CN210751617U - Automatic back flush filter of sewage strip - Google Patents

Abstract

The utility model relates to the technical field of filters, and aims to provide an automatic back-washing filter for sewage stripping, which comprises a filtering system and a back-washing system; the filtering system comprises a plurality of groups of filtering tanks, and a water inlet pipe and a water outlet pipe which are respectively connected with the upper end and the lower end of each filtering tank; the back flushing system comprises a displacement liquid pipe and a back flushing liquid pipe which are respectively connected with a water inlet pipe and a water outlet pipe, and the water inlet pipe is also connected with a drain pipe; when the filter material in the filter tank is blocked under the action of impurities and soft coke asphalt substances, the water inlet pipe is closed first, and purified water is introduced into the filter tank through the displacement pipe and the sewage is displaced; then the water outlet pipe is closed, the backwashing liquid pipe and the sewage discharge pipe are opened, and backwashing water is used for washing the filter material, so that automatic backwashing of the filter tank is realized; and when a group of filter tanks are subjected to backwashing, other filter tanks are in a normal filtering state, so that the filter system does not need to be stopped, the continuous effective operation of the filter system can be ensured, and the economic benefit is high.

Description

Automatic back flush filter of sewage strip

Technical Field

The utility model relates to the technical field of filters, in particular to automatic back flush filter of sewage strip.

Background

In the oil refining chemical industry, an atmospheric and vacuum distillation unit, a heavy oil catalytic unit, a hydrofining unit, a coking unit and the like all generate acidic sewage, the acidic sewage is an aqueous solution containing volatile weak electrolytes such as H2S, NH3, CO2 and the like, and contains pollutants such as phenol, cyanide, oil and the like, and the acidic sewage can cause great harm to the environment when directly discharged, so that the acidic sewage can be discharged only after the pollutants in the water reach a certain standard after being treated.

At present, the acidic stripping of the sewage is usually carried out by adopting a sewage stripping device in China, a single-tower pressurization side-draw stripping process is adopted, high-temperature steam is utilized to be in direct contact with the sewage, volatile harmful substances in the sewage are diffused into a gas phase according to a certain proportion, the water quality is purified and then discharged, and meanwhile, ammonia gas, ammonia water and acidic gas are extracted. The purified water can be used as the top of the catalytic fractionating tower and the electric desalting and water injection of an atmospheric and vacuum device, the ammonia water can be used as agricultural fertilizer, and the acid gas can be used as the raw material of a sulfur device.

However, the sewage also contains coke powder and soft coke asphalt substances generated by the polymerization of a coking device, which are not traditionally recognized physical particles and other impurities, and after the sewage enters a sewage stripping device, crystals are generated to block a hydrogen sulfide pipeline on one hand, so that a side line system is blocked, and other equipment is scaled or blocked, so that the following problems are caused: the pressure at the tower top is increased, and hydrogen sulfide is not discharged; hydrogen sulfide flow indication returns to zero, and tower top temperature decreases; the hydrogen sulfide content in the ammonia gas is increased; the hydrogen sulfide content in the purified water increases. More importantly, the heat supply, the hydrogen sulfide discharge amount, the ammonia circulation ratio and the oil removal which influence the stable operation of the stripping tower are four main factors, so that the sulfur-containing sewage cannot be separated, ammonia gas, ammonia water and acid gas cannot be extracted, the atmospheric pollution is increased, the discharge indexes cannot meet the national standard, and the economic benefit of the device is influenced.

For this reason, the raw sewage must be subjected to filtration of impurities and soft coke-like pitch substances before stripping. And the filter material is usually filled in the existing filter to form a filter layer for filtering, soft coke asphalt substances can be accumulated in the filter layer after working for a period of time, the filtering effect is influenced, the filter material needs to be shut down and manually cleaned, the operation is troublesome, and the economic benefit is low.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an automatic back flush filter of sewage strip has the back flush function, can show reduction human cost, improvement economic benefits.

The above technical purpose of the present invention can be achieved by the following technical solutions:

an automatic back-flushing filter for stripping sewage comprises a water inlet main pipe, a water outlet main pipe, a filtering tank and a back-flushing system; the filter tanks are provided with at least two groups, including a group A of filter tanks and a group B of filter tanks; the group A filter tanks and the group B filter tanks are internally provided with filter components; the upper branch of the water inlet main pipe is provided with a group A of water inlet pipes connected to the upper ends of the group A of filter tanks, and one end of the group A of water inlet pipes close to the water inlet main pipe is provided with a water inlet control valve; the upper branch of the water outlet main pipe is provided with a group A of water outlet pipes connected to the lower ends of the group A of filter tanks, and one end of the group A of water outlet pipes close to the water outlet main pipe is provided with a water outlet control valve; the backwashing system comprises a backwashing liquid header pipe, the upper branch of the backwashing liquid header pipe is provided with a group A backwashing liquid pipe connected to a group A water outlet pipe, and the group A backwashing liquid pipe is provided with a backwashing control valve; the A group of the water inlet pipes are connected with A group of the blow-off pipes, and the A group of the blow-off pipes are provided with blow-off control valves; the B group of filter tanks are connected with the same B group of water inlet pipes, B group of water outlet pipes, B group of backwashing liquid pipes and B group of sewage pipes.

Through adopting above-mentioned technical scheme, let in A group's filtration jar and B group's filtration jar and other groups filtration jar respectively with raw materials sewage through water inlet manifold to utilize filter assembly to filter, the filtered sewage after the filtration then flows out and gets into sewage steam stripping device through water outlet manifold. When the filtering assemblies in the A group of filtering tanks or the B group of filtering tanks or other groups of filtering tanks are blocked under the action of impurities and soft coke asphalt substances, so that the filtering speed is continuously reduced, closing the water inlet control valve on the corresponding water inlet pipe and the water outlet control valve on the corresponding water outlet pipe, enabling the group of filtering tanks to be in an off-line state in the filtering system, taking the A group of filtering tanks as an example, then opening the backwashing control valve on the A group backwashing liquid pipe and the sewage discharge control valve on the A group of sewage discharge pipes, introducing backwashing water into the A group of filtering tanks from bottom to top through the A group backwashing liquid pipe, flushing the filtering assemblies in the A group of filtering tanks by utilizing the backwashing water, and discharging the flushed impurities and soft coke asphalt substances upwards through the A group of sewage discharge pipes, namely completing the backwashing operation on the A group of filtering tanks, and having simple operation and low labor cost; then closing the backwashing control valve and the sewage discharge control valve, and re-opening the water inlet control valve and the water outlet control valve, so that the group A of filter tanks can re-enter the filter system, and performing backwashing operation on other groups of filter tanks in the same way; and when any group of filter tanks is subjected to back washing, at least one group of filter tanks in other groups of filter tanks is in a normal filtering state, so that the filter system does not need to be stopped, the continuous and effective operation of the filter system can be ensured, and the economic benefit is high.

The utility model discloses further set up to: the backwash system further comprises a displacement fluid main pipe; the upper branch of the replacement liquid main pipe is provided with a group A of replacement liquid pipes and a group B of replacement liquid pipes which are respectively connected with a group A of water inlet pipes and a group B of water inlet pipes; and the group A liquid displacement pipe and the group B liquid displacement pipe are both provided with a displacement control valve.

By adopting the technical scheme, taking the group A filter tank as an example, when the group A filter tank is subjected to backwashing operation, the water outlet control valve is not closed firstly after the water inlet control valve is closed, the replacement control valve on the group A replacement liquid pipe is opened, purified water is introduced into the group A filter tank through the group A replacement liquid pipe, and a sewage medium in the group A filter tank is completely replaced by the purified water. After the sewage is replaced, the water outlet control valve is closed, the backwashing control valve and the sewage discharge control valve are opened for backwashing, only purified water is left in the group A of filter tanks at the moment, the same purified water is used as backwashing water to perform backwashing on the filter assembly, and the flushed filtered water does not contain harmful substances such as H2S, NH3, CO2 and the like in the raw sewage which need to be stripped, so that the pollution to the environment caused by direct discharge is avoided.

The utility model discloses further set up to: a filter cavity is arranged in the filter tank; the filter assembly comprises a filter layer filled in the filter cavity and a water collector arranged at the bottom of the filter cavity; the water collector comprises a plurality of water collecting rods which are uniformly arranged along the circumferential direction of the center of the bottom of the filter cavity, and the water collecting rods are of hollow structures and are communicated with the water outlet pipe; a plurality of filter elements are arranged on the water collecting rod at intervals along the length direction of the water collecting rod.

By adopting the technical scheme, when the filter tank is in a normal filtering state, the raw material sewage entering the filter cavity is filtered by the filter layer, the contact area of the plurality of water collecting rods and the filtered sewage is increased, the filtered sewage can be uniformly collected and led out, the filtered sewage is further filtered by the filter element on the water collecting rod, and the filter material in the filter layer is prevented from entering the water collecting rod; when the filtering tank is in an off-line backwashing state, backwashing water is uniformly diffused to the bottom of the filtering cavity through the water collecting rod, so that the filtering layer is washed upwards comprehensively, and the backwashing effect can be improved.

The utility model discloses further set up to: the filter element comprises a circular tubular filter element and an end cover for plugging an opening at the end part of the filter element; the filtering element is formed by spirally winding metal wires with wedge-shaped sections, and a filtering gap is formed between every two adjacent layers of metal wires; the wedge-shaped section of the metal wire is arranged with a narrow inner part and a wide outer part.

By adopting the technical scheme, the filtering gap is provided with a V-shaped opening by the metal wire with the wedge-shaped section, and the opening at the outward side of the filtering gap is small; when the filtering tank is in a normal filtering state, the smaller outer side opening can effectively block larger particle impurities in the filtered sewage, and the opening is gradually enlarged inwards, so that the smaller particle impurities can be prevented from being blocked in a filtering gap, and the filtering smoothness is ensured; when the filtering tank is in an off-line backwashing state, backwashing water flows outwards from the inner side of the filtering piece through the water collecting rod communicated with the water outlet pipe, and the gradually reduced filtering gap increases the water pressure of the backwashing water after passing through, so that the backwashing effect is enhanced, and impurity particles blocked at the opening at the outer side of the filtering gap can be flushed out.

The utility model discloses further set up to: the filter layer comprises an upper filter layer, a middle filter layer and a lower filter layer which are distributed from top to bottom, and an upper filter material, a middle filter material and a lower filter material with gradually increased particle sizes are respectively filled in the upper filter layer, the middle filter layer and the lower filter layer.

By adopting the technical scheme, the filter material of the upper filter layer has small grain size, so that the gaps between the filter material and the upper filter layer are small, and the blocking effect on impurities with larger volume and soft coke asphalt substances is strong; the filter material particle size of the middle filter layer and the filter material particle size of the lower filter layer are large, so that when backwashing is carried out, backwashing water is washed upwards from bottom to top, the filter material is loosened more easily through gaps, the filter material particles are scrubbed mutually, and when the backwashing water enters the upper filter layer upwards, the backwashing water still can have large kinetic energy, and an impurity layer formed by intercepting impurities above the upper filter layer can be effectively scoured, so that the backwashing efficiency is improved to the maximum extent, and the required backwashing water and backwashing time are shortened. And through the even arrangement of collector pipe for the backwash water can wash the filter material in the same horizontal plane uniformly when upward movement, avoids producing the random flow, makes the phenomenon that the filter material in different intraformational layers appears mixing under random flow strikes.

The utility model discloses further set up to: the backwashing system also comprises a purified air main pipe; the upper branch of the purified air main pipe is provided with a group A of purified air pipes and a group B of purified air pipes which are respectively connected with a group A of water outlet pipes and a group B of water outlet pipes; and the A group of purification air pipes and the B group of purification air pipes are provided with purification air control valves.

Through adopting above-mentioned technical scheme, use A group's canister as an example, when carrying out the back flush to A group's canister, open the backwash control valve and open the purification wind control valve simultaneously to utilize the air compressor machine to let in compressed air in A group's canister, utilize compressed air and backwash water to wash the filter material simultaneously, make the filter material change in not hard up, thereby realize better scrubbing effect.

The utility model discloses further set up to: the backwashing system also comprises a backwashing steam main pipe; the backwashing steam main pipe is provided with a group A of backwashing steam pipes and a group B of backwashing steam pipes in a branching manner, and the group A of backwashing steam pipes and the group B of backwashing steam pipes are respectively connected to one ends of the group A of water outlet pipes and the group B of water outlet pipes, which are far away from the water outlet main pipe; the A group of backwashing steam pipes and the B group of backwashing steam pipes are both provided with steam control valves; the group A steam release pipe and the group B steam release pipe are respectively connected to the group A water inlet pipe and the group B water inlet pipe, and the group A steam release pipe and the group B steam release pipe are respectively provided with a steam release control valve; and the other ends of the group A steam release pipe and the group B steam release pipe are both connected with a torch system.

By adopting the technical scheme, the raw material sewage contains certain oil stains, so that the filter material is hardened after being used for a long time, the hardened filter material is difficult to clean through backwashing, and the oil stains need to be removed by using high-temperature steam; taking the A group of filter tanks as an example, closing all other pipelines connected to the A group of water inlet pipes and the A group of water outlet pipes, opening the steam control valve and the steam release control valve, introducing high-temperature steam into the A group of filter tanks by using the A group of water outlet pipes, taking oil stains condensed on filter materials out of the A group of steam release pipelines above the A group of filter tanks by using the steam, and introducing the oil stains into a torch system for combustion treatment, thereby achieving the effect of removing the oil stains.

The utility model discloses further set up to: the device also comprises a heat tracing system; the heat tracing system comprises a group A heat tracing inlet pipe and a group A heat tracing outlet pipe, and a group B heat tracing inlet pipe and a group B heat tracing outlet pipe which are used for conveying steam or hot water; a heat tracing cavity for wrapping the tank body is arranged on the outer side of the filtering tank; the group A heat tracing inlet pipe and the group A heat tracing outlet pipe are both communicated with the heat tracing cavity on the surface of the group A filter tank; and the group B heat tracing inlet pipe and the group B heat tracing outlet pipe are both communicated with the heat tracing cavity on the surface of the group B filter tank.

By adopting the technical scheme, according to the viscosity and physical property characteristics of the sewage, the temperature of the sewage is maintained within a certain specific range by introducing steam or hot water into the heat tracing cavity as external heat tracing, so that the viscosity of the sewage is most beneficial to filtering and backwashing.

The utility model discloses further set up to: the automatic control system is also included; the automatic control system comprises a PLC controller and a differential pressure transmitter which is connected between the water inlet main pipe and the water outlet main pipe and is electrically connected with the PLC controller; the water inlet control valve, the water outlet control valve, the backwashing control valve, the replacement control valve and the sewage discharge control valve are all electrically connected with the PLC, and the PLC can respectively control the opening and closing of the water inlet control valve, the water outlet control valve, the backwashing control valve, the replacement control valve and the sewage discharge control valve.

By adopting the technical scheme, the pressure head loss in each group of filtering tanks is monitored by using a differential pressure transmitter, and when the pressure head loss of inlet water and outlet water reaches a set value, the PLC automatically controls each valve to realize replacement and backwashing operation; and the PLC controller can control each group of filter tanks to carry out periodic backwashing at fixed time through a timer, and when the filter system runs to a set time, the replacement and backwashing operation is also automatically carried out.

The utility model discloses further set up to: the group A of filter tanks is provided with at least two, including a group A of first filter tanks and a group A of second filter tanks; the group A water inlet pipe comprises a first water inlet branch pipe and a second water inlet branch pipe which are connected to the upper ends of the group A first filter tank and the group A second filter tank in a branching manner; the A group of water outlet pipes comprise a first water outlet branch pipe and a second water outlet branch pipe which are connected to the bottoms of the A group of first filter tanks and the A group of second filter tanks in a branching mode.

By adopting the technical scheme, the plurality of filter tanks are used as a group to simultaneously carry out filtration, replacement and backwashing, the treatment capacity of the filter system is increased, and the burden of the automatic control system is reduced.

To sum up, the beneficial effects of the utility model are that:

1. raw material sewage is respectively introduced into the group A of filter tanks, the group B of filter tanks and other groups of filter tanks through a water inlet main pipe, and is filtered by utilizing the filter assembly, and the filtered sewage flows out through a water outlet main pipe and enters a sewage stripping device. When the filtering assemblies in the A group of filtering tanks or the B group of filtering tanks or other groups of filtering tanks are blocked under the action of impurities and soft coke asphalt substances, so that the filtering speed is continuously reduced, closing the water inlet control valve on the corresponding water inlet pipe and the water outlet control valve on the corresponding water outlet pipe, enabling the group of filtering tanks to be in an off-line state in the filtering system, taking the A group of filtering tanks as an example, then opening the backwashing control valve on the A group backwashing liquid pipe and the sewage discharge control valve on the A group of sewage discharge pipes, introducing backwashing water into the A group of filtering tanks from bottom to top through the A group backwashing liquid pipe, flushing the filtering assemblies in the A group of filtering tanks by utilizing the backwashing water, and discharging the flushed impurities and soft coke asphalt substances upwards through the A group of sewage discharge pipes, namely completing the backwashing operation on the A group of filtering tanks, and having simple operation and low labor cost; then closing the backwashing control valve and the sewage discharge control valve, and re-opening the water inlet control valve and the water outlet control valve, so that the group A of filter tanks can re-enter the filter system, and performing backwashing operation on other groups of filter tanks in the same way; when any group of filter tanks is subjected to back washing, at least one group of filter tanks in other groups of filter tanks is in a normal filtering state, so that the filter system does not need to be stopped, the continuous and effective operation of the filter system can be ensured, and the economic benefit is high;

2. the metal wire with the wedge-shaped cross section enables the filtering gap to be a V-shaped opening, and the opening at the outward side of the filtering gap is small; when the filtering tank is in a normal filtering state, the smaller outer side opening can effectively block larger particle impurities in the filtered sewage, and the opening is gradually enlarged inwards, so that the smaller particle impurities can be prevented from being blocked in a filtering gap, and the filtering smoothness is ensured; when the filter tank is in an off-line backwashing state, backwashing water flows outwards from the inner side of the filter element through the water collecting rod communicated with the water outlet pipe, and the gradually reduced filter gap increases the water pressure of the backwashing water after passing through, so that the backwashing effect is enhanced, and impurity particles blocked at the opening at the outer side of the filter gap can be flushed out;

3. the filter material of the upper filter layer has small grain size, so that the gaps among the filter materials are small, and the blocking effect on impurities with larger volume and soft coke asphalt substances is strong; the filter material particle size of the middle filter layer and the filter material particle size of the lower filter layer are large, so that when backwashing is carried out, backwashing water is washed upwards from bottom to top, the filter material is loosened more easily through gaps, the filter material particles are scrubbed mutually, and when the backwashing water enters the upper filter layer upwards, the backwashing water still can have large kinetic energy, and an impurity layer formed by intercepting impurities above the upper filter layer can be effectively scoured, so that the backwashing efficiency is improved to the maximum extent, and the required backwashing water and backwashing time are shortened. And through the even arrangement of collector pipe for the backwash water can wash the filter material in the same horizontal plane uniformly when upward movement, avoids producing the random flow, makes the phenomenon that the filter material in different intraformational layers appears mixing under random flow strikes.

Drawings

FIG. 1 is a schematic diagram of the overall system of the present invention;

FIG. 2 is a schematic view of the structure of the group A canister of the present invention;

fig. 3 is a schematic structural view of the water collector of the present invention;

fig. 4 is a schematic cross-sectional view of a filter cartridge according to the present invention.

Reference numerals: 1. a filtration system; 11. a filter tank; 111. group A of filter tanks; 1111. a group A first canister; 1112. a group A second canister; 112. group B of filter tanks; 113. a heat tracing cavity; 114. a filter chamber; 12. a water inlet main pipe; 121. a group of water inlet pipes; 13. a water outlet main pipe; 131. a group A of water outlet pipes; 132. discharging the pipeline; 2. a backwash system; 21. a replacement fluid main pipe; 211. group A displacement liquid pipe; 22. a backwash liquid header pipe; 221. a group of backwashing liquid pipes; 23. a main purified air pipe; 231. a group of purified air pipes; 24. backwashing the steam main pipe; 241. a group of backwashing steam pipes; 25. a group A of blow-off pipes; 26. group A of steam release pipes; 3. a heat tracing system; 31. group A heat tracing inlet pipe; 32. group A heat tracing outlet pipe; 4. an automatic control system; 41. a PLC controller; 42. a differential pressure transmitter; a. a water inlet control valve; b. a water outlet control valve; c. a replacement control valve; d. a backwash control valve; e. a purified air control valve; f. a blowdown control valve; g. a steam control valve; h. a steam release control valve; 5. a filter assembly; 51. a filter layer; 511. an upper filtering layer; 512. a middle filtering layer; 513. a lower filtering layer; 52. a water collector; 521. a water collection rod; 522. a filter element; 5221. a filter element; 5222. an end cap; 5223. the gap is filtered.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The embodiment discloses an automatic back-flushing filter for sewage stripping, which comprises a filtering system 1, a back-flushing system 2, a heat tracing system 3 and an automatic control system 4, as shown in fig. 1 and 2.

As shown in fig. 1 and 2, the filtration system 1 includes a plurality of sets of filtration tanks 11, a water inlet main pipe 12 and a water outlet main pipe 13 connected to the filtration tanks 11; wherein, a filtering cavity 114 is arranged in the filtering tank 11, a filtering component 5 for filtering impurities and soft coke asphalt substances is arranged in the filtering cavity 114, the water inlet main pipe 12 is responsible for providing raw material sewage, and the water outlet main pipe 13 is responsible for discharging the filtered sewage into the sewage stripping device.

The filtration tanks 11 are sequentially arranged into a group A of filtration tanks 111, a group B of filtration tanks 112 and a group … … X of filtration tanks, the water inlet main pipe 12 is provided with a group A water inlet pipe 121, a group B water inlet pipe and a group … … X water inlet pipe which are respectively connected with the group A filtration tanks 111, the group B filtration tanks 112 and the group … … X filtration tanks, and the water outlet main pipe 13 is provided with a group A water outlet pipe 131, a group B water outlet pipe and a group … … X water outlet pipe which are respectively connected with the group A filtration tanks 111, the group B filtration tanks 112 and the group … … X filtration tanks. One end of each group of water inlet pipes close to the water inlet main pipe 12 is provided with a water inlet control valve a; and one end of each group of water outlet pipes close to the water outlet main pipe 13 is provided with a water outlet control valve b.

Each group of filter tanks 11 comprises a plurality of filter tanks 11 connected in parallel, and for example, the group A of filter tanks 111 comprises a group A first filter tank 1111, a group A second filter tank 1112 and a group … … A Y filter tank, the branch on the group A water inlet pipe 121 is provided with a first water inlet branch pipe, a second water inlet branch pipe and a … … Y water inlet branch pipe which are respectively connected with the top ends of the group A first filter tank 1111, the group A second filter tank 1112 and the group … … A Y filter tank, the branch on the group A water outlet pipe 131 is provided with a first water outlet branch pipe, a second water outlet branch pipe and a … … Y water outlet branch pipe which are respectively connected with the bottom of the group A first filter tank 1111, the group A second filter tank 1112 and the group … … A Y filter tank. The plurality of filter tanks 11 are used as a group to simultaneously carry out filtration, replacement and backwashing, so that the treatment efficiency of the filter system 1 is improved, and the burden of the automatic control system 4 is reduced.

As shown in fig. 1 and 2, the backwash system 2 includes a displacement liquid header pipe 21, a backwash liquid header pipe 22, a purge air header pipe 23, and a backwash steam header pipe 24. The displacement liquid main pipe 21 and the backwash liquid main pipe 22 are both connected to a purified water source, the purified air main pipe 23 is connected to an air compressor, and the backwash steam main pipe 24 is connected to a steam generator.

The upper branch of the replacement liquid main pipe 21 is provided with a group A of replacement liquid pipes 211, a group B of replacement liquid pipes and a group … … X of replacement liquid pipes which are respectively connected with the group A of water inlet pipes 121, the group B of water inlet pipes and the group … … X of water inlet pipes, and each group of replacement liquid pipes is provided with a replacement control valve c; the backwash liquid header pipe 22 is provided with a group A backwash liquid pipe 221, a group B backwash liquid pipe and a group … … X backwash liquid pipe which are respectively connected with the group A water outlet pipe 131, the group B water outlet pipe and the group … … X water outlet pipe in a branching manner, and each group of backwash liquid pipes is provided with a backwash control valve d; the purified air main pipe 23 is branched and provided with a group A of purified air pipes 231, a group B of purified air pipes and a group … … X of purified air pipes which are respectively connected with the group A of water outlet pipes 131, the group B of water outlet pipes and the group … … X of water outlet pipes, and each group of purified air pipes is provided with a purified air control valve e; the A group of the water inlet pipes 121, the B group of the water inlet pipes and the … … X group of the water inlet pipes are respectively connected with the A group of the blow-off pipes 25, the B group of the blow-off pipes and the … … X group of the blow-off pipes, and each group of the blow-off pipes is provided with a blow-off control valve f.

Raw material sewage is respectively introduced into the group A of filter tanks 111, the group B of filter tanks 112 and other groups of filter tanks 11 through the water inlet main pipe 12 and is filtered by the filter assembly 5, and the filtered sewage flows out through the water outlet main pipe 13 and enters the sewage stripping device. When the filtering components 5 in one group of filtering tanks 11 are blocked under the action of impurities and soft coke asphalt substances, so that the filtering speed is continuously reduced, the backwashing operation is required to be carried out:

taking the group A of the filter tanks 111 as an example, the water inlet control valve a on the group A of the water inlet pipes 121 is closed first, so that the group A of the filter tanks 111 are in a semi-off-line state in the filter system 1; then, the replacement control valve c on the group A replacement liquid pipe 211 is opened, purified water is introduced into the group A filter tank 111 through the group A replacement liquid pipe 211, the sewage medium in the group A filter tank 111 is completely replaced by the purified water, and since the raw sewage itself contains a large amount of water, the filtered sewage replaced by the purified water can be directly discharged into the sewage stripping device through the group A water outlet pipe 131 without additional treatment; after the replacement is finished, closing the water outlet control valve b on the water outlet pipe 131 of the group A, so that the filter tank 111 of the group A is in a completely off-line state in the filter system 1; then, opening a backwashing control valve d on the group A backwashing liquid pipe 221, a purified air control valve e on the group A purified air pipe 231 and a sewage discharge control valve f on the group A sewage discharge pipe 25, simultaneously introducing backwashing water and compressed air into the group A filter tank 111 from bottom to top, and simultaneously washing the filter assembly 5 by using the compressed air and the backwashing water; because only purified water is left in the group A filter tanks 111 after replacement, the same purified water is used as backwash water to backwash the filter assembly 5, so that the flushed filtered water does not contain harmful substances such as H2S, NH3 and CO2 in raw material sewage and the like needing steam stripping, the pollution to the environment caused by direct discharge is avoided, and the flushed impurities and soft coke asphalt substances are upwards discharged through the group A drain pipes 25, namely the backwash operation on the group A filter tanks 111 is completed, the operation is simple, and the labor cost is low; then, the backwashing control valve d and the sewage discharge control valve f are closed, and the water inlet control valve a and the water outlet control valve b are opened again, so that the group A of filter tanks 111 can enter the filter system 1 again; the other groups of filter tanks 11 are backwashed by the same method, and the filter system 1 keeps at least one group of filter tanks 11 in an off-line state for rotation in normal operation, so that when any group of filter tanks 11 is backwashed, at least one group of filter tanks 11 in the other groups of filter tanks 11 is in a normal filtering state, and the filter tanks 11 after backwashing are kept in an off-line state for standby, so that the filter system 1 does not need to be stopped, the continuous effective operation of the filter system 1 can be ensured, and the economic benefit is high.

As shown in fig. 2, the filter assembly 5 includes a filter layer 51 filled in the filter chamber 114, and a water collector 52 installed at the bottom of the filter chamber 114. The filtering layer 51 comprises an upper filtering layer 511, a middle filtering layer 512 and a lower filtering layer 513 which are distributed from top to bottom, wherein upper filtering materials, middle filtering materials and lower filtering materials with gradually increased particle sizes are respectively filled in the upper filtering layer 511, the middle filtering layer 512 and the lower filtering layer 513, and the filtering materials of the upper filtering layer 511 have small particle sizes, so that gaps among the filtering materials are small, and the blocking effect on impurities with large volumes and soft coke asphalt substances is strong; the filter materials of the middle filter layer 512 and the lower filter layer 513 have large particle sizes, so that when backwashing is performed, backwashing water and compressed air are washed upwards from bottom to top, the filter materials are loosened more easily through gaps, the filter material particles are scrubbed mutually, and when the backwashing water enters the upper filter layer 511 upwards, the backwashing water still has large kinetic energy, and an impurity layer formed by intercepting impurities above the upper filter layer 511 can be effectively washed away, so that the backwashing efficiency is improved to the maximum extent, and the required backwashing water and backwashing time are reduced.

As shown in fig. 2 and 3, the water collector 52 comprises six water collecting rods 521 uniformly arranged in an umbrella rib shape along the circumferential direction of the bottom center of the filter cavity 114; the water collecting rod 521 is of a hollow structure, and the middle intersection of the six water collecting rods 521 is downward communicated with the water outlet pipe; the water collecting rod 521 is provided with a plurality of filter elements 522 at intervals along the length direction thereof. The contact area between the filtered sewage and the plurality of water collecting rods 521 is increased, the filtered sewage can be uniformly collected and led out, the filtered sewage is further filtered by using the filter element 522 on the water collecting rods 521, and the filter material in the filter layer 51 is prevented from entering the water collecting rods 521; a water distributor with a structure similar to that of the water collecting rod 521 is connected to the water inlet pipe above the filter tank 11, so that raw material sewage can uniformly enter the filter layer 51 downwards and uniformly drain upwards; when the filter tank 11 is in an off-line backwashing state, backwashing water is uniformly diffused to the bottom of the filter cavity 114 through the water collecting rod 521, so that the filter layer 51 is washed upwards comprehensively, and the backwashing effect can be improved.

As shown in fig. 3 and 4, the filter element 522 comprises a filter element 5221 which is in a round tube shape and is downwards communicated with the inner cavity of the water collecting rod 521, and an end cover 5222 for blocking the end opening of the filter element 5221; the filtering element 5221 is formed by spirally winding a metal wire with a wedge-shaped cross section, and the wedge-shaped cross section is narrow inside and wide outside, so that a filtering gap 5223 with a V-shaped opening is formed between two adjacent layers of metal wires. The opening on the outward side of the filtering gap 5223 is small, when the filtering tank 11 is in a normal filtering state, the small opening on the outer side can effectively block the larger particle impurities in the filtered sewage, and the opening is gradually enlarged inwards, so that the small particle impurities can be prevented from being blocked in the filtering gap 5223, and the filtering smoothness is ensured; when the filter tank 11 is in an off-line backwashing state, backwashing water and compressed air flow outwards from the inner side of the filter element 5221 through the water collecting rod 521 communicated with the water outlet pipe, and the gradually reduced filter gap 5223 increases the water pressure of the backwashing water after passing through, so that the backwashing effect is enhanced, and impurity particles blocked at the opening at the outer side of the filter gap 5223 can be flushed out.

As shown in fig. 1 and 2, the backwash steam main pipe 24 is branched and provided with a group a of backwash steam pipes 241, a group B of backwash steam pipes and a group … … X of backwash steam pipes which are respectively connected with a group a of water outlet pipes 131, a group B of water outlet pipes and a group … … X of water outlet pipes, and each group of backwash steam pipes is provided with a steam control valve g; the group A steam release pipes 26, the group B steam release pipes and the group … … X steam release pipes are respectively connected to the group A water inlet pipe 121, the group B water inlet pipe and the group … … X water inlet pipe, and each group of steam release pipes is provided with a steam release control valve h; the other ends of the group A steam release pipe 26, the group B steam release pipe and the group … … X steam release pipe are all connected with ground torches, and the ground torches comprise combustion towers and ignition devices. Because raw material sewage contains certain oil stains, the filter material can be hardened after the sewage is used for a long time, the hardened filter material is difficult to clean through backwashing, and the oil stains need to be removed by high-temperature steam; taking the group a of filter tanks 111 as an example, all other pipelines connected to the group a of water inlet pipes 121 and the group a of water outlet pipes 131 are closed, the steam control valve g and the steam release control valve h are opened, high-temperature steam is introduced into the group a of filter tanks 111 through the group a of water outlet pipes 131, oil dirt condensed on the filter material is taken out from the group a of steam release pipes 26 above through the steam, and the oil dirt is introduced into the combustion tower for combustion treatment, so that the oil dirt removing effect is achieved.

As shown in fig. 1, the heat tracing system 3 includes a group a heat tracing inlet pipe 31 and a group a heat tracing outlet pipe 32 for conveying steam or hot water, a group B heat tracing inlet pipe and a group B heat tracing outlet pipe, … … a group X heat tracing inlet pipe and a group X heat tracing outlet pipe; the outer side of the filtering tank 11 is provided with a heat tracing cavity 113 for wrapping the tank body, and the heat tracing inlet pipe and the heat tracing outlet pipe are respectively communicated with the lower end and the upper end of the heat tracing cavity 113. According to the characteristics of the viscosity and physical properties of the sewage, the temperature of the sewage is maintained within a certain specific range by introducing steam or hot water into the heat tracing cavity 113 as external tracing heat, so that the viscosity of the sewage is most beneficial to filtering and backwashing.

As shown in fig. 1, the automatic control system 4 includes a PLC controller 41, and differential pressure transmitters 42 connected between the water inlet main pipe 12 and the water outlet main pipe 13 and between each group of water inlet pipes and water outlet pipes, the PLC controller 41 adopts a siemens S7-200 control system, and the differential pressure transmitters 42 are electrically connected with the PLC controller 41; the water inlet control valve a, the water outlet control valve b, the backwashing control valve d, the replacement control valve c, the purified air control valve e and the sewage discharge control valve f are all pneumatic butterfly valves and are all electrically connected with the PLC 41; and the steam control valve g and the steam release control valve h are manual gate valves and are operated by manual control. The pressure head loss in each group of filter tanks 11 is monitored by using a differential pressure transmitter 42, and when the pressure head loss of inlet water and outlet water reaches a set value, the PLC 41 automatically controls each valve to realize replacement and backwashing operation; and the PLC 41 can control each group of filter tanks 11 to carry out periodic backwashing at fixed time through a timer, and when the filter system 1 runs to a set time, the replacement and backwashing operation is also automatically carried out.

As shown in FIG. 1, the bottoms of the A group of filter tanks 111, the B group of filter tanks 112 and the … … X group of filter tanks are connected with a purge pipeline 132, and the purge pipeline 132 is provided with a manual gate valve for completely discharging the liquid medium in each group of filter tanks 11 for convenient maintenance.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Claims (10)

1. An automatic back-flushing filter for sewage stripping comprises a water inlet main pipe (12), a water outlet main pipe (13), a filtering tank (11) and a back-flushing system (2); the filter tanks (11) are provided with at least two groups, including a group A of filter tanks (111) and a group B of filter tanks (112); the group A of filter tanks (111) and the group B of filter tanks (112) are internally provided with filter components (5); a group of water inlet pipes (121) connected to the upper ends of the group A of filter tanks (111) are arranged on the upper branch of the water inlet main pipe (12), and a water inlet control valve (a) is arranged at one end, close to the water inlet main pipe (12), of each group A of water inlet pipes (121); the upper branch of the water outlet main pipe (13) is provided with a group A of water outlet pipes (131) connected to the lower ends of the group A of filter tanks (111), and one end of the group A of water outlet pipes (131) close to the water outlet main pipe (13) is provided with a water outlet control valve (b); the backwashing system (2) comprises a backwashing liquid header pipe (22), an A group of backwashing liquid pipes (221) connected to an A group of water outlet pipes (131) are arranged on the backwashing liquid header pipe (22) in a branching manner, and a backwashing control valve (d) is arranged on the A group of backwashing liquid pipes (221); the A group of the water inlet pipes (121) is connected with an A group of the sewage discharge pipes (25), and a sewage discharge control valve (f) is arranged on the A group of the sewage discharge pipes (25); the group B filter tank (112) is connected with the same group B water inlet pipe, group B water outlet pipe, group B backwashing liquid pipe and group B sewage pipe.

2. The sewage stripping automatic backwashing filter of claim 1, wherein: the backwashing system (2) further comprises a replacement fluid main pipe (21); the upper branch of the replacement liquid main pipe (21) is provided with a group A of replacement liquid pipes (211) and a group B of replacement liquid pipes which are respectively connected with a group A of water inlet pipes (121) and a group B of water inlet pipes; and the group A liquid displacement pipe (211) and the group B liquid displacement pipe are both provided with a displacement control valve (c).

3. The sewage stripping automatic backwashing filter of claim 1, wherein: a filter cavity (114) is arranged in the filter tank (11); the filter assembly (5) comprises a filter layer (51) filled in the filter cavity (114) and a water collector (52) arranged at the bottom of the filter cavity (114); the water collector (52) comprises a plurality of water collecting rods (521) which are uniformly arranged along the circumferential direction of the center of the bottom of the filter cavity (114), and the water collecting rods (521) are of hollow structures and are communicated with the water outlet pipe; a plurality of filter elements (522) are arranged on the water collecting rod (521) at intervals along the length direction of the water collecting rod.

4. The sewage stripping automatic backwashing filter of claim 3, wherein: the filter element (522) comprises a tubular filter element (5221) and an end cover (5222) for plugging the end opening of the filter element (5221); the filtering element (5221) is formed by spirally winding metal wires with wedge-shaped sections, and a filtering gap (5223) is formed between every two adjacent layers of metal wires; the wedge-shaped section of the metal wire is arranged with a narrow inner part and a wide outer part.

5. The sewage stripping automatic backwashing filter of claim 3, wherein: the filter layer (51) comprises an upper filter layer (511), a middle filter layer (512) and a lower filter layer (513) which are distributed from top to bottom, wherein an upper filter material, a middle filter material and a lower filter material with gradually increased particle sizes are respectively filled in the upper filter layer (511), the middle filter layer (512) and the lower filter layer (513).

6. The sewage stripping automatic backwashing filter of claim 1, wherein: the backwashing system (2) also comprises a purified air main pipe (23); the upper branch of the purified air main pipe (23) is provided with a group A of purified air pipes (231) and a group B of purified air pipes which are respectively connected with a group A of water outlet pipes (131) and a group B of water outlet pipes; and the A group of purification air pipes (231) and the B group of purification air pipes are both provided with purification air control valves (e).

7. The sewage stripping automatic backwashing filter of claim 1, wherein: the backwashing system (2) further comprises a backwashing steam main pipe (24); a group of backwashing steam pipes (241) and a group of backwashing steam pipes B are arranged on the backwashing steam main pipe (24) in a branching manner, and the group A of backwashing steam pipes (241) and the group B of backwashing steam pipes are respectively connected to one ends, far away from the water outlet main pipe (13), of the group A of water outlet pipes (131) and the group B of water outlet pipes; the A group of backwashing steam pipes (241) and the B group of backwashing steam pipes are both provided with a steam control valve (g); the group A water inlet pipe (121) and the group B water inlet pipe are respectively connected with a group A steam release pipe (26) and a group B steam release pipe, and the group A steam release pipe (26) and the group B steam release pipe are respectively provided with a steam release control valve (h); the other ends of the group A steam release pipe (26) and the group B steam release pipe are both connected with a torch system.

8. The sewage stripping automatic backwashing filter of claim 1, wherein: also comprises a heat tracing system (3); the heat tracing system (3) comprises a group A heat tracing inlet pipe (31) and a group A heat tracing outlet pipe (32) for conveying steam or hot water, and a group B heat tracing inlet pipe and a group B heat tracing outlet pipe; a heat tracing cavity (113) which wraps the tank body is arranged at the outer side of the filter tank (11); the group A heat tracing inlet pipe (31) and the group A heat tracing outlet pipe (32) are both communicated with a heat tracing cavity (113) on the surface of the group A filter tank (111); the group B heat tracing inlet pipe and the group B heat tracing outlet pipe are both communicated with a heat tracing cavity (113) on the surface of the group B filter tank (112).

9. The sewage stripping automatic backwashing filter of claim 2, wherein: the automatic control system (4) is also included; the automatic control system (4) comprises a PLC (programmable logic controller) controller (41) and a differential pressure transmitter (42) which is connected between the water inlet main pipe (12) and the water outlet main pipe (13) and is electrically connected with the PLC controller (41); the water inlet control valve (a), the water outlet control valve (b), the backwashing control valve (d), the replacement control valve (c) and the sewage discharge control valve (f) are all electrically connected with the PLC (41), and the PLC (41) can respectively control the opening and closing of the water inlet control valve (a), the water outlet control valve (b), the backwashing control valve (d), the replacement control valve (c) and the sewage discharge control valve (f).

10. The sewage stripping automatic backwashing filter of claim 1, wherein: the group A of filter tanks (111) is provided with at least two, including a group A first filter tank (1111) and a group A second filter tank (1112); the group A water inlet pipe (121) comprises a first water inlet branch pipe and a second water inlet branch pipe which are connected to the upper ends of the group A first filter tank (1111) and the group A second filter tank (1112) in a branching manner; the group A water outlet pipe (131) comprises a first water outlet branch pipe and a second water outlet branch pipe which are connected to the bottoms of the group A first filter tank (1111) and the group A second filter tank (1112) in a branching mode.

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