Liquid level control device for desulfurization wastewater negative pressure evaporation equipment

Abstract

The utility model discloses a liquid level control device for desulfurization wastewater negative pressure evaporation equipment, which is characterized in that the upper part of the negative pressure evaporation equipment is provided with an overflow port, the overflow port is connected with a negative pressure overflow pipe, the negative pressure overflow pipe is provided with an isolating valve and a vacuum breaking valve, the isolating valve is close to the overflow port, and the vacuum breaking valve is far away from the overflow port; a vacuum meter is arranged on the negative pressure overflow pipe at the front end of the vacuum breaking valve; and the isolating valve, the vacuum breaking valve and the vacuum meter are all connected with a controller. The negative pressure overflow pipe and the negative pressure evaporation equipment are located in the same negative pressure environment, when the liquid level in the negative pressure evaporation equipment exceeds the overflow port, liquid overflows into the negative pressure overflow pipe, the vacuum meter detects that the pressure in the negative pressure overflow pipe exceeds a preset value, the vacuum breaking valve is opened, the overflow liquid is discharged, part of air enters the negative pressure overflow pipe, and the negative pressure state in the equipment is destroyed. The liquid level is prevented from rising; when the pressure value in the negative pressure overflow pipe is smaller than the preset value, the vacuum breaking valve is closed, the vacuum degree in the equipment is adjusted through opening and closing of the vacuum breaking valve, and the stable liquid level is recovered.

Description

Technical Field

[0001] The utility model belongs to the technical field of industrial wastewater zero-discharge treatment, and particularly relates to a liquid level control device for a desulfurization wastewater negative-pressure evaporation device. Background Technique

[0002] In the evaporation concentration and drying treatment systems of high-concentration polluted wastewater such as industrial wastewater and desulfurization wastewater, a negative-pressure multi-effect evaporation system is mostly used for concentration. During the operation of the system, the liquid level in the evaporation separator of the system needs to be strictly controlled and cannot be too high, otherwise scale will be formed on the demister at the upper part of the evaporation separator and the condensed water formed by the polluted secondary steam will be contaminated.

[0003] Due to the negative-pressure operation of the evaporation separator, an overflow port under normal pressure cannot be set and gravity overflow is impossible. When the liquid level suddenly rises abnormally, the demister will be submerged and even overflow into the next-stage heat exchanger, causing spread pollution and damage to the entire system. Once this phenomenon occurs, only shutdown and cleaning and maintenance can be carried out, seriously affecting normal production. At present, there is no particularly good liquid level control device.

[0004] In addition, due to the existence of evaporation and condensation phenomena, and the wastewater being highly concentrated and in a supersaturated state, the microwave transmitting and receiving surfaces of ultrasonic liquid level gauges and radar liquid level gauges are interfered by condensed water. The static pressure liquid level gauge cannot reflect the true liquid level under negative pressure. The visible interfaces of sight glasses and glass tube liquid level gauges are easily covered by pollutants, and the gamma radio frequency liquid level gauge is too expensive. Therefore, a magnetic flap liquid level gauge is generally set to measure the liquid level in the evaporation separator. However, the liquid inside the evaporation separator is desulfurization wastewater being concentrated, which has the characteristics of high viscosity, crystallization, and high scale formation tendency. General liquid level measurement methods are unstable due to the existence of negative pressure or vacuum. Moreover, when the liquid contacts the measuring component (such as a float) and the liquid is in the measuring device cavity, the liquid is in a "dead water" state with very little flow amplitude, and phenomena such as liquid salt crystallization, scale formation, flow channel blockage, and adhesion between the measuring component and the cavity will occur, thus unable to accurately measure the liquid level in the evaporation separator, resulting in consequences such as faults in the evaporation system. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the utility model provides a liquid level control device that can be matched with actual application conditions, achieving precise and reliable control of the liquid level in the evaporation separator of a multi-effect evaporation system under negative pressure, reducing the monitoring operation labor intensity of monitoring personnel, and enabling the equipment to safely and timely adjust the operation state during continuous operation.

[0006] The purpose of the utility model is achieved in the following way: a liquid level control device for a negative pressure evaporation device for desulfurization wastewater, an overflow port is arranged on the upper part of the negative pressure evaporation device, the overflow port is connected to a negative pressure overflow pipe, an isolation valve and a rupture valve are arranged on the negative pressure overflow pipe, the isolation valve is close to the overflow port, the rupture valve is far away from the overflow port, the isolation valve remains in a normally open state, a vacuum gauge is arranged on the negative pressure overflow pipe at the front end of the rupture valve, and the isolation valve, the rupture valve and the vacuum gauge are all connected to a controller.

[0007] The diameter of the negative pressure overflow pipe is larger than the diameter of the liquid inlet pipe of the negative pressure evaporation equipment.

[0008] A liquid level measuring device is also provided on the negative pressure evaporation equipment, and the liquid level measuring device includes a float, a pulley, a connecting rope, a float cavity, a magnetic float, an upper connecting pipe, and a lower connecting pipe. The upper connecting pipe on the upper part of the float cavity is connected to the upper interface of the negative pressure evaporation equipment, and the lower connecting pipe on the lower part is connected to the lower interface of the negative pressure evaporation equipment but is not connected. A first pulley is provided on the inner wall of the upper interface of the negative pressure evaporation equipment, and a second pulley is provided at the connection between the upper connecting pipe and the float cavity. The connecting rope passes around the first pulley and the second pulley, one end of which is connected to the magnetic float, and the other end is connected to the float. The float is located in the negative pressure evaporation equipment and floats on the liquid surface. A liquid level display panel and a signal remote transmission device are fixedly provided on the outer surface of the float cavity.

[0009] The upper and lower ends of the float cavity are provided with detachable sealing structures.

[0010] The sealing structure at the upper end of the float cavity is a flange cover or a threaded cover, and the sealing structure at the lower end of the float cavity is a flange cover or a threaded cover or a valve.

[0011] Compared with the prior art, the utility model adds an overflow port to the negative pressure evaporation equipment, and the overflow port is connected to the negative pressure overflow pipe, and the abnormally high liquid level overflows and discharges. The negative pressure overflow pipe and the negative pressure evaporation equipment are in the same negative pressure environment. When the vacuum of the negative pressure evaporation equipment changes suddenly, the liquid level fluctuates and exceeds the overflow port, and the liquid overflows into the negative pressure overflow pipe. As the liquid level in the negative pressure overflow pipe rises, the vacuum gauge detects the pressure in the negative pressure overflow pipe in real time. When the pressure exceeds the preset value, the air-breaking valve opens, the overflowing liquid is discharged, and part of the air enters the negative pressure overflow pipe, destroying the negative pressure state in the equipment and preventing the liquid level from rising. When the pressure value in the negative pressure overflow pipe measured by the vacuum gauge is less than the preset value, the air-breaking valve closes, and the vacuum degree in the equipment is adjusted and the stable liquid level is restored by opening and closing the air-breaking valve, so as to avoid the liquid level being immersed in the defogger and causing damage to the equipment, and quickly restore the equipment to normal operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0013] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention, and are not used to limit the scope of the present invention. After reading the contents of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the present invention.

[0014] like Figure 1 As shown, a liquid level control device for a negative pressure evaporation device for desulfurization wastewater is provided, an overflow port is provided on the upper part of a negative pressure evaporation device 1 with a demister 7 on the top, the overflow port is connected to a negative pressure overflow pipe 2, an isolation valve 3 and a rupture valve 4 are provided on the negative pressure overflow pipe 2, the isolation valve 3 is close to the overflow port, the rupture valve 4 is far away from the overflow port, the isolation valve 3 is kept in a normally open state, a vacuum gauge 5 is provided on the negative pressure overflow pipe at the front end of the rupture valve 4, and the isolation valve 3, the rupture valve 4 and the vacuum gauge 5 are all connected to a controller.

[0015] A liquid level control method for a negative pressure evaporation device for desulfurization wastewater, wherein the isolation valve 3 on the negative pressure overflow pipe 2 is kept open when the device is working. When the vacuum in the negative pressure evaporation device 1 changes suddenly, the internal liquid level fluctuates and exceeds the overflow port height of the negative pressure evaporation device. The liquid in the negative pressure evaporation device 1 flows from the overflow port into the negative pressure overflow pipe 2. As the liquid level in the negative pressure overflow pipe increases, the vacuum gauge 5 detects the pressure in the negative pressure overflow pipe in real time and transmits the pressure signal to the controller. When the pressure exceeds a preset value, the controller controls the air-breaking valve 4 to open, the overflow liquid is discharged, and part of the air enters the negative pressure overflow pipe, thereby destroying the negative pressure state in the device and preventing the liquid level from rising. When the pressure value in the negative pressure overflow pipe measured by the vacuum gauge is less than the preset value, the air-breaking valve 4 is closed, thereby realizing safe liquid level control of the negative pressure evaporation device for desulfurization wastewater and effectively preventing the liquid level from being submerged in the demister 7 and causing damage to the equipment.

[0016] Furthermore, the diameter of the negative pressure overflow pipe 2 is larger than the diameter of the liquid inlet pipe of the negative pressure evaporation device 1 , ensuring that when overflow occurs, the overflow capacity of the overflow pipe is greater than the liquid inlet volume of the negative pressure evaporation device 1 .

[0017] Furthermore, a liquid level measuring device 6 is also provided on the negative pressure evaporation device 1. The liquid level measuring device 6 includes a float 61, a pulley 62, a connecting rope 63, a float chamber 64, a magnetic float 65, an upper connection pipe 66 and a lower connection pipe 67. The upper connection pipe 66 at the upper part of the float chamber 64 is communicated with the upper part of the negative pressure evaporation device 1, and the lower connection pipe 67 at the lower part is connected but not communicated with the negative pressure evaporation device 1. A first pulley 621 is arranged on the inner wall of the upper interface of the negative pressure evaporation device 1, and a second pulley 622 is arranged at the connection part of the upper connection pipe 66 and the float chamber 64. The connecting rope 63 bypasses the first pulley 621 and the second pulley 622, one end is connected to the magnetic float 65, and the other end is connected to the float 61. The float 61 is located in the negative pressure evaporation device 1 and floats on the liquid surface. A liquid level display panel 68 and a signal remote transmission device 69 are fixedly arranged on the outer surface of the float chamber 64. As the liquid level rises, the magnetic float 65 continuously descends in the float chamber 64, and the liquid level situation in the negative pressure evaporation device is displayed in real time on the liquid level display panel 68. The magnetic float 65, the float chamber 64, etc. are not in contact with the liquid in the negative pressure evaporation device. Only the float 61 is in contact with the measured liquid, effectively preventing phenomena such as liquid salt crystallization, scaling, flow channel blockage, and measurement component adhesion, and there will be no false signals, and it can truly reflect the real liquid level in the negative pressure evaporation device.

[0018] The liquid level display panel 6 is for local display, including a panel with display scales and magnetic turning plates or magnetic turning columns corresponding to the scales; the two sides of the magnetic turning plates or magnetic turning columns are of obviously different colors. The movement of the magnetic float drives the magnetic turning plates or magnetic turning columns on the display panel to perform turning actions, and the color turning is used for local display of different liquid levels and corresponding to the scales on the liquid level display panel; the magnetic float drives the magnetic turning plates or magnetic turning columns to turn through up and down movement, and the magnetic turning plates or magnetic turning columns are connected to the signal remote transmission device to convert and form an electric signal and transmit it to a remote display, etc.

[0019] Detachable sealing structures are provided at the upper and lower ends of the float chamber 64. In a preferred solution, the sealing structure at the upper end of the float chamber 64 is a flange cover or a threaded cover or other forms, and the sealing structure at the lower end of the float chamber 64 is a flange cover or a threaded cover or a valve, so that condensate water can be discharged in time when the device is not operating for the liquid level measuring device 6.

[0020] Furthermore, the liquid level measuring device 6 is connected to a controller and interlocked with the air breaking valve 4. When the liquid level returns to the set normal value, the air breaking valve 4 is closed.

[0021] After the air-breaking valve 4 is closed, the interlocking relationship can be temporarily released, such as closing the isolation valve 3 manually or automatically, opening the air-breaking valve 4, and flushing the inner wall of the vacuum overflow pipe below the isolation valve 4, the vacuum gauge 5, and the air-breaking valve 4 with clean water to prevent highly concentrated liquid from remaining on the inner wall of the pipeline, the inner wall of the valve, and the liquid surface of the vacuum gauge, causing salt crystallization, vacuum gauge failure, air-breaking valve switch failure, etc. After cleaning, close the air-breaking valve, open the isolation valve, and restore the interlocking function.

[0022] The liquid level measuring device 6 is assembled according to the following steps:

[0023] 1) Place the float 61 on the solution to be tested and mark the position where the liquid surface is immersed;

[0024] 2) Open the sealing structure at the upper end of the float cavity 64 and install and fix the second pulley 622 at the connection between the upper pipe 66 and the float cavity 64;

[0025] 3) The first pulley 621 is mounted and fixed on the inner wall of the upper pipe 66 of the negative pressure evaporation device 1;

[0026] 4) Fix the liquid level display plate 68 and the signal remote transmission device 69 to the outer surface of the float chamber 64, and the reading of the liquid level display plate 68 gradually increases from high to low and from zero;

[0027] 5) Connect the upper pipe 66 on the upper part of the float chamber 64 to the upper interface of the negative pressure evaporation device 1, and a flange with a hole in the middle can be used to connect them;

[0028] 6) Connect the lower connecting pipe 67 at the bottom of the float chamber 64 to the lower interface of the negative pressure evaporation device 1, and use a flange with no hole in the middle to make it blocked;

[0029] 7) Fix one end of the connecting rope 63 to the magnetic float 65 and put it into the float cavity 64. The other end of the connecting rope 63 passes over the first pulley 621 and the second pulley 622 and is temporarily fixed to the buoy 61.

[0030] 8) Adjust the length of the connecting rope 63 between the magnetic float 65 and the buoy 61 so that the reading displayed on the liquid level display plate 68 matches the height of the mark on the immersion position of the buoy liquid surface, cut the connecting rope 63 to a suitable length and fix it to the buoy 61;

[0031] 9) Finally, reseal the sealing structure at the upper end of the float chamber 64.

[0032] The liquid level measuring device 6 can also be transformed from a magnetic flap (column) liquid level gauge, and the modification only needs to be carried out according to the following steps:

[0033] 1) Place the float on the solution to be tested and mark the position where the liquid surface is immersed;

[0034] 2) Open the sealing structure at the upper end of the float chamber of the magnetic turnover (column) liquid level gauge and take out the magnetic float;

[0035] 3) Fix the first pulley and the second pulley respectively on the inner wall of the upper interface of the negative pressure evaporation equipment and the connection part between the float chamber and the upper connecting pipe;

[0036] 4) Invert the liquid level display disk of the magnetic turnover (column) liquid level gauge, and the readings of the liquid level display disk increase gradually from high to low starting from zero;

[0037] 5) Connect the upper connecting pipe at the upper part of the float chamber with the upper interface of the negative pressure evaporation equipment. If there is a valve originally, cancel the valve;

[0038] 6) Add a partition board and connect it between the lower connecting pipe at the lower part of the float chamber and the lower interface of the negative pressure evaporation equipment. If there is a valve originally, cancel the valve;

[0039] 7) Fix one end of the connecting rope to the magnetic float, put it into the float chamber, let the other end of the connecting rope cross the first pulley and the second pulley, and temporarily fix it to the float;

[0040] 8) Adjust the length of the connecting rope between the magnetic float and the float, so that the reading shown on the liquid level display disk is consistent with the marked height of the immersion position of the liquid level of the float, cut the connecting rope to an appropriate length and fix it to the float;

[0041] 9) Re-seal the sealing structure at the upper end of the float chamber.

[0042] The above are only the preferred embodiments of the present utility model. It should be pointed out that for those skilled in the art, without departing from the overall concept of the present utility model, several changes and improvements can still be made, and these should also be regarded as the protection scope of the present utility model.

Claims

1. A liquid level control device for a negative pressure evaporation device of desulfurized wastewater, characterized in that: An overflow port is arranged at the top of the negative pressure evaporation device (1), and the overflow port is connected to a negative pressure overflow pipe (2). An isolation valve (3) and a piercing valve (4) are arranged on the negative pressure overflow pipe (2). The isolation valve (3) is close to the overflow port, and the piercing valve (4) is far from the overflow port. The isolation valve (3) is kept in a normally open state. A vacuum gauge (5) is arranged on the negative pressure overflow pipe at the front end of the piercing valve (4). The isolation valve (3), the piercing valve (4), and the vacuum gauge (5) are all connected to a controller.

2. The liquid level control device for the negative pressure evaporation equipment of desulfurized wastewater according to claim 1, wherein: The diameter of the negative pressure overflow pipe (2) is larger than the diameter of the liquid inlet pipe of the negative pressure evaporation device (1).

3. The liquid level control device for the negative pressure evaporation equipment of desulfurized wastewater according to claim 1, wherein: The negative pressure evaporation device (1) is also provided with a liquid level measuring device (6), the liquid level measuring device (6) comprising a float (61), a pulley (62), a connecting rope (63), a float cavity (64), a magnetic float (65), an upper connecting pipe (66), and a lower connecting pipe (67). The upper connecting pipe (66) at the upper part of the float cavity (64) is connected to the upper interface of the negative pressure evaporation device (1), and the lower connecting pipe (67) at the lower part is connected to the lower interface of the negative pressure evaporation device (1) but is not connected. The negative pressure evaporation device (1) A first pulley (621) is arranged on the inner wall of the upper interface, a second pulley (622) is arranged at the connection between the upper pipe (66) and the float cavity (64), a connecting rope (63) passes around the first pulley (621) and the second pulley (622), one end of which is connected to the magnetic float (65) and the other end of which is connected to the float (61), the float (61) is located in the negative pressure evaporation device (1) and floats on the surface of the liquid, and a liquid level display panel (68) and a signal remote transmission device (69) are fixedly arranged on the outer surface of the float cavity (64).

4. The liquid level control device for the negative pressure evaporation equipment of desulfurized wastewater according to claim 1, characterized in that: The upper and lower ends of the float cavity (64) are provided with detachable sealing structures.

5. The liquid level control device for the negative pressure evaporation equipment of desulfurized wastewater according to claim 4, characterized in that: The sealing structure at the upper end of the float cavity (64) is a flange cover or a threaded cover, and the sealing structure at the lower end of the float cavity (64) is a flange cover or a threaded cover or a valve.

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