Organic wastewater energy-saving treatment system

Abstract

According to the organic wastewater energy-saving treatment system provided by the invention, organic matters in organic wastewater can be greatly reduced through oil separation treatment of the reservoir and filtration and coalescence separation treatment of the filtration coalescence device, so that the purpose of recovering the organic matters is achieved; through multi-effect evaporation of the I-effect falling film evaporator, the II-effect falling film evaporator and the forced circulation evaporator, generated steam is recycled through the MVR compressor, cyclic utilization of secondary steam energy is achieved, and energy consumption is reduced; and the wastewater can be recycled through a multi-effect evaporation and resin adsorption treatment mode, and the recovery rate reaches 96%. The steam consumption for wastewater treatment can be reduced by 0.90 t / m < 3 >.

Description

TECHNICAL FIELD

[0001] The utility model belongs to wastewater treatment technical field relates to an organic wastewater energy -conserving treatment system. BACKGROUND

[0002] Organic wastewater usually contains a large amount of anthraquinone, aromatic hydrocarbon, trioctyl phosphate and other organic matters and alumina, potassium carbonate and other salts, and needs to be treated before discharging wastewater or recycling.

[0003] At present, the treatment method of organic wastewater is usually direct incineration, which leads to the fact that the organic matter in the organic wastewater cannot be recycled. At the same time, for the organic wastewater with insufficient heat value, fuel needs to be used to increase the heat value for blending combustion, causing energy waste. INVENTION CONTENTS

[0004] The utility model aims at providing an organic wastewater energy -conserving treatment system to solve the problem of energy waste in the existing organic wastewater incineration treatment.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0006] The application provides an organic wastewater energy -conserving treatment system, which comprises a water storage pool, a filtering and coalescing device, a first plate heat exchanger, a tube heat exchanger, an I-effect falling film evaporator, a II-effect falling film evaporator and a forced circulation evaporator connected in sequence; the I-effect falling film evaporator, the II-effect falling film evaporator and the forced circulation evaporator are connected with MVR compressors respectively, and the tube heat exchanger, the I-effect falling film evaporator, the II-effect falling film evaporator and the forced circulation evaporator are also connected with condensate tanks respectively; the condensate tank is connected to a second plate heat exchanger and a resin adsorption device in sequence after heat exchange with the first plate heat exchanger.

[0007] Preferably, the filtering and coalescing device comprises a homogenizing pool, a filter and a coalescing separator connected in sequence, the homogenizing pool is communicated with the water storage pool, and the coalescing separator is communicated with the first plate heat exchanger.

[0008] Preferably, the resin adsorption device comprises three adsorption tanks, and adopts a two-in-one standby operation mode.

[0009] The utility model has the following beneficial effects:

[0010] (1) The oil separation treatment of the water storage pool, the filtering and coalescing treatment of the filtering and coalescing device can greatly reduce the organic matter in the organic wastewater, and achieve the purpose of recycling the organic matter.

[0011] (2) Through the multi-effect evaporation of the I-effect falling film evaporator, the II-effect falling film evaporator and the forced circulation evaporator, the generated steam is recycled through the MVR compressor, the secondary steam energy is recycled and used, and the energy consumption is saved.

[0012] (3) The wastewater can be recycled through the multi-effect evaporation and the resin adsorption, and the recycling rate reaches 96%.

[0013] (4) The steam consumption for treating the wastewater can be reduced by 0.90t / m 3 . BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 a schematic diagram of an organic wastewater energy-saving treatment system provided by the embodiment of the application;

[0015] symbols represent:

[0016] 1-impoundment, 2-filtration and coalescence device, 3-first plate heat exchanger, 4-tube heat exchanger, 5-I-effect falling film evaporator, 6-II-effect falling film evaporator, 7-forced circulation evaporator, 8-MVR compressor, 9- condensate tank, 10-second plate heat exchanger, 11-resin adsorption device. DETAILED DESCRIPTION

[0017] The technical scheme of the application will be further explained and described through specific embodiments.

[0018] The embodiment of the application provides an organic wastewater energy-saving treatment system, which comprises an impoundment 1, a filtration and coalescence device 2, a first plate heat exchanger 3, a tube heat exchanger 4, an I-effect falling film evaporator 5, an II-effect falling film evaporator 6 and a forced circulation evaporator 7 which are sequentially connected in communication, and the I-effect falling film evaporator 5, the II-effect falling film evaporator 6 and the forced circulation evaporator 7 are all connected with an MVR compressor 8 respectively, and the tube heat exchanger 4, the I-effect falling film evaporator 5, the II-effect falling film evaporator 6 and the forced circulation evaporator 7 are all connected with a condensate tank 9 respectively; the condensate tank 9 is sequentially connected to a second plate heat exchanger 10 and a resin adsorption device 11 after heat exchange with the first plate heat exchanger 3, as shown in the accompanying drawings. Figure 1

[0019] Specifically, the impoundment 1 is a component for separating organic matters from wastewater. In the impoundment 1, the organic wastewater separates the suspended oil bead organic matters in the wastewater by using the density difference and gravity difference between the organic matters and the wastewater, the separated organic matters are recycled and utilized, and the separated wastewater is discharged into the filtration and coalescence device 2. In the application, the filtration and coalescence separation treatment is carried out after the oil content in the organic wastewater is reduced through the oil separation treatment of the impoundment 1, so as to prevent the viscous oil-like organic matters from blocking the filtration and coalescence device 2.

[0020] ​In the filtering and coalescing device 2, the wastewater is sequentially subjected to homogenization, filtration and coalescing separation treatment, and the treated wastewater is discharged into the first plate heat exchanger 3. The filtering and coalescing device 2 in the embodiment of the application comprises a homogenizing tank, a filter and a coalescing separator connected in sequence, wherein the homogenizing tank is connected to the water storage tank 1, and the coalescing separator is connected to the first plate heat exchanger 3. After the wastewater is homogenized in the homogenizing tank, it is discharged into the filter, and the solid suspended matter in the wastewater is filtered out by the filter bag in the filter. After the filtration of the solid suspended matter, the wastewater is discharged into the coalescing separator for coalescing separation treatment. The coalescing separator contains a coalescing filter element and a separation filter element, which capture and separate small oil droplets in the wastewater by utilizing the different affinity of the two filter element materials to different liquids, so as to further separate organic matter and wastewater and reduce the concentration of organic matter in the organic wastewater.

[0021] The wastewater separated by the coalescing separator is pressurized by a wastewater pump and then discharged into the first plate heat exchanger 3, and the temperature is raised to 95-100℃ by heat exchange with the first plate heat exchanger 3, so as to realize preliminary preheating of the wastewater. The preliminarily preheated wastewater is discharged into the tube heat exchanger 4, and the temperature is raised to 100-105℃ by heat exchange with the tube heat exchanger 4, and then the preheated wastewater is discharged into the I-effect falling film evaporator 5, so as to realize further preheating of the wastewater. The water condensate generated in the heat exchange and preheating process of the wastewater by the tube heat exchanger 4 is discharged into the condensate tank 9, and the non-condensable gases such as aromatics and oxygen overflow from the tube heat exchanger 4 and are sent to a boiler for incineration, so as to realize energy recycling.

[0022] In the I-effect falling film evaporator 5, primary steam is introduced into the outer tube of the I-effect falling film evaporator 5, which can heat the wastewater in the inner tube by heat exchange, so as to heat the wastewater. The heating temperature of the wastewater by the primary steam is 118℃, and the evaporation temperature of the wastewater is 109℃. Under the heat exchange action of the primary steam, the wastewater boils, and the secondary steam evaporated from the wastewater enters the falling film evaporation chamber in the I-effect falling film evaporator 5, and then the falling film evaporation chamber separates the secondary steam and the entrained liquid droplets. After mixing with the unevaporated wastewater, part of the wastewater is sent back to the top of the I-effect falling film evaporator 5 for reflux evaporation, and the other part of the wastewater enters the II-effect falling film evaporator 6 from the bottom of the I-effect falling film evaporator 5. The condensate formed by the heat exchange of the primary steam with the wastewater is discharged into the condensate tank 9. Part of the secondary steam is discharged into the II-effect falling film evaporator 6 as a heat source for heat exchange, and the other part is extracted by the MVR compressor 8.

[0023] In the embodiment of the application, the heat load of the I-effect falling film evaporator 5 is 6679kW, the heater type is a tubular heater, the separator volume is 8.7m 3 , and the separator separation factor is 0.35.

[0024] The II-effect falling-film evaporator 6 is a component for further evaporating water vapor in the wastewater, wherein the heating temperature of the II-effect falling-film evaporator 6 is 109℃, and the evaporation temperature of the wastewater is 98℃. The working process and principle of the II-effect falling-film evaporator 6 on the wastewater are the same as those of the I-effect falling-film evaporator 5, which will not be described here again. The same as the I-effect falling-film evaporator 5, the water condensate generated in the heat exchange process of the II-effect falling-film evaporator 6 on the wastewater is discharged into the condensate tank 9, and the secondary steam generated is drawn away by the MVR compressor 8.

[0025] In the embodiment of the present application, the heat load of the II-effect falling-film evaporator 6 is 6066kW, the heater type is a tubular heater, the separator volume is 13.2m 3 , and the separator separation factor is 0.45.

[0026] The wastewater treated by the II-effect falling-film evaporator 6 is discharged into the forced circulation evaporator 7, and after being warmed to 118℃ by the forced circulation evaporator 7, the wastewater is continuously evaporated and concentrated to form secondary steam and concentrated liquid. The evaporation temperature of the wastewater is 98℃. The concentrated liquid formed by evaporation is discharged into a concentrated liquid tank and transported to a waste liquid incinerator by a tank car for incineration treatment. The condensate generated in the evaporation treatment of the wastewater by the forced circulation evaporator 7 is also discharged into the condensate tank 9, and the secondary steam generated is drawn away by the MVR compressor 8.

[0027] In the embodiment of the present application, the heat load of the forced circulation evaporator 7 is 6372kW, the heater type is a tubular heater, the separator volume is 13.2m 3 , and the separator separation factor is 0.48.

[0028] In the MVR compressor 8, the MVR compressor 8 uses electric drive to compress the secondary steam to improve the temperature, pressure and heat content of the secondary steam, and improve the steam quality. In the embodiment of the present application, the temperature of the secondary steam is increased to 118℃ by the MVR compressor 8, and the pressure is increased to 0.15MPa. The secondary steam after warming and pressurizing is discharged into the I-effect falling-film evaporator 5 and the forced circulation evaporator 7, respectively, to participate in heat exchange. Thus, a circulating loop of secondary steam is formed among the I-effect falling-film evaporator 5, the II-effect falling-film evaporator 6, the forced circulation evaporator 7 and the MVR compressor 8.

[0029] In the embodiment of the present application, except for the start-up of the vehicle, only a small amount of primary steam is used in the entire evaporation process of the wastewater, and the use of the remaining steam is all the secondary steam recovered by the MVR compressor 8, which greatly reduces the energy input and realizes the recycling of the secondary steam, saving costs.

[0030] The column tube heat exchanger 4, the first effect falling film evaporator 5, the second effect falling film evaporator 6 and the forced circulation evaporator 7 discharge the condensate generated in the wastewater heat exchange evaporation treatment process into the condensate tank 9, and the condensate is pressurized by a condensate pump and then enters the first plate heat exchanger 3 to participate in the heat exchange preheating treatment of the wastewater. The condensate after heat exchange is discharged into the resin adsorption device 11 after heat exchange treatment by the second plate heat exchanger 10.

[0031] In the resin adsorption device 11, the resin adsorption device 11 adsorbs and treats the condensate and discharges it into the reclaimed water circulation system. The resin adsorption device 11 in the embodiment of the application includes three adsorption tanks and adopts a two-in-one standby operation mode. The two-in-one standby operation mode is to first adopt the method of adsorption of the adsorption tank A and the adsorption tank B in series, wherein the adsorption tank A is a first-stage adsorption tank and the adsorption tank B is a second-stage adsorption tank. When the COD of the effluent at the outlet of the adsorption tank A exceeds the standard, the mode is switched to the series connection of the adsorption tank B and the adsorption tank C, at this time, the adsorption tank B is a first-stage adsorption tank and the adsorption tank C is a second-stage adsorption tank. The adsorption tank A is standby after steam desorption treatment, and the cycle is realized to achieve continuous adsorption treatment. In the embodiment of the application, the COD standard of the effluent at the outlet of the adsorption tank is <60 mg / L. The effluent produced in the adsorption process of the resin adsorption device 11 enters the park as a circulating water supplement to improve the utilization rate.

[0032] Taking organic wastewater including water 95.89%, organic matter 1.61% and other salts 2.5% by mass fraction as an example, the working process of the organic wastewater energy-saving treatment system provided in the embodiment of the application includes:

[0033] S01: The organic wastewater in the water storage tank 1 separates the suspended oil beads of organic matter in the wastewater by using the density difference and gravity difference between the organic matter and the wastewater, the separated organic matter is recycled and utilized, and the separated wastewater is discharged into the filter coalescing device 2. In the filter coalescing device 2, the wastewater is homogenized, the solid suspended matter in the wastewater is filtered out by the filter bag in the filter, then the small oil beads in the wastewater are captured and separated by the affinity of different liquid polarities of the two filter core materials in the coalescing separator, the separation of the organic matter and the wastewater is further realized, and the concentration of the organic matter in the organic wastewater is reduced. The treated wastewater is discharged into the first plate heat exchanger 3.

[0034] S02: The waste water separated by the coalescing device 2 is pressurized by the waste water pump and discharged into the first plate heat exchanger 3. The temperature of the waste water is raised to 95-100°C by heat exchange with the first plate heat exchanger 3, realizing the preliminary preheating of the waste water. The preliminarily preheated waste water is discharged into the tube heat exchanger 4, and the temperature of the waste water is raised to 100-105°C by heat exchange with the tube heat exchanger 4. The preheated waste water is discharged into the I-effect falling film evaporator 5. The water condensate generated in the process of heat exchange and preheating of the waste water by the tube heat exchanger 4 is discharged into the condensate tank 9, and the non-condensable gases such as aromatic hydrocarbons and oxygen overflow from the tube heat exchanger 4 and are sent to a boiler for burning, realizing energy recycling.

[0035] S03: Primary steam is introduced into the outer tube of the I-effect falling film evaporator 5, which can heat the waste water in the inner tube by heat exchange. The heating temperature of the primary steam on the waste water is 118°C, and the evaporation temperature of the waste water is 109°C. Under the action of heat exchange of the primary steam, the waste water boils, and the secondary steam evaporated from the waste water carries part of the liquid droplets into the falling film evaporation chamber of the I-effect falling film evaporator 5, and the falling film evaporation chamber separates the secondary steam and the entrained liquid droplets. The liquid droplets are mixed with the unevaporated waste water, part of which is sent back to the top of the I-effect falling film evaporator 5 for reflux evaporation, and the other part of which is discharged from the bottom of the I-effect falling film evaporator 5 into the II-effect falling film evaporator 6. The condensate is formed in the process of heat exchange of the primary steam on the waste water, and the condensate is discharged into the condensate tank 9. Part of the secondary steam is discharged into the II-effect falling film evaporator 6 as a heat source for heat exchange, and the other part of the secondary steam is extracted by the MVR compressor 8.

[0036] S04: After the waste water enters the II-effect falling film evaporator 6, the secondary steam discharged from the I-effect falling film evaporator 5 exchanges heat with the waste water in the II-effect falling film evaporator 6. The heating temperature in the II-effect falling film evaporator 6 is 109°C, the evaporation temperature is 98°C, and the separation factor is 0.45. The waste water boils after heat exchange, and the secondary steam evaporated from the waste water carries part of the liquid droplets into the falling film evaporation chamber of the II-effect falling film evaporator 6, and the falling film evaporation chamber separates the secondary steam and the entrained liquid droplets. The liquid droplets are mixed with the unevaporated waste water to form secondary waste water, part of which is sent back to the top of the II-effect falling film evaporator 6 for reflux evaporation, and the other part of which is discharged from the bottom of the II-effect falling film evaporator 6 into the forced circulation evaporator 7. The condensate is formed in the process of heat exchange of the secondary steam on the waste water, and the condensate is discharged into the condensate tank 9. The secondary steam is extracted by the MVR compressor 8.

[0037] S05: The secondary wastewater is heated to 118℃ by the forced circulation evaporator 7, and then the evaporation and concentration of the wastewater are continued, forming secondary steam and concentrated liquid. The evaporation temperature of the wastewater is 98℃. The concentrated liquid formed by evaporation is sent to the concentrated liquid tank and transported to the waste liquid incinerator by the tank car for incineration treatment. The condensate generated during the evaporation treatment of the wastewater by the forced circulation evaporator 7 is also discharged into the condensate tank 9, and the secondary steam generated is extracted by the MVR compressor 8.

[0038] S06: The condensate generated during the heat exchange and evaporation treatment of the wastewater by the tube heat exchanger 4, the I-effect falling film evaporator 5, the II-effect falling film evaporator 6 and the forced circulation evaporator 7 is all discharged into the condensate tank 9, and then pressurized by the condensate pump and sent to the first plate heat exchanger 3 to participate in the heat exchange and preheating treatment of the wastewater. The condensate after heat exchange is treated by the second plate heat exchanger 10 and then discharged into the resin adsorption device 11. After the treatment of the resin adsorption device 11, the condensate is discharged into the reclaimed water circulation system. The water quality index of the treated water of the resin adsorption device 11 is: pH≥6.5, COD content≤60ppm, BOD content≤0.3ppm, and ammonia nitrogen content≤5ppm.

[0039] S07: In the MVR compressor 8, the MVR compressor 8 uses electric drive to compress the secondary steam evaporated by the I-effect falling film evaporator, the II-effect falling film evaporator and the forced circulation evaporator, so as to increase the temperature, pressure and heat enthalpy of the secondary steam. The secondary steam after temperature and pressure increase is discharged into the I-effect falling film evaporator 5 and the forced circulation evaporator 7 to participate in heat exchange. In this way, a circulating loop of secondary steam is formed among the I-effect falling film evaporator 5, the II-effect falling film evaporator 6, the forced circulation evaporator 7 and the MVR compressor 8.

[0040] In the embodiment of the present application, the steam consumption for treating organic wastewater is reduced by 0.90t / m 3 . The organic wastewater treatment capacity is 15m 3 / h, and the annual running time is 8000h. The annual saving of steam is 108496t, and the power consumption is increased by 354.21 million kWh. Compared with the conventional wastewater treatment device, 85.26kgce of energy consumption per ton of wastewater is saved.

[0041] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An energy-saving organic wastewater treatment system, characterized in that, The system includes a water storage tank (1), a filtration and coalescence device (2), a first plate heat exchanger (3), a shell and tube heat exchanger (4), a first-effect falling film evaporator (5), a second-effect falling film evaporator (6), and a forced circulation evaporator (7) connected in sequence. The first-effect falling film evaporator (5), the second-effect falling film evaporator (6), and the forced circulation evaporator (7) are all connected to an MVR compressor (8), and the shell and tube heat exchanger (4), the first-effect falling film evaporator (5), the second-effect falling film evaporator (6), and the forced circulation evaporator (7) are also connected to a condensate tank (9). The condensate tank (9) exchanges heat with the first plate heat exchanger (3) and is then connected in sequence to a second plate heat exchanger (10) and a resin adsorption device (11).

2. The energy-saving organic wastewater treatment system according to claim 1, characterized in that, The filtration and coalescence device (2) includes a homogenizing tank, a filter and a coalescence separator connected together. The homogenizing tank is connected to the water storage tank (1) and the coalescence separator is connected to the first plate heat exchanger (3).

3. The energy-saving organic wastewater treatment system according to claim 1, characterized in that, The resin adsorption device (11) includes three adsorption tanks, which are operated in a two-in-one standby mode.

Images