Combined skid-mounted sewage treatment system and working method

Abstract

The invention relates to a combined skid-mounted sewage treatment system. The system comprises a pipeline mixer, an elliptical stacked machine, an air flotation device, a sludge tank and a stacked screw machine. The combined skid-mounted sewage treatment system disclosed by the invention has the beneficial effects that the combined skid-mounted sewage treatment system is mounted on a skid-mounted device adopting a compact design and modular components, can be directly put into a 40-chi container, and is very suitable for being used in sewage treatment scenes in places with limited spaces; high mobility is achieved, the device can be easily transported to a needed place and can be rapidly assembled and disassembled, and excessive transportation cost does not need to be consumed; the solid-liquid separation work can be conveniently carried out in the sewage treatment process; and the treated wastewater can reach the reinjection standard, so that cyclic utilization is realized, water resources are saved, and the dosage of chemical agents can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated water resource management, and in particular relates to a combined skid-mounted sewage treatment system and a working method. Background Art

[0002] Traditional skid-mounted sewage treatment equipment requires regular inspection, cleaning, and replacement of parts. The normal operation of the equipment also requires professional operation and management, and the labor and material costs are high. In addition, the sewage sludge mixture obtained by traditional skid-mounted sewage treatment equipment during sewage treatment needs to be transported to professional solid-liquid separation equipment for solid-liquid separation. The transportation cost is high, and the solid-liquid separation equipment is very easy to clog. There are many mechanical moving parts in traditional skid-mounted sewage treatment equipment, and its stability and reliability are low. Summary of the invention

[0003] The object of the present invention is to overcome the deficiencies in the prior art and to provide a combined skid-mounted sewage treatment system and a working method.

[0004] This combined skid-mounted sewage treatment system is installed on multiple skids and includes: a pipeline mixer, an elliptical stacker, an air flotation device, a sludge tank and a spiral stacker;

[0005] The pipeline mixer is provided with a sewage inlet and a sewage outlet, the water inlet main pipe for conveying the sewage to be treated is connected to the sewage inlet of the pipeline mixer, and the sewage outlet of the pipeline mixer is connected to the elliptical mixer through a sewage pipe;

[0006] The elliptical stacker is provided with a sludge discharge pipe and a sludge filtrate discharge pipe, wherein the sludge discharge pipe is connected to the sludge inlet provided on the sludge pool, and the sludge filtrate discharge pipe is connected to the liquid inlet on the air flotation device;

[0007] The air flotation device is provided with a mud discharge port, which is connected to the sludge tank through a pipeline; the air flotation device is also provided with an emptying port, which is connected to the air flotation filtrate collection device provided in the outside through an air flotation filtrate emptying pipeline; a scraping device is provided in the air flotation device;

[0008] A sludge outlet is provided on the sludge pool, the sludge outlet of the sludge pool is connected to a sludge pump, and the sludge pump is connected to a screw stacking machine.

[0009] Preferably, the pipeline mixer is a static pipeline mixer, and the sewage outlet of the pipeline mixer is also connected to the emptying pipeline A; a mixing unit is fixedly provided in the mixing pipeline of the static pipeline mixer, and the mixing unit is used to change the flow state of the fluid in the static pipeline mixer, so that different fluids are fully mixed and a good dispersion effect is achieved. No mechanical moving parts are arranged in the pipeline mixer, so the pipeline mixer has a high degree of stability and reliability.

[0010] As a preferred embodiment: the pipeline mixer, the elliptical stacker and the flotation device are each provided with a matching dosing device, which does not require manual intervention, can improve work efficiency and accuracy, and is simple and convenient to operate, reducing manual intervention and operational complexity; a spiral feeder is used inside the device to add powder, and the speed is closed-loop controlled to ensure uniform, dispersed and high-precision feeding; the elliptical stacker is also connected to the emptying pipeline B; the part of the dosing device that contacts the medium is made of stainless steel, which has good corrosion resistance.

[0011] As a preference: the dosing device is a three-chamber automatic dosing device (the device is a highly integrated integrated design, integrating multiple parts such as dissolving medicine and storing liquid, with a compact design, easy to install and use); or the dosing device includes a medicine storage device and a dosing pump; the dosing device is made of PP material, which has good acid and alkali resistance, oil resistance and solvent resistance, is not easily corroded by chemicals, can be used for a long time at high temperature, has good heat resistance, can be sterilized at a temperature above 100°C, and will not deform at 150°C without external force. In addition, it has excellent mechanical properties, with relatively high strength, hardness and elasticity, especially its resistance to bending fatigue.

[0012] Preferably: a centrifugal pump is provided on the sludge filtrate discharge pipeline of the elliptical stacker, and the centrifugal pump is used to convey the sludge filtrate treated by the elliptical stacker to the flotation device (the centrifugal pump has a simple and compact structure. For the same conveying volume, the centrifugal pump occupies a small area, is light in weight, consumes less material, and has a lower foundation requirement than a double-layer pump, so the installation cost is low); the centrifugal pump is directly connected to a pole or pole motor, and the transmission structure is simple and easy to install; there is no valve in the centrifugal pump, so it is suitable for conveying suspensions, and the special design can also convey suspensions of large solids, and the centrifugal pump has fewer parts, fewer failures, is durable, has low maintenance costs, is easy to manage, and works reliably, and its output can be arbitrarily adjusted by the discharge valve or even fully closed, and there is no danger of unlimited increase in the pressure head.

[0013] As a preferred embodiment: a sludge screw pump is also provided in the elliptical stacking machine, and the sludge screw pump is used to pump the sludge in the elliptical stacking machine into the sludge discharge pipe; a sludge screw pump is provided on the connecting pipe between the sludge discharge port on the flotation device and the sludge pool, and the sludge screw pump is used to collect the sludge and scum obtained by the flotation device into the sludge pool; a sludge screw pump matched with the screw stacking machine is also provided, and is used to discharge the sludge from the screw stacking machine; the sludge screw pump has a simple internal structure, is not easily susceptible to wear, has low maintenance costs, and has a long service life; the pump has a stable transmission and a very low operating noise compared to other pumps. It is particularly advantageous when conveying high-viscosity liquids, and effectively avoids problems such as cavitation and reflux during fluid pumping, so that the flow rate and pressure are stable; the sludge screw pump has strong adaptability to the medium, is not prone to blockage anomalies, and is suitable for conveying various high-viscosity, high-temperature, easy-to-crystallize, and highly corrosive liquids; and the pump has good self-priming ability and can overcome the suction resistance of the liquid to a certain extent; the screw stacking machine and the flotation device are also connected to an emptying pipe C.

[0014] As a preferred embodiment: elliptical disks are continuously arranged in the elliptical stacking machine, the elliptical disks are fixed on the rotor, and the rotor is electrically connected to the driving device; the elliptical disks can rotate continuously between the gaps in the elliptical stacking machine, thereby realizing the solid-liquid separation of the pretreated sewage entering the elliptical stacking machine, and at the same time also having the effect of cleaning the inside of the elliptical stacking machine.

[0015] Preferably, the sludge pool is of a cone structure, which has a larger bottom area than the prior art, so that suspended solids are accumulated more evenly at the bottom of the sludge pool, shortening the time required for solid sedimentation and improving solid sedimentation efficiency; the bottom of the cone-shaped sludge pool has a certain slope from the periphery to the center, so that the solids settled at the bottom of the sludge pool are more easily concentrated to the center of the pool, which is convenient for cleaning and reduces the accumulation of bottom sludge.

[0016] The working method of the combined skid-mounted sewage treatment system includes the following steps:

[0017] Step 1: The sewage to be treated is passed into the pipeline mixer, and the pipeline mixer pre-treats the sewage: the pipeline mixer mixes the sewage flowing through the pipeline mixer evenly; at the same time, the supporting dosing device of the pipeline mixer provides acidic or alkaline agents into the pipeline mixer according to the sewage quality;

[0018] Step 2: The sewage pre-treated by the pipeline mixer flows into the elliptical stacker through the sewage outlet on the pipeline mixer. The elliptical stacker performs a second treatment on the sewage flowing into it: the dosing device adds medicine into the elliptical stacker according to the water quality of the sewage entering the elliptical stacker; the elliptical stacker performs solid-liquid separation on the sewage without vibration and noise. The driving device works, and the elliptical disks continuously arranged in the elliptical stacker rotate continuously between the gaps in the elliptical stacker under the drive of the rotating rotor, and the gaps in the elliptical stacker are cleaned while the solid-liquid separation is performed to prevent the elliptical stacker from being blocked. , the processing capacity will not decrease due to blockage; ensure the efficient operation and long-term stability of the equipment; there is no need to backwash the gaps of the elliptical stacker, so it is relatively easy to maintain, and its simple structure reduces the need for maintenance. The elliptical stacker can be widely used in various sludge dehydration, especially for sludge dehydration of oily garbage, pasture feces, crushed garbage, plastics and other industries; the rotation of the rotor transports the solids produced by solid-liquid separation, thereby improving the processing efficiency; the moisture content of the sludge obtained after solid-liquid separation by the elliptical stacker is 78%-85%;

[0019] Step 3: The sludge filtrate obtained by the second treatment of the elliptical stacker is transported to the flotation device by a centrifugal pump, and the sludge separated by the second treatment is pumped into the sludge tank by the sludge screw pump (the sludge tank is a commonly used facility in the wastewater treatment system, mainly used for sedimentation and centralized treatment. The structure of the tank is relatively simple, and it does not require high-intensity operation. The maintenance cost is low and it has the characteristics of high efficiency and stability; and compared with other large-scale sewage treatment equipment, the cone sludge tank occupies a smaller area and is suitable for use in limited spaces such as skid-mounted); the flotation device performs a third treatment on the sludge filtrate;

[0020] Step 4, the sludge and scum obtained by the third treatment of the flotation device are pumped into the sludge pool by the sludge screw pump; the flotation filtrate obtained by the third treatment of the flotation device is discharged through the drain port on the flotation device; the sludge gathered in the sludge pool is pumped into the screw stacker by the sludge screw pump; the screw stacker further separates the solid and liquid of the sludge entering therein, and then squeezes and dehydrates it (the screw stacker uses the screw extrusion principle, the extrusion force generated by the change of the screw diameter and pitch, and the tiny gap between the floating ring and the fixed ring to achieve the extrusion dehydration of the sludge), and dehydrates the sludge to a set moisture content range for subsequent transportation and disposal; the screw stacker can separate solid impurities and suspended matter in sewage, improve the treatment effect of wastewater, the equipment is compact in design, small in footprint, simple to operate, can realize continuous unmanned operation, and has corrosion resistance, can operate stably in harsh environments, and its self-cleaning function also reduces maintenance costs and water consumption.

[0021] Preferably, in step 3, when the flotation device performs the third treatment on the sludge filtrate: the matching dosing device injects the agent into the flotation device according to the water quality of the sludge filtrate in the flotation device, so as to improve the sewage treatment effect of the flotation device; the highly dispersed tiny bubbles generated by the flotation device make the surface of the suspended particles hydrophobic and easy to adhere to the tiny bubbles, so that the density of the suspended particles is reduced and floats to the water surface to form a foam layer, and then the foam layer is scraped off by the scraping device to complete the solid-liquid separation or liquid-liquid separation, and remove the suspended matter and pollutants (such as grease, fiber, heavy metal ions, etc.) in the sludge filtrate.

[0022] The beneficial effects of the present invention are:

[0023] The mixing pipe of the static pipeline mixer of the present invention is fixedly provided with a mixing unit body, and the mixing unit body is used to change the flow state of the fluid in the static pipeline mixer, so that different fluids are fully mixed and a good dispersion effect is achieved. No mechanical moving parts are arranged in the pipeline mixer, so the pipeline mixer has high stability and reliability;

[0024] The present invention continuously arranges elliptical plates in the elliptical stacking machine, and the elliptical plates can rotate continuously between the gaps in the elliptical stacking machine, thereby achieving solid-liquid separation of the pre-treated sewage entering the elliptical stacking machine, and also achieving the effect of cleaning the inside of the elliptical stacking machine;

[0025] The sludge pool of the present invention is a cone structure, which has a larger bottom area than the prior art, so that the suspended matter is accumulated more evenly at the bottom of the sludge pool, shortening the time required for solid sedimentation and improving the solid sedimentation efficiency;

[0026] The combined skid-mounted sewage treatment system designed in the present invention is installed on a skid with compact design and modular components, and can be directly placed in a 40-foot container. It is very suitable for use in sewage treatment scenarios in places with limited space (such as military camps, temporary construction sites, mining operations, etc.); it is highly mobile, can be easily transported to where it is needed, can be quickly installed and disassembled, and does not require excessive transportation costs; it is also convenient for solid-liquid separation during sewage treatment; the wastewater treated by the combined skid-mounted sewage treatment system of the present invention can meet the reinjection standard, achieve recycling, save water resources, and reduce the use of chemical agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a combined skid-mounted sewage treatment system according to an embodiment of the present invention.

[0028] Explanation of the accompanying drawings: pipeline mixer 1, sewage inlet 2, sewage outlet 3, dosing device 4, dosing pump 5, water inlet main pipe 6, emptying pipe A7, elliptical stacking machine 8, centrifugal pump 9, sludge pump 10, sludge discharge pipe 11, emptying pipe B12, sludge filtrate discharge pipe 13, emptying pipe C14, sewage pipe 15, flotation device 16, sludge tank 17, flotation filtrate emptying pipe 19, screw stacking machine 20. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0030] Example 1

[0031] like Figure 1 As shown, a combined skid-mounted sewage treatment system includes a 1# skid, a 2# skid and a 3# skid; the 1# skid is equipped with a pipeline mixer 1, a dosing device 4 (chemical dosing device HTJY1000PP (chemical), an alkali dosing device HTJY2000PP (alkali) and an acid dosing device HTJY2000PP (acid)) and three sets of matching dosing pumps 5 (one for use and one for standby); the 2# skid is equipped with an elliptical stacker 8 (KDS1224), matching filtrate centrifugal pumps 9 (one for use and one for standby), a PA C's dosing device 4 (HTJY3000PP (PAC)), 304PAM's dosing device 4 (HTJY2000 (304PAM)), two sets of matching dosing pumps 5 and 1# sludge screw pump; 3# skid is equipped with air flotation device 16 (DAF15), sludge tank 17, screw stacking machine 20 (MDS312), 304PAM's dosing device (HTJY1000 (304PAM)), matching dosing pumps (one for use and one for backup), 2# sludge screw pump and 3# sludge screw pump.

[0032] The contact part between the dosing device and the medium is made of stainless steel, which has good corrosion resistance; the dosing device is made of PP material, which has good acid and alkali resistance, oil resistance and solvent resistance, is not easily corroded by chemicals, and can be used for a long time at high temperature. It has good heat resistance and can be sterilized at a temperature above 100°C. It will not deform at 150°C without external force. It also has excellent mechanical properties, with high strength, hardness and elasticity, especially its resistance to bending fatigue.

[0033] The pipeline mixer 1 is provided with a sewage inlet 2 and a sewage outlet 3. The water inlet main pipe 6 for conveying the sewage to be treated is connected to the sewage inlet 2 of the pipeline mixer 1. The sewage outlet 3 of the pipeline mixer 1 is connected to the elliptical mixer 8 through a sewage pipe 15. The sewage outlet 3 of the pipeline mixer 1 is also connected to an emptying pipe A7. A mixing unit is fixedly provided in the mixing pipe of the static pipeline mixer. The mixing unit is used to change the flow state of the fluid in the static pipeline mixer so that different fluids are fully mixed and a good dispersion effect is achieved. No mechanical moving parts are provided in the pipeline mixer, so the pipeline mixer has a high degree of stability and reliability.

[0034] The elliptical stacking machine 8 is provided with a sludge discharge pipe 11 and a sludge filtrate discharge pipe 13, wherein the sludge discharge pipe 11 is connected to the sludge inlet provided on the sludge tank 17, and the sludge filtrate discharge pipe 13 is connected to the liquid inlet on the flotation device 16; the elliptical stacking machine 8 is also connected to an emptying pipe B12; a centrifugal pump 9 is provided on the sludge filtrate discharge pipe 13 of the elliptical stacking machine 8, and the centrifugal pump 9 is used to transport the sludge filtrate treated by the elliptical stacking machine 8 to the flotation device 16. The centrifugal pump has a simple and compact structure and is easy to use. The centrifugal pump occupies a small area, is light in weight, consumes less materials, and has a lower foundation requirement than a double pump, so the installation cost is low); the centrifugal pump adopts a 2-pole or 4-pole motor direct connection, and the transmission structure is simple and easy to install; there is no valve in the centrifugal pump, so it is suitable for conveying suspensions. The special design can also convey suspensions of large solids. In addition, the centrifugal pump has few parts, few failures, is durable, has low maintenance costs, is easy to manage, and works reliably. The output can be adjusted arbitrarily by the discharge valve or even fully closed, and there will be no unlimited increase in pressure head. Danger; a sludge screw pump is also provided in the elliptical stacking machine 8, and the sludge screw pump is used to pump the sludge in the elliptical stacking machine into the sludge discharge pipe; a sludge screw pump is provided on the connecting pipe between the sludge discharge port on the flotation device 16 and the sludge tank 17, and the sludge screw pump is used to collect the sludge and scum obtained by the flotation device into the sludge tank; a sludge screw pump matched with the screw stacking machine 20 is also provided, and is used to discharge the sludge from the screw stacking machine; the sludge screw pump has a simple internal structure, is not easily susceptible to wear, has low maintenance costs, and has a long service life; the pump transmission Smooth operation, with much lower operating noise than other pumps, is particularly advantageous when conveying high-viscosity liquids, effectively avoiding cavitation, backflow and other problems during fluid pumping, and making flow and pressure stable; the sludge screw pump has strong adaptability to the medium, is not prone to blockage, and is suitable for conveying various high-viscosity, high-temperature, easy-to-crystallize, and highly corrosive liquids; and the pump has good self-priming ability, which can overcome the suction resistance of the liquid to a certain extent; the screw stacking machine 20 and the air flotation device 16 are also connected to the emptying pipe C14;

[0035] The elliptical discs are continuously arranged in the elliptical stacking machine 8, and the elliptical discs are fixed on the rotor, and the rotor is electrically connected to the driving device; the elliptical discs can rotate continuously between the gaps in the elliptical stacking machine 8, so as to achieve the solid-liquid separation of the pre-treated sewage entering the elliptical stacking machine, and also play the effect of cleaning the inside of the elliptical stacking machine;

[0036] The air flotation device 16 is provided with a mud discharge port, which is connected to the sludge tank 17 through a pipeline; the air flotation device 16 is also provided with an emptying port, which is connected to the air flotation filtrate collection device provided in the outside through the air flotation filtrate emptying pipeline 19; the air flotation device 16 is provided with a scraping device;

[0037] A sludge outlet is provided on the sludge pool 17, and the sludge outlet of the sludge pool 17 is connected to the sludge pump 10, and the sludge pump 10 is connected to the screw stacking machine 20; the sludge pool 17 is a cone structure, and compared with the prior art, the sludge pool has a larger bottom area, so that the suspended matter is accumulated more evenly at the bottom of the sludge pool, shortening the time required for solid sedimentation and improving the solid sedimentation efficiency; the bottom of the cone-structured sludge pool 17 has a certain slope from the periphery to the center, so that the solids settled at the bottom of the sludge pool are more easily concentrated to the center of the pool, which is convenient for cleaning and reduces the accumulation of bottom mud.

[0038] Example 2

[0039] On the basis of Example 1, this example provides a working method of the combined skid-mounted sewage treatment system in Example 1: the sewage is first preliminarily treated by the 1# skid-mounted static pipeline mixer, and then flows to the 2# skid-mounted elliptical stacker for secondary treatment. The sludge treated by the elliptical stacker enters the 3# skid-mounted sludge pool, and the sludge filtrate of the elliptical stacker enters the 3# skid-mounted flotation device for the third treatment. The sewage treated by the flotation device also flows into the sludge pool, and is finally pumped into the screw stacker by the sludge pump for comprehensive treatment.

[0040] Step 1, the sewage to be treated is passed into the pipeline mixer 1, and the pipeline mixer 1 pre-treats the sewage: the pipeline mixer 1 mixes the sewage flowing through the pipeline mixer 1 evenly; at the same time, the supporting dosing device 4 of the pipeline mixer 1 provides chemical agents into the pipeline mixer 1 according to the sewage quality, and the dosing device HTJY1000PP (chemical) and the supporting dosing pump (one for use and one for standby) provide chemical agents into the pipeline mixer 1; the dosing device HTJY2000PP (alkali) and the supporting dosing pump (one for use and one for standby) provide sodium bicarbonate into the pipeline mixer 1, which is used to soften hard water, neutralize acidic water, remove impurities such as iron and manganese in water, and can also be used to remove scale. The added pH value is 8.3 and the concentration is 0.2kg / m 3; The dosing device HTJY2000PP (acid) and the matching dosing pump (one for use and one for standby) provide oxalic acid to the pipeline mixer 1. Oxalic acid is used to remove metal ions such as calcium and magnesium in water, thereby reducing the hardness of water and improving water quality. Its dosing pH value is 2.06 and the concentration is 0.01 mol / L. The concentration protection range of oxalic acid needs to be adjusted according to specific circumstances. Generally speaking, 10 to 50 mol of oxalic acid, i.e. 900 to 4500 g of oxalic acid, can be added to 1 ton of water;

[0041] Pretreatment is an important part of the wastewater treatment process. Its purpose is to create good conditions for subsequent biological treatment or deep treatment, and to remove harmful substances in the wastewater as much as possible to ensure the treatment effect and the normal operation of the treatment equipment. Because impurities such as suspended solids, colloids, organic matter, heavy metal ions, etc. in sewage will have adverse effects on subsequent treatment processes, such as clogging filter membranes, reducing biological treatment efficiency, etc.; pretreatment can effectively remove these impurities, improve the water quality of sewage, and create good conditions for subsequent treatment; and pretreatment can reduce the concentration of pollutants in wastewater, reduce the burden of subsequent treatment, and improve the treatment efficiency of the entire sewage treatment system; at the same time, pretreatment can also prevent certain substances from damaging subsequent treatment equipment and extend the service life of the treatment equipment; in addition, the purpose of wastewater pretreatment is to provide wastewater that meets emission standards or reuse requirements for subsequent treatment. Pretreatment can reduce the concentration of pollutants in wastewater so that it meets national or regional emission standards or reuse requirements;

[0042] Step 2, the sewage pre-treated by the pipeline mixer 1 flows into the elliptical stacking machine 8 through the sewage outlet 3 on the pipeline mixer 1, and the elliptical stacking machine 8 performs a second treatment on the sewage flowing therein: the dosing device 4 adds medicine into the elliptical stacking machine 8 according to the water quality of the sewage entering the elliptical stacking machine 8; the elliptical stacking machine 8 performs solid-liquid separation on the sewage without vibration and noise, and the driving device works. The elliptical disks continuously arranged in the elliptical stacking machine 8 are driven by the rotating rotor to rotate continuously between the gaps in the elliptical stacking machine 8, and the gaps in the elliptical stacking machine 8 are cleaned while the solid-liquid separation is performed to prevent The elliptical stacker is prevented from being blocked, and the processing capacity will not be reduced due to blockage; the efficient operation and long-term stability of the equipment are ensured; there is no need to backwash the gaps of the elliptical stacker, so it is relatively easy to maintain, and its simple structure reduces the need for maintenance. The elliptical stacker can be widely used in various sludge dehydration, especially for sludge dehydration of oily garbage, pasture feces, crushed garbage, plastics and other industries; the rotation of the rotor transports the solids produced by solid-liquid separation, thereby improving the processing efficiency; the moisture content of the sludge obtained after solid-liquid separation by the elliptical stacker is 78%-85%;

[0043] Step 3, the sludge filtrate obtained by the second treatment of the elliptical stacker 8 is transported to the flotation device 16 by the centrifugal pump 9, and the sludge separated by the second treatment is pumped into the sludge tank 17 by the sludge screw pump (the sludge tank is a commonly used facility in the wastewater treatment system, mainly used for sedimentation and centralized treatment. The structure of the tank is relatively simple, and it does not require high-intensity operation. The maintenance cost is low and it has the characteristics of high efficiency and stability; and compared with other large-scale sewage treatment equipment, the cone sludge tank occupies a smaller area and is suitable for use in limited spaces such as skid-mounted);

[0044] Secondary sewage treatment is a process for further purifying sewage. It is carried out after pretreatment, and its main purpose is to remove organic matter in pretreated sewage. This process can significantly reduce pollutants in sewage, so that it can meet the requirements of agricultural irrigation water and wastewater discharge standards. Specifically, secondary treatment can remove nutrients in sewage, such as BOD, nitrogen, phosphorus, etc., which is crucial to reduce or eliminate pollution to water bodies. Although sewage after secondary treatment may still cause pollution to natural water bodies under certain conditions, this risk can be significantly reduced by fully removing the biological content in human excrement, food residues, soap water and washing water.

[0045] The flotation device 16 performs a third treatment on the sludge filtrate: the matching dosing device HTJY3000PP (PAC) and the matching dosing pump (one for use and one for standby) inject PAC reagent into the flotation device 16 according to the water quality of the sludge filtrate in the flotation device 16; the matching dosing device HTJY2000 (304PAM) and the matching dosing pump (one for use and one for standby) inject PAM reagent into the flotation device 16 according to the water quality of the sludge filtrate in the flotation device 16 to improve the sewage treatment effect of the flotation device; the highly dispersed tiny bubbles generated by the flotation device 16 make the surface of the suspended particles hydrophobic and easy to adhere to the tiny bubbles, so that the density is reduced and floats to the water surface to form a foam layer, and then the foam layer is scraped off by the scraping device to complete the solid-liquid separation or liquid-liquid separation, and remove the suspended matter and pollutants (such as grease, fiber, heavy metal ions, etc.) in the sludge filtrate;

[0046] The skid-mounted system is a tertiary treatment of sewage. The main function of the tertiary sewage treatment is to further purify the water quality, eliminate pollution, and ensure that the water quality meets strict environmental protection emission standards or reuse standards. As the last level of the three levels of sewage treatment, it is a measure for advanced sewage treatment. The goal of this stage is to further remove the non-biodegradable organic matter, phosphorus, nitrogen and other nutrients in the sewage, as well as possible pathogens, on the basis of secondary treatment, by using flotation and spiral stacking machines. Tertiary treatment can significantly improve water quality and ensure that the water quality reaches higher standards. The tertiary sewage treatment of the skid-mounted system plays an indispensable role in ensuring the safety of the water environment and improving the efficiency of water resource utilization.

[0047] Step 4: The sludge and scum obtained by the third treatment of the flotation device 16 are pumped into the sludge tank 17 by the sludge screw pump; the flotation filtrate obtained by the third treatment of the flotation device 16 is discharged through the emptying port on the flotation device 16; the sludge gathered in the sludge tank 17 is pumped into the screw stacking machine 20 (MDS312) by the sludge screw pump; the screw stacking machine is provided with dosing by the dosing device HTJY1000 (304PAM) and the matching dosing pump (one for use and one for backup); the screw stacking machine 20 further separates the solid and liquid of the sludge entering therein, and then squeezes and dehydrates it (the screw stacking machine passes Through the screw extrusion principle, the extrusion force generated by the change of screw diameter and pitch, as well as the tiny gap between the floating ring and the fixed ring, is used to extrude and dehydrate the sludge, and dehydrate the sludge to the set moisture content range for subsequent transportation and disposal; the screw stacking machine can separate solid impurities and suspended matter in sewage and improve the treatment effect of wastewater. The equipment has a compact design, small footprint, simple operation, and can achieve continuous unmanned operation. It is also corrosion-resistant and can operate stably in harsh environments. Its self-cleaning function also reduces maintenance costs and water consumption.

[0048] The combined skid-mounted sewage treatment system can achieve rapid and efficient gel breaking and viscosity reduction by adopting a specific treatment process, while efficiently removing many pollutants such as suspended solids, oil, colloids, etc., so as to achieve real-time and efficient treatment of fracturing return fluid, meet the reinjection standard, and be recycled; this treatment method can not only save water resources and reduce the amount of chemical agents, but also reduce pollution to the environment. Its high treatment efficiency and small footprint make the system outstanding in terms of treatment efficiency and environmental friendliness. In addition, the design of the skid-mounted sewage treatment equipment takes into account the mobility and flexibility of the equipment, and can quickly establish sewage treatment facilities in different locations, with strong adaptability and stable and reliable treatment effects; the customizable design of this equipment can be adjusted according to different water quality and treatment requirements to meet specific needs; the installation and transportation of the equipment is also extremely convenient, without the need to build a separate equipment room, and the ground installation method is convenient for later maintenance and repair, and it also has the characteristics of low temperature resistance, ensuring stable operation under various environmental conditions. In summary, these three sets of skid-mounted integrated sewage treatment systems have become ideal choices for treatment projects of various sizes due to their high efficiency, energy saving, environmental protection, as well as their mobility and flexibility. They are of great significance for improving water quality and protecting the environment.

Claims

1. A combined skid-mounted sewage treatment system, the combined skid-mounted sewage treatment system is installed on multiple skids, characterized in that: The combined skid-mounted sewage treatment system comprises: a pipeline mixer (1), an elliptical stacker (8), an air flotation device (16), a sludge tank (17) and a spiral stacker (20); The pipeline mixer (1) is provided with a sewage inlet (2) and a sewage outlet (3); a water inlet main pipe (6) for conveying sewage to be treated is connected to the sewage inlet (2) of the pipeline mixer (1); and the sewage outlet (3) of the pipeline mixer (1) is connected to the elliptical stacker (8) via a sewage pipe (15); The elliptical stacker (8) is provided with a sludge discharge pipe (11) and a sludge filtrate discharge pipe (13), wherein the sludge discharge pipe (11) is connected to a sludge inlet provided on the sludge pool (17), and the sludge filtrate discharge pipe (13) is connected to a liquid inlet on the air flotation device (16); The air flotation device (16) is provided with a mud discharge port, which is connected to the sludge pool (17) through a pipeline; the air flotation device (16) is also provided with an emptying port, which is connected to the outside world through an air flotation filtrate emptying pipeline (19); and a scraping device is provided inside the air flotation device (16); A mud outlet is provided on the mud pool (17), the mud outlet of the mud pool (17) is connected to a mud pump (10), and the mud pump (10) is connected to a screw stacking machine (20).

2. The combined skid-mounted sewage treatment system according to claim 1 is characterized in that: The pipeline mixer (1) is a static pipeline mixer. The sewage outlet (3) of the pipeline mixer (1) is also connected to an emptying pipeline A (7). A mixing unit is fixedly provided in the mixing pipeline of the static pipeline mixer.

3. The combined skid-mounted sewage treatment system according to claim 1 is characterized in that: The pipeline mixer (1), the elliptical stacker (8) and the air flotation device (16) are each provided with a matching dosing device (4); the elliptical stacker (8) is also connected to an exhaust pipe B (12); and the part of the dosing device (4) that contacts the medium is made of stainless steel.

4. The combined skid-mounted sewage treatment system according to claim 3 is characterized in that: The dosing device (4) is a three-chamber automatic dosing device (4); or the dosing device (4) comprises a medicine storage device and a dosing pump (5); and the dosing device (4) is made of PP material.

5. The combined skid-mounted sewage treatment system according to claim 1 is characterized in that: A centrifugal pump (9) is provided on the sludge filtrate discharge pipe (13) of the elliptical stacker (8), and the centrifugal pump (9) is used to transport the sludge filtrate treated by the elliptical stacker (8) to the air flotation device (16).

6. The combined skid-mounted sewage treatment system according to claim 1 is characterized in that: The elliptical stacking machine (8) is also provided with a sludge screw pump; a sludge screw pump is provided on the connecting pipe between the sludge discharge port on the air flotation device (16) and the sludge pool (17); a sludge screw pump matching the screw stacking machine (20) is also provided; the screw stacking machine (20) and the air flotation device (16) are also connected to an emptying pipe C (14).

7. The combined skid-mounted sewage treatment system according to claim 1 is characterized in that: The elliptical discs are continuously arranged in the elliptical stacking machine (8), and the elliptical discs are fixed on a rotor, and the rotor is electrically connected to a driving device; the elliptical discs can rotate continuously between the gaps in the elliptical stacking machine (8).

8. The combined skid-mounted sewage treatment system according to claim 1 is characterized in that: The sludge pool (17) is a cone-shaped structure; the bottom of the cone-shaped sludge pool (17) has a certain slope from the periphery to the center.

9. A method for operating the combined skid-mounted sewage treatment system according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, the sewage to be treated is passed into the pipeline mixer (1), and the pipeline mixer (1) pre-treats the sewage: the pipeline mixer (1) mixes the sewage flowing through the pipeline mixer (1) uniformly; at the same time, the matching dosing device (4) of the pipeline mixer (1) provides an acidic agent or an alkaline agent into the pipeline mixer (1) according to the sewage quality; Step 2, the sewage pre-treated by the pipeline mixer (1) flows into the elliptical stacking machine (8) through the pipeline through the sewage outlet (3) on the pipeline mixer (1), and the elliptical stacking machine (8) performs a second treatment on the sewage flowing therein: the dosing device (4) adds medicine into the elliptical stacking machine (8) according to the water quality of the sewage entering the elliptical stacking machine (8); the elliptical stacking machine (8) performs solid-liquid separation on the sewage, the driving device works, and the elliptical disks continuously arranged in the elliptical stacking machine (8) are driven by the rotating rotor to rotate continuously between the gaps in the elliptical stacking machine (8), thereby performing solid-liquid separation and cleaning the gaps in the elliptical stacking machine (8); the rotation of the rotor transports the solids generated by the solid-liquid separation; Step 3, the sludge filtrate obtained after the second treatment by the elliptical stacker (8) is transported to the flotation device (16) by the centrifugal pump (9), and the sludge separated by the second treatment is pumped into the sludge tank (17) by the sludge screw pump; the flotation device (16) performs a third treatment on the sludge filtrate; Step 4, the sludge and scum obtained after the third treatment by the flotation device (16) are pumped into the sludge pool (17); the flotation filtrate obtained after the third treatment by the flotation device (16) is discharged through the discharge port on the flotation device (16); the sludge gathered in the sludge pool (17) is pumped into the screw stacking machine (20); the screw stacking machine (20) further separates the solid and liquid of the sludge entering therein, and then squeezes and dehydrates the sludge to a set moisture content range.

10. The working method of the combined skid-mounted sewage treatment system according to claim 9, characterized in that: When the flotation device (16) performs the third treatment on the sludge filtrate in step 3: the matching dosing device (4) injects a reagent into the flotation device (16) according to the water quality of the sludge filtrate in the flotation device (16); the highly dispersed micro-bubbles generated by the flotation device (16) cause the suspended particles to adhere to the micro-bubbles and float to the water surface to form a foam layer, and then the foam layer is scraped off by a scraping device to remove the suspended matter and pollutants in the sludge filtrate.

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