the outlet of the first water pump (5) through a pipeline, the water inlet on the first water pump (5) is connected to the primary sedimentation tank (1) through a pipeline, the wastewater outlet on the heat exchanger (4) is connected to the constant temperature tank (3) through a pipeline, the water inlet on the second water pump (6) is connected to the constant temperature tank (3) through a pipeline, and the water outlet on the second water pump (6) is connected to the anaerobic section inlet (2) through a pipeline; The industrial exchange water outlet on the heat exchanger (4) is connected to the industrial water pipeline mechanism via a pipeline, and the industrial exchange water inlet on the heat exchanger (4) is connected to a third water pump (7) via a pipeline; The temperature control module comprises a temperature detection module capable of real-time monitoring of the wastewater in the pipeline and the constant temperature pool (3), and a plurality of electric regulating valve modules connected to the pipeline, wherein the electric regulating valve module, the temperature detection module, the first water pump (5), the second water pump (6), and the third water pump (7) are electrically connected.

2. The pulp and papermaking wastewater cooling temperature control system according to claim (1), characterized in that: The electric regulating valve module comprises a first electric regulating valve (8) arranged between the first water pump (5) and the heat exchanger (4), and a second electric regulating valve (9) connected to the industrial exchange water inlet.

3. The pulp and papermaking wastewater cooling temperature control system according to claim 2, characterized in that: The industrial water pipeline mechanism comprises a main water pipe (10) connected to the industrial exchange water outlet and a plurality of auxiliary water pipes (11) connected to the main water pipe (10), and each of the auxiliary water pipes (11) is provided with a solenoid valve (12).

4. The wastewater cooling temperature control system for pulping and papermaking according to claim 3 is characterized in that: The temperature detection module comprises a first temperature sensor arranged at the industrial exchange water inlet, a second temperature sensor arranged at the industrial exchange water outlet, and a third temperature sensor arranged in the constant temperature pool (3).

5. The pulp and papermaking wastewater cooling temperature control system according to claim 4, characterized in that: The first water pump (5) and the second water pump (6) are variable frequency pumps.

6. The pulp and papermaking wastewater cooling temperature control system according to claim 5, characterized in that: The exterior of the constant temperature pool (3) is coated with a thermal insulation layer.

7. The pulp and papermaking wastewater cooling temperature control system according to claim 6, characterized in that: The length of the pipeline between the constant temperature pool (3) and the inlet (2) of the anaerobic section is less than (2) m, and the outer periphery of the pipeline section is coated with thermal insulation cotton.

8. A method for cooling and controlling the temperature of wastewater used in pulping and papermaking, using the temperature control system for cooling and controlling the wastewater used in pulping and papermaking as described in claim 7, characterized in that: The following steps are included: Step 1: connecting the industrial exchange water inlet on the heat exchanger (4) to industrial water of constant temperature and pressure, opening the first electric regulating valve, the second electric regulating valve (9), and the first water pump (5), closing the second water pump (6), and opening at least one of the solenoid valves (12); Step 2: pumping the wastewater in the primary sedimentation tank (1) into the heat exchanger (4) by means of the first water pump (5), and monitoring the temperature of the wastewater in the pipeline and the constant temperature tank (3) in real time by means of the first temperature sensor, the second temperature sensor and the third temperature sensor; Step three, comparing the wastewater temperature detected by the third temperature sensor with the temperature range (35°C-38°C); when the temperature in the constant temperature water pool is within the temperature range (35°C-38°C), the second water pump (6) is started; when the temperature in the constant temperature water pool is not within the temperature range (35°C-38°C), the second water pump (6) is turned off, and the flow rate and flow velocity of the wastewater and industrial water in the heat exchanger (4) are increased or decreased through the first water pump (5), the first electric regulating valve, the third water pump (7), and the second electric regulating valve (9) until the temperature in the constant temperature water pool is within the temperature range (35°C-38°C).

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