Anti-surge BSD-MVR frequency-modulated steam blowing system

Abstract

The present invention relates to the field of evaporation technology, and specifically to an anti-surge BSD-MVR frequency modulation steam blowing system. The anti-surge BSD-MVR frequency modulation steam blowing system provided by the present invention is composed of a temperature and pressure transmitter, an MVR compressor, a BSD evaporator, a heat exchanger, a secondary heat pump, an air pump and a water pump; the temperature and pressure transmitter is connected to the MVR compressor, the secondary heat pump, the air pump and the water pump, and transmits the temperature and pressure parameters of the MVR compressor input and output ends to the secondary heat pump, the air pump and the water pump in real time. The temperature and pressure transmitter controls the evaporation temperature and reduces the surge risk of the MVR compressor by controlling the speed of the motor of the secondary heat pump, the air pump and the water pump; the MVR compressor is connected to the secondary heat pump and the air pump; the water pump is connected to the heat exchanger and the wastewater input end; the heat exchanger is connected to the BSD evaporator and the condensed water outlet; the BSD evaporator is connected to the heat exchanger through two channels, one channel is used to receive the wastewater preheated by the heat exchanger, and the other channel is used to transport steam to the heat exchanger; the BSD evaporator is connected to the secondary heat pump.

Description

Technical Field

[0001] The present invention relates to the technical field of evaporation, and in particular to an anti-surge BSD-MVR frequency modulation blowing and evaporation system. Background Art

[0002] Evaporation is a widely used concentration and separation method, and its processing objects include various liquid-liquid, gas-liquid and solid-liquid solutions, suspensions, emulsions, etc.

[0003] Previous evaporation technologies include MVR (mechanical vapor recompressor) evaporation, single-effect evaporation, multi-effect evaporation, falling film evaporation, pressure spray drying, low-temperature vacuum evaporation, and membrane distillation. Multi-effect evaporation involves operating several evaporators in series. The first evaporator (first effect) uses live steam as heating steam, while subsequent evaporators use secondary steam from the previous effect as heating steam. Mechanical vapor recompression (MVR) uses the secondary steam generated by evaporation to increase its temperature through a compressor, where it is used again as a heat source to heat the evaporating liquid, achieving heat recycling. Falling film evaporation evenly distributes the liquid through a liquid distribution device, causing it to flow in a uniform film along the inner wall of the heat exchange tubes. The heating effect of shell-side steam evaporates and concentrates saline wastewater. Pressure spray drying uses a diaphragm pump to spray the liquid into a mist of droplets at high pressure, which then descends co-currently with hot air. Most of the fine particles are collected at the bottom of the tower, while the exhaust gas and its fine particles are separated by a cyclone separator. Low-temperature vacuum evaporation uses a high vacuum to lower the evaporation temperature of the material. Rotating rollers within the evaporator increase the evaporation area and capacity of the equipment. The material is heated by contact with the rotating roller surface, forming a thin film evaporation. Membrane distillation is a membrane process with phase change, simultaneously transferring heat and mass. The driving force for mass transfer is the vapor partial pressure difference between the components permeating the hydrophobic membrane on both sides.

[0004] The main methods of evaporation achieved by these technologies include thermal evaporation and air humidity gradients. 1) The solution, suspension, or emulsion to be evaporated is evenly distributed onto heated tubes or plates, evaporating solvents such as water through boiling-point evaporation. 2) The solution (solvent + solvent) is baked to achieve boiling-point evaporation. 3) Utilizing humidity differences between air temperatures, the evaporation process relies on aerodynamics. These methods are characterized by low thermal efficiency and high evaporation costs. The BDS (blowing steam device, or BSD) utilizes a unique "blowing + spraying + steaming" integrated evaporation mechanism: blowing transfers the solution from the evaporation chamber to the vapor collection chamber and directly heats the solution; spraying converts the solution into droplets. Steaming separates the solvent from the solute.

[0005] Energy conservation and emission reduction are essential considerations for any large-scale complete equipment. The primary methods for recovering residual heat energy in evaporation equipment are MVR compressors, screw compressors, and air energy compressors. MVR compressors are the most commonly used.

[0006] Because the steam generated by the BDS contains a large amount of water or other solvents, using a conventional MVR compressor can easily cause surge, leading to rapid aging of equipment components and equipment failure, or even instantaneous equipment decomposition and explosion, resulting in serious production accidents. Therefore, anti-surge MVR compressors are essential. However, simply using an anti-surge MVR compressor does not eliminate the conditions for surge. Therefore, temperature and pressure transmitters are needed to further control the flow rate and temperature of the inlet water, inlet air, and secondary hot gas to completely eliminate the conditions that cause MVR compressor surge and ensure production safety. Summary of the Invention

[0007] The anti-surge BSD-MVR frequency modulation steam blowing system provided by the present invention is composed of a temperature and pressure transmitter, an MVR compressor, a BSD evaporator, a heat exchanger, a secondary heat pump, an air pump and a water pump; the temperature and pressure transmitter is connected to the MVR compressor, the secondary heat pump, the air pump and the water pump, and transmits parameters such as temperature and pressure at the input and output ends of the MVR compressor to the secondary heat pump, the air pump and the water pump in real time. The temperature and pressure transmitter controls the evaporation temperature and reduces the surge risk of the MVR compressor by controlling the speed of the motors of the secondary heat pump, the air pump and the water pump; the MVR compressor is connected to the secondary heat pump and the air pump; the water pump is connected to the heat exchanger and the wastewater input end; the heat exchanger is connected to the BSD evaporator and the condensate outlet; the BSD evaporator is connected to the heat exchanger through two channels, one channel is used to receive wastewater preheated by the heat exchanger, and the other channel is used to transport steam to the heat exchanger; the BSD evaporator is connected to the secondary heat pump.

[0008] Specifically, the MVR compressor recovers the residual heat energy in the heat exchanger to generate secondary hot gas.

[0009] Specifically, the heat exchanger preheats the steam generated by the BSD evaporator to the solution input by the water pump, and at the same time condenses the steam generated by the BSD evaporator.

[0010] The specific secondary heat pump, air pump and water pump transport the secondary hot gas, condensed warm gas and raw liquid respectively.

[0011] The anti-surge BSD-MVR frequency modulation blowing and steaming system provided by the present invention can be widely used in chemical, electrical, textile, papermaking, metal processing, machinery, plastic and rubber, petroleum, coking and leather manufacturing industries, various mining industries, electricity, gas and water supply, environmental protection, laundry services and scientific research and other fields where evaporation, concentration and separation are required.

[0012] The anti-surge BSD-MVR frequency modulation steam blowing system provided by the present invention has the following beneficial effects:

[0013] 1. Residual heat energy is recovered through the anti-surge MVR compressor, and the motors of the secondary hot gas pump, air pump and water pump are further controlled by the temperature and pressure transmitter to further reduce the surge risk of the anti-surge MVR compressor.

[0014] 2. Realize the practical application of BSD high-efficiency evaporation technology; eliminate compressor surge caused by the mismatch between input and output temperature and pressure of MVR compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of a BSD-MVR frequency modulation steaming system for anti-surge in a specific embodiment of the present invention.

[0016] Among them, 1-temperature and pressure transmitter; 2-MVR compressor; 3-BSD evaporator; 4-heat exchanger; 5-secondary heat pump; 6-air pump; 7-water pump. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] like Figure 1 As shown, the anti-surge BSD-MVR frequency modulation steaming system provided by the present invention is composed of a temperature and pressure transmitter 1, an MVR compressor 2, a BSD evaporator 3, a heat exchanger 4, a secondary heat pump 5, an air pump 6 and a water pump 7; the temperature and pressure transmitter 1 is connected to the MVR compressor 2, the secondary heat pump 5, the air pump 6 and the water pump 7, and transmits the temperature and pressure parameters of the input and output ends of the MVR compressor 2 to the secondary heat pump 5, the air pump 6 and the water pump 7 in real time. The temperature and pressure transmitter 1 controls the evaporation temperature and reduces the surge risk of the MVR compressor 2 by controlling the speed of the three pump motors; the MVR compressor 2 is connected to the secondary heat pump 5 and the air pump 6; the water pump 7 is connected to the heat exchanger 4 The heat exchanger 4 connects the BSD evaporator 3 and the condensate outlet. The BSD evaporator 3 is connected to the heat exchanger 4 via two channels: one for receiving wastewater preheated by the heat exchanger 4 and the other for delivering steam to the heat exchanger 4. The BSD evaporator 3 is connected to the secondary heat pump 5. The MVR compressor 2 recovers residual heat energy from the heat exchanger 4 to generate secondary hot gas. The heat exchanger 4 preheats the steam generated by the BSD evaporator 3 to the solution input by the water pump 7 and condenses the steam generated by the BSD evaporator 3. The secondary heat pump 5, air pump 6, and water pump 7 transport the secondary hot gas, the condensed warm gas, and the raw liquid, respectively. This system can be widely used in manufacturing industries such as chemical, electrical, textile, papermaking, metalworking, machinery, plastics and rubber, petroleum, coking, and leather, as well as various mining industries, electricity, gas, and water supply, environmental protection, laundry services, and scientific research, where evaporation, concentration, and separation are required.

[0019] [Example] Using the anti-surge BSD-MVR frequency modulation blowing and evaporation system to evaporate landfill membrane concentrate

[0020] At a certain landfill, leachate is processed through pretreatment, biochemical treatment, and membrane treatment to form a membrane concentrate, which typically contains 6.3% insoluble solids. Due to the poor biodegradability of the membrane concentrate, it has traditionally been treated by reinjecting it back into the landfill. However, this method can increase the total insoluble solids concentration in the landfill's leachate, making treatment increasingly difficult and costly.

[0021] Using the anti-surge BSD-MVR frequency-modulated evaporation system pilot test equipment provided by this invention, using electricity as a heat source, the volume of membrane concentrate can be reduced. Within 24 hours, approximately 46.04 tons of membrane concentrate can be concentrated to 4.43 tons of residual solids, with the remainder volatilized as steam, resulting in a volume reduction of approximately 91.0%. The evaporation cost within 24 hours (excluding equipment depreciation, employee salaries calculated at 300 yuan / day, and one management staff, and the average industrial electricity price of 1.5 yuan / kWh) is approximately 74.12 yuan / ton.

Claims

1. Anti-surge BSD-MVR frequency modulation steam blowing system, characterized by: The system consists of a temperature and pressure transmitter, an MVR compressor, a BSD evaporator, a heat exchanger, a secondary heat pump, an air pump and a water pump; the temperature and pressure transmitter is connected to the MVR compressor, the secondary heat pump, the air pump and the water pump to transmit the temperature and pressure parameters of the MVR compressor input and output ends to the secondary heat pump, the air pump and the water pump in real time; the temperature and pressure transmitter controls the evaporation temperature and reduces the surge risk of the MVR compressor by controlling the speed of the motors of the secondary heat pump, the air pump and the water pump; the MVR compressor is connected to the secondary heat pump and the air pump; the water pump is connected to the heat exchanger and the wastewater input end; the heat exchanger is connected to the BSD evaporator and the condensate outlet; The BSD evaporator is connected to the heat exchanger through two channels, one channel is used to receive the wastewater preheated by the heat exchanger, and the other channel is used to transport steam to the heat exchanger; the BSD evaporator is connected to the secondary heat pump.

2. The anti-surge BSD-MVR frequency modulation steam blowing system according to claim 1, characterized in that: The MVR compressor recovers residual heat energy in the heat exchanger to generate secondary hot gas.

3. The anti-surge BSD-MVR frequency modulation steam blowing system according to claim 1 or 2, characterized in that: The heat exchanger preheats the steam generated by the BSD evaporator and the solution input by the water pump, and condenses the steam generated by the BSD evaporator.

4. The anti-surge BSD-MVR frequency modulation steam blowing system according to claim 1 or 2, characterized in that: The secondary heat pump, air pump and water pump transport the secondary hot gas, the condensed warm gas and the raw liquid respectively.

5. The anti-surge BSD-MVR frequency modulation steam blowing system according to claim 3, characterized in that: The secondary heat pump, air pump and water pump transport the secondary hot gas, the condensed warm gas and the raw liquid respectively.

6. The anti-surge BSD-MVR frequency modulation blowing and steaming system according to claim 1 or 2 is used in scenarios requiring evaporation, concentration and separation in the fields of chemistry, electricity, textiles, papermaking, metal processing, machinery, plastics and rubber, petroleum, coking and leather manufacturing, various mining industries, electricity, gas and water supply, environmental protection, laundry services and scientific research.

7. The anti-surge BSD-MVR frequency modulation blowing and steaming system as described in claim 3 or 5 is used in scenarios requiring evaporation, concentration and separation in the chemical, electrical, textile, papermaking, metal processing, machinery, plastic and rubber, petroleum, coking and leather manufacturing industries, various mining industries, electricity, gas and water supply, environmental protection, laundry services and scientific research fields.

8. The anti-surge BSD-MVR frequency modulation blowing and steaming system as claimed in claim 4 is used in scenarios requiring evaporation, concentration and separation in the fields of chemistry, electricity, textiles, papermaking, metal processing, machinery, plastics and rubber, petroleum, coking and leather manufacturing, various mining industries, electricity, gas and water supply, environmental protection, laundry services and scientific research.

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