Gypsum crystal precipitation sludge neutralization and solid-liquid separation device

Abstract

The utility model discloses a gypsum crystallization precipitation sludge neutralization and solid-liquid separation device, which comprises a neutralization tank, a sludge pump and a solid-liquid separation tank, the outer part of the neutralization tank is connected with the solid-liquid separation tank, the inner wall of one side of the neutralization tank is connected with a gypsum crystallization precipitation sludge pipe, and the inner wall of the other side of the neutralization tank is connected with a nanofiltration concentrated solution pipe. A stirrer is installed in the middle of the neutralization tank, a sludge pump is installed outside the neutralization tank, the feeding end of the sludge pump is connected with the bottom end of the neutralization tank, the discharging end of the sludge pump is fixedly connected with a connecting pipe, a central vertical flow pipe is installed in the solid-liquid separation tank, and the end of the connecting pipe is connected with the top of the central vertical flow pipe. The device has the beneficial effects that the landfill leachate nanofiltration concentrated solution is used as a neutralizer for crystallizing and precipitating sludge by acid gypsum, so that the effective alkalinity of the landfill leachate nanofiltration concentrated solution is fully utilized, acid-base neutralization is achieved, the cost of additional alkaline agents is avoided, inorganic salt is not introduced, and the increase of the power consumption of membrane separation is avoided.

Description

Technical Field

[0001] The utility model relates to the field of garbage leachate treatment, in particular to a gypsum crystal precipitation sludge neutralization and solid-liquid separation device. Background Art

[0002] In the field of landfill leachate treatment, the MBR+NF combined process has become the mainstream treatment technology, but it will produce nanofiltration concentrate that accounts for about 15-20% of the volume of the original leachate. At present, the resource treatment process of nanofiltration concentrate with material separation membrane as the main body and gypsum crystallization precipitation to regulate the concentration of secondary ions has become one of the main technical approaches with great application prospects. However, the gypsum sludge produced by gypsum crystallization precipitation has a particle size mainly distributed in the range of 10-90μm, with a median particle size of 32μm. It is a sludge with finer particles and is easy to settle. The formed sludge is dense, and the water content can easily be lower than 60%. The fluidity is very poor, and it is very easy to deposit in the pipeline and cause blockage. The commonly used dehydration methods such as plate and frame filter presses are not effective. The gypsum sludge just discharged from the gypsum crystallization precipitation structure is in an acidic state, with a pH generally between 2.5 and 3.0. It still has the ability to crystallize, which can easily cause blockage of the filter cloth and pipelines. Therefore, it needs to be neutralized to a pH value of above 5 to inhibit or stop crystallization. For this purpose, we propose a gypsum crystallization precipitation sludge neutralization and solid-liquid separation device. Utility Model Content

[0003] The utility model aims to solve the shortcomings of the existing acidic gypsum crystal precipitation sludge solid-liquid separation technology and proposes a gypsum crystal precipitation sludge neutralization and solid-liquid separation device.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a gypsum crystallization precipitation sludge neutralization and solid-liquid separation device, comprising a neutralization tank, a sludge pump and a solid-liquid separation tank, the outside of the neutralization tank is connected to the solid-liquid separation tank, the inner wall of one side of the neutralization tank is connected to the gypsum crystallization precipitation sludge pipe, the inner wall of the other side of the neutralization tank is connected to the nanofiltration concentrated liquid pipe, a stirrer is installed in the middle of the neutralization tank, a sludge pump is installed on the outside of the neutralization tank, the feed end of the sludge pump is connected to the bottom end of the neutralization tank, the discharge end of the sludge pump is fixedly connected to a connecting pipe, a central vertical flow pipe is installed in the solid-liquid separation tank, the end of the connecting pipe is connected to the top of the central vertical flow pipe, the top of the solid-liquid separation tank is connected to an overflow pipe, the top of the solid-liquid separation tank is located below the overflow pipe and is equidistantly connected to an outlet pipe in the vertical direction, and the end of the outlet pipe is connected to the overflow pipe.

[0005] Preferably, the end of the gypsum crystallization sedimentation sludge pipe passes through the neutralization tank, and a pneumatic butterfly valve on the gypsum crystallization sedimentation sludge pipe is installed on the outside of one end of the gypsum crystallization sedimentation sludge pipe located outside the neutralization tank, and the end of the nanofiltration concentration pipe passes through the neutralization tank, and a nanofiltration concentrated liquid pipe ball valve is installed on the outside of one end of the nanofiltration concentrated liquid pipe located outside the neutralization tank.

[0006] Preferably, a liquid level gauge is installed on the side wall of the neutralization tank away from the gypsum crystallization sedimentation sludge pipe, a ball valve on the neutralization tank outlet pipe is installed on the outside of the feed pipe of the sludge pump, and a ball valve on the sludge pump outlet pipe is installed on the outside of the discharge pipe of the sludge pump, and a float flowmeter on the sludge pump outlet pipe is installed on the outside of the connecting pipe located at one end of the sludge pump.

[0007] Preferably, a screw conveyor is installed at the bottom end of the solid-liquid separation tank, and the inclination angle of the screw conveyor is less than thirty degrees.

[0008] Preferably, a ball valve on the multi-layer drainage pipe on the solid-liquid separation tank is installed on the outside of the water outlet pipe.

[0009] Compared with the prior art, the beneficial effects of the utility model are:

[0010] 1. The neutralization tank of the utility model is provided with a mechanical stirrer, which can achieve excellent stirring, mixing and neutralization effect for the gypsum crystal precipitation sludge which is easy to deposit densely.

[0011] 2. In the utility model, the landfill leachate nanofiltration concentrate is used as a neutralizer for the acidic gypsum crystallization precipitation sludge, which makes full use of the effective alkalinity of the landfill leachate nanofiltration concentrate to achieve acid-base neutralization, thereby eliminating the cost of adding alkaline agents and not introducing inorganic salts, thereby avoiding increasing the power consumption of membrane separation.

[0012] 3. The solid-liquid separation tank in the utility model adopts a central vertical flow pipe for water inlet, and the water is evenly distributed; the multi-layer pipe discharges the supernatant liquid, which can fully discharge the upper clear liquid of the deposited sludge, which is conducive to the spiral transportation and discharge of the deposited sludge; the use of a screw conveyor for sludge discharge avoids the problem that the sludge with a water content higher than 10% is easily blocked during the pipeline transportation process; at the same time, because the water content of the deposited sludge is lower than 60%, it meets the water content index requirements of conventional sludge treatment and disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0014] In the figure: 1. Pneumatic butterfly valve on gypsum crystallization sedimentation sludge pipe; 2. Neutralization tank; 3. Mixer; 4. Ball valve on nanofiltration concentrate pipe; 5. Liquid level meter; 6. Ball valve on neutralization tank outlet pipe; 7. Sludge pump; 8. Ball valve on sludge pump outlet pipe; 9. Ball valve on multi-layer drainage pipe on solid-liquid separation tank; 10. Float flowmeter on sludge pump outlet pipe; 11. Central vertical flow pipe; 12. Solid-liquid separation tank; 13. Screw conveyor; 14. Overflow pipe; 15. Outlet pipe; 16. Gypsum crystallization sedimentation sludge pipe; 17. Nanofiltration concentrate pipe; 18. Connecting pipe. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] See also Figure 1 The utility model provides a technical solution: a gypsum crystallization precipitation sludge neutralization and solid-liquid separation device, comprising a neutralization tank 2, a sludge pump 7 and a solid-liquid separation tank 12, the outside of the neutralization tank 2 is connected to the solid-liquid separation tank 12, the inner wall of one side of the neutralization tank 2 is connected to a gypsum crystallization precipitation sludge pipe 16, the inner wall of the other side of the neutralization tank 2 is connected to a nanofiltration concentrated liquid pipe 17, and a stirrer 3 is installed in the middle of the neutralization tank 2.

[0017] It should be noted that the gypsum crystallization sedimentation sludge is intermittently discharged into the neutralization tank 2 through the gypsum crystallization sedimentation sludge pipe 16, and at the same time, the leachate nanofiltration concentrate flows continuously into the neutralization tank 2 through the nanofiltration concentrate pipe 7, and the two are gradually neutralized under mixing in the mixer 3.

[0018] A sludge pump 7 is installed outside the neutralization tank 2, and the feed end of the sludge pump 7 is connected to the bottom end of the neutralization tank 2, and the discharge end of the sludge pump 7 is fixedly connected to a connecting pipe 18. A central vertical flow pipe 11 is installed in the solid-liquid separation tank 12, and the end of the connecting pipe 18 is connected to the top of the central vertical flow pipe 11. The top of the solid-liquid separation tank 12 is connected to an overflow pipe 14, and the top of the solid-liquid separation tank 12 is located below the overflow pipe 14 and is equidistantly connected to an outlet pipe 15 in the vertical direction, and the end of the outlet pipe 15 is connected to the overflow pipe 14.

[0019] It should be noted that when the utility model is working:

[0020] Step 1: Open the pneumatic butterfly valve 1 on the gypsum crystallization sedimentation sludge pipe to discharge the sludge into the neutralization tank 2 in an intermittent manner;

[0021] Step 2: Open the ball valve 4 on the leachate nanofiltration concentrate pipe, control the appropriate flow rate to flow into the neutralization tank 2 in a continuous manner, and the hydraulic retention time in the tank is not less than 1 hour;

[0022] Step 3: Start the mixer 3 and run it continuously;

[0023] Step 4: Open the ball valve 6 on the outlet pipe of the neutralization tank 2 and the ball valve 8 on the pipeline after the sludge pump 7. The muddy water is lifted by the sludge pump 7 controlled by the liquid level meter 6 through the outlet pipe, passes through the ball valve 8 and the float flowmeter 10, and then enters the central vertical flow pipe 11 of the solid-liquid separation tank 12, and then settles in the solid-liquid separation tank to form a supernatant and deposited sludge. During the sedimentation process, the supernatant is discharged from the overflow pipe 14;

[0024] Step 5: The liquid level in the neutralization tank 2 is at a low level, and the sludge pump stops running;

[0025] Step 6: After continuing to settle for 30 minutes, open the multi-layer outlet pipes 9 on the wall of the solid-liquid separation tank from top to bottom, and try to remove the supernatant;

[0026] Step 7: After the supernatant is discharged, the screw conveyor 13 is started to discharge the deposited sludge, which is then packed into snakeskin bags for further disposal.

[0027] The end of the gypsum crystallization sedimentation sludge pipe 16 passes through the neutralization tank 2, and the outer side of the gypsum crystallization sedimentation sludge pipe 16 located at one end outside the neutralization tank 2 is installed with a pneumatic butterfly valve 1 on the gypsum crystallization sedimentation sludge pipe. The end of the nanofiltration concentration industry pipe 17 passes through the neutralization tank 2, and the nanofiltration concentrated liquid pipe 17 is located at one end outside the neutralization tank 2 and a nanofiltration concentrated liquid pipe ball valve 4 is installed on the outer side.

[0028] It should be noted that the pneumatic butterfly valve 1 on the gypsum crystallization sedimentation sludge pipe is opened to discharge the sludge into the neutralization tank 2 in an intermittent manner, and the ball valve 4 on the leachate nanofiltration concentrate pipe is opened to control the appropriate flow rate to flow into the neutralization tank 2 in a continuous manner, and the hydraulic retention time in the tank is not less than 1 hour.

[0029] A liquid level meter 5 is installed on the side wall of the neutralization tank 2 away from the gypsum crystallization sedimentation sludge pipe 16, a ball valve 6 on the neutralization tank outlet pipe is installed on the outside of the feed pipe of the sludge pump 7, and a ball valve 8 on the sludge pump outlet pipe is installed on the outside of the discharge pipe of the sludge pump 7, and a float flowmeter 10 on the sludge pump outlet pipe is installed on the outside of the connecting pipe 18 located at one end of the sludge pump 7.

[0030] It should be noted that the pneumatic butterfly valve 1 on the gypsum crystallization sedimentation sludge pipe is opened to allow the gypsum crystallization sedimentation sludge to be discharged into the neutralization tank 2 in an intermittent manner. At the same time, the ball valve 4 on the leachate nanofiltration concentrate pipe is opened to allow the nanofiltration concentrate to flow into the neutralization tank 2 in a continuous manner. The mixer 3 also runs continuously. After the neutralization reaction is not less than 1 hour, the pH value of the mud-water mixture reaches above 5, and then it is lifted through the liquid outlet pipe and the ball valve 6 thereon, and the sludge pump 7 controlled by the liquid level meter 5 passes through the ball valve 8 and the float flowmeter 10 and enters the central vertical flow pipe 11 of the solid-liquid separation tank 12, and then precipitates in the solid-liquid separation tank to form supernatant and sedimented sludge.

[0031] A screw conveyor 13 is installed at the bottom end of the solid-liquid separation tank 12, and the inclination angle of the screw conveyor 13 is less than thirty degrees.

[0032] It should be noted that after the supernatant in the solid-liquid separation tank 12 is drained, the screw conveyor 13 is started to discharge the deposited sludge, which is then packed into bellows bags for further disposal. The inclination angle of the screw conveyor 13 is less than thirty degrees, so that the screw conveyor 13 can smoothly convey the sludge.

[0033] The outer side of the water outlet pipe 15 is provided with a ball valve 9 on the multi-layer drain pipe of the solid-liquid separation tank.

[0034] It should be noted that the ball valve 9 on the multi-layer drainage pipe on the solid-liquid separation tank can control the on-off of the outlet pipe 15. During the static process, the ball valve 9 on the multi-layer drainage pipe on the solid-liquid separation tank is controlled to be closed to separate the sewage inside the solid-liquid separation tank 12 into solid and liquid. After the solid-liquid separation is completed, the ball valve 9 on the multi-layer drainage pipe on the solid-liquid separation tank is opened to discharge and collect the supernatant on the top of the solid-liquid separation tank 12.

[0035] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one of such features.

[0037] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gypsum crystallization precipitation sludge neutralization and solid-liquid separation device, characterized in that: The invention comprises a neutralization tank (2), a sludge pump (7) and a solid-liquid separation tank (12), wherein the outside of the neutralization tank (2) is connected to the solid-liquid separation tank (12), the inner wall of one side of the neutralization tank (2) is connected to a gypsum crystallization precipitation sludge pipe (16), the inner wall of the other side of the neutralization tank (2) is connected to a nanofiltration concentrated liquid pipe (17), a stirrer (3) is installed in the middle of the neutralization tank (2), a sludge pump (7) is installed outside the neutralization tank (2), and the feed end of the sludge pump (7) is connected to the bottom end of the neutralization tank (2). The discharge end of the sludge pump (7) is fixedly connected to a connecting pipe (18), a central vertical flow pipe (11) is installed in the solid-liquid separation tank (12), the end of the connecting pipe (18) is connected to the top of the central vertical flow pipe (11), the top of the solid-liquid separation tank (12) is connected to an overflow pipe (14), the top of the solid-liquid separation tank (12) is located below the overflow pipe (14) and is equidistantly connected to a water outlet pipe (15) in the vertical direction, and the end of the water outlet pipe (15) is connected to the overflow pipe (14).

2. A gypsum crystal precipitation sludge neutralization and solid-liquid separation device according to claim 1, characterized in that: The end of the gypsum crystallization sedimentation sludge pipe (16) passes through the neutralization tank (2), and a pneumatic butterfly valve (1) on the gypsum crystallization sedimentation sludge pipe is installed on the outside of one end of the gypsum crystallization sedimentation sludge pipe (16) located outside the neutralization tank (2). The end of the nanofiltration concentrated liquid pipe (17) passes through the neutralization tank (2), and a nanofiltration concentrated liquid pipe ball valve (4) is installed on the outside of one end of the nanofiltration concentrated liquid pipe (17) located outside the neutralization tank (2).

3. A gypsum crystal precipitation sludge neutralization and solid-liquid separation device according to claim 1, characterized in that: A liquid level meter (5) is installed on a side wall of the neutralization tank (2) away from the gypsum crystallization sedimentation sludge pipe (16), a ball valve (6) on the neutralization tank outlet pipe is installed on the outside of the feed pipe of the sludge pump (7), and a ball valve (8) on the sludge pump outlet pipe is installed on the outside of the discharge pipe of the sludge pump (7), and a float flowmeter (10) on the sludge pump outlet pipe is installed on the outside of the connecting pipe (18) located at one end of the sludge pump (7).

4. A gypsum crystal precipitation sludge neutralization and solid-liquid separation device according to claim 1, characterized in that: A screw conveyor (13) is installed at the bottom end of the solid-liquid separation tank (12), and the inclination angle of the screw conveyor (13) is less than thirty degrees.

5. A gypsum crystal precipitation sludge neutralization and solid-liquid separation device according to claim 1, characterized in that: A ball valve (9) on the multi-layer drainage pipe on the solid-liquid separation tank is installed on the outer side of the water outlet pipe (15).

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