A triple-effect wastewater evaporator for evaporating benzoic acid wastewater

Abstract

The invention discloses a triple-effect wastewater evaporator for evaporating benzoic acid wastewater, and relates to the technical field of wastewater treatment. The invention comprises a raw material tank, a liquid outlet pipe is installed at the bottom of the raw material tank, a separation tank is installed on one side of the liquid outlet pipe, a volume adjustment mechanism is arranged between the liquid outlet pipe and the separation tank, a liquid guide pipe is installed on one side of the separation tank, a heating tank is installed on one side of the liquid guide pipe, a heater is installed on one side of the bottom of the heating tank, a liquid separator is installed on the side of the heating tank away from the heater, a three-way valve is installed on the liquid separator, an air outlet pipe is installed on one side of the bottom of the heating tank, and a return air pipe is installed between the heating tank and the separation tank. The invention maintains the solution capacity in the separation tank in a stable state by installing a volume adjustment mechanism between the separation tank and the liquid outlet pipe, which is convenient for controlling the heating time and the internal and external temperature difference after heating, reducing the heat loss time and avoiding the heat dissipation phenomenon caused by the temperature difference.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a triple-effect wastewater evaporator for evaporating benzoic acid wastewater. Background Art

[0002] The goal of benzoic acid wastewater treatment is to remove or reduce harmful substances such as benzoic acid to the standard to reduce its threat to the environment and human health. During the treatment process, sodium chloride mixed with benzoic acid can be concentrated through multi-effect evaporation. When the triple-effect evaporator is in use, the solution is heated to boiling through heat exchange, and the vaporized solvent is discharged to increase the concentration of the solution. The new steam generated after the steam is heated to the first effect is used as the heat source for the second effect. After the second effect is heated to boiling, the steam generated is used as the heat source for the third effect. The water in the vaporized wastewater is separated through hierarchical heating to achieve the purpose of separating benzoic acid.

[0003] The patent specification with publication number CN113198194B discloses an energy-saving and environmentally friendly triple-effect evaporator, which includes a first evaporation tower, a second evaporation tower and a third evaporation tower connected in series through a mixing cylinder, wherein the first evaporation tower, the second evaporation tower and the third evaporation tower all include a tower body, the outside of the tower body is covered with an external heating chamber composed of a spirally wound tube body, and the outside of the external heating chamber is covered with a thermal insulation material; the top and bottom of the external heating chamber are respectively connected to an upper ventilation chamber and a lower ventilation chamber; the upper ventilation chamber and the lower ventilation chamber are respectively connected to the spirally wound tube body through pipelines; the upper ventilation chamber and the lower ventilation chamber are connected through an internal heating tube body.

[0004] When a multi-stage evaporator is in use, a large amount of heat will be dissipated during the transmission due to the need for multi-stage transmission. This technical solution improves the structure of the mixing drum, the steam connection method between each tower body, and the steam heating structure in the tower body by setting the structural form of a mixing drum, so as to improve the evaporation effect of each tower body and achieve energy saving. The disadvantage of this technical solution is that the heat loss is related to the temperature difference between the inside and outside of the evaporator separation tank and the circulation time. The greater the temperature difference or the longer the separation time, the faster the loss. Under the same heating source, if the capacity in the separation tank is too high, the heating cycle of the solution is longer, and the long separation time leads to increased heat loss. If the capacity in the separation tank is too small, the steam volume is small and the temperature rises too fast. The large temperature difference between the inside and outside leads to heat loss. This solution changes the steam circulation method through the structure, but cannot solve the problem of energy loss due to temperature difference and time consumption. Summary of the invention

[0005] The purpose of the present invention is to provide a triple-effect wastewater evaporator for evaporating benzoic acid wastewater. The technical problems to be solved are as follows: the existing triple-effect wastewater evaporator cannot control the amount of solution in the separation tank during use, resulting in a low thermal energy utilization rate.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A triple-effect wastewater evaporator for evaporating benzoic acid wastewater comprises a raw material tank, a liquid outlet pipe is installed at the bottom of the raw material tank, a separation tank is installed on one side of the liquid outlet pipe, a volume regulating mechanism is arranged between the liquid outlet pipe and the separation tank, and the volume regulating mechanism is used to control the solution content in the separation tank; a liquid guide pipe is installed at one side of the separation tank, a heating tank is installed at one side of the liquid guide pipe, a heater is installed at one side of the bottom of the heating tank, a liquid separator is installed at the side of the heating tank away from the heater, a three-way valve is installed on the liquid separator, an air outlet pipe is installed at one side of the bottom of the heating tank, a return air pipe is installed between the heating tank and the separation tank, and the return air pipe is used to accelerate the vaporization of the solution.

[0008] As a further solution of the present invention: the regulating mechanism includes a liquid level meter installed on the top of the separation tank, a flow control valve is installed in the middle of the liquid outlet pipe, and the liquid level meter is electrically connected to the flow control valve.

[0009] As a further solution of the present invention: the liquid level meter includes a liquid level sensing rod extending to the bottom of the interior of the heating tank, and a liquid level controller is installed on the top of the liquid level sensing rod.

[0010] As a further solution of the present invention: the flow control valve includes a motor, the motor is electrically connected to the liquid level controller, a driving gear is installed at the output end of the bottom surface of the motor, a driven gear is installed on one side of the driving gear, a lifting screw is fixedly connected to the middle of the driven gear, the lifting screw is threadedly connected to the flow control valve stem, the bottom of the flow control valve stem is conical, and a flow control port is arranged at the bottom.

[0011] As a further solution of the present invention: the liquid guide tube is arranged on one side of the bottom of the separation tank, and a liquid inlet chamber and a liquid outlet chamber are respectively arranged on both sides of the bottom of the heating tank, a partition is arranged between the liquid inlet chamber and the liquid outlet chamber, an air blocking plate is arranged on the top of the partition, and multiple heating tubes are evenly installed on the top of the air blocking plate, and multiple spoilers are alternately arranged above the air blocking plate inside the heating tank.

[0012] As a further solution of the present invention: the heater is installed on one side of the liquid inlet chamber, the return air pipe is installed between the top of the separation tank and the top of the heating tank, and the outlet pipe is installed above the air baffle and located below the spoiler at the bottom.

[0013] As a further solution of the present invention: the liquid separation tube includes a main pipe connected to the liquid outlet cavity, the three-way valve is installed on one side of the main pipe, a reflux pipe is installed between one side of the three-way valve and the top of the separation tank, and a pipette is installed on the side away from the heating tank.

[0014] As a further solution of the present invention: a nozzle is provided at one end of the reflux pipe inside the heating tank.

[0015] Beneficial effects of the present invention:

[0016] 1. The present invention measures the amount of solution in the separation tank through a liquid level controller by setting a volume adjustment mechanism, and controls the motor of the flow control valve through the liquid level controller. The motor adjusts the flow rate of the flow control valve stem to the flow control port by forward and reverse rotation, thereby controlling the flow rate of the liquid inlet to the separation tank through the liquid outlet pipe, and completing the stable control of the amount of solution in the separation tank. Therefore, when the heating efficiency of the heater is determined, the total amount of the solution to be heated can be maintained in a dynamic constant state, and the heating temperature can be controlled, thereby avoiding the heat energy loss caused by the excessive temperature difference between the inside and the outside, and improving the energy utilization rate;

[0017] Furthermore, since the volume of the solution in the heating tank is controlled to a relatively small amount that does not affect the temperature difference between the inside and outside, the single circulation time of the solution in the separation tank and the heating tank is shortened, and the number of required cycles is also reduced, so that the predetermined multi-effect transmission temperature value is reached faster, thereby accelerating the overall speed of the multi-effect transmission. The increase in the solution transmission speed leads to a shortened energy consumption time, thereby further improving energy utilization efficiency;

[0018] 2. The present invention provides a nozzle, an air return pipe and a plurality of spoilers. When the heated solution is refluxed into the heating tank to generate steam, the heat exchange area between the solution and the top space in the heating tank is increased by the nozzle, thereby accelerating the steam generation efficiency. The steam is refluxed into the heating tank by means of the air return pipe, and the solution is uniformly heated by means of the spoilers that are continuously and alternately installed in a folded direction, thereby improving the heating efficiency of the solution, reducing the heating time of the solution, improving the processing efficiency and avoiding energy loss caused by multiple long-term heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a side structural schematic diagram of the present invention;

[0022] Figure 3 is a partial cross-sectional view of the flow control mechanism of the present invention;

[0023] Figure 4 is a half-section view of the heat exchanger and separator of the present invention;

[0024] Figure 5 The present invention Figure 4 A magnified detail of the center point A;

[0025] Figure 6 The present invention Figure 4 Enlarged detail of point B in the middle.

[0026] In the figure: 1. raw material tank; 2. liquid outlet pipe; 3. separation tank; 4. adjusting mechanism; 41. liquid level meter; 411. liquid level sensing rod; 412. liquid level controller; 42. flow control valve; 421. motor; 422. driving gear; 423. driven gear; 424. lifting screw; 425. flow control valve rod; 426. flow control port; 5. liquid guide tube; 6. heating tank; 61. liquid inlet chamber; 62. liquid outlet chamber; 63. partition; 64. air blocking plate; 65. heating tube; 66. spoiler; 7. heater; 8. liquid dispensing tube; 81. main pipe; 82. reflux pipe; 83. pipette; 9. three-way valve; 10. air outlet pipe; 11. air return pipe; 12. nozzle. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figures 1 to 6 As shown, a triple-effect wastewater evaporator for evaporating benzoic acid wastewater comprises a raw material tank 1, a feed port is arranged on one side of the top of the raw material tank 1 for adding benzoic acid wastewater, a liquid outlet pipe 2 is arranged on the bottom of the raw material tank 1, a separation tank 3 is arranged on the side of the liquid outlet pipe 2 away from the raw material tank 1, a volume regulating mechanism 4 is arranged between the liquid outlet pipe 2 and the separation tank 3, the volume regulating mechanism 4 is used to control the solution content in the separation tank 3, a liquid guide pipe 5 is arranged on one side of the bottom of the separation tank 3, a heating tank 6 is arranged on one side of the liquid guide pipe 5, a heater 7 is arranged on one side of the bottom of the heating tank 6, a liquid separator 8 is arranged on the side of the heating tank 6 away from the heater 7, a three-way valve 9 is arranged on the liquid separator 8, an air outlet pipe 10 is arranged on one side of the bottom of the heating tank 6, a return air pipe 11 is arranged between the heating tank 6 and the separation tank 3, and the return air pipe 11 is used to accelerate the vaporization of the solution;

[0029] It should be noted that liquid pumps (not shown) are installed at the liquid outlet pipe 2, the liquid guide pipe 5 and the liquid distribution pipe 8 to provide power for solution transportation; this structure is the first effect of the three-effect evaporator. Except for the difference in the initial device for providing the solution, the remaining structures and functions of the other two effects are the same, so only the first effect is demonstrated.

[0030] like Figure 1 , Figure 3 , Figure 4 and Figure 6As shown, after the solution enters the raw material tank 1, it is transported to the top position of the separation tank 3 through the liquid outlet pipe 2. The regulating mechanism 4 includes a liquid level gauge 41 installed at the top of the separation tank 3, a flow control valve 42 is installed in the middle of the liquid outlet pipe 2, and the liquid level gauge 41 is electrically connected to the flow control valve 42. The liquid level gauge 41 includes a liquid level sensing rod 411 at the bottom, and a liquid level controller 412 is installed on the top of the liquid level sensing rod 411. The flow control valve 42 includes a motor 421 at the top, and the motor 421 is electrically connected to the liquid level controller 412. A driving gear 422 is installed at the output end of the bottom of the motor 421, and a driven gear 423 is installed on one side of the driving gear 422. A lifting screw 424 is fixedly connected to the middle of the driven gear 423, and the lifting screw 424 is threadedly connected to a flow control valve stem 425. The bottom of the flow control valve stem 425 is conical, and a flow control port 426 is arranged at the bottom.

[0031] It should be noted that the flow control port 426 is arranged on the path of the liquid outlet pipe 2 through which the solution circulates. After the solution enters the separation tank 3, the liquid level sensing rod 411 is submerged by the solution. Since the hydraulic pressure on the bottom of the liquid level sensing rod 411 is different at different depths of the solution, the depth of the solution in the separation tank 3 can be measured by the liquid level controller 412 at the top through the submerged depth. When the solution content is relatively high, the liquid level controller 412 controls the motor 421 to rotate, the motor 421 drives the driving gear 422 to rotate, the driving gear 422 drives the driven gear 423 to rotate, the driven gear 423 drives the lifting screw 424 to press down, and the conical surface at the bottom of the flow control valve stem 425 partially blocks the flow control port 426 to reduce the speed at which the solution enters the separation tank 3. When the solution content is relatively low, the motor 421 is rotated in the opposite direction to increase the speed at which the solution enters. Since the liquid outlet speed of the three-way valve 9 entering the next effect is substantially constant, accurate control of the solution content in the separation tank 3 is achieved.

[0032] like Figure 2 , Figures 4 to 6 As shown, the liquid guide tube 5 is arranged on one side of the bottom of the separation tank 3, and a liquid inlet chamber 61 and a liquid outlet chamber 62 are respectively arranged on both sides of the bottom of the heating tank 6, a partition 63 is arranged between the liquid inlet chamber 61 and the liquid outlet chamber 62, and an air blocking plate 64 is arranged on the top of the partition 63. A large number of U-shaped heating tubes 65 are evenly installed on both sides of the top of the blocking plate 64 to adapt to the liquid inlet chamber 61 and the liquid outlet chamber 62, and the heater 7 is installed on one side of the liquid inlet chamber 61. A plurality of spoilers 66 are alternately arranged vertically in an S shape above the air blocking plate 64 inside the heating tank 6, and the return air pipe 11 is installed between the top of the separation tank 3 and the top of the heating tank 6, and the outlet pipe 10 is installed above the air blocking plate 64 and is located below the bottom spoiler 66;

[0033] The liquid dispensing pipe 8 includes a main pipe 81 connected to the liquid outlet chamber 62, a three-way valve 9 is installed on one side of the main pipe 81, a reflux pipe 82 is installed between one side of the three-way valve 9 and the top of the separation tank 3, a nozzle 12 is arranged at the reflux pipe 82 inside the heating tank 6, which is used to increase the heat interaction area of ​​the heated solution and improve the steam generation rate, and a pipette 83 is installed on the side away from the heating tank 6;

[0034] It should be noted that when the solution enters the heating tank 6 from the separation tank 3, it first enters the liquid inlet chamber 61, is then heated by the heater 7, and then rises and then falls through one side of the heating pipe 65, falls back to the liquid outlet chamber 62 and flows into the liquid separation pipe 8. The three-way valve 9 installed at the liquid separation pipe 8 opens the valves of the main pipe 81 and the reflux pipe 82, and the heated solution is sprayed into the heating tank 6 through the nozzle 12. When it falls from the top of the heating tank 6 to the bottom of the tank, a large amount of steam will be generated due to the large heat exchange area and the fact that it has been heated. At the same time, the solution enters the liquid inlet chamber 61 again through the liquid guide pipe 5. The steam is heated again, and the heating action is repeated. The temperature of the steam in the upper part of the heating tank 6 gradually increases, and the content increases. The generated steam enters the heating tank 6 through the return pipe 11. With the help of the continuous alternating bending of the spoiler 66, the solution in the heating pipe 65 is evenly heated, thereby improving the heating effect of the solution and accelerating the vaporization speed of the solution in the separation tank 3. After heating, it is transferred to the next effect through the outlet pipe 10. After multiple cycles of separation, the three-way valve 9 closes the return pipe 82 and connects the pipette 83 to transfer the heated solution to the next effect, and cooperates with the steam to perform multi-effect evaporation.

[0035] Furthermore, since the regulating mechanism 4 can control the amount of solution in the heating tank 6, the control capacity is about 25% to 40%. Preferably, the amount of solution in the heating tank 6 is controlled to be 30% of the capacity. Specifically, when the solution content is higher than this, the heating cycle for heating the solution to a temperature required to enter the next effect becomes longer. The long-term heating causes the solution to circulate multiple times between the separation tank 3 and the heating tank 6. A large amount of heat loss will occur in the excessive circulation pipeline part. When the solution content is too low, the heating of the heater 7 causes the solution to heat up too quickly, which will cause the temperature difference between the circulating solution and the external environment to increase. The high temperature difference causes the heat loss rate to accelerate. When its capacity is always maintained at 30%, the heating cycle is shorter, and the temperature difference between the heated solution and the external environment is also small, thereby avoiding heat energy loss and improving energy utilization efficiency.

[0036] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A triple-effect wastewater evaporator for evaporating benzoic acid wastewater, comprising a raw material tank (1), a liquid outlet pipe (2) is installed at the bottom of the raw material tank (1), and a separation tank (3) is installed on one side of the liquid outlet pipe (2), characterized in that: A volume regulating mechanism (4) is provided between the liquid outlet pipe (2) and the separation tank (3), and the volume regulating mechanism (4) is used to control the solution content in the separation tank (3), and the controlled volume is 25% to 40% of the total volume of the separation tank (3); a liquid guide pipe (5) is installed on one side of the separation tank (3), a heating tank (6) is installed on one side of the liquid guide pipe (5), a heater (7) is installed on one side of the bottom of the heating tank (6), a liquid separation pipe (8) is installed on the side of the heating tank (6) away from the heater (7), a three-way valve (9) is installed on the liquid separation pipe (8), an air outlet pipe (10) is installed on one side of the bottom of the heating tank (6), and an air return pipe (11) is installed between the heating tank (6) and the separation tank (3), and the air return pipe (11) is used to accelerate the vaporization of the solution; The regulating mechanism (4) comprises a liquid level meter (41) installed at the top of the separation tank (3), a flow control valve (42) is installed in the middle of the liquid outlet pipe (2), and the liquid level meter (41) is electrically connected to the flow control valve (42); The liquid level meter (41) comprises a liquid level sensing rod (411) extending to the bottom of the interior of the heating tank (6), and a liquid level controller (412) is installed on the top of the liquid level sensing rod (411); The flow control valve (42) comprises a motor (421), the motor (421) being electrically connected to the liquid level controller (412), a driving gear (422) being installed at the output end of the bottom surface of the motor (421), a driven gear (423) being installed at one side of the driving gear (422), a lifting screw (424) being fixedly connected to the middle of the driven gear (423), the lifting screw (424) being threadedly connected to a flow control valve stem (425), the bottom of the flow control valve stem (425) being conical, and a flow control port (426) being arranged at the bottom; The liquid guide tube (5) is arranged at one side of the bottom of the separation tank (3); a liquid inlet cavity (61) and a liquid outlet cavity (62) are respectively arranged on both sides of the bottom of the heating tank (6); a partition plate (63) is arranged between the liquid inlet cavity (61) and the liquid outlet cavity (62); an air blocking plate (64) is arranged at the top of the partition plate (63); a plurality of heating tubes (65) are evenly installed at the top of the air blocking plate (64); and a plurality of spoiler plates (66) are alternately arranged above the air blocking plate (64) inside the heating tank (6); The heater (7) is installed on one side of the liquid inlet chamber (61), the air return pipe (11) is installed between the top of the separation tank (3) and the top of the heating tank (6), and the air outlet pipe (10) is installed above the air blocking plate (64) and is located below the spoiler (66) at the bottom.

2. A triple-effect wastewater evaporator for evaporating benzoic acid wastewater according to claim 1, characterized in that: The liquid dispensing pipe (8) comprises a main pipe (81) connected to the liquid outlet chamber (62), the three-way valve (9) is installed on one side of the main pipe (81), a reflux pipe (82) is installed between one side of the three-way valve (9) and the top of the separation tank (3), and a pipette (83) is installed on the side away from the heating tank (6).

3. A triple-effect wastewater evaporator for evaporating benzoic acid wastewater according to claim 2, characterized in that: The reflux pipe (82) is provided with a nozzle (12) at one end inside the heating tank (6).

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