CN212334813U - Closed oily sewage treatment plant - Google Patents

Abstract

The utility model discloses a closed oily sewage treatment device, wherein the upper part in a tank body is an adjusting section, and the lower part is a homogenizing section; an oil-water separation unit is arranged in the homogenizing section; the device comprises a circulating water distribution assembly fixed at the liquid level of a homogenizing section, wherein the assembly is connected with a sewage inlet on the side wall of a tank body and is used for enabling sewage to enter the homogenizing section along the annular direction to form circulation so as to generate oil-water separation; the device also comprises a purified water collecting component at the lower part of the homogenizing section, which is connected with a purified water outlet on the side wall of the tank body and is used for receiving and discharging the purified water which moves downwards after oil-water separation; the oil collecting assembly is arranged in the center of the tank body and communicated with an oil discharge port arranged on the side wall of the tank body; the lower part of the tank body is provided with a homogenizing unit, and the bottom of the tank body is provided with a sludge scraping unit for homogenizing and discharging sludge. The utility model discloses not only safe and reliable can high-efficient separation water, oil and solid sludge moreover, and can long period operation.

Description

Closed oily sewage treatment plant

Technical Field

The utility model belongs to the technical field of sewage treatment, a closed oily sewage treatment plant is related to.

Background

The oil removing treatment of oily sewage in petroleum and chemical enterprises is generally composed of a lifting tank, an adjusting tank, a homogenizing tank, an oil separating tank and other technological facilities. The adjusting tank needs 24-48 hours of capacity to relieve the impact of incoming water and keep the downstream flow stable, and the homogenizing tank needs 12-24 hours of capacity and is matched with a stirrer to homogenize the water quality. The oil separation tank is of a horizontal slow flow structure so as to enable oil in the sewage to float upwards by gravity, and an oil (slag) scraping machine is used for removing the oil, so that the oil removal of the sewage is completed.

These prior art installations suffer from the following drawbacks: 1. the occupied area is large; 2. the oil gas pollution is serious because the pool surface is huge; 3. a cover plate can be added for preventing pollution, but an oil-gas explosion dangerous environment is easily formed; 4. the adjusting tank is used for ensuring stable outflow and coping with water inflow change, the water level of the adjusting tank is changed, otherwise, the adjusting tank has no adjusting capacity, and therefore equipment needs to be lifted after the adjusting tank is adjusted; the regulating tank has large area and long retention time, and floating oil accumulation needs to be removed by an oil scraper; because the pool surface is large, most of the pool surfaces are not provided with the oil scraper, and accumulated oil cannot be discharged; similarly, the bottom sludge cannot be removed; 5. the homogenizing tank has the same oil and sludge discharging problem as the adjusting tank; the homogenizing tank is provided with a fixed water level, stirring equipment is arranged in the homogenizing tank to enable water quality to be uniform, and the homogenizing tank is difficult to stir uniformly due to the fact that the tank surface is large, so that the equipment maintenance rate is high; 6. the oil separation tank is a facility depending on gravity separation and requires small stable flow velocity of water flow; the oil-water separation effect depends on the water flow speed, the buoyancy distance and the hydraulic retention time; the hydraulic retention time of the prior art is 1-2 hours, and the standard of the oil content of the effluent is controlled below 150 mg/L.

Chinese patent document CN104150546B proposes a closed adjusting tank for removing solids and oil to improve the oil-water separation efficiency, specifically, a filtering facility is used to remove solid sludge, the oil-containing sewage after solid removal is separated into layers by cyclone separation and density difference natural phase separation, and then discharged through different discharge ports. However, this patent has two drawbacks: firstly, the long-period operation cannot be realized, the filter is easily blocked by the solid sludge treated by the filtering device, and the long-period operation cannot be realized without the assistance of a backwashing technology; secondly, the method is unsafe, has no corresponding discharge facilities, has complex components of oily sewage and has flash explosion risk, and safety accidents are easily caused if proper discharge facilities are not arranged.

Chinese patent document CN202671253U proposes a closed oil, water and solid three-phase separation scheme using cyclone separation; specifically, the inlet water is directly conveyed into the cyclone, and oil, water and solid phases are separated by cyclone, so that the phase separation speed is increased, and the retention time is reduced. However, this solution also has significant drawbacks: the oil phase has large water content, and the oil collecting pipe directly collects the oil phase from the outlet of the cyclone, and according to the particle separation principle of the cyclone, the outlet of the cyclone is an oil-water entrained mixture, so that a large amount of water can be directly removed, and the oil-water separation can be thoroughly realized only by secondary separation; secondly, the method is unsafe, has no corresponding discharge facilities, has complex components of oily sewage and has flash explosion risk, and safety accidents are easily caused if proper discharge facilities are not arranged.

In view of the shortcomings of the prior art, there is a need for a closed oily sewage treatment device which is safe and reliable, can efficiently separate water, oil and solid sludge, and can operate for a long period.

Disclosure of Invention

To the problem that above-mentioned prior art exists, the utility model aims at providing a safe and reliable, can high-efficient separation water, oil and solid sludge, and can long period running's closed oily sewage treatment plant.

The utility model aims at providing a closed oily sewage treatment plant, the technical scheme who adopts as follows:

a closed oily sewage treatment device comprises a tank body, wherein the upper part in the tank body is an adjusting section, and the lower part in the tank body is a homogenizing section; an oil-water separation unit is arranged in the homogenizing section; the oil-water separation unit comprises a circulation water distribution assembly fixed at the liquid level of the homogenizing section, the circulation water distribution assembly is connected with a sewage inlet on the side wall of the tank body and used for enabling sewage to enter the homogenizing section in the annular direction to form circulation, free oil particles float on the water surface and accumulate towards the center of the liquid level under the action of circulation, and water moves downwards under the action of gravity to generate oil-water separation;

the water tank also comprises a purified water collecting component which is arranged at the lower part of the homogenizing section in the tank body and corresponds to the circulating water distribution component, and the purified water collecting component is connected with a purified water outlet on the side wall of the tank body and is used for receiving and discharging the purified water which moves downwards after the oil-water separation;

the oil collecting assembly is arranged in the center of the tank body and communicated with an oil outlet arranged on the side wall of the tank body;

the circulating water distribution assembly is characterized in that a homogenizing unit is further arranged on the lower side of the circulating water distribution assembly in the tank body, a sludge scraping unit is arranged on the lower side of the homogenizing unit, a sludge discharge port is formed in the bottom of the tank body, and the sludge scraping unit is matched with the sludge discharge port to discharge sludge deposited at the bottom of the tank body.

Preferably, the circulation water distribution assembly comprises a water distribution ring pipe connected with the sewage inlet, and a plurality of water distribution short pipes are distributed on the water distribution ring pipe along the tangential direction.

Furthermore, the annular diameter of the water distribution ring pipe is 0.85 to 0.95 times of the inner diameter of the tank body.

Furthermore, the diameter of the water distribution short pipe close to the sewage inlet end is smaller than that of the water distribution short pipe far away from the sewage inlet end.

Furthermore, the corresponding chord length of the interval between the adjacent water distribution short pipes is 100 and 500 mm.

Furthermore, the tangential included angle alpha between the water distribution short pipe and the water distribution circular pipe is 60-80 degrees.

Further, the length of the water distribution short pipe is 50 mm.

Preferably, the oil collecting assembly comprises an oil collecting device arranged on a central shaft of the tank body, and the oil collecting device floats on the liquid level and vertically floats between the lowest liquid level and the highest liquid level of the homogenizing section;

the bottom of the oil collector is respectively connected with a plurality of L-shaped oil conveying pipes; the vertical straight pipe sections of the L-shaped oil delivery pipes are free telescopic pipes, and the horizontal sections are arranged in a radially overhanging mode along the tank body and communicated with an oil discharge port located on the side wall of the lower portion of the tank body.

Preferably, the purified water collecting assembly comprises an annular drainage collecting pipe which is arranged at the lower part of the homogenizing section and corresponds to the circulating water distribution assembly, and water collecting holes are alternately and uniformly distributed on the side walls of two sides of the annular drainage collecting pipe along the radial direction of the tank body; the device also comprises a vertical pressure regulating pipe connected with the annular drainage collecting pipe at the lower part of the homogenizing section, and the vertical pressure regulating pipe is connected with a purified water drainage outlet on the side wall of the tank body.

Further, the homogenizing unit comprises a reflux pump arranged on the outer side of the tank body, an inlet of the reflux pump is connected with the annular drainage collecting pipe, and an outlet of the reflux pump is connected with the reflux pipeline; the backflow pipeline is connected with the sewage inlet, so that purified water returns to the sewage inlet of the tank body for homogenization.

Furthermore, the sludge scraping unit comprises a water turbine arranged at the center of the bottom of the tank body, the input end of the water turbine is communicated with the backflow pipeline, the output end of the water turbine is axially connected with a sludge scraping plate along the center of the tank body, the sludge scraping plate is positioned on the lower side of the annular drainage collecting pipe, and the diameter of the sludge scraping plate is smaller than the inner diameter of the tank body; therefore, the reflux pump drives the purified water to flow in the reflux pipeline, and further drives the water turbine to continuously operate to drive the mud scraper to scrape mud.

Furthermore, the distance between the annular drainage collecting pipe and the mud scraper is 500-1000 mm.

Furthermore, the bottom plate of the mud scraping plate and the tank body is loosely attached.

Furthermore, the diameter of the mud scraper is 0.9-0.98 times of the inner diameter of the tank body.

Furthermore, the bottom of the tank body is provided with a mud collecting hopper, and the bottom of the mud collecting hopper is provided with a mud discharging opening.

Further, the reflux pump is provided with an air suction device or adopts a dissolved air pump.

Preferably, the top of the tank body is provided with a breather valve, a nitrogen supplementing valve and a pressure measuring instrument; the device also comprises a tank nitrogen sealing pressure control system;

the breather valve, the nitrogen supplementing valve and the pressure measuring instrument are all electrically connected with the tank nitrogen seal pressure control system.

Further, the opening pressure of the breather valve is set in the tank nitrogen-sealed pressure control system: 1.5-2KPag, closing pressure is 1.1KPag, the opening pressure of the nitrogen supplementing valve is set to be 0.3KPa, and the closing pressure is set to be 0.9 KPa.

Utilize the utility model discloses an above-mentioned device can also provide a closed oily sewage treatment process, include following step:

sewage enters a circulating water distribution assembly fixed at the liquid level of a homogenizing section in the tank body from a sewage inlet, so that the sewage enters the tank body along the annular direction and forms circulating flow at the liquid level, and free oil particles in the sewage float on the water surface and are accumulated towards the center of the liquid level under the action of the circulating flow; the water moves downwards under the action of gravity and is discharged from a purified water discharge port after being collected by the purified water collecting component;

along with the prolonging of the sewage treatment time, oil drops on the water surface gradually accumulate to form an oil layer, and the oil layer is collected by the oil collecting assembly and then is discharged out of the tank body through the oil discharge port; solid impurities in water are settled by gravity and deposited at the bottom of the tank body, and the sludge in the solid-containing sewage deposited at the bottom of the tank body is removed by a sludge scraping unit;

wherein, homogeneity section department in the jar internal is in the steady state that sinks, when intake water quality of water takes place undulantly, opens the purified water backward flow that homogeneity unit will purify waste water collection assembly and collect to the sewage water inlet, carries out the homogeneity to jar internal intaking.

Preferably, sewage enters a water distribution ring pipe fixed at the liquid level of a homogenizing section in the tank body from a sewage inlet, and horizontally enters the tank along the tangential direction through a water distribution short pipe to form circulation on the liquid level, and free oil particles in the sewage directly float on the water level due to low density and are accumulated towards the center of the liquid level under the action of the circulation; the water moves downwards under the action of gravity, is collected by the annular drainage collecting pipe and is discharged through the purified water discharge port; along with the prolonging of the sewage treatment time, oil drops on the water surface gradually accumulate to form an oil layer, and the oil layer is collected by an oil collector floating on the liquid surface and is discharged out of the tank body through an oil discharge port through an L-shaped oil conveying pipe; solid impurities in water are settled by gravity and deposited at the bottom of the tank body, purified water collected by the annular drainage collecting pipe is pumped into a backflow pipeline by starting a backflow pump, the formed backflow water flow drives a water turbine to rotate, the rotating water turbine drives a mud scraper, and sludge deposited at the bottom of the tank body is sent out of the tank body; the sludge sent out of the tank body falls into a sludge accumulation hopper and is discharged through a sludge discharge port;

the homogenizing section in the tank body is in a stable sinking state, and when the quality of inlet water fluctuates, an external reflux pump is started to return purified water collected by the annular drainage and collection pipe to a sewage inlet of the tank body for homogenization; meanwhile, the backflow water flow pressurizes and drives a water turbine positioned at the center of the bottom of the tank body, and the effluent returns to a sewage inlet of the tank body for homogenization; meanwhile, the water turbine drives the mud scraper to scrape mud.

Preferably, the top of the tank body is provided with a breather valve, a nitrogen supplementing valve and a pressure measuring instrument; when the pressure of the breather valve of the tank body is higher than the set pressure, controlling the breather valve to open and the nitrogen supplement valve to close, and discharging the waste gas in the tank into the VOCs treatment system; and when the pressure of the breather valve of the tank body is lower than the set pressure, controlling the nitrogen supplementing valve to be opened and the breather valve to be closed.

The utility model discloses can bring following beneficial effect:

1) the oil-water separation device separates oil and water through the oil-water separation unit, the water enters the bottom of the tank body under the action of gravity and is discharged through the purified water collection assembly, and the oil is discharged through the oil collection assembly; solid impurities in the water are settled by gravity, deposited at the bottom of the tank body and discharged by a sludge scraping unit; the homogenizing unit can homogenize water when water inlet fluctuates, so that the treatment device integrates sewage regulation, homogenization, oil removal and sludge removal into a closed tank, has a simple structure and high integration level, greatly reduces the floor area and is about 1/4 of the prior art; the construction cost is low, and a large amount of mud scraping, oil scraping, stirring and civil engineering cost is avoided; and can high-efficient separation water, oil and solid sludge, realize higher deoiling efficiency, and can long period steady operation.

2) The utility model discloses a closed jar body, this processing apparatus is through experimental back, and it is efficient to degrease, realizes that the water oil content is less than 80 mg/L. Meanwhile, after the volatile gas is collected, the volatile gas is treated in a centralized way, which is beneficial to improving the environment. The unorganized discharge of Volatile Organic Compounds (VOCs) contained in the sewage caused by the open structure of the traditional oil removing device is avoided.

3) The utility model discloses sewage treatment plant's dwell time in sewage treatment process is short, and the equipment container is little, and the construction cost is low to reduce the treatment cost to containing sewage, improve economic suitability.

4) The utility model discloses a sewage treatment plant has excellent security performance, and the nitrogen seal can eliminate the burning things which may cause a fire disaster and gas exchange passageway, blocks aerobic environment, eliminates conflagration and explosion danger.

Drawings

Fig. 1 is a schematic structural diagram of the closed oily sewage treatment device of the utility model.

Fig. 2 is a schematic structural view of the circulation water distribution assembly in fig. 1.

The notations in the figures have the following meanings:

1-tank body; a-adjusting section, B-homogenizing section;

10-sewage inlet, 11-purified water outlet, 12-oil outlet, 13-sludge outlet, 14-bottom plate,

15-a mud bucket, 16-a breather valve, 17-a nitrogen supplement valve and 18-a pressure measuring instrument;

2-circulation water distribution assembly, 20-water distribution ring pipe, 21-water distribution short pipe;

3-purified water collecting component, 30-annular drainage collecting pipe, 31-vertical pressure regulating pipe;

4-oil receiving assembly, 40-oil receiving device and 41-L type oil conveying pipe;

5-homogenizing unit, 50-reflux pump, 51-reflux pipeline;

6-sludge scraping unit, 60-water turbine, 61-mud scraping plate.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the specific embodiments. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

According to an embodiment provided by the utility model, as shown in fig. 1, the closed oily sewage treatment device comprises a tank body 1, wherein the upper part in the tank body 1 is an adjusting section A, and the lower part is a homogenizing section B; an oil-water separation unit is arranged in the homogenizing section B; the oil-water separation unit comprises a circulation water distribution assembly 2 fixed at the liquid level of the homogenizing section, the circulation water distribution assembly 2 is connected with a sewage inlet 10 on the side wall of the tank body 1 and used for enabling sewage to enter the homogenizing section B along the annular direction to form circulation, free oil particles float on the water surface and accumulate towards the center of the liquid surface under the action of circulation, and water moves downwards under the action of gravity to generate oil-water separation;

the water purifier also comprises a purified water collecting component 3 which is arranged at the lower part of the homogenizing section B in the tank body 1 and corresponds to the circulating water distribution component 2, and the purified water collecting component 3 is connected with a purified water discharge port 11 on the side wall of the tank body 1 and is used for receiving and discharging purified water which moves downwards after oil-water separation;

the oil recovery device also comprises an oil recovery component 4 arranged in the center of the tank body 1, wherein the oil recovery component 4 is communicated with an oil discharge port 12 arranged on the side wall of the tank body 1;

a homogenizing unit 5 is also arranged at the lower side of the circulating water distribution assembly 2 in the tank body 1; the lower side of the homogenizing unit 5 is provided with a sludge scraping unit 6, the bottom of the tank body 1 is provided with a sludge discharge port 13, and the sludge scraping unit 6 is matched with the sludge discharge port 13 to discharge sludge deposited at the bottom of the tank body 1.

The closed oily sewage treatment device provided by the embodiment separates oil and water through the oil-water separation unit, the water enters the bottom of the tank body 1 under the action of gravity and is discharged through the purified water collection component 3, and the oil is discharged through the oil collection component 4; solid impurities in the water are settled by gravity, deposited at the bottom of the tank body 1 and discharged by the sludge scraping unit 6; and homogeneity unit 5 can also carry out the homogeneity when the inflow is undulant to, this deoiling device collects sewage regulation, homogeneity and deoiling, desilt integration in inclosed jar body 1, simple structure, the integrated level is high, can reduce area, and high-efficient separation water, oil and solid mud realize higher deoiling efficiency, and can long period stable operation. Wherein, the liquid level of the homogenizing section refers to the boundary liquid level of the adjusting section A and the homogenizing section B, and the homogenizing section B is a sewage part formed after the oily sewage is introduced; the adjusting section is a cavity formed between the sewage part and the top of the tank body 1. The side wall of the tank body 1 is provided with a sewage inlet 10 and a purified water outlet 11, the inlet water is variable flow, the outlet water is fixed flow, and the inlet and outlet water quantity difference is adjusted by the capacity of the upper cavity of the tank body 1. Thereby realizing the function of sewage regulation through the floating of the liquid level in the tank at the upper part containing cavity.

According to another embodiment of the present invention, as shown in fig. 1, the present invention is a closed oily sewage treatment device, and this embodiment is based on embodiment 1, and as a preferred embodiment, as shown in fig. 2, the circulation water distribution assembly 2 includes a water distribution ring pipe 20 connected to the sewage inlet 10, and a plurality of water distribution short pipes 21 are distributed on the water distribution ring pipe 20 along the tangential direction. In the embodiment, a horizontal tangential water distribution mode can be formed by the plurality of water supplementing short pipes 21 which are arranged on the water distribution ring pipe 20 in a cutting way, so that the disturbance of water inflow to the homogenizing section B is reduced to the maximum extent, and the oil-water separation efficiency is improved.

As another preferred embodiment, the diameter of the short water distribution pipes 21 near the sewage inlet 10 end is smaller than that of the short water distribution pipes 21 far from the sewage inlet 10 end, so as to ensure that the flow of each short water distribution pipe 21 is kept equivalent under different pressure heads, and promote the formation of stable annular water flow; the utility model discloses variable diameter water distribution nozzle stub 21's design makes into water evenly distributed on the cross-section, improves the uniformity of oily sewage dwell time in the oil-water separation unit, avoids the rivers short circuit.

Preferably, the annular diameter of the water distribution ring pipe 20 is 0.85 to 0.95 times of the inner diameter of the tank body 1. Preferably, the interval between the adjacent water distribution short pipes 21 corresponds to the chord length of 100 and 500 mm. Preferably, the tangential included angle between the water distribution short pipe 21 and the water distribution circular pipe 20 is 60-80 °. More preferably, the length of the water distribution short pipe is 50 mm. Therefore, in the embodiment, the matching of the water distribution ring pipe 20 and the short water distribution pipes 21 can realize the tangential diversion and uniform distribution of the inlet water along the water distribution ring pipe 20, and form a circulation on the liquid surface, so that the free oil particles in the sewage directly float on the water surface and are accumulated towards the center of the liquid surface under the circulation effect to perform efficient oil-water separation.

As a preferred further embodiment, the oil collecting assembly 4 comprises an oil collecting device 40 arranged on the central shaft of the tank body 1, wherein the oil collecting device 40 floats on the liquid surface and vertically floats between the lowest liquid level and the highest liquid level of the homogenizing section B;

the bottom of the oil collector 40 is respectively connected with a plurality of L-shaped oil pipelines 41; the vertical straight pipe sections of the L-shaped oil delivery pipes 41 are all free telescopic pipes, and the horizontal sections are all arranged in a hanging mode along the radial direction of the tank body 1 and are communicated with an oil discharge port 12 located on the side wall of the lower portion of the tank body 1.

In this embodiment, the oil collector 40 floats vertically by its own buoyancy, continuously collects oil between the lowest liquid level and the highest liquid level by the free expansion of the straight vertical pipe section, and discharges the collected oil out of the tank 1 through the horizontal section. Wherein, the oil collector 40 adopts a floating circular flow oil collector in the prior art, and plays the roles of collecting and discharging oil. The telescopic tube can be directly purchased from the market, and the free telescopic tube also has the existing structure and can be purchased, so the specific structure of the telescopic tube is not further detailed and described herein.

As a preferred further embodiment, the purified water collecting assembly 3 comprises an annular drainage collecting pipe 30 which is arranged at the lower part of the homogenizing section B and corresponds to the circulating water distribution assembly 2, and water collecting holes are alternately distributed on two side walls of the annular drainage collecting pipe 30 along the radial direction of the tank body 1; the device also comprises a vertical pressure regulating pipe 31 connected with the annular drainage collecting pipe 30 at the lower part of the homogenizing section B, and the vertical pressure regulating pipe 31 is connected with the purified water discharge port 11 on the side wall of the tank body 1.

In this embodiment, the water collecting hole on the side wall of the annular drainage collecting pipe 30 is used for receiving the purified water obtained by oil-water separation, and meanwhile, the water collecting hole is formed on the side wall, so that the settled solid impurities can be prevented from directly entering the annular drainage collecting pipe 30. The vertical pressure regulating pipe 31 can play a role in buffering and regulating pressure of purified water in the annular drainage collecting pipe 30, and promotes stable drainage of the purified water; and the liquid level of the homogenizing section is adjusted by utilizing the water level difference between the vertical pressure regulating pipe 31 and the annular drainage collecting pipe 30, and the automatic adjustment between the water inlet and the water outlet of the sewage to be treated is realized by adjusting the water inflow of the water inlet 10 through the liquid level. In practical application, the diameter of the water collecting hole on the annular drainage collecting pipe 30 is 20-50 mm. The distance between the unilateral water collecting holes on the annular drainage collecting pipe 30 is 3-4 times of the diameter of the water collecting holes.

Preferably, the homogenizing unit 5 comprises a reflux pump 50 arranged at the outer side of the tank body 1, wherein the inlet of the reflux pump 50 is connected with the annular drainage collecting pipe 30, and the outlet of the reflux pump is connected with a reflux pipeline 51; the return pipe 51 is connected to the sewage inlet 10 to return the purified water to the sewage inlet 10 of the tank 1 for homogenization. Therefore, when the quality of the inlet water fluctuates, the purified water is pumped back to the sewage inlet 10 of the tank body 1 by starting the reflux pump 50, and the homogenization process is realized.

More preferably, the sludge scraping unit 6 comprises a water turbine 60 arranged at the center of the bottom of the tank body 1, the input end of the water turbine 60 is communicated with the return pipeline 51, the output end of the water turbine 60 is axially connected with a mud scraper 61 along the center of the tank body 1, the mud scraper 61 is positioned at the lower side of the annular drainage collecting pipe 30, and the diameter of the mud scraper 61 is smaller than the inner diameter of the tank body 1; therefore, the reflux pump 50 drives the purified water to flow in the reflux pipeline, and further drives the water turbine to continuously operate, and drives the mud scraper to scrape mud. The arrangement of the embodiment utilizes the reflux pump and the reflux pipeline 51 in the homogenizing unit 5 to provide driving force for the water turbine 60 in the sludge scraping unit 6, the structure is more compact and concentrated, and the sludge scraping is realized while the homogenizing is realized. The reflux pump 50 is provided outside the bottom of the tank.

Further preferably, the distance between the annular drainage collecting pipe 30 and the mud scraping plate 61 is kept to be 500-1000 mm, and if the distance is too short, the quality of the discharged water is intermittently influenced during intermittent mud scraping; if the distance is too long, the residence time of the homogenization and mud scraping treatment is reduced. In addition, the water collecting holes of the annular drainage collecting pipe 30 are arranged on the side wall, so that the disturbance caused by intermittent mud scraping can be avoided, and the floating mud is prevented from entering the annular drainage collecting pipe 30.

In the above embodiment, the mud scraper 61 is loosely attached to the bottom plate 14 of the tank 1, that is, the rotating surface of the mud scraper 61 is fitted to the bottom plate 14, and the mud scraper 61 is spaced from the bottom plate 14 of the tank 1. Preferably, the diameter of the mud scraper 61 is 0.9-0.98 times of the inner diameter of the tank body 1. Preferably, the bottom of the tank body 1 is provided with a mud collecting hopper 15, and the bottom of the mud collecting hopper 15 is provided with a mud discharging port 13. Preferably, the reflux pump 50 is attached with an air suction device or the reflux pump 50 adopts a dissolved air pump, so that the dissolved air pump can be matched with annular water distribution of sewage inflow to realize a dissolved air floatation function and be beneficial to oil-water separation.

As another preferred embodiment, the top of the tank body 1 is provided with a breather valve 16, a nitrogen supplement valve 17 and a pressure measuring instrument 18; the device also comprises a tank nitrogen sealing pressure control system;

the breather valve 16, the nitrogen supplement valve 17 and the pressure measuring instrument 18 are all electrically connected with the tank nitrogen-sealed pressure control system.

When the pressure of the breather valve 16 in the tank is higher than the set pressure in the tank nitrogen-sealed pressure control system, the tank nitrogen-sealed pressure control system controls the breather valve 16 to open and the nitrogen supplementing valve 17 to close, and the waste gas in the tank is discharged into the VOCs treatment system; when the pressure in the tank is lower than a set value in the tank nitrogen-sealed pressure control system, the tank nitrogen-sealed pressure control system controls the opening of the nitrogen supplementing valve 17 and the closing of the breather valve 16 so as to balance the pressure in the tank; meanwhile, the nitrogen seal protects flammable and explosive upper-layer floating oil, and the safe operation of the system is ensured. In practical application, the opening pressure of a breather valve is set in the tank nitrogen-sealed pressure control system: 1.5-2KPag, closing pressure is 1.1KPag, the opening pressure of the nitrogen supplementing valve is set to be 0.3KPa, and the closing pressure is set to be 0.9 KPa. This jar body nitrogen seals pressure control system's automatic control can ensure to be in the nitrogen in jar and seal the pressure-fired state a little, improve the utility model discloses the security performance of device and the reliable and stable nature of operation. It should be noted here that, the tank nitrogen-sealed pressure control system can adopt a PLC control system, and realizes the monitoring of the pressure in the tank 1, and improves the safety of operation.

In addition, it should be noted that the PLC control system is a control device commonly used in the prior art, and is a new-generation industrial control device formed by introducing a microelectronic technology, a computer technology, an automatic control technology and a communication technology on the basis of a conventional sequence controller, and is intended to replace sequential control functions such as a relay, execution logic, timing, counting and the like, and establish a flexible remote control system. Specifically, the PLC control system can be Siemens S7-1200 or S7-1500 series PLC.

On the basis of the foregoing embodiment, the utility model discloses can also provide a closed oily sewage treatment process, combine fig. 1, 2 to show, include following step:

sewage enters a circulating water distribution assembly 2 fixed at the liquid level of a homogenizing section B in a tank 1 from a sewage inlet 10, so that the sewage enters the tank 1 along the circular direction and forms circulating current on the liquid level, and free oil particles in the sewage float on the water level and are accumulated towards the center of the liquid level under the action of the circulating current; the water moves downwards under the action of gravity and is discharged from a purified water discharge port 11 after being collected by the purified water collecting component 3;

along with the prolonging of the sewage treatment time, oil drops on the water surface gradually accumulate to form an oil layer, and the oil layer is collected by the oil collecting component 4 and then is discharged out of the tank body through the oil discharge port 12; solid impurities in water are settled by gravity and deposited at the bottom of the tank body 1, and the sludge in the solid-containing sewage deposited at the bottom of the tank body 1 is removed by a sludge scraping unit 6;

wherein, the homogeneity section in jar body 1 is in the steady state that sinks, and when intake water quality of water takes place undulantly, opens homogeneity unit 5 and flows back the purified water that the purified water collection subassembly 3 was collected to sewage water inlet 10, carries out the homogeneity to the intaking in jar body 1.

According to the closed oily sewage treatment process provided by the embodiment, oil and water are separated by the oil-water separation unit, the water enters the bottom of the tank body 1 under the action of gravity and is discharged through the purified water collection component 3, and the oil is discharged through the oil collection component 4; solid impurities in the water are settled by gravity, deposited at the bottom of the tank body 1 and discharged by the sludge scraping unit 6; and the homogenization unit 5 can be used for homogenizing when water inlet fluctuates, so that the oil removing process integrates sewage regulation, homogenization, oil removal and sludge removal in the closed tank body 1, the operation is simple and convenient, the integration level is high, the oil removing efficiency is improved, the water, oil and solid sludge can be efficiently separated, and the long-period stable operation can be realized. Wherein the liquid level of the homogenizing section refers to the boundary liquid level of the regulating section and the homogenizing section. Wherein, under the running state, sewage forms the steady flow state of even decline in homogeneity section B, because the homogeneity time is very long (12-24 hours), can form the quasi-static gravity settling condition, is far superior to the deoiling separation condition of oil interceptor, ensures higher deoiling rate.

In this embodiment, specifically:

the circulation water distribution assembly 2 comprises a water distribution ring pipe 20 connected with the sewage inlet 10, and a plurality of water distribution short pipes 21 are distributed on the water distribution ring pipe 20 along the tangential direction; the purified water collecting component 3 comprises an annular drainage collecting pipe 30 which is arranged at the lower part of the homogenizing section B and corresponds to the circulating water distribution component 2, and water collecting holes are alternately and uniformly distributed on the side walls of two sides of the annular drainage collecting pipe 30 along the radial direction of the tank body 1; the device also comprises a vertical pressure regulating pipe 31 connected with the annular drainage collecting pipe 30 at the lower part of the homogenizing section B; therefore, sewage enters a water distribution ring pipe 20 fixed at the liquid level of a homogenizing section B in the tank body 1 from a sewage inlet 10, and horizontally enters the tank body 1 along the tangential direction through a short water distribution pipe 21 to form circulation on the liquid level, and free oil particles in the sewage directly float on the liquid level due to low density and are accumulated towards the center of the liquid level under the action of circulation; the water moves downward under the action of gravity, is collected by the annular drainage collecting pipe 30, and is discharged through the purified water discharge port 11 through the vertical pressure regulating pipe 31.

The oil receiving assembly 4 comprises an oil receiving device 40 arranged on the central shaft of the tank body, and the oil receiving device 40 floats on the liquid level and vertically floats between the lowest liquid level and the highest liquid level of the homogenizing section; the bottom of the oil collector 40 is respectively connected with a plurality of L-shaped oil pipelines 41; the vertical straight pipe sections of the L-shaped oil conveying pipes 41 are free telescopic pipes, and the horizontal sections are arranged in a hanging mode along the radial direction of the tank body and communicated with an oil discharge port located on the side wall of the lower portion of the tank body; therefore, with the extension of the sewage treatment time, oil drops on the water surface gradually accumulate to form an oil layer, and the oil layer is collected by the oil collector 40 floating on the liquid surface and then discharged out of the tank body 1 through the oil discharge port 12 through the L-shaped oil delivery pipe 41.

The homogenizing unit comprises a reflux pump 50 arranged on the outer side of the tank body, the inlet of the reflux pump 50 is connected with the annular drainage collecting pipe 30, the outlet of the reflux pump is connected with a reflux pipeline 51, and the reflux pipeline 51 is connected with the sewage inlet 10; the sludge scraping unit 6 comprises a water turbine 60 arranged at the center of the bottom of the tank body 1, the input end of the water turbine 60 is communicated with the return pipeline 51, and the output end of the water turbine 60 is axially connected with a mud scraping plate 61 along the center of the tank body 1; therefore, solid impurities in water are settled by gravity and deposited at the bottom of the tank body 1, purified water collected by the annular drainage collecting pipe 30 is pumped into the backflow pipeline 51 by starting the backflow pump 50, the formed backflow water flow drives the water turbine 60 to rotate, the rotating water turbine 60 drives the mud scraping plate 61, and sludge deposited at the bottom of the tank body 1 is sent out of the tank body 1; the sludge sent out of the tank body 1 falls into a sludge collecting hopper 15 and is discharged through a sludge discharge port 13; wherein, the homogenizing section B in the tank body 1 is in a stable sinking state, when the quality of the raw material water inlet source fluctuates, the external reflux pump 50 is started, and the purified water collected by the annular drainage and collection pipe 30 returns to the sewage inlet 10 of the tank body 1 for homogenizing; meanwhile, the backflow water flow pressurizes and drives the water turbine 60 located at the center of the bottom of the tank body 1, and the water turbine 60 drives the mud scraping plate 61 to scrape mud.

In the embodiment, sewage is subjected to cyclone separation along the annular direction in the circulating water distribution assembly 2, so that the oil-water separation efficiency is improved, then sunken water is discharged through the annular drainage collecting pipe 30 and the vertical pressure regulating pipe 31 of the purified water collecting assembly 3, the liquid level of the homogenizing section is regulated by utilizing the water level difference between the vertical pressure regulating pipe 31 and the annular drainage collecting pipe 30, the water inflow of the water inlet 10 is regulated by utilizing the liquid level of the homogenizing section, and the automatic regulation of the water inflow and the water drainage of the sewage to be treated is realized; floating to collect oil through an oil collector 40 of the oil collecting assembly 4 and then discharging the oil out of the tank body 1 through an oil outlet 12 through an L-shaped oil conveying pipe 41; then, the continuously sinking water passes through the homogenizing unit 5 and the sludge scraping unit 6 to synchronously carry out sludge discharge and homogenizing treatment. Thereby realizing the high-efficient separation water, oil and solid sludge, improving deoiling efficiency.

As a preferred embodiment, the outlet water velocity of the water distribution short pipe is controlled between 1.5m/s and 3.5 m/s; if the velocity is too high, it has little effect on enhancing oil droplet coalescence; if the velocity is too low, the cyclone separation and coalescence of the oil and water are not facilitated.

As another preferred embodiment, the return flow of the return pump 50 is controlled to be 50% -120% of the water inflow at the sewage inlet 10; the intermittent reflux in the range can counteract water quality fluctuation and drive the water turbine to rotate, if the water quality fluctuation is too low, the water turbine cannot be driven, and if the water quality fluctuation is too high, the sedimentation of high solid-containing sewage can be influenced.

As a preferred further embodiment, the top of the tank body 1 is provided with a breather valve 16, a nitrogen supplement valve 17 and a pressure measuring instrument 18; when the pressure of the breather valve 16 of the tank body 1 is higher than the set pressure, the breather valve 16 is controlled to be opened, the nitrogen supplementing valve 17 is controlled to be closed, and the waste gas in the tank is discharged into the VOCs treatment system; when the pressure of the breather valve 16 of the tank body 1 is lower than the set pressure, the nitrogen supplementing valve 17 is controlled to be opened, and the breather valve 16 is controlled to be closed.

Specifically, the opening pressure of the breather valve is set as follows: 1.5-2KPag, closing pressure is 1.1 KPag; the opening pressure of the nitrogen supplementing valve is set to be 0.3KPa, and the closing pressure is set to be 0.9 KPa. The setting of this parameter can protect 1 pressure stability of jar body, ensures that the jar body is in the inert safe environment of nitrogen seal pressure-fired state all the time.

By utilizing the embodiment, the oil removal treatment is carried out on the oily sewage, and the following application examples are formed:

application example 1

Sewage with oil content of 2000-5000mg/L is sent into a water distribution ring pipe 20 fixed at the liquid level of a homogeneous section B in the tank body 1 from a sewage inlet 10, horizontally enters the tank body 1 along the tangential direction through a water distribution short pipe 21, the water flow speed of an outlet of the water distribution short pipe 21 is controlled to be 3m/s, circulation is formed on the liquid level, and free oil particles in the sewage directly float on the liquid level due to low density and are accumulated towards the center of the liquid level under the circulation effect; the water moves downwards under the action of gravity, is collected by the annular drainage collecting pipe 30 and is discharged through the purified water discharge port 11 by the vertical pressure regulating pipe 31;

along with the prolonging of the sewage treatment time, oil drops on the water surface gradually accumulate to form an oil layer, and the oil layer is collected by an oil collector 40 floating on the liquid surface and then is discharged out of the tank body 1 through an oil discharge port 12 through an L-shaped oil conveying pipe 41; solid impurities in water are settled by gravity and deposited at the bottom of the tank body 1, purified water collected by the annular drainage collecting pipe 30 is pumped into a backflow pipeline 51 by starting the backflow pump 50, the backflow amount of the backflow pump 50 is controlled to be 100% of the water inflow at the sewage inlet 10, the formed backflow water flow drives the water turbine 60 to rotate, the rotating water turbine 60 drives the mud scraping plate 61, and sludge deposited at the bottom of the tank body 1 is sent out of the tank body 1; the sludge sent out of the tank body 1 falls into a sludge collecting hopper 15 and is discharged through a sludge discharge port 13;

wherein, the homogenizing section B in the tank body 1 is in a stable sinking state, and when the quality of the inlet water fluctuates, the external reflux pump 50 is started to return the purified water collected by the annular drainage collecting pipe 30 to the sewage inlet 10 of the tank body 1 for homogenization; meanwhile, the backflow water flow drives the water turbine 60 at the bottom center of the tank body 1 in a pressurizing manner, and the water turbine 51 drives the mud scraper 52 to scrape mud.

After the treatment of 15 hours of retention time, the effluent oil content is 76 mg/L.

Comparative example 1

Sequentially introducing the sewage with the oil content of 2000-5000mg/L into the traditional process equipment: the treatment of the lifting pool, the adjusting pool, the homogenizing pool and the oil separation pool is carried out, and after the treatment with the total retention time of 56 hours, the content of the effluent oil is 200-400 mg/L.

Comparative example 2

The sewage with oil content of 1000-3000 mg/L is sequentially introduced into the traditional process equipment: the treatment of the lifting pool, the adjusting pool, the homogenizing pool and the oil separation pool is carried out, and after the treatment with the total retention time of 52 hours, the content of the effluent oil is 200-300 mg/L.

Application example 2

This example is substantially the same as the processing steps of application example 1, except that:

oil content of inlet water: 2000-5000 mg/L;

controlling the flow velocity of water flow at the outlet of the water distribution short pipe as follows: 3.5 m/s.

After the treatment with the retention time of 15 hours, the oil content of the effluent water is 72 mg/L.

Application example 3

This example is substantially the same as the processing steps of application example 1, except that:

oil content of inlet water: 1000-3000 mg/L;

controlling the flow velocity of water flow at the outlet of the water distribution short pipe as follows: 2 m/s.

After the treatment with the retention time of 16 hours, the oil content of the effluent water is 75 mg/L.

Application example 4

This example is substantially the same as the processing steps of application example 1, except that:

oil content of inlet water: 1000-3000 mg/L;

controlling the flow velocity of water flow at the outlet of the water distribution short pipe as follows: 1.5 m/s.

After the treatment of 15 hours of retention time, the effluent oil content is 76 mg/L.

Application example 5

This example is substantially the same as the processing steps of application example 1, except that:

oil content of inlet water: 1000-3000 mg/L;

controlling the flow velocity of water flow at the outlet of the water distribution short pipe as follows: 3.5 m/s.

After the treatment with the retention time of 17 hours, the oil content of the effluent water is 70 mg/L.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (10)

1. The utility model provides a closed oily sewage treatment plant which characterized in that:

the tank comprises a tank body, wherein the upper part in the tank body is an adjusting section, and the lower part in the tank body is a homogenizing section; an oil-water separation unit is arranged in the homogenizing section; the oil-water separation unit comprises a circulation water distribution assembly fixed at the liquid level of the homogenizing section, the circulation water distribution assembly is connected with a sewage inlet on the side wall of the tank body and used for enabling sewage to enter the homogenizing section in the annular direction to form circulation, free oil particles float on the water surface and accumulate towards the center of the liquid level under the action of circulation, and water moves downwards under the action of gravity to generate oil-water separation;

the water tank also comprises a purified water collecting component which is arranged at the lower part of the homogenizing section in the tank body and corresponds to the circulating water distribution component, and the purified water collecting component is connected with a purified water outlet on the side wall of the tank body and is used for receiving and discharging the purified water which moves downwards after the oil-water separation;

the oil collecting assembly is arranged in the center of the tank body and communicated with an oil outlet arranged on the side wall of the tank body;

a homogenizing unit is further arranged at the lower side of the circulating water distribution assembly in the tank body; the downside of homogeneity unit is equipped with mud and strikes off the unit, the bottom of the jar body is equipped with the mud mouth, mud strikes off the unit with the cooperation of mud mouth is discharged the mud of deposiing in jar body bottom.

2. The closed oily sewage treatment plant according to claim 1, characterized in that:

the circulation water distribution assembly comprises a water distribution ring pipe connected with the sewage inlet, and a plurality of water distribution short pipes are distributed on the water distribution ring pipe along the tangential direction.

3. The closed oily sewage treatment plant according to claim 2, characterized in that:

the annular diameter of the water distribution ring pipe is 0.85-0.95 times of the inner diameter of the tank body; and/or the presence of a gas in the gas,

the diameter of the water distribution short pipe close to the sewage inlet end is smaller than that of the water distribution short pipe far away from the sewage inlet end; and/or the presence of a gas in the gas,

the corresponding chord length of the interval between the adjacent water distribution short pipes is 100 and 500 mm; and/or the presence of a gas in the gas,

the tangential included angle alpha between the water distribution short pipe and the water distribution ring pipe is 60-80 degrees; and/or the presence of a gas in the gas,

the length of the water distribution short pipe is 50 mm.

4. The closed oily sewage treatment plant according to claim 1, characterized in that:

the oil receiving assembly comprises an oil receiving device arranged on a central shaft of the tank body, and the oil receiving device floats on the liquid level and vertically floats between the lowest liquid level and the highest liquid level of the homogenizing section;

the bottom of the oil collector is respectively connected with a plurality of L-shaped oil conveying pipes; the vertical straight pipe sections of the L-shaped oil delivery pipes are free telescopic pipes, and the horizontal sections are arranged in a radially overhanging mode along the tank body and communicated with an oil discharge port located on the side wall of the lower portion of the tank body.

5. The closed oily sewage treatment plant according to claim 1, characterized in that:

the purified water collecting assembly comprises an annular drainage collecting pipe which is arranged at the lower part of the homogenizing section and corresponds to the circulating water distribution assembly, and water collecting holes are alternately and uniformly distributed on the side walls of two sides of the annular drainage collecting pipe along the radial direction of the tank body; the device also comprises a vertical pressure regulating pipe connected with the annular drainage collecting pipe at the lower part of the homogenizing section, and the vertical pressure regulating pipe is connected with a purified water drainage outlet on the side wall of the tank body.

6. The closed oily sewage treatment plant according to claim 5, characterized in that:

the homogenizing unit comprises a reflux pump arranged on the outer side of the tank body, the inlet of the reflux pump is connected with the annular drainage collecting pipe, and the outlet of the reflux pump is connected with the reflux pipeline; the backflow pipeline is connected with the sewage inlet, so that purified water returns to the sewage inlet of the tank body for homogenization.

7. The closed oily sewage treatment plant according to claim 6, characterized in that:

the sludge scraping unit comprises a water turbine arranged at the center of the bottom of the tank body, the input end of the water turbine is communicated with the backflow pipeline, the output end of the water turbine is axially connected with a mud scraper along the center of the tank body, the mud scraper is positioned on the lower side of the annular drainage collecting pipe, and the diameter of the mud scraper is smaller than the inner diameter of the tank body; therefore, the reflux pump drives the purified water to flow in the reflux pipeline, and further drives the water turbine to continuously operate to drive the mud scraper to scrape mud.

8. The closed oily sewage treatment plant according to claim 7, characterized in that:

the distance between the annular drainage collecting pipe and the mud scraper is 500-1000 mm; and/or the presence of a gas in the gas,

the mud scraping plate is loosely attached to the bottom plate of the tank body; and/or the presence of a gas in the gas,

the diameter of the mud scraper is 0.9-0.98 times of the inner diameter of the tank body; and/or the presence of a gas in the gas,

a sludge accumulation hopper is arranged at the bottom of the tank body, and a sludge discharge port is arranged at the bottom of the sludge accumulation hopper; and/or the presence of a gas in the gas,

the reflux pump is attached with an air suction device or adopts a dissolved air pump.

9. The closed oily sewage treatment plant according to claim 1, characterized in that:

the top of the tank body is provided with a breather valve, a nitrogen supplement valve and a pressure measuring instrument; the device also comprises a tank nitrogen sealing pressure control system;

the breather valve, the nitrogen supplementing valve and the pressure measuring instrument are all electrically connected with the tank nitrogen seal pressure control system.

10. The closed oily sewage treatment plant according to claim 9, characterized in that:

the opening pressure of a breather valve is set in the tank body nitrogen-sealed pressure control system: 1.5-2KPag, closing pressure is 1.1KPag, the opening pressure of the nitrogen supplementing valve is set to be 0.3KPa, and the closing pressure is set to be 0.9 KPa.

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