Conditioning and dewatering system for biochemical mud-water mixture and control method of conditioning and dewatering system

Abstract

The invention discloses a conditioning dehydration system for a biochemical mud-water mixture and a control method thereof, an ORP instrument and an aeration disc are arranged in a relay mud storage tank, and a remote control system controls aeration of the relay mud storage tank according to information fed back by the ORP instrument; a conductivity meter is arranged in the flocculant preparation box, and the remote control system accurately controls the concentration of the agent according to information fed back by the conductivity meter; the relay sludge storage tank is connected to the biochemical tank through a pipeline with a delivery pump and a flow meter and connected to the mixer through a pipeline with a sludge inlet pump and a flow meter, the flocculant preparation box is connected to the mixer through a pipeline with a chemical inlet pump and a flow meter, and the remote control system controls the sludge concentration meter according to information fed back by the flow meter and the sludge concentration meter. And the operation of related pumps is controlled, and the mud-water mixture and the medicament are conveyed into the mixer according to an accurate proportion. The device has the characteristics of high automation degree and capability of realizing automatic adjustment under a fluctuating working condition, and realizes self-adaptive control of medicament addition and sludge concentration.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a conditioning and dehydration system for a biochemical mud-water mixture and a control method thereof. Background Art

[0002] The activated sludge process is widely used in the treatment of various types of sewage. This technology will produce a certain amount of microorganisms while degrading pollutants in the water. In order to ensure the stability of the amount of microorganisms in the biochemical pool, part of the mud-water mixture needs to be discharged regularly. Because the content of microorganisms in the mud-water mixture is low, in order to reduce the subsequent treatment volume and cost (transportation and disposal), the mixture generally needs to be dehydrated. Microorganisms are relatively stable in the mud-water mixture and it is difficult for spontaneous flocs to settle. In order to improve the subsequent dehydration efficiency, polyacrylamide (PAM) is generally added to the mud-water mixture for sludge floc sedimentation. Generally, PAM is added to water at a fixed ratio, and a solution is formed after dissolution and maturation. The solution is then pumped into the mud-water mixture and mixed and then enters the back-end dehydration equipment for dehydration.

[0003] The dosage of PAM is affected by multiple factors such as molecular weight, cationic degree, solubility and maturity, dosage concentration, sludge concentration of mud-water mixture and sludge properties. The operation mode is mainly based on fixed dosage, that is, fixed PAM concentration and dosage flow rate. The fixed dosage method has lower requirements for on-site personnel, but there is a problem that it is impossible to track changes in working conditions in time, which is easy to cause problems such as increased agent consumption or poor dewatering sludge effect. If a non-fixed dosage method is adopted, the inspection and testing workload of on-site operators will increase, and there will still be a lag in the adjustment operation.

[0004] Chinese patent application 202210594859.4 discloses a sludge conditioning method, which adopts a sequential batch quantitative conditioning method, and uses sequential batch dosing, circulating mixing, and forced stirring to adjust the sludge. However, this scheme is a sequential batch conditioning method, which is only suitable for small batch processing, and lacks monitoring of flocculant solution. It is still impossible to control the amount of agent dissolved, and it is also impossible to achieve adaptive adjustment of agent concentration and dosage according to different sludge concentrations.

[0005] Chinese patent application 202311700612.7 discloses an intelligent dewatering device for engineering mud and its control method. This technical solution obtains the corresponding flow rate, density, stirring speed and other parameters through online instruments or image imaging technology, and realizes the linkage control of sludge amount, dosage and effect. However, this solution is only applicable to plate-and-frame dewatering of inorganic sludge (i.e., very low microbial content), and cannot monitor the degree of maturation of PAM. It is difficult to obtain overall parameters (such as the first capillary water absorption time and sludge specific resistance SRF). It is not suitable for biochemical sludge with high microbial content (microorganisms contain intracellular water and bound water that cannot be removed) and centrifugal dewatering. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a conditioning and dehydration system for a biochemical sludge-water mixture which has a compact structure, is easy to operate, has a high reliability, a high degree of automation and can achieve autonomous adjustment under fluctuating working conditions, and a control method thereof, in order to address the problems existing in the existing biochemical sludge dehydration process, such as long-term denaturation, uncertain feed concentration, drift of flocculant preparation concentration, and inaccurate dosage of reagents.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A conditioning and dehydration system for a biochemical mud-water mixture, comprising: a relay mud storage tank, a flocculant preparation box, a biochemical tank, a centrifuge and a mixer; the relay mud storage tank is provided with an ORP meter and a liquid level meter connected to a remote control system, and the relay mud storage tank is also provided with an aeration disk connected to an external aeration fan; the remote control system controls the aeration fan to aerate the relay mud storage tank according to data information fed back by the ORP meter; the biochemical tank is provided with a sludge concentration meter for detecting the sludge concentration in the biochemical tank; the relay mud storage tank is connected to the biochemical tank through a pipeline with a delivery pump and a third flow meter, the delivery pump, the sludge concentration meter and the third flow meter are all connected to the remote control system, and the remote control system controls the operation of the delivery pump according to data information fed back by the liquid level meter, the sludge concentration meter and the third flow meter, so as to realize automatic aeration of the mud-water mixture in the biochemical tank according to a preset amount. The mud is transported to a relay mud storage tank; the relay mud storage tank is connected to a mixer via a pipeline with a mud feed pump and a first flow meter, and the flocculant preparation box is connected to the mixer via a pipeline with a drug feed pump and a second flow meter; a conductivity meter is provided in the flocculant preparation box, and the mud feed pump, the first flow meter, the conductivity meter, the second flow meter and the drug feed pump are all connected to a remote control system, and the remote control system controls the drug concentration in the flocculant preparation tank within a preset range according to the data information fed back by the conductivity meter, and controls the operation of the mud feed pump and the drug feed pump according to the data information fed back by the first flow meter and the second flow meter, and transports the mud-water mixture and the drug to the mixer in a preset ratio for uniform mixing, so as to realize autonomous adjustment of the mixed dosage of the mud-water mixture and the drug under fluctuating working conditions; the mixer is connected to a centrifuge via a pipeline to realize mud-water separation.

[0009] As a further improvement of the present invention, an agitator is provided in the relay mud storage tank to achieve stirring of the mud-water mixture; the upper part of the stirring shaft of the agitator adopts a hollow tube, and the upper part of the stirring shaft passes through the top of the relay mud storage tank to collect odor in the relay mud storage tank.

[0010] As a further improvement of the present invention, the flocculant preparation box is obtained by connecting multiple boxes in series, and the second to last box is equipped with a conductivity meter and a pH meter, and the last box is equipped with a conductivity meter, and the pH meter is connected to the remote control system; the last box is connected to the mixer through a pipeline with a drug feed pump.

[0011] As a further improvement of the present invention, the output end of the centrifuge is respectively connected to a screw conveyor and a dewatering clear liquid tank, the sludge separated in the centrifuge is transported to a sludge bin via the screw conveyor, and the supernatant separated in the centrifuge is stored in a dewatering clear liquid tank.

[0012] As a further improvement of the present invention, a turbidity meter is provided on the connecting pipe between the centrifuge and the dewatered clear liquid tank to detect the turbidity of the supernatant; the turbidity meter is connected to the remote control system.

[0013] As a further improvement of the present invention, aeration plates are installed at intervals of 30 to 100 cm at the bottom of the relay mud storage tank.

[0014] As a general technical concept, the present invention also provides a control method for a conditioning and dehydration system based on the above-mentioned biochemical mud and water mixture, comprising the following steps:

[0015] Step S1, the remote control system calculates the sludge discharge amount of the biochemical pool according to the data fed back by the liquid level meter and the sludge concentration meter;

[0016] Step S2, the remote control system starts the delivery pump, and the biochemical pool delivers the mud-water mixture to the relay mud storage tank. When the mud-water mixture fed back by the third flow meter reaches a preset value, the remote control system turns off the delivery pump and calculates the sludge concentration in the relay mud storage tank;

[0017] Step S3, the remote control system controls the dosage of the flocculant preparation box according to the conductivity data fed back by the conductivity meter in the last two boxes of the flocculant preparation box, so as to achieve accurate control of the flocculant concentration;

[0018] Step S4, the remote control system controls the operation of the mud feed pump and the drug feed pump, and the first flow meter and the second flow meter feed back the flow rates of the mud-water mixture and the drug to the remote control system in real time, so that the mud-water mixture and the drug are transported to the mixer according to a preset ratio and mixed evenly;

[0019] Step S5, the mixed material in the mixer is transported to a centrifuge for solid-liquid separation, and a turbidity meter monitors the turbidity of the supernatant discharged from the centrifuge in real time and feeds the data back to the remote control system; the dewatered sludge separated in the centrifuge is transported to a sludge bin via a screw conveyor.

[0020] As a further improvement of the present invention, in step S1 and step S2, the control of sludge discharge includes:

[0021] Set the discharge sequence of the mud-water mixture of the biochemical pool. The discharge sequence includes two parts: time period and planned discharge amount. The time period is the discharge interval, and the planned discharge amount refers to the amount of mud-water mixture discharged to the relay mud storage tank in a single time. When the discharge is triggered, the discharge amount is controlled according to the following formula;

[0022] Actual discharge volume = planned discharge volume + previous carryover volume - current volume in the relay sludge storage tank; the current volume is calculated by measuring the remaining liquid level in the relay sludge storage tank with a liquid level meter;

[0023] The previous carryover amount = the previous planned emission amount - the previous actual emission amount;

[0024] After the sludge discharge is completed, the remote control system calculates the actual sludge concentration of the sludge-water mixture in the relay sludge storage tank according to formula (1):

[0025] MLSS 实 =(V 排 *MLSS 排 +V 存 *MLSS 存 ) / (V 排 +V 存 ) Formula (1)

[0026] MLSS 实 -----The actual sludge concentration entering the mixer, in g / L;

[0027] V 排 ------Newly discharged sludge volume, unit: m 3 ;

[0028] MLSS 排 ------The sludge concentration of the newly discharged sludge, in g / L;

[0029] V 存 -----The volume of sludge stored in the relay sludge tank, unit: m 3 ;

[0030] MLSS 存 -----The sludge concentration of the sludge remaining in the relay sludge storage tank, in g / L;

[0031] MLSS 存 =(V1*MLSS1+V2*MLSS2) / (V1+V2) Formula (2)

[0032] MLSS 存 -----The sludge concentration of the sludge remaining in the relay sludge storage tank, in g / L;

[0033] V1-----The amount of sludge retained in the relay sludge storage tank, unit: m 3 ;

[0034] V2-----The amount of sludge newly discharged into the relay sludge storage tank, unit: m 3 ;

[0035] MLSS1-----The sludge concentration retained in the relay sludge storage tank, unit: g / L;

[0036] MLSS2------The concentration of sludge newly discharged into the relay sludge storage tank, in g / L;

[0037] According to formula (2), the sludge concentration retained in the relay sludge storage tank after the Nth time is deduced in sequence. If the relay sludge storage tank is in a continuous feeding and discharging condition, the average value of the sludge concentration meter in the two most recent biochemical tanks is taken as the actual sludge concentration value.

[0038] As a further improvement of the present invention, in step S3, the flocculant concentration control process includes: setting the conductivity curve and pH upper and lower limits of the flocculant at 0.5‰ to 3.5‰, wherein the pH value of the second-to-last box is used for alarm, the conductivity of the second-to-last box is used to control the dosage, and the conductivity of the last box is used to control the frequency of the drug feed pump; in step S5, if the turbidity is higher or lower than the set value for two consecutive times, the remote control system will issue an alarm; when a high value alarm is issued for 4 to 6 consecutive times, the centrifuge will automatically stop.

[0039] As a further improvement of the present invention, in step S4, the dosage of the agent is controlled according to formula (3):

[0040] Q 药 =1000*MLSS 实 *Q 泥 *D*K / (c*ρ 药 ) Formula (3)

[0041] K=A 标准 / A 实际

[0042] Where:

[0043] A 标准 -----Theoretical conductivity of flocculant solution, in μs / cm;

[0044] A 实际 -----The actual conductivity detected after the flocculant is configured, in μs / cm;

[0045] K------adjustment coefficient, used to characterize the effect of flocculant solution, dimensionless;

[0046] Q 药------Flocculating agent addition flow rate, unit is m 3 / h;

[0047] MLSS 实 ------The actual sludge concentration entering the mixer, in g / L;

[0048] Q 泥- ------Mixer inlet mud flow rate, unit is m 3 / h;

[0049] D------flocculant unit consumption, that is, the amount of flocculation required for one ton of absolute dry sludge, in kg / t;

[0050] c------The concentration of flocculant solution; that is, the weight ratio of the dissolved flocculant to the flocculant solution, unit ‰;

[0051] ρ 药 ----- is the mass of flocculant per unit volume, in kg / m 3 .

[0052] Compared with the prior art, the advantages of the present invention are:

[0053] 1. The conditioning and dehydration system of the biochemical mud-water mixture of the present invention and the control method thereof are as follows: an ORP meter and a liquid level meter connected to a remote control system are provided in the relay mud storage tank; an aeration plate connected to an external aeration fan is also provided in the relay mud storage tank; the remote control system controls the aeration fan to aerate the relay mud storage tank according to the data information fed back by the ORP meter, so as to prevent the sludge in the relay mud storage tank from being converted into anaerobic sludge; a sludge concentration meter is provided in the biochemical tank; the remote control system controls the operation of the delivery pump according to the data information fed back by the liquid level meter, the sludge concentration meter and the flow meter, so as to realize accurate delivery of the mud-water mixture in the biochemical tank to the relay mud storage tank according to the preset amount; a conductivity meter is provided in the flocculant preparation box; the remote control system controls the operation of the delivery pump according to the data information fed back by the conductivity meter , achieving precise control of the agent concentration in the flocculant preparation box within a preset range, ensuring that the agent fully exerts its efficacy; the relay sludge storage tank is connected to the mixer through a pipeline with a sludge feed pump and a first flow meter, and the flocculant preparation box is connected to the mixer through a pipeline with a drug feed pump and a second flow meter, and the sludge feed pump, the first flow meter, the second flow meter and the drug feed pump are all connected to the remote control system, which controls the operation of the sludge feed pump and the drug feed pump according to the data information fed back by the first flow meter and the second flow meter, and transports the mud-water mixture and the agent to the mixer in a preset ratio for uniform mixing, thereby achieving autonomous adjustment of the mixed dosage of the mud-water mixture and the agent under fluctuating working conditions, improving the utilization efficiency of the flocculant, and meeting the needs of automatic sludge discharge control under different biochemical sludge concentrations.

[0054] 2. The conditioning and dehydration system of the biochemical sludge-water mixture and the control method thereof of the present invention realize precise control of the PAM agent during the maturation and addition process by setting a conductivity meter in the last two boxes of the flocculant preparation box and a pH meter in the penultimate box, thereby solving the problems of flocculant preparation concentration drift and inaccurate agent addition in the traditional biochemical sludge dehydration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of the structural principle of a conditioning and dehydration system for a biochemical mud-water mixture in a specific embodiment of the present invention;

[0056] Figure 2 It is a schematic diagram of the conditioning and dehydration process of the biochemical mud-water mixture in a specific embodiment of the present invention;

[0057] Legend: 1. Relay sludge storage tank; 2. Flocculant preparation box; 3. Biochemical tank; 4. Centrifuge; 5. Screw conveyor; 6. Deodorization system; 7. Aeration fan; 8. Agitator; 9. Mud feed pump; 10. First flow meter; 11. Delivery pump; 12. ORP meter; 13. Conductivity meter; 14. pH meter; 15. Mixer; 16. Turbidimeter; 17. Second flow meter; 18. Drug feed pump; 19. Dehydration clear liquid tank; 20. Liquid level meter; 21. Sludge concentration meter; 22. Third flow meter; 23. Aeration disk. DETAILED DESCRIPTION

[0058] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0059] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0061] Example 1

[0062] like Figure 1 As shown, the conditioning and dehydration system of the biochemical sludge-water mixture of the present invention comprises: a relay sludge storage tank 1, a flocculant preparation box 2, a biochemical tank 3, a centrifuge 4 and a mixer 15. The relay sludge storage tank 1 is provided with an ORP meter 12 and a liquid level meter 20 connected to the remote control system, and the relay sludge storage tank 1 is also provided with an aeration plate 23 connected to an external aeration fan 7; the remote control system controls the aeration fan 7 to aerate the relay sludge storage tank 1 according to the data information fed back by the ORP meter 12. The biochemical tank 3 is provided with a sludge concentration meter 21 for detecting the sludge concentration in the biochemical tank 3. The relay sludge storage tank 1 is connected to the biochemical pool 3 through a pipeline with a delivery pump 11 and a third flowmeter 22. The delivery pump 11, the sludge concentration meter 21 and the third flowmeter 22 are all connected to the remote control system. The remote control system controls the operation of the delivery pump 11 according to the data information fed back by the liquid level meter 20, the sludge concentration meter 21 and the third flowmeter 22, so as to accurately deliver the mud-water mixture in the biochemical pool 3 to the relay sludge storage tank 1 according to the preset amount. The relay sludge storage tank 1 is connected to the mixer 15 through a pipeline with a mud feed pump 9 and a first flowmeter 10, and the flocculant preparation tank 2 is connected to the mixer 15 through a pipeline with a drug feed pump 18 and a second flowmeter 17. The flocculant preparation box 2 is provided with a conductivity meter 13, and the mud feed pump 9, the first flow meter 10, the conductivity meter 13, the second flow meter 17 and the drug feed pump 18 are all connected to the remote control system. The remote control system controls the concentration of the agent in the flocculant preparation box 2 within a preset range according to the data information fed back by the conductivity meter 13. The remote control system controls the operation of the mud feed pump 9 and the drug feed pump 18 according to the data information fed back by the first flow meter 10 and the second flow meter 17, and transports the mud-water mixture and the agent to the mixer 15 in a preset ratio for uniform mixing, so as to realize the self-adjustment of the mixed amount of the mud-water mixture and the agent under fluctuating working conditions. The mixer 15 is connected to the centrifuge 4 through a pipeline to realize mud-water separation.

[0063] In this embodiment, the relay sludge storage tank 1 is a capacity adjustment tank for the sludge-water mixture, and has no sludge concentration and sedimentation function. The remote control system can specifically adopt a PLC control system, which has a simple principle, convenient operation and precise control.

[0064] like Figure 1As shown, the centrifuge 4 can adjust the differential speed and the rotation speed. The output ends of the centrifuge 4 are respectively connected to the screw conveyor 5 and the dewatering clear liquid tank 19. The sludge separated in the centrifuge 4 is transported to the sludge bin via the screw conveyor 5. The lower side of the bottom shell of the middle section of the screw conveyor 5 has an automatically opened and closed sampling port to facilitate checking the quality of the sludge. The supernatant separated in the centrifuge 4 is stored in the dewatering clear liquid tank 19. Furthermore, a turbidity meter 16 is provided on the connecting pipe between the centrifuge 4 and the dewatering clear liquid tank 19 to detect the turbidity of the supernatant. Moreover, the turbidity meter 16 is connected to the remote control system, and the remote control system can judge the working state of the centrifuge 4 according to the data information fed back by the turbidity meter 16, and control the start and stop of the centrifuge 4.

[0065] like Figure 1 As shown, a stirrer 8 is provided in the relay mud storage tank 1 to stir the mud-water mixture. The upper part of the stirring shaft of the stirrer 8 is a hollow tube, and the upper part of the stirring shaft passes through the top of the relay mud storage tank 1 to collect the odor in the relay mud storage tank 1 and transport the odor to the deodorization system 6 through a pipeline.

[0066] Specifically, the agitator 8 can be of paddle type or frame type, and is used to stir the mud-water mixture in the relay mud storage tank 1 to ensure that the mud and water are continuously in a mixed state. The agitator shaft is a hollow tube that passes through the top section of the tank and has openings on both sides for collecting odors in the tank.

[0067] like Figure 1 As shown, the aeration plates 23 are installed at intervals of 30 to 100 cm at the bottom of the tank. The aeration fan 7 and the aeration plates 23 are used to aerate the mud-water mixture in the relay mud storage tank 1 when the mud is not discharged for a long time, so as to ensure that the mud in the tank is not deformed into anaerobic sludge.

[0068] In this embodiment, the agitator 8 in the relay sludge storage tank 1 is started intermittently and is set according to the sludge settling characteristics. The ORP meter 12 detects the ORP value once every 1 to 6 hours, and the agitator 8 is started 15 to 30 minutes before the detection. When the ORP value is lower than 50Mv, the aeration fan 7 is started to aerate the pool, and the hourly aeration volume is 3 to 10 times the volume of the pool. The ORP value is detected 30 minutes after the aeration is completed. If it is still lower than 50Mv, the aeration process is repeated. The gas brought in or generated by the aeration is collected by the stirring shaft and then enters the deodorization or discharge.

[0069] like Figure 1 As shown, the flocculant preparation box 2 is obtained by connecting four boxes in series, and a stirring device is provided in the box, and a continuous water inlet and outlet operation mode is adopted. The second to last box is equipped with a conductivity meter 13 and a pH meter 14, and the last box is equipped with a conductivity meter 13, and the conductivity meter 13 and the pH meter 14 are both connected to the remote control system; the last box is connected to the mixer 15 through a pipeline with a drug inlet pump 18.

[0070] like Figure 2 As shown, in this embodiment, a control method for the conditioning and dehydration system based on the above-mentioned biochemical mud and water mixture is also provided, comprising the following steps:

[0071] Step S1 : The remote control system calculates the sludge discharge amount of the biochemical pool 3 according to the data fed back by the liquid level meter 20 and the sludge concentration meter 21 .

[0072] Step S2, the remote control system starts the delivery pump 11, and the biochemical pool 3 delivers the mud-water mixture to the relay sludge storage tank 1. When the mud-water mixture fed back by the third flow meter 22 reaches a preset value, the remote control system turns off the delivery pump 11 and calculates the sludge concentration in the relay sludge storage tank 1.

[0073] Step S3: The remote control system controls the dosage of the flocculant preparation box 2 according to the conductivity data fed back by the conductivity meter 13 in the last two boxes of the flocculant preparation box 2, so as to achieve accurate control of the flocculant concentration. In the flocculant preparation box 2, the flocculant is added by spiral feeding.

[0074] Step S4, the remote control system controls the operation of the mud feed pump 9 and the drug feed pump 18, and the first flow meter 10 and the second flow meter 17 feed back the flow of the mud-water mixture and the drug to the remote control system in real time, so that the mud-water mixture and the drug are delivered to the mixer 15 according to a preset ratio and mixed evenly.

[0075] Step S5, the mixed material in the mixer 15 is transported to the centrifuge 4 for solid-liquid separation, and the turbidity meter 16 monitors the turbidity of the supernatant discharged from the centrifuge 4 in real time, and feeds the data back to the remote control system. The dewatered sludge separated in the centrifuge 4 is transported to the sludge bin via the screw conveyor 5. Further, the supernatant is allowed to have a turbidity of 10 to 300 NTU, and the turbidity meter 16 is put into monitoring 15 to 30 minutes after the centrifuge 4 is started, and is monitored every 10 to 60 minutes. If the turbidity is higher or lower than the set value twice in a row, the remote control system will issue an alarm. When a high-value alarm is issued for 4 to 6 consecutive times, the centrifuge 4 automatically stops.

[0076] In step S1 and step S2 of this embodiment, the control of sludge discharge includes:

[0077] Set the discharge sequence of the mud-water mixture of the biochemical pool 3. The discharge sequence includes two parts: the time period and the planned discharge amount. The time period is the discharge interval, that is, the interval between two mud discharges; the planned discharge amount refers to the amount of mud-water mixture discharged to the relay mud storage pool 1 in a single time; when the discharge is triggered, the discharge amount is controlled according to the following formula;

[0078] Actual discharge volume = planned discharge volume + previous carryover volume - current volume in relay sludge storage tank 1; wherein, the current volume is calculated by measuring the remaining liquid level in relay sludge storage tank 1 with the liquid level meter 20.

[0079] The previous carryover amount = the previous planned emission amount - the previous actual emission amount; the previous carryover amount can be accumulated across times.

[0080] After the actual discharge volume is obtained, the remote control system opens the valve from the biochemical pool 3 to the relay sludge storage pool 1, starts the delivery pump 11, and when the third flow meter 22 detects that the flow meter cumulative volume reaches the actual discharge volume, the valve is closed and the delivery pump 11 stops. Each time the biochemical pool 3 discharges, the sludge concentration in the discharged mud-water mixture is the arithmetic average of the detection values ​​of the sludge concentration meter 21 for the previous 1 to 6 times.

[0081] After the sludge discharge is completed, the remote control system calculates the actual sludge concentration of the sludge-water mixture in the relay sludge storage tank 1 according to formula (1):

[0082] MLSS 实 =(V 排 *MLSS 排 +V 存 *MLSS 存 ) / (V 排 +V 存 ) Formula (1)

[0083] MLSS 实 -----The actual sludge concentration entering the mixer 15, in g / L;

[0084] V 排 ------Newly discharged sludge volume, unit: m 3 ;

[0085] MLSS 排 ------The sludge concentration of the newly discharged sludge, in g / L;

[0086] V 存 -----The volume of sludge stored in relay sludge tank 1, unit: m 3 ;

[0087] MLSS 存 -----The sludge concentration of the sludge remaining in the relay sludge storage tank 1, in g / L;

[0088] MLSS 存 =(V1*MLSS1+V2*MLSS2) / (V1+V2) Formula (2)

[0089] MLSS 存 -----The sludge concentration of the sludge remaining in the relay sludge storage tank 1, in g / L;

[0090] V1-----The amount of sludge retained in relay sludge tank 1, unit: m 3 ;

[0091] V2-----The amount of sludge newly discharged into the relay sludge storage tank 1, unit: m 3 ;

[0092] MLSS1-----The sludge concentration retained in relay sludge storage tank 1, unit: g / L;

[0093] MLSS2------The concentration of sludge newly discharged into the relay sludge storage tank, in g / L;

[0094] According to formula (2), the sludge concentration retained in the relay sludge tank 1 after the Nth time is deduced in sequence. If the relay sludge tank 1 is in a continuous feeding and discharging condition, the average value of the sludge concentration meter 21 in the two most recent biochemical tanks 3 is taken as the actual sludge concentration value.

[0095] In step S3, the flocculant concentration control process includes: setting the conductivity curve (generally linear) and pH value (only upper and lower limits) of the flocculant 0.5‰ to 3.5‰, and setting the pH value and conductivity range of the last two boxes. Among them, the pH value of the second-to-last box is only used for alarm, and the conductivity is used to control the drug feeding screw (allowed ±10%), and the drug feeding screw speed increases by ±5 to 10% for every deviation of ±5% (excluding the aforementioned allowable deviation range). The conductivity of the last box is used to control the frequency of the drug feeding pump 18 (allowed ±5%).

[0096] In step S4, the dosage of the reagent is controlled according to formula (3):

[0097] Q 药 =1000*MLSS 实 *Q 泥 *D*K / (c*ρ 药 ) Formula (3)

[0098] K=A 标准 / A 实际

[0099] Where:

[0100] A 标准 -----Theoretical conductivity of flocculant solution, in μs / cm;

[0101] A 实际 -----The actual conductivity detected after the flocculant is configured, in μs / cm;

[0102] K------adjustment coefficient, used to characterize the effect of flocculant solution, dimensionless;

[0103] Q 药 ------Flocculating agent addition flow rate, unit is m 3 / h;

[0104] MLSS 实 ------The actual sludge concentration entering the mixer 15, in g / L;

[0105] Q 泥- ------Mixer 15 mud flow rate, unit is m 3 / h;

[0106] D------flocculant unit consumption, that is, the amount of flocculation required for one ton of absolute dry sludge, in kg / t;

[0107] c------The concentration of flocculant solution; that is, the weight ratio of the dissolved flocculant to the flocculant solution, unit ‰;

[0108] ρ 药 ----- is the mass of flocculant per unit volume, in kg / m 3 .

[0109] Example 2

[0110] In the conditioning and dehydration system of the biochemical sludge-water mixture of Example 1, which is specifically a high-ammonia nitrogen wastewater biochemical treatment system, the sludge concentration of the biochemical pool 3 is 10-20 g / L, there is no traditional secondary sedimentation tank, and only a 120m 3 Relay sludge storage tank 1. A paddle-type stirring device is installed on the top of the relay sludge storage tank 1, and the stirring shaft draws air to the biochemical deodorization. A microporous aeration disk is arranged at the bottom of the relay sludge storage tank 1, and the aeration micropores are arranged at intervals of 50cm. A Roots blower is installed outside the relay sludge storage tank 1, and the air volume is 600Nm 3 / h. The flocculant preparation is a triple box type, and the dehydrator is a horizontal centrifugal.

[0111] The sludge concentration of biochemical pool 3 is recorded every 12 hours, and the sludge is discharged once a day, continuously, with a single discharge of 200m 3 The ORP value of the relay sludge tank 1 is tested every 6 hours, and the ORP value is set to 50mv. After it is lower than 50mv, aeration is performed for 15 minutes each time. If it is not turned on all day, aeration is turned on for 10 minutes.

[0112] Set the conductivity of the reagent at 0.5‰ to 120us / cm, 1‰ to 236us / cm, 2‰ to 500us / cm, and 3‰ to 702us / cm, and draw a curve to input into the program. Set the solution pH to 3-5, set the dosing concentration to 1.5‰, and the deviation to ±5% of the spiral speed increase by ±5%. Set the absolute dry unit consumption to 27kg / t.

[0113] The turbidity of the supernatant is set to 150-300 NTU, and the turbidity meter 16 is put into monitoring 20 minutes after the centrifuge 4 is started, and monitoring is performed every 30 minutes.

[0114] The changes in the main production indicators before and after the system was put into use are shown in Table 1.

[0115] Table 1 Comparison of key data before and after system commissioning

[0116] project Before commissioning After commissioning On-duty inspection 8 people / day 2 people / day Absolute dry agent consumption 33~35kg / t 27.3kg / t Dewatered sludge solid content 18.7～20.2％ 19.1～20.1％

[0117] It can be seen from Table 1 that by adopting the conditioning and dehydration system in Example 1, the number of on-duty inspections is reduced, and the consumption of reagents is also reduced, but the solid content of the dehydrated sludge is basically unchanged, indicating that the conditioning and dehydration system of the present invention can reduce the cost of biochemical sludge dehydration, and has a high degree of automation, thereby reducing the labor intensity of operators.

[0118] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A conditioning and dehydration system for a biochemical mud-water mixture, characterized in that: include: A relay sludge storage tank (1), a flocculant preparation box (2), a biochemical tank (3), a centrifuge (4) and a mixer (15); the relay sludge storage tank (1) is provided with an ORP meter (12) and a liquid level meter (20) connected to a remote control system, and the relay sludge storage tank (1) is also provided with an aeration plate (23) connected to an external aeration fan (7); the remote control system controls the aeration fan (7) to aerate the relay sludge storage tank (1) according to data information fed back by the ORP meter (12); the biochemical tank (3) is provided with a sludge concentration meter (21) to Used to detect the sludge concentration in the biochemical pool (3); the relay sludge storage pool (1) is connected to the biochemical pool (3) through a pipeline with a delivery pump (11) and a third flow meter (22); the delivery pump (11), the sludge concentration meter (21) and the third flow meter (22) are all connected to a remote control system; the remote control system controls the operation of the delivery pump (11) based on data information fed back by the liquid level meter (20), the sludge concentration meter (21) and the third flow meter (22), so as to realize automatic delivery of the sludge-water mixture in the biochemical pool (3) to the relay according to a preset amount. The relay sludge storage tank (1) is connected to the mixer (15) through a pipeline with a sludge feed pump (9) and a first flow meter (10), and the flocculant preparation box (2) is connected to the mixer (15) through a pipeline with a drug feed pump (18) and a second flow meter (17); the flocculant preparation box (2) is provided with a conductivity meter (13), and the sludge feed pump (9), the first flow meter (10), the conductivity meter (13), the second flow meter (17) and the drug feed pump (18) are all connected to a remote control system, and the remote control system is based on According to the data information fed back by the conductivity meter (13), the concentration of the agent in the flocculant preparation box (2) is controlled within a preset range. The remote control system controls the operation of the mud feed pump (9) and the agent feed pump (18) according to the data information fed back by the first flow meter (10) and the second flow meter (17), and delivers the mud-water mixture and the agent to the mixer (15) in a preset ratio for uniform mixing, thereby realizing autonomous adjustment of the mixed dosage of the mud-water mixture and the agent under fluctuating working conditions; the mixer (15) is connected to the centrifuge (4) through a pipeline to realize mud-water separation.

2. The conditioning and dehydration system for biochemical mud and water mixture according to claim 1, characterized in that: The relay mud storage tank (1) is provided with a stirrer (8) to stir the mud-water mixture; the upper part of the stirring shaft of the stirrer (8) is a hollow tube, and the upper part of the stirring shaft passes through the top of the relay mud storage tank (1) to collect odor in the relay mud storage tank (1).

3. The conditioning and dehydration system for biochemical mud and water mixture according to claim 2, characterized in that: The flocculant preparation box (2) is obtained by connecting a plurality of boxes in series, and the second to last box is equipped with a conductivity meter (13) and a pH meter (14), and the last box is equipped with a conductivity meter (13), and the pH meter (14) is connected to a remote control system; the last box is connected to a mixer (15) via a pipeline with a drug feed pump (18).

4. The conditioning and dehydration system for biochemical mud and water mixture according to any one of claims 1 to 3, characterized in that: The output end of the centrifuge (4) is respectively connected to a screw conveyor (5) and a dewatering clear liquid tank (19); the sludge separated in the centrifuge (4) is transported to a sludge bin via the screw conveyor (5); and the supernatant separated in the centrifuge (4) is stored in the dewatering clear liquid tank (19).

5. The conditioning and dehydration system for biochemical mud and water mixture according to claim 4, characterized in that: A turbidity meter (16) is provided on the connecting pipe between the centrifuge (4) and the dewatered clear liquid tank (19) for detecting the turbidity of the supernatant; the turbidity meter (16) is connected to a remote control system.

6. The conditioning and dehydration system for biochemical mud and water mixture according to any one of claims 1 to 3, characterized in that: Aeration plates (23) are installed at intervals of 30 to 100 cm at the bottom of the relay mud storage tank (1).

7. A control method for a conditioning and dehydration system of a biochemical mud-water mixture based on any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1, the remote control system calculates the sludge discharge amount of the biochemical pool (3) according to the data fed back by the liquid level meter (20) and the sludge concentration meter (21); Step S2, the remote control system starts the delivery pump (11), and the biochemical pool (3) delivers the mud-water mixture to the relay mud storage pool (1). When the mud-water mixture fed back by the third flow meter (22) reaches a preset value, the remote control system turns off the delivery pump (11) and calculates the sludge concentration in the relay mud storage pool (1); Step S3, the remote control system controls the dosage of the flocculant preparation box (2) according to the conductivity data fed back by the conductivity meter (13) in the last two boxes of the flocculant preparation box (2), so as to achieve accurate control of the flocculant concentration; Step S4, the remote control system controls the operation of the mud feed pump (9) and the drug feed pump (18), and the first flow meter (10) and the second flow meter (17) feed back the flow rates of the mud-water mixture and the drug to the remote control system in real time, so that the mud-water mixture and the drug are transported to the mixer (15) in a preset ratio and mixed evenly; Step S5: The mixed material in the mixer (15) is transported to the centrifuge (4) for solid-liquid separation. The turbidity of the supernatant discharged from the centrifuge (4) is monitored in real time by the turbidity meter (16), and the data is fed back to the remote control system. The dewatered sludge separated in the centrifuge (4) is transported to the sludge bin via the screw conveyor (5).

8. The control method according to claim 7, characterized in that: In step S1 and step S2, the control of sludge discharge includes: The discharge sequence of the mud-water mixture of the biochemical pool (3) is set, and the discharge sequence includes two parts: a time period and a planned discharge amount. The time period is the discharge interval, and the planned discharge amount refers to the amount of mud-water mixture discharged to the relay mud storage pool (1) in a single time. When the discharge is triggered, the discharge amount is controlled according to the following formula; Actual discharge amount = planned discharge amount + previous residual amount - current amount in the relay sludge storage tank (1); wherein the current amount is calculated by measuring the residual liquid level in the relay sludge storage tank (1) with the liquid level meter (20); The previous carryover amount = the previous planned emission amount - the previous actual emission amount; After the sludge discharge is completed, the remote control system calculates the actual sludge concentration of the sludge-water mixture in the relay sludge storage tank (1) according to formula (1): MLSS 实 =(V 排 *MLSS 排 +V 存 *MLSS 存 ) / (V 排 +V 存 ) formula(1) MLSS 实 -----actual sludge concentration entering the mixer (15), in g / L; V 排 ------Newly discharged sludge volume, unit: m 3 ; MLSS 排 ------The sludge concentration of the newly discharged sludge, in g / L; V 存 -----The volume of sludge stored in the intermediate sludge storage tank (1), in m 3 ; MLSS 存 -----The sludge concentration of the sludge retained in the intermediate sludge storage tank (1), in g / L; <h2 style=";text-align:left;direction:ltr">MLSS<h2 style=";text-align:left;direction:ltr"> 存 <h2 style=";text-align:left;direction:ltr"> (V1*MLSS1+V2*MLSS2) / (V1+V2) (2) MLSS 存 -----The sludge concentration of the sludge retained in the intermediate sludge storage tank (1), in g / L; V1-----The amount of sludge retained in the relay sludge tank (1), unit: m 3 ; V2-----The amount of sludge newly discharged into the relay sludge storage tank (1), unit: m 3 ; MLSS1-----The concentration of sludge retained in the intermediate sludge storage tank (1), in g / L; MLSS2------The concentration of sludge newly discharged into the relay sludge storage tank (1), in g / L; According to formula (2), the sludge concentration retained in the relay sludge storage tank (1) after the Nth time is deduced in sequence. If the relay sludge storage tank (1) is in a continuous inlet and outlet condition, the average value of the sludge concentration meter (21) in the two most recent biochemical tanks (3) is taken as the actual sludge concentration value.

9. The control method according to claim 7, characterized in that: In step S3, the flocculant concentration control process includes: setting the conductivity curve and pH upper and lower limits of the flocculant at 0.5‰ to 3.5‰, wherein the pH value of the second-to-last box is used for alarm, the conductivity of the second-to-last box is used for controlling the dosage, and the conductivity of the last box is used for controlling the frequency of the drug feed pump (18); in step S5, if the turbidity is higher or lower than the set value twice in a row, the remote control system will issue an alarm; when the high value alarm is issued 4 to 6 times in a row, the centrifuge (4) will automatically stop.

10. The control method according to claim 7, characterized in that: In step S4, the dosage of the agent is controlled according to formula (3): Q 药 =1000*MLSS 实 *Q 泥 *D*K / (c*ρ 药 ) Formula (3) K=A 标准 / A 实际 Where: A 标准 -----Theoretical conductivity of flocculant solution, in μs / cm; A 实际 -----The actual conductivity detected after the flocculant is configured, in μs / cm; K------adjustment coefficient, used to characterize the effect of flocculant solution, dimensionless; Q 药 ------Flocculating agent addition flow rate, unit is m 3 / h; MLSS 实 ------The actual sludge concentration entering the mixer (15), in g / L; Q 泥- ------ Mud flow rate into the mixer (15), in m 3 / h; D------flocculant unit consumption, that is, the amount of flocculation required for one ton of absolute dry sludge, in kg / t; c------The concentration of flocculant solution; that is, the weight ratio of the dissolved flocculant to the flocculant solution, unit ‰; ρ 药 ----- is the mass of flocculant per unit volume, in kg / m 3 .

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