Cyclone flotation separation device and self-cleaning method of the device

Abstract

The present invention discloses a cyclone flotation separation device and a self-cleaning method of the device. The device includes an air flotation tank with upper and lower heads, the air flotation tank is an inner and outer cylinder structure, and a cyclone guide is provided at the connection between the water inlet of the outer cylinder and the lower end of the inner cylinder; the device also includes: an oil collecting pan, which is a bowl-shaped structure with an opening at the bottom, arranged above the inner cylinder; the separated oil from the center of the inner cylinder collected by the oil collecting pan is discharged through an oil collecting pipeline; a self-cleaning unit, which includes a drainage subunit arranged along the outer edge of the bowl-shaped structure for flushing the oil collecting pan and a purge subunit located above the oil collecting pan. The present invention can realize the self-cleaning of the device, and through conventional cleaning and / or deep cleaning, the device can still ensure the oil removal effect under long-term operation.

Description

Technical Field

[0001] The invention relates to the technical field of oil- and solid-containing sewage treatment, and in particular to a cyclone flotation separation device and a self-cleaning method of the device. Background Art

[0002] Cyclone dissolved air flotation technology is a hybrid separation technology that couples the principles of centrifugal separation and dissolved air flotation. It can efficiently separate oily and suspended matter wastewater. It uses a dissolved air generator to produce a large number of highly dispersed micron-sized bubbles (average particle size 20-40um, minimum particle size 5um), which can form adhesions with floating oil and tiny solid suspended matter particles in the wastewater, and separate water, oil and solid phases under the action of internal and external cyclone flow fields. It is currently widely used in the treatment of oily wastewater on offshore platforms.

[0003] According to its structural characteristics, the cyclone flotation separation device can be divided into the upward cyclone flotation process and the downward cyclone flotation process. The main difference between the two processes is the inlet position of the oily wastewater to be separated. Both processes adopt an inner and outer cylinder structure, that is, a hollow inner cylinder is set in the middle of the large outer cylinder. The inner cylinder is mostly cylindrical, and an oil collecting pan is set above the inner cylinder. Under the action of the flow field of the inner and outer cylinders, oil impurities such as oil flocs are collected by the oil collecting pan and then discharged, and the clean water is discharged from the lower part of the outer cylinder, so that the clean water that meets the separation requirements is obtained.

[0004] Chinese patent application CN102417212A discloses a cyclone flotation separation device for treating oily wastewater. The device includes a cyclone flotation combination mechanism and a gas-liquid mixing mechanism; the cyclone flotation combination mechanism includes a cylindrical body and an upper head and a lower head matched with the two ends of the cylindrical body; a spherical bowl-shaped oil collecting cover with a bottom opening is connected to the inner wall of the cylindrical body; a rectifier cylinder is fixedly connected to the lower open end of the oil collecting cover; at least one cyclone guide vane is provided on the inner wall of the cylindrical body at a position corresponding to the position of the rectifier cylinder, and the cyclone guide vane surrounds the rectifier cylinder in a manner of an ascending angle, and a spacing is provided between the cyclone guide vane and the rectifier cylinder; an exhaust port, a pressure gauge and an oil outlet are provided on the upper head; a water outlet is provided on the lower head, and the water outlet is connected to a drain pipe; the gas-liquid mixture outlet of the gas-liquid mixing mechanism is connected to a tangential inlet pipe, and the tangential inlet pipe is connected to the cylindrical body, and the connection point between the tangential inlet pipe and the cylindrical body is provided near the starting end of the cyclone guide vane.

[0005] The cyclone flotation device operates continuously during operation. During operation, the liquid level in the oil collecting tank will fluctuate up and down according to the separation index setting of the device. Especially when the liquid level in the oil collecting tank drops rapidly during the start-up and shutdown of the device, the oil flocs in the oil collecting tank will condense on the wall of the oil collecting pan. During long-term operation, a large amount of oil flocs will accumulate, affecting the oil removal effect of the device.

[0006] Therefore, there is an urgent need for a cyclone flotation separation device and a self-cleaning method for the device. By setting a self-cleaning unit, daily routine cleaning and deep cleaning can be achieved, so that the cyclone flotation separation device can ensure the oil removal effect under long-term operation.

[0007] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] The object of the present invention is to provide a cyclone flotation separation device and a self-cleaning method for the device, which can realize self-cleaning of the device, and through conventional cleaning and / or deep cleaning, the device can still ensure the oil removal effect under long-term operation.

[0009] To achieve the above-mentioned purpose, according to the first aspect of the present invention, there is provided a cyclone flotation separation device, comprising an air flotation tank with upper and lower heads, the air flotation tank being an inner and outer cylinder structure, and a cyclone guide vane is provided at the connection between the water inlet of the outer cylinder and the lower end of the inner cylinder; the device also comprises: an oil collecting pan, which is a bowl-shaped structure with an opening at the bottom, arranged above the inner cylinder; the separated oil from the center of the inner cylinder collected by the oil collecting pan is discharged through an oil collecting pipeline; a self-cleaning unit, which comprises a drainage sub-unit arranged along the outer edge of the bowl-shaped structure for flushing the oil collecting pan, and a purge sub-unit located above the oil collecting pan.

[0010] Furthermore, in the above technical solution, the drainage sub-unit may include: an inner baffle plate, which is provided on a platform on the outer edge of the bowl-shaped structure and arranged in a ring shape, and is used to gather clean water from the water outlet pipeline of the flotation tank; an outer baffle plate, which is covered on the top of the inner baffle plate, has a straight portion connected to the inner wall of the outer cylinder and a vertical portion extending downward along the end side of the straight portion, and the lower end of the vertical portion is lower than the upper end of the inner baffle plate, and is used to generate a certain initial pressure for the clean water overflowing from the inner baffle plate and evenly divert it to the inclined surface of the oil collecting pan.

[0011] Furthermore, in the above technical solution, a drainage inlet is provided on the wall of the outer cylinder at a position corresponding to the deflection inner baffle, and the drainage inlet can be connected to the water outlet pipeline through a drainage pipeline.

[0012] Furthermore, in the above technical solution, the purge subunit may include: a purge pipe, which is connected to the top of the upper head through a flange and communicates with the gas dissolving tank through an air flow pipeline, and the part of the purge pipe extending into the upper head has an inclined angle.

[0013] Furthermore, in the above technical solution, a threaded adjustment portion may be provided at the connection between the purge pipe and the flange for adjusting the height of the purge pipe; the height adjustment and the setting of the tilt angle are used to fully cover the oil collecting pan during the purge process.

[0014] Furthermore, in the above technical solution, the water inlet of the dissolved air tank can be connected to the water outlet pipeline of the air flotation tank through a dissolved air water inlet pipeline, and a dissolved air generating device can be provided on the dissolved air water inlet pipeline.

[0015] Furthermore, in the above technical solution, the dissolved air generating device is used to inject tiny bubbles into clean water from the water outlet pipeline of the air flotation tank to form dissolved air water; the water outlet of the dissolved air tank can be connected to the water inlet pipeline of the air flotation tank.

[0016] Furthermore, in the above technical solution, a dosing device may be provided on the drainage pipeline for automatically adding a cleaning agent into the drainage pipeline when it is determined that the thickness of the oil flocs on the oil collecting tray reaches a set value.

[0017] Furthermore, in the above technical solution, the dosing device can automatically open the switch of the medicine storage tank after receiving the over-standard signal from the oil floc thickness monitor, and the cleaning agent enters the drainage pipeline through the dosing port.

[0018] Furthermore, in the above technical solution, the oil floc thickness monitor may include: an oil scraper groove, which is arranged on the inclined surface of the oil collecting pan and maintains a certain angle with the inclined surface; a pressure sensor, which is arranged at the top of the oil scraper groove, and when the oil scraper groove is full of oil flocs and pressure is formed on the top, an over-standard signal is generated.

[0019] According to a second aspect of the present invention, the present invention provides a self-cleaning method for a cyclone flotation separation device, comprising the following steps: A. when the device is in normal operation, after oil flocs are condensed on the surface of the bowl-shaped structure of the oil collecting pan, clean water from the water outlet pipeline of the flotation tank is drained to the outer edge of the bowl-shaped structure, and the inclined surface of the bowl-shaped structure is flushed through a drainage sub-unit; and / or, B. high-pressure gas from the dissolved air tank is introduced from the upper head of the flotation tank, and the oil collecting pan is purged through a purging sub-unit located above the oil collecting pan.

[0020] Furthermore, in the above technical solution, step A can be specifically as follows: A1, agglomerating the clean water from the water outlet pipeline of the flotation tank on the platform at the outer edge of the bowl-shaped structure; A2, forming a certain initial pressure on the agglomerated clean water, and evenly diverting it to the inclined surface of the bowl-shaped structure.

[0021] Furthermore, in the above technical solution, step B may specifically include: during the purging process, the oil collecting pan is fully covered by adjusting the height of the purging pipe of the purging subunit.

[0022] Furthermore, in the above technical solution, the self-cleaning method may also include the following steps: C. automatically adding a cleaning agent into the drainage pipeline when it is determined that the thickness of the oil flocs on the oil collecting tray reaches a set value.

[0023] Further, in the above technical solution, step C may specifically include: C1, setting an oil scraper groove on the inclined surface of the oil collecting pan, and when the oil scraper groove is filled with oil flocs and forms pressure on the top, an over-standard signal is generated; C2, sending a control instruction to the dosing device based on the over-standard signal, turning on the switch of the medicine storage tank, and introducing the cleaning agent into the drainage pipeline through the dosing port.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The device and the self-cleaning method of the present invention can effectively clean the oil collecting pan without using any mechanism other than the cyclone flotation separation device: that is, no external air source and water source are required, the recycling of water and air is achieved, and the operating cost of the device is low;

[0026] 2) The compact cyclone flotation separation device of the present invention can effectively improve the oil and solid removal effect of the device, better meet the problem of long-term continuous operation of the cyclone flotation device under high oil content conditions, and can be cleaned without disassembly, which has the technical advantages of convenient and thorough cleaning;

[0027] 3) The present invention can effectively reduce the impurity content of oil flocs deposited on the oil collecting pan by returning the clean water purified by the flotation tank to the drainage sub-unit, and flushing the oil flocs condensed on the surface of the oil collecting tank under the diversion effect of the drainage sub-unit; at the same time, high-pressure gas is introduced through the reflux of the purge sub-unit to purge the oil collecting pan, so that the oil flocs in the oil collecting pan are cleaned more thoroughly, and the purge range can be adjusted by adjusting the thread; the degree of condensation of oil flocs can be quantified by the oil floc thickness monitor, and the chemical cleaning mode is turned on when the oil content reaches the set value, which can further optimize the cleaning effect.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, and to make the above and other purposes, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of the cyclone flotation separation device of the present invention.

[0030] Figure 2 It is a cross-sectional schematic diagram of the drainage subunit in the cyclone flotation separation device of the present invention (also showing the dosing device and the oil scraping tank).

[0031] Figure 3 It is a top view schematic diagram of the drainage subunit in the cyclone flotation separation device of the present invention (the oil scraping groove has been removed).

[0032] Figure 4 It is a schematic structural diagram of a purge subunit in a cyclone flotation separation device of the present invention.

[0033] Description of main reference numerals:

[0034] 1-air flotation tank, 10-outer cylinder, 10A-water inlet, 10B-water outlet, 10C-slag discharge port, 10D-air inlet, 100-water inlet pipeline, 101-water outlet pipeline, 102-slag discharge pipeline, 11-inner cylinder, 12-upper head, 13-lower head, 14-oil collecting tray, 15-oil collecting pipeline, 150-oil discharge pipeline, 16-drainage subunit, 160-drainage pipeline, 1601-dosing device, 1601A-drug storage tank, 1601B-dosing port, 161-baffle inner baffle, 162-baffle outer baffle, 17-purge pipe, 170-airflow pipeline, 171-adjustment thread, 18-oil scraper groove, 181-signal line, 19-flange;

[0035] 2-dissolved air tank, 20-dissolved air water pipeline, 21-dissolved air generating device, 22-dissolved air water inlet pipeline. DETAILED DESCRIPTION

[0036] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0037] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0038] In this document, for the convenience of description, spatial relative terms such as "below", "below", "down", "above", "above", "upper", etc. may be used to describe the relationship between one element or feature and another element or feature in the accompanying drawings. It should be understood that the spatial relative terms are intended to include different orientations of the object in use or operation in addition to the orientation depicted in the figure. For example, if the object in the figure is turned over, the element described as being "below" or "below" other elements or features will be oriented "above" the element or feature. Therefore, the exemplary term "below" can include both below and above. Objects may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used in this document should be interpreted accordingly.

[0039] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable.

[0040] Example 1

[0041] like Figure 1 As shown, the present invention provides a cyclone flotation separation device, including a flotation tank 1 and a dissolved air tank 2. The flotation tank 1 is an inner and outer cylinder structure, including an outer cylinder 10 and an inner cylinder 11. The diameter of the inner cylinder can be 65%-85% of the diameter of the outer cylinder. The flotation tank 1 has an upper head 12 and a lower head 13. A cyclone guide (not shown in the figure) is provided at the connection between the water inlet 10A of the outer cylinder 10 and the lower end of the inner cylinder 11. An oil collecting pan 14 and a self-cleaning unit of the oil collecting pan are also provided in the flotation tank 1 of the present invention. Among them, the oil collecting pan 14 is a bowl-shaped structure with an opening at the bottom, which is arranged above the inner cylinder 11. The separated oil from the center of the inner cylinder 11 collected by the oil collecting pan 14 is discharged to the oil discharge pipeline 150 outside the outer cylinder through the oil collecting pipeline 15.

[0042] The working process of the cyclone flotation separation device of the present invention is as follows: the oily and solid-containing sewage to be separated is mixed with the dissolved air water from the dissolved air water pipeline 20 in the water inlet pipeline 100 and then enters the outer cylinder 10 of the flotation tank 1 from the water inlet 10A, and enters the inner cylinder 11 in a spiral rising state under the action of the inlet cyclone guide (not shown in the figure). During the rising and floating process of the sewage in the inner cylinder 11, the oil is concentrated in the middle, enters the oil collecting tray 14, and is transported to the oil discharge pipeline 150 outside the tank through the oil collecting pipeline 15. The water flow diffuses between the inner cylinder 11 and the outer cylinder 10, flows from top to bottom, and the solid impurities in the sewage are discharged through the slag discharge port 10C and transported to the outside through the slag discharge pipeline 102. The remaining purified clean water is discharged from the water outlet 10B and divided into three paths in the water outlet pipeline 101. Most of the clean water is discharged to other devices through the water outlet pipeline 101, and about 15%-35% of the clean water enters the dissolved gas tank 2 through the dissolved gas water inlet pipeline 22. Before entering the dissolved gas tank 2, it is first injected with tiny bubbles through the dissolved gas generating device 21. The dissolved gas tank 2 is connected to the air flotation tank 1 through the air flow pipeline 170. The mixed dissolved gas water flows into the inlet pipeline 100 through the dissolved gas water pipeline 20.

[0043] Further Figure 1 As shown, the device of the present invention further comprises a self-cleaning unit for cleaning the oil collecting pan 14, and the self-cleaning unit comprises a drainage sub-unit 16 arranged along the outer edge of the bowl-shaped structure of the oil collecting pan 14 for flushing the oil collecting pan, and a purge sub-unit (i.e., purge pipe 17) located above the oil collecting pan 14. The self-cleaning unit of the present invention can effectively clean the oil collecting pan without the aid of any mechanism other than the cyclone flotation separation device, and the clean water used by the drainage sub-unit 16 comes from the water discharged from the flotation tank 1, while the high-pressure gas used by the purge sub-unit comes from the dissolved gas tank 2 of the device of the present invention.

[0044] Further Figure 2As shown, the drainage subunit 16 specifically includes an inner baffle plate 161 and an outer baffle plate 162. The inner baffle plate 161 is arranged on a platform at the outer edge of the bowl-shaped structure of the oil collecting pan 14, and is arranged in an annular shape as a whole (see Figure 3 ), the baffle plate 161 plays a role similar to an overflow weir, and is used to gather clean water from the water outlet pipeline 101 of the flotation tank. Specifically, a drainage inlet is provided on the outer cylinder wall at the corresponding position of the baffle plate 161, and the drainage inlet is connected to the water outlet pipeline 101 through the drainage pipeline 160 (refer to Figure 1 ). One of the three routes of the flotation tank outlet pipeline 101 flows back to the drainage sub-unit 16 through the drainage pipeline 160, and the clean water gathers along the annular baffle inner baffle 161. When the liquid level rises to the upper edge of the baffle inner baffle 161, an overflow effect is generated. The baffle outer baffle 162 is wrapped above the baffle inner baffle 161, and has a straight portion connected to the inner wall of the outer cylinder and a vertical portion extending downward along the end side of the straight portion, and the lower end of the vertical portion is lower than the upper edge of the baffle inner baffle 161. The vertical portion of the baffle outer baffle 162 is used in combination with the baffle inner baffle 161, so that the clean water overflowing from the baffle inner baffle 161 can generate a certain initial pressure and evenly divert it to the inclined surface of the oil collecting pan 14.

[0045] Further Figure 2 As shown, preferably but not restrictively, when the oil flocs on the oil collecting pan 14 are large in area and have a certain thickness and need to be deeply cleaned, a cleaning agent can be used to participate in the cleaning. Specifically, a dosing device 1601 (refer to Figure 1 ), which is used to automatically add cleaning agents to the drainage line 160 when it is determined that the thickness of the oil flocs on the oil collecting pan 14 reaches a set value. Further, the dosing device 1601 can be connected to an oil floc thickness monitor, and the oil floc thickness monitor may include an oil scraper 18 and a pressure sensor (not shown in the figure), wherein the oil scraper 18 is arranged on the inclined surface of the oil collecting pan and maintains a certain angle with the inclined surface, so that it is easier to scrape the oil flocs on the inclined surface. The pressure sensor can be arranged at the top of the scraper trough 18. When the scraper trough 18 is full of oil flocs and pressure is formed on the top, an over-standard signal about the thickness of the oil flocs is formed. After receiving the over-standard signal from the oil floc thickness monitor through the signal line 181, the dosing device 1601 automatically turns on the switch of the drug storage tank 1601A, and the cleaning agent can enter the drainage line 160 through the dosing port 1601B and mix with the clean water. The cleaning agent of the present invention can be octoxynol or the like.

[0046] Further Figure 4As shown, the purge subunit is specifically a purge pipe 17, which is connected to the top of the upper head 12 through a flange 19 and is connected to the dissolved air tank 2 through an airflow pipeline 170. The portion of the purge pipe extending into the upper head 12 has an inclination angle, that is, the extension direction of the free end of the purge pipe 17 is at a certain angle to the vertical plane, and the preferred angle is 15-75 degrees. The inclined purge pipe can clean the oil collecting pan 14. Preferably, but not restrictively, a threaded adjustment portion (i.e., an adjustment thread 171) is provided at the connection between the purge pipe 17 and the flange 19, which can be used to adjust the height of the purge pipe 17. The height adjustment and the setting of the inclination angle can achieve full coverage of the purge area of ​​the oil collecting pan 14 during the purge process. The high-pressure gas source for purging comes from the dissolved air tank 2 in the device of the present invention. For further reference Figure 1 The function of the gas dissolving tank 2 is mainly to provide dissolved gas water for mixing with sewage, and to generate a large number of highly dispersed micron-sized bubbles by using the dissolved gas generating device arranged on the dissolved gas water inlet pipeline. The micron-sized bubbles can form an adhesion body with the floating oil and tiny solid suspended particles in the sewage, and perform water-oil-solid three-phase separation under the action of the internal and external vortex flow fields. High-pressure gas will also be generated in the gas dissolving tank 2. The present invention utilizes this part of high-pressure gas and introduces it into the flotation tank 1 to achieve the purge of the oil collecting tray 14. The dissolved gas generating device includes a dissolved gas pump, an ejector and other components, which will not be described in detail here. The gas can be selected from nitrogen, air, light hydrocarbons, etc. by analyzing the composition of the raw water and the composition of the oil pollution according to the principle of like dissolves like and the principle of chemical reaction.

[0047] Example 2

[0048] The present invention also provides a self-cleaning method for a cyclone flotation separation device, which involves a daily cleaning mode and a deep cleaning mode. The method comprises the following steps:

[0049] Daily cleaning mode:

[0050] Step S101, when the cyclone flotation separation device of the present invention is in normal operation, after a certain area of ​​oil floccules are condensed on the surface of the bowl-shaped structure of the oil collecting pan 14, clean water from the water outlet pipeline 101 of the flotation tank 1 is drained to the outer edge of the bowl-shaped structure, and the inclined surface of the bowl-shaped structure is washed by the drainage sub-unit 16. Specifically, the clean water from the water outlet pipeline 101 of the flotation tank 1 can first be coalesced on the platform of the outer edge of the bowl-shaped structure; then the coalesced clean water forms a certain initial pressure and is evenly diverted to the inclined surface of the bowl-shaped structure.

[0051] In step S102, the high-pressure gas from the dissolved gas tank in the cyclone flotation separation device of the present invention is introduced from the upper head of the flotation tank 1, and the oil collecting pan 14 is purged through the purging subunit located above the oil collecting pan 14. Preferably, but not restrictively, during the purging process, the height of the purging pipe 17 of the purging subunit can be adjusted to form a full coverage of the purging area of ​​the oil collecting pan 14. It should be noted here that step S101 and step S102 can be performed separately or in combination, and the cleaning effect is better when used in combination.

[0052] Deep cleaning mode:

[0053] That is, based on step S101, the following steps may also be included:

[0054] Step S103, when it is determined that the thickness of the oil flocs on the oil collecting pan 14 reaches a set value, a cleaning agent is automatically added to the drainage pipeline. Preferably, but not restrictively, the set value can be the oil floc thickness value that can be monitored by the pressure sensor. This step may further include: setting an oil scraper groove 18 on the inclined surface of the oil collecting pan 14, when the oil scraper groove 18 is full of oil flocs and forms pressure on the top, an over-standard signal is generated; according to the over-standard signal, a control instruction is sent to the dosing device 1601 to turn on the switch of the drug storage tank 1601A, and then the cleaning agent is introduced into the drainage pipeline 160 through the dosing port 1601B. After the cleaning agent is added, the oil flocs can be condensed and washed away by the flushing action of the water flow, so that the cleaning is more thorough, that is, deep cleaning is achieved.

[0055] Furthermore, when the cyclone flotation separation device of the present invention is shut down and needs to be cleaned on a large scale, the cleaning agent can be sprayed out from the dosing port 1601B after the sewage in the device is drained, or high-temperature steam can be introduced through the purge pipe 17 to purge the oil collecting pan.

[0056] The following is a specific example:

[0057] This example uses Figure 1 The cyclone flotation separation device shown in the figure uses oily wastewater from an offshore platform. The oil impurity content in the wastewater is about 400ppm, and the wastewater treatment capacity is about 30m 3 / h. The dissolved air generating device uses a dissolved air pump, and the dissolved air water volume is 3m 3 / h, and nitrogen is used as the dissolved gas. After being treated by the device of the present invention, the petroleum oil impurity content in the outlet clean water is reduced to 28ppm on average, and the oil removal rate is 94%. After self-cleaning of the drainage subunit and the purge subunit, there is basically no oil flocs remaining on the surface of the oil collecting pan.

[0058] By adopting the device and the self-cleaning method of the present invention, the oil collecting pan can be effectively cleaned without the aid of any mechanism other than the cyclone flotation separation device: the clean water used by the drainage subunit comes from the water discharged from the flotation tank, and the high-pressure gas used by the purge subunit comes from the dissolved gas tank of the device of the present invention, and no external gas source and water source are required, thus realizing the recycling of water and gas, and the operating cost of the device is low; by adopting the compact cyclone flotation separation device of the present invention, the oil and solid removal effect of the device can be effectively improved, and the problem of long-term continuous operation of the cyclone flotation device under high oil content conditions can be better met, and at the same time, it does not need to be disassembled. The cleaning has the technical advantages of being convenient and thorough. The present invention can return the clean water purified by the flotation tank to the drainage sub-unit, and wash the oil flocs condensed on the surface of the oil collecting tank under the diversion effect of the drainage sub-unit, which can effectively reduce the impurity content of the oil flocs deposited on the oil collecting pan. At the same time, the high-pressure gas is introduced through the reflux of the purge sub-unit to purge the oil collecting pan, which can more thoroughly clean the oil flocs in the oil collecting pan, and the purge range can be adjusted by adjusting the thread. The degree of condensation of the oil flocs can be quantified by the oil floc thickness monitor, and the chemical cleaning mode is turned on when the oil content reaches the set value, which can further optimize the cleaning effect.

[0059] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A cyclone flotation separation device, characterized in that: The device comprises an air flotation tank with upper and lower heads, the air flotation tank is an inner and outer cylinder structure, and a swirl guide is provided at the connection between the water inlet of the outer cylinder and the lower end of the inner cylinder; the device also comprises: An oil collecting pan, which is a bowl-shaped structure with an open bottom, is arranged above the inner cylinder; the separated oil from the center of the inner cylinder collected by the oil collecting pan is discharged through an oil collecting pipeline; The self-cleaning unit comprises a drainage subunit arranged along the outer edge of the bowl-shaped structure and used for flushing the oil collecting pan, and a purge subunit located above the oil collecting pan.

2. The cyclone flotation separation device according to claim 1, characterized in that: The drainage subunit comprises: A baffle plate, which is disposed on a platform at the outer edge of the bowl-shaped structure and arranged in a ring shape, and is used to coalesce clean water from the water outlet pipeline of the flotation tank; The outer baffle plate is covered on the top of the inner baffle plate, and has a straight portion connected to the inner wall of the outer cylinder and a vertical portion extending downward along the end side of the straight portion. The lower end of the vertical portion is lower than the upper end of the inner baffle plate, and is used to generate a certain initial pressure for the clean water overflowing from the inner baffle plate and evenly divert it to the inclined surface of the oil collecting pan.

3. The cyclone flotation separation device according to claim 2, characterized in that: A drainage inlet is provided on the wall of the outer cylinder at a position corresponding to the deflection inner baffle, and the drainage inlet is connected with the water outlet pipeline through a drainage pipeline.

4. The cyclone flotation separation device according to claim 1, characterized in that: The purge subunit comprises: The purge pipe is connected to the top of the upper end cap through a flange and is communicated with the gas dissolving tank through an air flow pipeline. The portion of the purge pipe extending into the upper end cap has an inclined angle.

5. The cyclone flotation separation device according to claim 4, characterized in that: A threaded adjustment portion is provided at the connection between the purge pipe and the flange, which is used to adjust the height of the purge pipe; the height adjustment and the setting of the inclination angle are used to fully cover the oil collecting pan during the purge process.

6. The cyclone flotation separation device according to claim 4, characterized in that: The water inlet of the dissolved air tank is connected with the water outlet pipeline of the air flotation tank through a dissolved air water inlet pipeline, and a dissolved air generating device is arranged on the dissolved air water inlet pipeline.

7. The cyclone flotation separation device according to claim 6, characterized in that: The dissolved air generating device is used to inject tiny bubbles into the clean water from the water outlet pipeline of the air flotation tank to form dissolved air water; the water outlet of the dissolved air tank is connected to the water inlet pipeline of the air flotation tank.

8. The cyclone flotation separation device according to claim 3, characterized in that: The drainage pipeline is provided with a dosing device for automatically adding a cleaning agent to the drainage pipeline when it is determined that the thickness of the oil flocs on the oil collecting tray reaches a set value.

9. The cyclone flotation separation device according to claim 8, characterized in that: After receiving the over-standard signal from the oil floc thickness monitor, the dosing device automatically turns on the switch of the drug storage tank, and the cleaning agent enters the drainage pipeline through the dosing port.

10. The cyclone flotation separation device according to claim 9, characterized in that: The oil floc thickness monitor comprises: An oil scraping groove is arranged on the inclined surface of the oil collecting pan and maintains a certain angle with the inclined surface; The pressure sensor is arranged at the top of the oil scraping groove. When the oil scraping groove is filled with oil flocs and pressure is formed on the top, the over-standard signal is generated.

11. A self-cleaning method for a cyclonic flotation separation device, characterized in that: The steps include: A. When the device is in normal operation, after oil flocs condense on the surface of the bowl-shaped structure of the oil collecting pan, clean water from the water outlet pipeline of the flotation tank is drained to the outer edge of the bowl-shaped structure, and the inclined surface of the bowl-shaped structure is flushed through the drainage subunit; and / or, B. Introduce the high-pressure gas from the dissolved gas tank from the upper head of the flotation tank, and purge the oil collecting pan through the purge subunit located above the oil collecting pan.

12. The self-cleaning method of the cyclone flotation separation device according to claim 11, characterized in that: The step A is specifically as follows: A1. The clean water from the water outlet pipeline of the flotation tank is aggregated on the platform at the outer edge of the bowl-shaped structure; A2. The clean water after coalescence is subjected to a certain initial pressure and evenly distributed to the inclined surface of the bowl-shaped structure.

13. The self-cleaning method of the cyclone flotation separation device according to claim 11, characterized in that: The step B specifically comprises: During the purging process, the oil collecting pan is fully covered by adjusting the height of the purging pipe of the purging subunit.

14. The self-cleaning method of the cyclone flotation separation device according to claim 12, characterized in that: The self-cleaning method also comprises the steps of: C. When it is determined that the thickness of the oil flocs on the oil collecting pan reaches a set value, a cleaning agent is automatically added to the drainage pipeline.

15. The self-cleaning method of the cyclone flotation separation device according to claim 14, characterized in that: The step C specifically comprises: C1. An oil scraper groove is set on the inclined surface of the oil collecting pan. When the oil scraper groove is filled with oil flocs and forms pressure on the top, an over-standard signal is generated; C2. Send a control instruction to the dosing device according to the exceeding standard signal, turn on the switch of the medicine storage tank, and introduce the cleaning agent into the drainage pipeline through the dosing port.

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