Equipment for synchronously removing petroleum, suspended solids and COD (Chemical Oxygen Demand) in acidic water

Abstract

The utility model discloses equipment for synchronously removing petroleum, suspended matters and COD (Chemical Oxygen Demand) in acidic water, which relates to the field of refinery sewage treatment and comprises a floating oil rapid separation tank, a deep synergy separation tank and a dirty oil dehydration tank, and a sewage outlet of the floating oil rapid separation tank is connected with a sewage inlet of the deep synergy separation tank; a sewage outlet of the deep cooperative separation tank is connected with the acidic water stripping device, dirty oil outlets of the floating oil rapid separation tank and the deep cooperative separation tank are connected with a dirty oil inlet of the dirty oil dehydration tank, a dirty oil outlet of the dirty oil dehydration tank is connected with the floating oil separation tank, and a sewage outlet is connected with the sewage tank. The device disclosed by the utility model realizes synchronous removal of petroleum, suspended matters and COD (Chemical Oxygen Demand) in the acidic water production sewage, avoids the situation that a steam stripping device of a sewage treatment plant is impacted due to high content of petroleum, suspended matters and COD, and has the effects of high removal efficiency, low energy consumption and reduction of treatment cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of refinery sewage treatment, is applicable to the drainage treatment process of coking device, more specifically, it relates to a kind of equipment for removing petroleum, suspended solids and COD in acidic water simultaneously. BACKGROUND

[0002] In petrochemical and refining industry, oil refining and chemical production process will inevitably produce acidic wastewater containing H2S, NH3 and CO2 and other volatile weak electrolytes. Such wastewater is complex in composition, containing not only the above-mentioned acidic gases, but also often mixed with phenolic compounds, cyanide and various forms of oil pollutants (such as floating oil, dispersed oil, emulsified oil and dissolved oil). Direct discharge will cause significant harm to the environment, so it must be strictly treated before discharge.

[0003] In particular, the sulfur-containing wastewater produced by the coking device of the refinery has extremely high difficulty in treatment due to its high oil content, high emulsification characteristics and harsh conditions such as containing coke powder, which has become a major technical problem faced by current production plants processing poor-quality crude oil. In view of the different forms of oil pollutants, the industry has developed various oil removal technologies, including physical, chemical, physical-chemical and biological methods. Among them, physical oil removal methods play an important role in the treatment of oil-containing wastewater and deep pretreatment in petrochemical industry devices, such as gravity separation method, filtration method, membrane separation method, coarse granulation method and cyclone separation method.

[0004] However, the existing technology has many limitations. Although gravity separation method can remove floating oil above 60 μm and is simple to operate and widely used, it has poor removal effect on smaller oil droplets and emulsified oil. Although cyclone oil removal and filtration oil removal have certain applications, as production indicators improve and the emulsification problem caused by processing of poor-quality oil intensifies, these methods have been difficult to meet the increasingly stringent oil removal requirements and the demand for continuous operation period. In particular, in the face of upstream electric desalting wastewater, coking wastewater and tank area cutting water, which are severely emulsified and contain colloid and asphaltene suspended solids, the filtration method is easy to block, has large removal rate fluctuation and is easy to damage; the membrane separation method has high operation and maintenance cost, poor thermal stability, poor corrosion resistance and easy pollution; although the cyclone oil removal has strong adaptability to operation condition fluctuation, it has low removal rate for oil droplets below 20 μm and heavy oil with high density.

[0005] The current domestic traditional oil refining wastewater treatment process (such as large tank gravity sedimentation - dosing air flotation - biochemical treatment) has many shortcomings: large equipment floor area, large amount of reagent consumption; the oil-containing dregs produced by reagent flocculation are hazardous waste, which can easily cause secondary pollution, and sludge drying facilities are required; the air flotation process has high air consumption and produces VOCs gas pollution; the overall operation cost is high, about 1.8-2.2 yuan / ton of water.

[0006] Therefore, in view of the limitations of the prior art and the increasingly stringent environmental protection requirements, it is necessary to develop and apply a more adaptable equipment for simultaneously removing oil, suspended solids and COD in acidic water. Utility model content

[0007] In view of this problem in actual application, the utility model aims at providing an equipment for simultaneously removing oil, suspended solids and COD in acidic water, which has the ability of efficiently removing oil, suspended solids and COD, so as to effectively reduce the burden of the acidic water stripping device, reduce the labor intensity of the operating personnel, simultaneously realize the recycling of the entrained waste oil resources in the acidic water, avoid resource waste, improve the economy and clean operation level of the device, and the specific scheme is as follows:

[0008] An equipment for simultaneously removing oil, suspended solids and COD in acidic water, comprising a floating oil rapid separation tank, a deep collaborative separation tank and a waste oil dehydration tank, wherein:

[0009] The waste water outlet of the floating oil rapid separation tank is connected with the waste water inlet of the deep collaborative separation tank, the waste water outlet of the deep collaborative separation tank is connected with an acidic water stripping device, the waste oil outlets of the floating oil rapid separation tank and the deep collaborative separation tank are connected with the waste oil inlet of the waste oil dehydration tank, and the waste oil outlet of the waste oil dehydration tank is connected with the floating oil separation tank and the waste water outlet is connected with a waste water tank.

[0010] Further, the floating oil rapid separation tank comprises a horizontal floating oil rapid separation tank body and a self-adapting cyclone separation core unit, a sand removal unit, a rectifying unit, a rapid separation unit and a corrugated rapid sedimentation unit which are sequentially arranged in the tank body along the axial direction of the tank body.

[0011] Further, the self-adapting cyclone separation core unit is composed of a main pipe and a vice pipe combined column-cone type cyclone separation pipe.

[0012] Further, the sand removal unit is composed of multiple layers of sand removal plates which are uniformly and obliquely arranged along the axial direction of the floating oil rapid separation tank body.

[0013] Further, the rectifying unit is composed of multiple layers of rectifying plates which are uniformly and horizontally arranged along the axial direction of the floating oil rapid separation tank body.

[0014] Further, the rapid separation unit is composed of multiple layers of rapid separation plates which are uniformly and vertically arranged along the axial direction of the floating oil separation tank body, and each rapid separation plate is arranged in parallel with each other.

[0015] Further, the corrugated rapid sedimentation unit is composed of multiple layers of corrugated plates which are uniformly and parallelly arranged along the axial direction of the floating oil separation tank body, and small holes are formed at the wave crests and wave troughs of the corrugated plates.

[0016] Further, the deep synergistic separation tank comprises a horizontal deep synergistic separation tank body and a suspended matter filtering unit and a fiber coagulation extraction separation unit installed in the tank body and arranged along the tank body in sequence.

[0017] Further, the suspended matter filtering unit is arranged by using mixed filter elements with different surface interface properties.

[0018] Further, the fiber coagulation extraction separation unit is woven by using fibers with different surface interface properties.

[0019] Further, the dirty oil dewatering tank is installed with a heterogeneous fiber coalescence demulsification unit and a Botten rapid separation unit.

[0020] Further, the floating oil rapid separation tank, the deep synergistic separation tank and the dirty oil dewatering tank are all provided with an oil-water interface level meter.

[0021] Compared with the prior art, the device has the following beneficial effects:

[0022] The device is provided, and the device can realize synchronous removal of oil, suspended matter and COD in acidic water, avoid impact of high oil, suspended matter and COD content on a stripping device of a sewage treatment plant, and can also recycle and utilize the separated dirty oil.

[0023] The entire device process does not need PAC / PAM medicaments, does not produce dangerous waste containing oily sludge, does not need air blowing, and the complete facility device is closed and does not cause VOCs gas pollution generated by traditional air floating air blowing. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a device connection schematic diagram of an acidic water oil, suspended matter and COD synchronous removal process in an embodiment of the device;

[0025] Figure 2 FIG. 3 is a structure schematic diagram of a floating oil rapid separation tank in an embodiment of the device;

[0026] Figure 3 FIG. 4 is a structure schematic diagram of a deep synergistic separation tank in an embodiment of the device;

[0027] Figure 4 FIG. 5 is a structure schematic diagram of a dirty oil dewatering tank in an embodiment of the device.

[0028] REFERENCE SIGNS:

[0029] 100. Rapid oil-floating separator; 101. First wastewater inlet; 102. First baffle; 103. Adaptive cyclone separator core unit; 104. Sand removal unit; 105. Rectifying unit; 106. Rapid separation unit; 107. Corrugated rapid settling unit; 108. Oily waste collection bag; 109. First oil-water interface gauge; 110. First oily waste outlet; 111. Connecting pipe; 112. Rapid oil-floating separator body; 113. First wastewater outlet;

[0030] 200. Deep co-separation tank; 201. Second wastewater inlet; 202. Second baffle; 203. Suspended solids filtration unit; 204. Second oil-water interface gauge; 205. Second sludge / oil outlet; 206. Fiber coagulation extraction separation unit; 207. Third oil-water interface gauge; 208. Third sludge / oil outlet; 209. Deep co-separation tank body; 210. Second wastewater outlet;

[0031] 300. Oily waste dewatering tank; 301. Oily waste inlet; 302. Heterogeneous fiber coalescence demulsification unit; 303. Corrugated rapid separation unit; 304. Fourth oily waste outlet; 305. Oily waste coalescence dewatering tank body; 306. Third wastewater outlet; 307. Fourth oil-water interface gauge. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0033] This embodiment provides a device for the simultaneous removal of petroleum hydrocarbons, suspended solids, and COD from acidic water, such as... Figure 1 As shown, the system includes a rapid oil separation tank 100, a deep co-separation tank 200, and a sludge dehydration tank 300. The first wastewater outlet 113 of the rapid oil separation tank 100 is connected to the second wastewater inlet 201 of the deep co-separation tank 200. The second wastewater outlet of the deep co-separation tank 200 is connected to an acidic water stripping device. The first sludge outlet 110 of the rapid oil separation tank 100, the second sludge outlet 205 of the deep co-separation tank 200, and the third sludge outlet 208 are connected to the sludge inlet 301 of the sludge dehydration tank 300. The fourth sludge outlet 304 of the sludge dehydration tank 300 is connected to the oil separation tank, and the third wastewater outlet 306 is connected to a wastewater tank (not shown in the figure).

[0034] More specifically, such as Figure 2 As shown, the rapid oil separation tank 100 includes a horizontal rapid oil separation tank body 112 and an adaptive cyclone separation core unit 103, a sand removal unit 104, a rectification unit 105, a rapid separation unit 106, and a corrugated rapid settling unit 107 installed in the tank body and arranged sequentially along the tank body axis.

[0035] The first sewage inlet 101 is arranged on one side of the floating oil rapid separation tank body 112, the first partition plate 102 is arranged in the tank body, and the tank body and the first partition plate 102 form a space, the sewage inlet is communicated with the space, the adaptive cyclone separation core unit 103 is arranged on the top of the first partition plate 102, the sand removal unit 104, the flow regulation unit 105 and the rapid separation unit 106 are sequentially and adjacently arranged and spaced apart from the adaptive cyclone separation core unit 103, the corrugated rapid sedimentation unit 107 is arranged and spaced apart from the sand removal unit 104, the flow regulation unit 105 and the rapid separation unit 106, the oil collection bag 108 is communicated with the rear end of the corrugated rapid sedimentation unit 107 on the top of the floating oil rapid separation tank body 112 through the communication pipe 111, the first oil outlet 110 is arranged on the top of the oil collection bag 108, and the first sewage outlet 113 is arranged at the bottom of the tank body and located at the rear end of the corrugated rapid sedimentation unit 107.

[0036] The adaptive cyclone separation core unit 103 is composed of a main pipe and a vice pipe combined column-cone cyclone separation pipe, preferably a structure combined with one central main pipe and three vice pipes. A self-adaptive multi-phase integrated separation device disclosed in a patent with the publication number CN112387013B can be used. The liquid oil in the acidic water sewage and the suspended solids adhered to the liquid oil are separated by cyclone.

[0037] The sand removal unit 104 is composed of multiple sand removal plates arranged uniformly and obliquely along the axis of the floating oil rapid separation tank body 112, and the oblique angle is preferably 55-60°. The suspended solids and other pollutants in the acidic water sewage are removed by the multiple sand removal plates.

[0038] The flow regulation unit 105 is composed of multiple flow regulation plates arranged uniformly and horizontally along the axis of the floating oil rapid separation tank body 112, and each flow regulation plate is arranged parallel to each other, and the parallel plate spacing is preferably 15-20mm. The flow regulation plates effectively weaken the cyclone speed, so that the suspended solids are more easily precipitated.

[0039] The rapid separation unit 106 is composed of multiple rapid separation plates arranged uniformly and vertically along the axis of the floating oil separation tank body, and each rapid separation plate is arranged parallel to each other, and the plate spacing is preferably 15-20mm. The floating oil in the sewage is rapidly separated out by the rapid separation plates.

[0040] The corrugated rapid sedimentation unit 107 is composed of multiple corrugated plates arranged uniformly and parallelly along the axis of the floating oil separation tank body, and small holes are opened at the wave crests and wave troughs of the corrugated plates, and the small hole diameter is preferably 3-5mm. The suspended solids in the sewage are rapidly settled by the corrugated plates.

[0041] More specifically, as Figure 3As shown, the deep collaborative separation tank 200 includes a horizontal deep collaborative separation tank body 209 and a suspended solids filtration unit 203, a fiber coagulation extraction separation unit 206 installed in the tank body and arranged in sequence along the axial direction of the tank body.

[0042] The deep collaborative separation tank body 209 is provided with a second sewage inlet 201 on one side, and a second partition plate 202 is arranged inside the tank body, which forms a convex space (not shown in the figure) with the tank body. The suspended solids filtration unit 203 is located on one side near the inlet end at the top of the convex space, and the fiber coagulation extraction separation unit 206 is located on one side near the outlet end at the top of the convex space. The second oil outlet 205 is provided on the top of the deep collaborative separation tank body 209 above the middle position of the convex space, so that the second oil outlet 205 is located in the middle position between the suspended solids filtration unit 203 and the fiber coagulation extraction separation unit 206. The third oil outlet 208 is provided at the top of the tank body at the rear end of the convex space, and the second sewage outlet 210 is provided at the bottom of the tank body at the rear end of the convex space.

[0043] The suspended solids filtration unit 203 is arranged by mixing filter elements with different surface interface properties, and the particle materials are preferably PTFE, 316L stainless steel and quartz sand. The suspended solids filtration unit 203 is used to intercept the suspended solid particles in the oil-containing sewage.

[0044] The fiber coagulation extraction separation unit 206 is woven by fibers with different surface interface properties, and the fibers are preferably PTFE and 316L stainless steel fibers. The fiber coagulation extraction separation unit 206 is used to realize efficient separation of oil, suspended solids and COD.

[0045] More specifically, as shown, Figure 4 The oil dewatering tank 300 includes an oil dewatering tank body 305 and an anisotropic fiber coalescence demulsification unit 302 and a Botten rapid separation unit 106 arranged in sequence along the axial direction of the oil dewatering tank body 305.

[0046] The oil dewatering tank body 305 is provided with an oil inlet 301 on one side, and the fourth oil outlet 304 is provided at the top of the oil dewatering tank body 305 and at the rear end of the Botten rapid separation unit 106. The third sewage outlet 306 is provided at the bottom of the tank body and at the rear end of the Botten rapid separation unit 106.

[0047] The anisotropic fiber coalescence demulsification unit 302 is used to destroy the stable emulsification state between oil droplets and water droplets in the oil-containing sewage through the coalescence of anisotropic fibers, so as to realize oil-water separation.

[0048] The Botten rapid separation unit 106 separates water and impurities from the oil to obtain relatively pure oil products.

[0049] The oily water dewatering tank 300 can adopt an existing coalescence dewatering device for coalescence dewatering of the oily water, such as the modular combined high-efficiency separation device disclosed in the patent authorization announcement No. CN103706149B. Therefore, the specific structure of the heterogeneous fiber coalescence demulsification unit 302 and the botanical rapid separation unit 106 will not be described here.

[0050] In addition, the floating oil rapid separation tank 100, the deep synergistic separation tank 200, and the oily water dewatering tank 300 are all provided with automatic oil-water interface monitoring and automatic oil and water discharge functions. Specifically, in the floating oil rapid separation tank 100: a first oil-water interface meter 109 is arranged between the oily water collection bag 108 and the floating oil rapid separation tank body 112; in the deep synergistic separation tank 200: a second oil-water interface meter 204 and a third oil-water interface meter 207 are arranged between the deep synergistic separation tank body 209 and the second oily water outlet 205 and the third oily water outlet 208, respectively; in the oily water dewatering tank 300: a fourth oil-water interface meter 307 is arranged between the oily water dewatering tank 300 body 305 and the third oily water outlet 306. The automatic oil and water discharge function can be realized by using an oil pump and a water pump (not shown in the figure).

[0051] More specifically, the deep synergistic separation tank 200 is also provided with a backwash water outlet (not shown in the figure), and the backwash water outlet of the deep synergistic separation tank 200 and the oily water outlet of the oily water dewatering tank 300 are both connected to the oily water inlet of the oily water tank (not shown in the figure) for settlement separation or air floatation separation of the backwash water and the oily water produced in the coalescence dewatering process.

[0052] More specifically, the device adopts an overall closed device so that the treatment medium is not in contact with the atmosphere throughout the process, achieving the effect of pollution-free treatment process.

[0053] Based on the given acid water oil, suspended solids and COD synchronous removal equipment, the embodiment also gives an acid water oil, suspended solids and COD synchronous removal process.

[0054] The acid water oily water, suspended solids and COD synchronous removal process includes the following steps:

[0055] Step 1) The acid water discharged from the coking device drainage system enters the floating oil rapid separation tank 100 and removes the floating oil through the floating oil rapid separation process, obtaining the first oily water and the acid water oily water after removing the oily water, and the floating oil separation tank has a floating oil separation efficiency of greater than 98wt%;

[0056] Step 2) After the removal of the floating oil, the acidic water sewage enters the deep synergistic separation tank 200, and the suspended solids, oil and COD are simultaneously deeply removed through the deep synergistic separation process, so that the secondary oil and the purified acidic water sewage are obtained, the purified acidic water sewage is sent to the acidic water stripping device, the content of the suspended solids in the water out of the deep synergistic separation tank 200 is reduced to less than 20 m / L, the content of the oil is reduced to less than 80 mg / L, and the COD removal efficiency is greater than 40%.

[0057] In the process, the suspended solids filtering unit 203 of the deep synergistic separation tank 200 is backwashed, and the backwashing interval is not less than 7 days.

[0058] More specifically, the process further includes resource recycling of the oil: the primary oil and the secondary oil obtained by separation are sent to the oil dehydration tank 300 for dehydration, so that the water content is reduced to less than 1 wt%, and the oil and the sewage are obtained after dehydration. In which: the dehydrated oil is pumped to the front of the floating oil separation tank, and is deeply dehydrated before being recycled, and the oil resource utilization rate is greater than 90%; the discharged sewage is pumped to the sewage tank for separation.

[0059] More specifically, the process of the present application further includes sending the sewage discharged from the oil dehydration tank 300 and the suspended solids-containing sewage backwashed from the deep synergistic separation tank 200 to the sewage tank for sedimentation separation, and treating the floating sludge and the bottom mud obtained by separation, so as to remove the mud and suspended solids carried in the acidic water sewage from the sewage treatment system.

[0060] In the acidic water oil, suspended solids and COD removal process implemented by the present embodiment, no PAC / PAM agent is added during the whole treatment process, and no air is needed, and the complete equipment device is closed, which does not cause VOCs gas pollution caused by traditional air flotation and air blowing.

[0061] In general, the whole equipment process avoids the impact of high oil content, suspended solids and COD content on the sewage stripping device, and the separated oil is deeply dehydrated and then recycled, so that the process has the effects of completely closed treatment, low energy consumption and high oil resource recycling efficiency.

[0062] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the technical field, some improvements and decorations without departing from the principles of the present application shall also be considered as the protection scope of the present application.

Claims

1. An apparatus for simultaneous removal of oil, suspended solids and COD in sour water, characterized in that, It comprises a floating oil quick separation tank, a deep collaborative separation tank and a waste oil dehydration tank, wherein: The waste water outlet of the floating oil quick separation tank is connected with the waste water inlet of the deep collaborative separation tank, the waste water outlet of the deep collaborative separation tank is connected with an acidic water stripping device, the waste oil outlet of the floating oil quick separation tank and the deep collaborative separation tank is connected with the waste oil inlet of the waste oil dehydration tank, and the waste oil outlet of the waste oil dehydration tank is connected with the floating oil separation tank and the waste water outlet is connected with the waste water tank. The floating oil quick separation tank comprises a horizontal floating oil quick separation tank body and a self-adapting cyclone separation core unit, a sand removing unit, a rectifying unit, a quick separation unit and a corrugated quick settling unit which are installed in the tank body and arranged along the axial direction of the tank body in sequence. The deep collaborative separation tank comprises a horizontal deep collaborative separation tank body and a suspended matter filtering unit and a fiber coagulation extraction separation unit which are installed in the tank body and arranged along the axial direction of the tank body in sequence.

2. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein The self-adapting cyclone separation core unit is composed of a main pipe and a vice pipe combined column-cone type cyclone separation pipe.

3. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein The sand removing unit is composed of multiple layers of sand removing plates which are uniformly and obliquely arranged along the axial direction of the floating oil quick separation tank body.

4. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein The rectifying unit is composed of multiple layers of rectifying plates which are uniformly and horizontally arranged along the axial direction of the floating oil quick separation tank body.

5. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein The quick separation unit is composed of multiple layers of quick separation plates which are uniformly and vertically arranged along the axial direction of the floating oil separation tank body, and each quick separation plate is arranged in parallel.

6. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein The corrugated quick settling unit is composed of multiple layers of corrugated plates which are uniformly and parallelly arranged along the axial direction of the floating oil separation tank body, and small holes are formed at the wave crests and wave troughs of the corrugated plates.

7. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein the apparatus is characterized by, The suspended matter filtering unit is arranged by using mixed filter cores with different surface interface properties.

8. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein, The fiber coagulation extraction separation unit is arranged by using fibers with different surface interface properties.

9. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein, The waste oil dehydration tank is installed with a heterogeneous fiber coalescence demulsification unit and a wave-based quick separation unit.

10. The apparatus for simultaneously removing oil, suspended solids and COD in sour water according to claim 1, wherein, The floating oil quick separation tank, the deep collaborative separation tank and the waste oil dehydration tank are all provided with oil-water interface level meters.

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