CN211339039U - Oil removing filter and sewage treatment system with same - Google Patents

Abstract

The present disclosure relates to an oil removing filter, and a sewage treatment system having the oil removing filter. The deoiling filter includes: an inlet through which oily water to be treated enters the oil removal filter; a distribution system arranged to distribute oily water from the inlet into the filter layer 7; the filter layer 7 is arranged above the distribution system and comprises a filter material capable of capturing oil drops; an oil-water separator comprising a separator inlet above the filter layer 7, a separator outlet above the separator inlet, and a separator channel extending from the separator inlet to the separator outlet, wherein the separator channel has a varying cross-section, the oil-water separator promoting separation of oil-containing water into a filtered water portion and a grease portion; a filtered water outlet through which the filtered water portion exits the oil removal filter; a grease outlet at a location higher than the filtered water outlet, the grease portion exiting the oil removal filter through the grease outlet.

Description

Oil removing filter and sewage treatment system with same

Technical Field

The present disclosure relates to an oil removing filter, and a sewage treatment system having the oil removing filter.

Background

The oil removing and collecting process of industrial waste water is of great significance for reducing environmental pollution and recovering oil. The process of removing oil and collecting oil from condensate, the process of removing oil from oil field waste water, and the process of recovering organic solvent in metallurgical industry using organic solvent extraction all need to use waste water oil removing device.

The existing oil removing device comprises a natural oil removing device, an inclined plate/inclined tube oil removing device, an air flotation oil removing device and the like.

Natural oil removal belongs to the field of physical oil removal, and is mainly used for treating oily sewage by utilizing gravity, and oil floats upwards by utilizing the density difference of the oil and the water according to the density difference of the oil and the water so as to achieve the aim of oil-water separation. However, the natural oil removing device neglects influence factors such as non-uniformity of water flow in and out of the water distribution port, flocculation in floating of oil droplet particles and the like. The natural oil removing device considers that the oil droplet particles are subjected to gravity separation in an ideal state, that is, assuming that the water flow velocities of the points on the water passing section are equal, and the horizontal component velocity when the oil droplet particles float upward is equal to the water flow velocity, the oil droplet particles float upward at a constant velocity, and the oil droplet particles float upward to the water surface and are removed. Therefore, the natural oil removal method has low oil-water separation efficiency and large occupied area.

The oil removal of the inclined plate/inclined pipe is one of the most common oil removal methods in the prior art, and also belongs to the field of physical oil removal. The basic principle of swash plate/pipe degreasing is "shallow sedimentation", which is based on the shallow pool theory proposed in harea america (Hazen) in the early 20 th century. In order to facilitate the flow and removal of oil droplets which float to the upper part of the inclined plate/inclined tube, the shallow separation tank is inclined at an angle (usually 45-60 °) exceeding the angle of repose of the dirty oil flow, thereby forming a so-called inclined plate/inclined tube oil removal tank. In theory, no matter how the angle of the inclined plate is, the removal efficiency is improved by a factor which is equivalent to the factor that the total horizontal projection area of the inclined plate is increased by compared with the water surface area without the inclined plate (of course, the actual effect cannot reach the ideal factor because of factors such as specific arrangement of the inclined plate, influence of inlet and outlet water flow, interference of flow state between plates, oil accumulation and the like). The swash plate/pipe chute deoiling device is compactly arranged, but the fluid state interference between plates can be caused due to the specific arrangement mode of the swash plate, the distribution uniformity of inlet and outlet water flow and the like, the actual operation effect is not ideal due to the influence of accumulated oil, and the operation and maintenance are inconvenient.

The air flotation oil removal device can be divided into two categories according to the way that gas is introduced into water: a dissolved air flotation device and a dispersed air flotation device.

In the dissolved air flotation device, gas is firstly dissolved in water under pressure, and then the dissolved air water is introduced into the head end or the bottom of the flotation device and is uniformly distributed. After the pressure is reduced, the gas dissolved in the water is released, so that oil droplets and suspended matters in the treated water are adsorbed to the bubbles, and the floating aggregation is removed.

As for the dispersion air flotation device, it can be divided into a rotary type flotation device and a jet type flotation device. The mechanical rotor of the rotary flotation device rotates to generate liquid silt vortex on a gas-liquid interface, and the silt vortex gas-liquid interface can extend to the bottom of the separation chamber along with the increase of the rotating speed. In the air cavity at the center of vortex, the pressure is lower than the atmospheric pressure, which causes the steam in the gas phase space at the upper part of the separation chamber to move downwards and to be mixed with the water phase through the rotor to form a gas-water mixture. Then the oil is driven by the rotation of the rotor to diffuse to the periphery, and a cyclic process of mixing, colliding, adsorbing, gathering and floating up with oil and suspended matters to be removed is formed. Each flotation unit of the jet type flotation device is provided with an ejector, purified water is pumped into the ejector of the flotation unit by a pump, and a nozzle in the ejector generates low air pressure locally, so that gas in a gas phase space at the upper part of the flotation unit flows to the nozzle of the ejector, so that the gas and the water are fully mixed in a diffusion section behind the outlet of the nozzle, and then the gas and the water flow into the middle lower part of the flotation unit to be mixed with treated sewage to form oil, suspended matters and bubbles to be adsorbed, gathered and floated for removal.

The air flotation oil removing device has high energy consumption because sewage needs to be pressurized. In addition, since the requirement of floating up with bubbles is oil particles that have been destabilized from water, the separation effect is not good for small particle size or emulsified oil.

SUMMERY OF THE UTILITY MODEL

The present solution addresses the above mentioned problems and needs and provides a new type of oil removal filter which solves the above mentioned problems and brings other technical effects by adopting the following technical features.

The present disclosure first provides an oil removing filter, which includes: an inlet through which oily water to be treated enters the oil removal filter; a distribution system arranged to distribute the oily water from the inlet into the filtration layer; the filter layer is arranged above the distribution system and comprises a filter material capable of capturing oil drops; an oil-water separator comprising a separator inlet located above the filter layer, a separator outlet located above the separator inlet, and a separator passage extending from the separator inlet to the separator outlet, wherein the separator passage has a varying cross-section, the oil-water separator facilitating separation of the oil-containing water into a filtered water portion and a grease portion; a filtered water outlet through which the filtered water portion exits the oil removal filter; a grease outlet at a location higher than the filtered water outlet, the grease portion exiting the oil removal filter through the grease outlet.

With the above feature, since the area of the separator passage forming the flow area of the oil and water is varied, the speed difference between the oil and water is gradually increased while the oil and water pass through the separator passage, thereby more effectively separating the oil-containing water into the filtered water portion and the grease portion. In addition, the relative arrangement among the distribution system, the filter layer and the oil-water separator is matched, so that the whole oil removing filter has the advantages of high oil-water separation efficiency, small occupied area, convenience in operation and maintenance, low energy consumption and the like.

According to a preferred embodiment, the separator channel of the oil-water separator has a tapered section with a gradually decreasing cross-sectional area from bottom to top.

By the characteristics, after the mixture of oil and water enters the oil-water separator, the water passing area is gradually reduced, so that a relatively large ascending flow speed is generated. Simultaneously, because the density of oil is less than water for the velocity difference between them progressively increases, such velocity difference is convenient for float the oil reservoir and rises to bed body upper portion, realizes the smooth separation of profit.

According to a preferred aspect, the separator passage of the oil water separator further has a straight section located above the tapered section, the cross-sectional area of the straight section being substantially constant.

By the above features, the straight cylinder section has a good guiding effect on oil and water.

According to a preferred version, the inlet is further configured for backwash water to enter the oil removal filter, and the distribution system is further configured to distribute backwash water into the filtration layer, and the oil removal filter further comprises: a backwash water collection tank having an upper opening configured to guide backwash water to a backwash water outlet; and a backwash water outlet which receives backwash water from the backwash water collection tank and guides the same out of the oil removing filter. Wherein the width of the backwash water collection tank is changed from bottom to top.

Through the characteristics, the oil removal filter can be backwashed to remove solid particle impurities in the filter layer. Moreover, the change of the width of the backwashing water collecting tank can enable the backwashing water to have sudden change of flow velocity in the rising process, so that the backwashing water can not wash away fluidized filter material particles, and the sludge washed away from the filter material can be well taken away.

According to a preferred scheme, the width of the backwashing water collecting tank is gradually widened from bottom to top and then gradually narrowed.

Through the characteristics, the flow rate of the backwash water is increased from small to large in the rising process, so that suspended substances in the backwash water rise quickly to separate from the filter material layer, and the filter material suspended substances are cleaned conveniently. Then to the upper part of backwash water collecting tank, the surface that overflows becomes big, and the velocity of flow diminishes, and the partial filter material of winding in the backwash water can progressively precipitate and return to the filter layer this moment, but the partial mud that washes down can continue to enter into backwash water collecting tank and get rid of. In this way, flushing is achieved more efficiently.

According to a preferred version, the width of the upper part of the backwash water collection tank is substantially constant.

By the above features, the backwash water collection tank is facilitated to form a stable structure.

According to a preferred embodiment, the backwash water collection tank is arranged horizontally along a diameter of the oil removal filter.

According to a preferred scheme, the oil removing filter further comprises a backwashing gas inlet, and backwashing gas enters the oil removing filter through the backwashing gas inlet and is distributed through the distribution system.

Through the characteristics, in this way, backwashing can be carried out by matching backwashing gas and backwashing water together in the backwashing process so as to achieve a better flushing effect.

According to a preferred version, the dispensing system comprises a filter pad head or a perforated tube.

Through the characteristics, the filter head of the filter plate or the perforated pipe is beneficial to improving the uniformity and stability of water distribution of the oil removing filter.

The present disclosure also provides a wastewater treatment system comprising the oil removal filter according to any of the above aspects.

The best modes for carrying out the present disclosure will be described in more detail below with reference to the accompanying drawings so that the features and advantages of the present disclosure can be readily understood.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments of the present disclosure will be briefly described below. The drawings are intended to depict only some embodiments of the disclosure, and not all embodiments of the disclosure are limited thereto.

FIG. 1 illustrates one embodiment of an oil removal filter according to the present disclosure;

FIG. 2 illustrates a schematic diagram of a preferred embodiment of a fuel water separator that may be used in the oil removal filter;

fig. 3 shows a schematic of a cross section of a preferred solution of a backwash water collection tank that can be used in an oil filter.

List of reference numerals

1 inlet port

2 backwash gas inlet

3 backwashing water outlet

4 filtered water outlet

5 exhaust port

6 grease outlet

7 Filter layer

8 oil-water separator

81 separator inlet

82 separator outlet

83 tapered section

84 straight barrel section

9 backwashing water collecting tank

10 dispensing system

Detailed Description

In order to make the objects, technical solutions and advantages of the present disclosure more clear, solutions of various embodiments will be described below in conjunction with the accompanying drawings of specific embodiments of the present disclosure. Like reference symbols in the various drawings indicate like elements. It should be noted that the described embodiments are only some of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in the description and claims of the present disclosure are not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not necessarily denote a limitation of quantity. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

The upflow oil removal filter provided by the present disclosure is mainly used for removing oil substances suspended in water, particularly (but not limited to) oil substances with a particle size in a range of 1-20 μm.

Fig. 1 illustrates one embodiment of an oil removal filter according to the present disclosure. The features of the oil removing filter proposed by the present disclosure will be described with reference to fig. 1. It should be noted that the embodiment shown in fig. 1 is only a preferred embodiment, and is not used to limit the scope of the present disclosure.

The bed of the oil removal filter is preferably generally cylindrical in shape as a whole, as shown in fig. 1. The oil removal filter comprises an inlet 1, via which inlet 1 oil-containing water to be treated enters the oil removal filter. The inlet 1 may be located near the bottom of the oil removal filter. After entering the deoiling filter through the inlet 1, the oily water travels along the respective pipe to the distribution system 10 of the deoiling filter. The inlet 1 may also admit backwash water, as will be described further below. Oily water flows generally from bottom to top in the oil removal filter, and therefore the oil removal filter is also called an upflow oil removal filter.

The distribution system 10 is arranged at or near the bottom position of the oil removal filter. The distribution system 10 is arranged to distribute the oily water from said inlet 1 as evenly as possible into the filter layer 7. The distribution system 10 preferably includes filter plate headers or perforated pipes to provide uniform distribution of oil-containing water, backwash water and backwash gas, which help to improve the uniformity and stability of the oil filter feed water distribution.

The filter layer 7 is arranged above the dispensing system 10 and comprises a filter material capable of capturing oil droplets.

The oil removal filter also comprises an oil-water separator 8, which is located above the filter layer 7 and can be located at a higher level of the entire oil removal filter. The arrangement of the oil-water separator 8 in the oil removal filter can be seen from fig. 1, and the specific shape of a preferred embodiment of the oil-water separator 8 can be seen from fig. 2. The oil water separator 8 includes a separator inlet 81 located above the filter layer 7, a separator outlet 82 located above the separator inlet 81, and a separator passage extending from the separator inlet 81 to the separator outlet 82. The mixture of oil and water passes along the separator channel from bottom to top through the oil-water separator 8. Wherein the separator channel has a varying cross-section, the oil-water separator 8 promoting separation of oil-containing water into a filtered water fraction and a grease fraction.

The oil removal filter also comprises a filtered water outlet 4 and a grease outlet 6. The filtered water portion passes through the filtered water outlet 4 leaves the oil removal filter, and the grease portion passes through the grease outlet 6 leaves the oil removal filter. Since the density of the oil is lower than that of the water, the grease outlet 6 is positioned higher than the filtered water outlet 4 so that the grease outlet 6 can be at a higher location of a grease portion collection area to facilitate grease exiting the oil filter and the filtered water outlet 4 can be at a relatively lower filtered water collection area to facilitate filtered water exiting the oil filter. Preferably, the grease outlet 6 is located at the top of the oil removal filter and may be provided with an oil-water interface gauge nearby to control the discharge of oil.

With the above basic structure, the oil removing process of the oil removing filter is as follows: oily water first enters the oil removal filter through the inlet 1 and travels along the corresponding pipes to the distribution system 10. The distribution system 10 distributes the oily water more evenly into the filter layer 7, where the oily water passes through the filter material of the filter layer 7 at a certain upward flow velocity from bottom to top, and fine oil droplet particles suspended in the oily water are intercepted by the filter material. As the quantity of oil drops intercepted by the filter material is increased, the oil drops form an oil film. Since the oil film has a lower density than water, the oil film moves to the upper layer with the water flow. The oil-water separator 8, which is located above the filter layer 7, promotes the separation of oil and water by changing the upward flow velocity, and specifically, oil and water enter the separator channel upward from the separator inlet 81 and exit from the separator outlet 82 above. Since the area of the separator passage forming the flow area of the oil and water is varied and since the oil and water have a density difference, the velocity difference between the oil and water increases gradually as they pass through the separator passage, thereby separating the oil-containing water into a filtered water fraction and a grease fraction. The separated filtered water portion collects in the upper portion of the oil removal filter at the lower, grease portion upper, and the filtered water portion leaves the oil removal filter through a relatively lower, filtered water outlet 4 and the grease portion leaves the oil removal filter through a relatively higher, grease outlet 6.

Due to the relative arrangement of the distribution system 10, the filter layer 7 and the oil-water separator 8 and the special design of the separator channel of the oil-water separator 8, the oil removing filter has the advantages of high oil-water separation efficiency, small occupied area, convenience in operation and maintenance, low energy consumption and the like.

Referring to fig. 2, a preferred configuration of the oil water separator 8 is shown. The separator passage of the oil water separator 8 preferably has a tapered section 83 whose cross-sectional area gradually decreases from bottom to top. Wherein, the diameter of the lower part of the oil-water separator 8 can be consistent with the diameter of the filter bed body, so that the ascending flow velocity just entering the oil-water separator 8 is the ascending flow velocity of the bed body, and after entering the oil-water separator 8, the water passing area is gradually reduced, thereby generating larger ascending flow velocity. Simultaneously, because the density of oil is less than water for the velocity difference between them progressively increases, such velocity difference is convenient for float the oil reservoir and rises to bed body upper portion, realizes the smooth separation of profit.

Referring also to fig. 2, the separator passage of the oil water separator 8 also has a straight cylindrical section 84 above the tapered section 83, the cross-sectional area of the straight cylindrical section 84 being substantially constant. The straight section 84 has a flow guiding effect on the oil and water.

Since solid particle impurities in the oily water are trapped in the filter layer 7 and gradually accumulate in the filter layer 7, after a period of operation, the oil filter needs to be flushed, called backwashing. The oil removal filter should preferably be backwashed periodically.

To this end, the inlet 1 of the oil removal filter is also configured for backwash water to enter the oil removal filter, and the distribution system 10 is also configured to distribute backwash water into the filtration layer 7. Thus, backwash water enters the oil water separator 8 through the inlet 1 and is uniformly distributed into the filter layer 7 by the distribution system 10 to wash the filter material.

In addition, the oil removal filter also comprises a backwash water collection tank 9 and a backwash water outlet 3. The backwash water collection tank 9 is an open-topped tank structure configured to guide backwash water to the backwash water outlet 3. The backwash water collection tank 9 may be an elongated straight tank, preferably arranged horizontally along a diameter of the oil removal filter. That is, the backwash water collection tank intersects the longitudinal center axis of the oil removal filter. The outlet portion of the backwash water collection tank 9 may be located at one end thereof, and the backwash water outlet 3 may be located at a position lower than the backwash water collection tank 9 to receive backwash water from the backwash water collection tank 9 and guide it out of the oil removal filter.

Fig. 3 shows a cross section of a preferred embodiment of the backwash water collection trough 9 and the width of the backwash water collection trough 9 with the letter w. It can be seen that according to a preferred embodiment, the width of the backwash water collection trough 9 varies from bottom to top. The width change of the backwashing water collecting tank 9 can enable the backwashing water to suddenly change in flow velocity in the rising process, so that the backwashing water can not wash away fluidized filter material particles, and the sludge washed away from the filter material can be well taken away.

More preferably, the width of the backwash water collection tank 9 is gradually widened from the bottom to the top and then gradually narrowed. Thus, the backwashing water collection tank has an approximately hexagonal structure portion, so that the backwashing water undergoes a sudden change in flow velocity during the rising process: firstly, the flow velocity is increased from small to big, so that suspended substances in the backflushing water quickly rise to separate from the filter layer 7, and the filter material suspended substances are convenient to clean. Then to backwash water catch bowl upper portion part, overflow the surface grow, the velocity of flow diminishes, and the partial filter material of winding in the backwash water can progressively precipitate and return to in filter layer 7 this moment, but the partial mud that washes down can continue to enter into backwash water catch bowl and get rid of, like this, realizes washing more effectively.

Preferably, the width of the upper part of the backwash water collection tank 9 is substantially constant from bottom to top. This facilitates the formation of a stable structure of the backwash water collection tank 9.

Preferably, the oil removal filter further comprises a backwash gas inlet 2. Backwash gas, such as compressed air, may enter the oil removal filter via the backwash gas inlet 2 and be distributed via the distribution system 10. Backwash gas may exit via a vent 5 located at the top of the oil removal filter. Therefore, in the backwashing process, backwashing gas and backwashing water can be matched together for backwashing, so that a better flushing effect is achieved. The provision of the backwash gas inlet 2 also helps to control the flushing intensity, thereby both avoiding sudden fluidisation to flush away the mud particles and ensuring removal of the sludge from the filter material.

Typical applications of the upflow deoiling filter may include:

(1) and continuously removing oil and collecting oil from the condensate. Wherein for such applications, oil coalescence during oil removal is dominant;

(2) oil removal from oilfield wastewater, particularly wastewater having a hydrocarbon/suspended solids ratio greater than 5. For this application, among other things, the filtering function of the oil removal filter plays a relatively major role in the oil removal process;

(3) organic solvents are recovered in the metallurgical industry where extraction is carried out using organic solvents.

In addition, the oil removal filter may be part of a sewage treatment system, and the filtered water portion flowing therefrom may continue to be purified and treated by the sewage treatment system.

It should be noted that the above is only an exemplary application of the oil removing filter proposed by the present disclosure. The degreasing filter may be applied to other processes by those skilled in the art.

While the exemplary embodiments of the oil removal filter and sewage treatment system proposed by the present disclosure have been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that various modifications and changes can be made to the specific embodiments described above and various combinations of the technical features and structures proposed by the present disclosure can be made without departing from the concept of the present disclosure, and the scope of the present disclosure is defined by the appended claims.

Claims (10)

1. An oil removal filter, characterized in that the oil removal filter comprises:

an inlet (1) through which oily water to be treated enters an oil removal filter;

a distribution system (10) arranged to distribute the oily water from the inlet (1) into the filter layer (7);

the filter layer (7) is arranged above the distribution system (10) and comprises a filter material capable of capturing oil drops;

a water oil separator (8) comprising a separator inlet (81) located above the filter layer (7), a separator outlet (82) located above the separator inlet (81), and a separator channel extending from the separator inlet (81) to the separator outlet (82), wherein the separator channel has a varying cross-section, the water oil separator (8) facilitating separation of the oil-containing water into a filtered water portion and a grease portion;

a filtered water outlet (4), through which the filtered water portion leaves the oil removal filter (4);

a grease outlet (6) which is positioned higher than the filtered water outlet (4), the grease part passes through the grease outlet (6) and leaves the oil removing filter.

2. The oil removal filter according to claim 1, wherein the separator channel of the oil water separator (8) has a tapered section (83) with a gradually decreasing cross-sectional area from bottom to top.

3. The deoiling filter of claim 2, characterized in that the separator channel of the deoiling separator (8) further has a straight cylindrical section (84) above the tapered section (83), the cross-sectional area of the straight cylindrical section (84) being constant.

4. An oil removal filter according to claim 1, characterized in that the inlet (1) is further configured for backwash water to enter the oil removal filter, and the distribution system (10) is further configured to distribute backwash water into the filtration layer (7), and the oil removal filter further comprises:

a backwash water collection tank (9) open at an upper portion thereof and configured to guide backwash water to the backwash water outlet (3);

a backwash water outlet (3) which receives backwash water from the backwash water collection tank (9) and directs it out of the oil removal filter;

wherein the width of the backwash water collection tank (9) is changed from bottom to top.

5. The oil removal filter according to claim 4, wherein the width of the backwash water collection tank (9) is gradually widened from bottom to top and then gradually narrowed.

6. The oil removal filter according to claim 5, wherein the width of the upper portion of the backwash water collection tank (9) is constant.

7. An oil filter according to claim 4, characterized in that the backwash water collection trough (9) is arranged horizontally along a diameter of the oil filter.

8. An oil removal filter according to claim 4, characterized in that it further comprises a backwash gas inlet (2), backwash gas entering the oil removal filter via the backwash gas inlet (2) and being distributed via the distribution system (10).

9. The deoiling filter of claim 1 wherein said distribution system (10) comprises a filter pad head or a perforated tube.

10. A sewage treatment system comprising the oil removal filter of any one of claims 1 to 9.

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