Device and method for collecting supernate in oil-containing sludge tank

Abstract

The invention provides an oily sludge tank supernatant collection device and method.The device comprises a floating type liquid collector, a liquid level detector, a water pump and an electric control cabinet, the liquid level detector is used for detecting the submerging depth of the floating type liquid collector, and the liquid level detector and the water pump are both in electric signal connection with the electric control cabinet; and the electric control cabinet is used for receiving the submerging depth data of the liquid level detector in real time and sending a signal to the water pump according to the submerging depth data to control the start and stop of the water pump. The floating liquid receiver is mounted in the sludge tank and floats up and down along with the liquid level, the liquid level detector is adopted to detect the submerging depth of the floating liquid receiver, and the electric control cabinet sends a signal according to the submerging depth, controls the water pump to start and stop and pumps out supernate. The device can also be used for collecting floating oil in an oil removal tank, an oil separation tank and a sewage tank.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield wastewater treatment, and in particular relates to a device and method for collecting supernatant liquid from an oily sludge pool. Background Art

[0002] A large amount of produced water is produced during crude oil extraction. The produced water is generally treated and then injected back into the formation to replenish formation energy. The produced water contains petroleum, mineral impurities, organic matter, etc., and a large amount of oily sludge will be generated during the treatment process.

[0003] At present, the treatment of oily sludge is to set up a sludge pool in the water treatment station to receive the oily sludge and various sewage generated in the station. After the oily sludge in the pool is concentrated by sedimentation, the supernatant enters the sewage pool, and the bottom sludge is regularly cleaned and transported out. Whether the supernatant can be collected and discharged in a timely and effective manner directly affects the effect of sludge concentration. There are two ways to collect the supernatant, one is to use a fixed collection pipe, and the other is to use a floating liquid collection device. The former sets collection pipes at different heights on the wall of the sludge pool. Before collection, according to the interface between the supernatant and the sludge, open the collection pipe valve corresponding to the liquid level to collect the liquid. The latter uses a floating liquid collector or decanter floating on the liquid surface to collect the liquid.

[0004] However, both of the above two methods need to detect the interface between the supernatant and the sludge and the thickness of the supernatant before collection. The existing mud-water interface detection is mainly achieved by sampling observation or ultrasonic mud level meter detection (or mud-water interface meter). The sampling observation workload is large and is greatly affected by the operator's operation method. It cannot be measured continuously and cannot accurately participate in control; the ultrasonic mud level meter has a large measurement error. The patent announcement number published by the State Intellectual Property Office is CN2316014Y. The patent name is a device for discharging the supernatant after the mixed liquid settles. The thickness of the supernatant layer is detected by the mud-water interface detector and then transmitted to the control instrument, thereby driving the motor to rotate, driving the sprocket and transmission chain to rotate, driving the drainage main pipe to rotate, and starting to drain. However, the detector probe needs to be immersed in the liquid. Due to the complex composition of the liquid in the sludge pool and the high content of impurities such as asphalt, wax, and colloid, the sludge is easy to adhere to the probe, causing measurement errors. At the same time, the high cost of ultrasonic level meters also affects their popularization and application. Summary of the invention

[0005] The purpose of the present invention is to provide a supernatant collection device for an oily sludge pool to overcome the above-mentioned technical problems existing in the prior art.

[0006] Another object of the present invention is to provide a method for collecting supernatant liquid from an oily sludge pool, which can automatically collect the supernatant liquid according to the thickness of the supernatant liquid in the sludge pool, and the detection and control are accurate.

[0007] To this end, the technical solution provided by the present invention is as follows: A supernatant collection device for an oily sludge pool comprises a floating liquid collector, a liquid level detector, a water pump and an electric control cabinet. The liquid level detector is used to detect the submersion depth of the floating liquid collector. The liquid level detector and the water pump are both connected to the electric control cabinet by electrical signals. The electric control cabinet is used to receive the submersion depth data of the liquid level detector in real time, and send a signal to the water pump to control the start and stop of the water pump according to the submergence depth data. The floating liquid collector includes a special-shaped floating chamber, a connecting support and a disc-shaped liquid suction port. There are multiple special-shaped floating chambers, and the multiple special-shaped floating chambers are surrounded by the connecting support to form a regular polygon. The disc-shaped liquid suction port is located at the center of the regular polygon, and the multiple special-shaped floating chambers are connected to the disc-shaped liquid suction port through the connecting support.

[0008] The special-shaped floating chamber is in the shape of a truncated cone that is small at the top and large at the bottom. The interior of the special-shaped floating chamber is a cavity, and a liquid injection port is provided on the top of the special-shaped floating chamber.

[0009] The disc-shaped liquid suction port includes a horizontal disc, a liquid outlet pipe and a plurality of liquid inlet holes. The liquid outlet pipe is arranged on the lower end surface of the horizontal disc. The center of the horizontal disc is a connecting space. The plurality of liquid inlet holes are arranged horizontally and are evenly distributed along the circumference of the horizontal disc. The plurality of liquid inlet holes are separated by partitions and are all connected to the connecting space. The liquid outlet pipe is connected to the connecting space, and the water pump is connected to the liquid outlet pipe through a hose.

[0010] It also includes a guide bracket, which is arranged in a regular polygon, and the bottom of the guide bracket is fixed to the sludge tank.

[0011] An instrument installation tube is arranged on the top of the disc-shaped liquid suction port, the liquid level detector is installed in the instrument installation tube, a plurality of through holes are opened on the instrument installation tube, and a filter screen is wrapped outside the instrument installation tube.

[0012] There are three special-shaped floating chambers, and the connecting support connects the disc-shaped liquid suction port and the three special-shaped floating chambers into a whole, and the disc-shaped liquid suction port is arranged below the liquid surface.

[0013] A method for collecting supernatant liquid from an oily sludge pool, using a supernatant liquid collecting device for an oily sludge pool, wherein oily sludge water is discharged into the sludge pool, a floating liquid collector floats up with the liquid level, a liquid level detector detects the submerged depth of a disc-shaped liquid suction port of the floating liquid collector in real time and sends the result to an electric control cabinet, and when the submerged depth of the disc-shaped liquid suction port reaches a set value H1, the electric control cabinet sends a signal to a water pump, the water pump starts, and the supernatant liquid is pumped out; As the water pump runs, the supernatant gradually decreases, the liquid level drops, and the floating liquid collector drops along with the liquid level. When the submerged depth of the disc-shaped suction port drops to H2, the electric control cabinet sends a signal to the water pump, and the water pump stops.

[0014] At the beginning of the discharge of oily sludge water into the sludge pool, the sludge pool contains oily sludge water with a density between the supernatant and the sludge. The floating liquid collector generates a large buoyancy and the disc-shaped liquid suction port is shallowly submerged. At this time, the submerged depth is greater than H2 and less than

[0015] The beneficial effects of the present invention are: The supernatant liquid collecting device provided by the present invention is a device for collecting supernatant liquid from an oily sludge pool. The device is installed in the sludge pool, and floats up and down with the liquid level. A liquid level detector is used to detect the submerged depth of the floating liquid collector. The electric control cabinet sends a signal according to the submerged depth to control the start and stop of the water pump to extract the supernatant liquid. The device can also be used to collect floating oil in oil removal tanks, oil separators, and sewage pools.

[0016] Compared with the existing upward or downward suction methods, the disc-shaped liquid suction port of the floating liquid collector in the supernatant collection device of the oily sludge pool has a horizontal disc-shaped main body, which is divided into multiple horizontal liquid inlet holes by partitions. The disc-shaped liquid suction port adopts a horizontal direction to uniformly inlet liquid, and will not suck in upper air to produce vortex, nor will it suck in bottom sludge.

[0017] The method of the present invention takes into account that the interface between the supernatant and the sludge layer is not clear, but the solid content is quite different. Different solid contents result in different densities. For a floating liquid collector, the weight is constant. To obtain the same buoyancy, a larger volume of liquid needs to be displaced in the supernatant area, that is, the submergence depth is large (H1), and a smaller volume of liquid needs to be displaced in the sludge area, and the submergence depth is small (H2). The method indirectly determines the position of the mud-water interface by detecting the submergence depth of the disc-shaped liquid suction port, rather than directly detecting the mud-water interface, and the detection is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of an implementation method of the present invention; Figure 2 It is a front view of an implementation method of a floating liquid collector; Figure 3 It is a top view of an embodiment of a floating liquid collector; Figure 4 It is a front view of the disc-shaped liquid suction port; Figure 5 It is a top view of the disc-shaped liquid suction port; Figure 6 Liquid level control indication Figure 1 ; Figure 7 Liquid level control indication Figure 2 .

[0019] ​In the figure: 1. floating liquid collector; 2. water pump; 3. electric control cabinet; 4. liquid level detector; 5. hose; 6. sludge tank; 7. guide bracket; 8. disc-shaped liquid suction port; 9. special-shaped floating bin; 10. instrument mounting pipe; 11. liquid injection port; 12. liquid outlet pipe; 13. partition; 14. connecting support; 15. filter screen; 16. through hole. DETAILED DESCRIPTION

[0020] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0021] The exemplary embodiments of the present invention are now described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0022] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0023] Example 1 This embodiment provides a supernatant collection device for an oily sludge pool, such as Figure 1 As shown, it includes a floating liquid collector 1, a liquid level detector 4, a water pump 2 and an electric control cabinet 3. The liquid level detector 4 is used to detect the submergence depth of the floating liquid collector 1. The liquid level detector 4 and the water pump 2 are both connected to the electric control cabinet 3 by electrical signals. The electric control cabinet 3 is used to receive the submergence depth data of the liquid level detector 4 in real time, and send a signal to the water pump 2 to control the start and stop of the water pump 2 according to the submergence depth data. The oil-containing sludge pool supernatant collection device provided by the present invention can automatically collect the supernatant according to the thickness of the supernatant in the sludge pool 6, by installing the floating liquid collector 1 in the sludge pool 6, floating up and down with the liquid level, using the liquid level detector 4 to detect the submerged depth of the floating liquid collector 1, and the electric control cabinet 3 sends a signal according to the submerged depth to control the start and stop of the water pump 2 to extract the supernatant. The present invention can also be used for collecting floating oil in oil removal tanks, oil separators, and sewage pools.

[0024] Example 2 On the basis of Example 1, this embodiment provides a supernatant collection device for an oily sludge pool, wherein the floating liquid collector 1 includes a special-shaped floating bin 9, a connecting support 14 and a disc-shaped liquid suction port 8, wherein the special-shaped floating bins 9 are multiple, and the multiple special-shaped floating bins 9 are surrounded by the connecting support 14 to form a regular polygon, and the disc-shaped liquid suction port 8 is located at the center of the regular polygon, and the multiple special-shaped floating bins 9 are connected to the disc-shaped liquid suction port 8 through the connecting support 14.

[0025] like Figure 2 As shown, the connecting support 14 connects and fixes the disc-shaped liquid suction port 8 and a plurality of special-shaped floating chambers 9 into a whole. The disc-shaped liquid suction port 8 is lifted by the special-shaped floating chambers 9 and floats at a certain depth below the liquid surface.

[0026] Example 3 Based on Example 1, this example provides a supernatant collection device for an oily sludge pool, wherein the special-shaped floating bin 9 is a truncated cone with a small top and a large bottom, the interior of the special-shaped floating bin 9 is a cavity, and a liquid injection port 11 is opened on the top of the special-shaped floating bin 9.

[0027] Due to the density of the supernatant (1g / cm 3 ) and the sludge density after concentration (about 1.1g / cm 3 ) gap is small, the use of special-shaped floating chamber 9 can effectively increase the variation range of submerged depth under different densities and improve the reliability of instrument detection. Figure 2 As shown, the shape of the special-shaped floating warehouse 9 is formed by overlapping two cylinders, the diameter of the cylinder is small at the top and large at the bottom, and the inside is connected and hollow. The special-shaped floating warehouse 9 is provided with a liquid injection port 11, and liquid can be injected into the special-shaped floating warehouse 9 through the liquid injection port 11 to adjust the counterweight.

[0028] Example 4 Based on Example 1, this example provides a supernatant collection device for an oily sludge pool, such as Figure 4 As shown, the disc-shaped liquid suction port 8 includes a horizontal disc, a liquid outlet pipe 12 and a plurality of liquid inlet holes. The liquid outlet pipe 12 is arranged on the lower end surface of the horizontal disc. The center of the horizontal disc is a connecting space. The plurality of liquid inlet holes are horizontally arranged and evenly distributed along the circumference of the horizontal disc. The plurality of liquid inlet holes are separated by partitions 13 and are all connected to the connecting space. The liquid outlet pipe 12 is connected to the connecting space. The water pump 2 is connected to the liquid outlet pipe 12 through a hose 5.

[0029] Compared with the conventional upward or downward suction method, the disc-shaped suction port 8 is a horizontal disc-shaped body, which is divided into a plurality of horizontal liquid inlet holes (such as Figure 5 As shown in FIG. 1 ), the disc-shaped liquid suction port 8 is used to uniformly feed liquid in the horizontal direction (as shown in FIG. Figure 4As shown in the figure), the upper air will not be sucked in to generate vortex flow, nor will the bottom sludge be sucked in. The liquid outlet pipe 12 of the disc-shaped liquid suction port 8 is installed downwardly perpendicular to the horizontal disc and connected to the inlet of the water pump 2 through the hose 5.

[0030] Example 5 On the basis of Example 1, this example provides a supernatant collection device for an oily sludge pool, further comprising a guide bracket 7 , wherein the guide bracket 7 is arranged in a regular polygon, and the bottom of the guide bracket 7 is fixed to the sludge pool 6 .

[0031] like Figure 1 As shown, the guide bracket 7 is installed between the floating liquid collector connecting supports 14, and the bottom is fixed to the sludge pool 6, ensuring that the floating liquid collector 1 floats up and down along the guide bracket 7 as the water level changes, and will not drift with the water flow.

[0032] Example 6 Based on Example 1, this example provides a supernatant collection device for an oily sludge pool, wherein an instrument mounting tube 10 is provided at the top of the disc-shaped liquid suction port 8, the liquid level detector 4 is installed in the instrument mounting tube 10, a plurality of through holes 16 are opened on the instrument mounting tube 10, and a filter screen 15 is wrapped around the instrument mounting tube 10.

[0033] like Figure 1 As shown, the liquid level detector 4 is installed in the instrument installation tube 10 on the upper part of the disc-shaped liquid suction port 8 to detect the submerged depth of the disc-shaped liquid suction port 8, and the signal is transmitted to the electric control cabinet 3. The side wall of the instrument installation tube 10 is provided with a plurality of through holes 16, and a filter screen 15 is wrapped outside to block water quality impurities and avoid affecting the detection accuracy. In this embodiment, the liquid level detector 4 is a low-cost and commonly used float liquid level gauge.

[0034] Example 7 Based on Example 1, this example provides a supernatant collection device for an oily sludge pool, such as Figure 3 As shown, there are three special-shaped floating chambers 9, and the connecting support 14 connects the disc-shaped liquid suction port 8 and the three special-shaped floating chambers 9 into a whole, and the disc-shaped liquid suction port 8 is arranged below the liquid surface.

[0035] There are three special-shaped floating warehouses 9, which are evenly distributed around the disc-shaped liquid aspirator to ensure the balance of the disc-shaped liquid aspirating port 8. A liquid injection port 11 is provided on the special-shaped floating warehouse 9. Liquid can be injected into the special-shaped floating warehouse 9 through the liquid injection port 11 to adjust the counterweight.

[0036] The special-shaped floating chamber 9 is a hollow structure. When the floating liquid collector 1 is installed for the first time, the submerged depth of the disc-shaped liquid suction port 8 should be set according to the density changes of the supernatant and sludge areas. In the supernatant area, the liquid density is small, the buoyancy is small, and the submerged depth is large, which is set to H1. At the boundary between the supernatant area and the sludge area, the liquid density is large, the buoyancy is large, and the submerged depth is small, which is set to H2. The signal limit of the detection device 4 is set accordingly: H1 is the pump start value, and H2 is the pump stop value. Figure 6 , Figure 7 .

[0037] Example 8 The present embodiment provides a method for collecting supernatant from an oily sludge pool, using a supernatant collecting device for an oily sludge pool, wherein the oily sludge water is discharged into the sludge pool 6, and the floating liquid collector 1 floats up with the liquid level, and the liquid level detector 4 detects the submerged depth of the disc-shaped liquid suction port 8 of the floating liquid collector 1 in real time and sends it to the electric control cabinet 3, and when the submerged depth of the disc-shaped liquid suction port 8 reaches the set value H1, the electric control cabinet 3 sends a signal to the water pump 2, and the water pump 2 starts to pump out the supernatant; As the water pump 2 runs, the supernatant gradually decreases, the liquid level drops, and the floating liquid collector 1 drops along with the liquid level. When the submerged depth of the disc-shaped liquid suction port 8 drops to H2, the electric control cabinet 3 sends a signal to the water pump 2, and the water pump 2 stops.

[0038] Principle of the invention: In view of the unclear interface between the supernatant and the sludge layer, but the large difference in solid content, different solid content means different density. For the floating liquid collector 1, the weight is constant. To obtain the same buoyancy, a larger volume of liquid needs to be displaced in the supernatant area, that is, the submerged depth is large (H1), such as Figure 6 As shown in the figure; in the sludge area, a smaller volume of liquid needs to be displaced and the submerged depth is small (H2), such as Figure 7 This method indirectly determines the position of the mud-water interface by detecting the submerged depth of the disc-shaped liquid suction port 8, rather than directly detecting the mud-water interface, thereby improving the detection accuracy.

[0039] Example 9 Based on Example 8, this example provides a method for collecting supernatant liquid from an oily sludge pool. In the early stage of discharging the oily sludge water into the sludge pool 6, the sludge pool 6 contains oily sludge water with a density between the supernatant liquid and the sludge. The floating liquid collector 1 generates a large buoyancy, and the disc-shaped liquid suction port 8 is submerged at a shallow depth. At this time, the submerged depth is greater than H2 and less than

[0040] ​During operation: when the oily sludge water generated by the treatment station is discharged into the sludge pool 6, the floating liquid collector 1 floats up with the water flow. At this time, the pool is filled with oily sludge water with a density between the supernatant and the sludge. The buoyancy generated by the special-shaped floating bin 9 is large, and the submergence depth of the disc-shaped liquid suction port 8 is shallow. At this time, the submergence depth of the disc-shaped liquid suction port 8>H2,

[0041] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.​

Claims

1. A supernatant collection device for an oily sludge pool, characterized in that: It includes a floating liquid collector, a liquid level detector, a water pump and an electric control cabinet. The liquid level detector is used to detect the submergence depth of the floating liquid collector. Both the liquid level detector and the water pump are electrically connected to the electric control cabinet. The electric control cabinet is used to receive the submergence depth data of the liquid level detector in real time and send a signal to the water pump according to the submergence depth data to control the start and stop of the water pump.

2. The supernatant liquid collecting device for an oily sludge pool according to claim 1, characterized in that: The floating liquid collector includes a special-shaped floating bin, a connecting support member and a disc-shaped liquid suction port. There are multiple special-shaped floating bins. The multiple special-shaped floating bins form a regular polygon through the connecting support member. The disc-shaped liquid suction port is located at the center of the regular polygon. The multiple special-shaped floating bins are all connected to the disc-shaped liquid suction port through the connecting support member.

3. The supernatant liquid collecting device for an oily sludge pool according to claim 2, characterized in that: The special-shaped floating bin is in the shape of a frustum of a cone with a smaller top and a larger bottom. The inside of the special-shaped floating bin is a cavity, and a liquid injection port is opened at the top of the special-shaped floating bin.

4. The supernatant liquid collecting device for an oily sludge pool according to claim 2, characterized in that: The disc-shaped liquid suction port includes a horizontal disc, a liquid outlet pipe and multiple liquid inlet holes. The liquid outlet pipe is arranged on the lower end surface of the horizontal disc. The center of the horizontal disc is a communication space. The multiple liquid inlet holes are horizontally arranged and evenly distributed along the circumference of the horizontal disc. The multiple liquid inlet holes are separated by partition plates and are all communicated with the communication space. The liquid outlet pipe is communicated with the communication space. The water pump is communicated with the liquid outlet pipe through a hose.

5. The supernatant liquid collecting device for an oily sludge pool according to claim 2, characterized in that: It also includes a guiding bracket. The guiding bracket is arranged inside the regular polygon, and the bottom of the guiding bracket is fixed to the sludge pool.

6. The supernatant liquid collecting device for an oily sludge pool according to claim 2, characterized in that: An instrument installation pipe is arranged at the top of the disc-shaped liquid suction port. The liquid level detector is installed inside the instrument installation pipe. Multiple through holes are opened on the instrument installation pipe, and a filter screen is wrapped outside the instrument installation pipe.

7. The supernatant liquid collecting device for an oily sludge pool according to any one of claims 2 to 6, characterized in that: There are three special-shaped floating bins. The connecting support member connects the disc-shaped liquid suction port and the three special-shaped floating bins into a whole. The disc-shaped liquid suction port is arranged below the liquid surface.

8. A method for collecting supernatant liquid from an oily sludge pool, using a supernatant liquid collecting device for an oily sludge pool according to any one of claims 2 to 6, characterized in that: The oily sludge water is discharged into the sludge pool. The floating liquid collector floats with the liquid level. The liquid level detector detects the submergence depth of the disc-shaped liquid suction port of the floating liquid collector in real time and sends it to the electric control cabinet. When the submergence depth of the disc-shaped liquid suction port reaches the set value H1, the electric control cabinet sends a signal to the water pump, and the water pump starts to pump out the supernatant liquid. As the water pump operates, the supernatant liquid gradually decreases and the liquid level drops. The floating liquid collector drops with the liquid level. When the submergence depth of the disc-shaped liquid suction port drops to H2, the electric control cabinet sends a signal to the water pump, and the water pump stops pumping.

9. The method for collecting supernatant from an oily sludge pool according to claim 8, characterized in that: In the initial stage when the oily sludge water is discharged into the sludge pool, the sludge pool is filled with oily sludge water, and its density is between that of the supernatant liquid and the sludge. The buoyancy generated by the floating liquid collector is large, and the submergence depth of the disc-shaped liquid suction port is shallow. At this time, the submergence depth is greater than H2 and less than <H1, and the water pump does not start.

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