Closed dehydration system of oil product tank

Abstract

The utility model relates to the technical field of oil product dehydration, in particular to a closed dehydration system of an oil product tank. The closed dehydration system of the oil product tank comprises a zero-position tank arranged underground, a dehydration tank and an auxiliary tank, the dehydration tank and the auxiliary tank are arranged above the zero-position tank, an inner cavity of the zero-position tank is divided into a dirty oil cavity and a sewage cavity by a vertically-arranged partition plate, the upper portion of the dirty oil cavity is communicated with the upper portion of the sewage cavity, and the bottom of the sewage cavity is connected with a water outlet pipe. The water outlet pipe is communicated with a first sewage well through a first sewage pipe, and a sewage water meter is arranged on the first sewage pipe; the bottom of the dewatering tank is connected with a dewatering pipe, the dewatering pipe is connected with a second sewage pipe and a first drainage pipe through a first communicating pipe, the second sewage pipe is communicated with a second sewage well, the first communicating pipe is provided with a drainage water meter, the first drainage pipe is connected with a second drainage pipe, and an outlet of the second drainage pipe is arranged at the bottom of the sewage cavity. The sewage treatment device saves labor cost and resources, avoids environmental pollution, and reduces sewage treatment difficulty.

Description

Technical Field

[0001] The utility model relates to the technical field of oil dehydration, in particular to a closed dehydration system for an oil tank. Background Art

[0002] Water is the main by-product in the oil and gas production process and the oil refining process. Therefore, the dehydration and water discharge operation of the storage tanks of petrochemical enterprises is an important task in the storage and transportation process. The use of artificial dehydration often results in oil in the discharged water.

[0003] After crude oil or refined oil is demulsified by physical or chemical methods, oil and water are automatically separated in the oil tank due to the difference in density. In order to remove the water at the bottom of the tank, manual timed dehydration is usually used. During the dehydration process, the operator needs to observe at the water cut-off. However, since the visual characteristics of dirty oil and water are not obviously different, it is difficult to grasp the dehydration nodes manually, and the phenomenon of oil in the dehydration water often occurs.

[0004] Artificial dehydration not only involves a large workload, but also causes oil to be carried over from the water, which increases the difficulty of subsequent sewage treatment. At the same time, the volatilization of oil and gas will cause waste of resources and environmental pollution. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a closed dehydration system for oil tanks, which saves labor costs, saves resources, avoids environmental pollution, and reduces the difficulty of sewage treatment.

[0006] The utility model discloses a closed dehydration system for oil product tanks, comprising a zero-level tank arranged underground, a dehydration tank and an auxiliary tank arranged above the zero-level tank, wherein the internal cavity of the zero-level tank is divided into a dirty oil cavity and a sewage cavity by a vertically arranged partition, the dirty oil cavity and the sewage cavity are connected to each other at the top, the sewage cavity is connected to a water outlet pipe at the bottom, the water outlet pipe is connected to a first sewage well through a first sewage pipe, and a sewage water meter is arranged on the first sewage pipe; the bottom of the dehydration tank is connected to a dehydration pipe, the dehydration pipe is connected to a second sewage pipe and a first drainage pipe through a first connecting pipe, the second sewage pipe is connected to a second sewage well, a drainage water meter is installed on the first connecting pipe, the first drainage pipe is connected to the second drainage pipe, and the outlet of the second drainage pipe is arranged at the bottom of the sewage cavity; the bottom of the auxiliary tank is connected to a liquid inlet pipe, the liquid inlet pipe is connected to an oil inlet pipe through a second connecting pipe, the inlet of the oil inlet pipe is arranged at the bottom of the dirty oil cavity, and a machine pump is arranged on the second connecting pipe;

[0007] The first sewage pipe is provided with a sewage solenoid valve, the first connecting pipe is provided with a drainage solenoid valve, the sewage water measuring instrument is electrically connected to the sewage solenoid valve, and the drainage water measuring instrument is electrically connected to the drainage solenoid valve.

[0008] Preferably, there are at least two drainage water measuring instruments and two sewage water measuring instruments. The test results of multiple instruments are more accurate and more referenceable.

[0009] Preferably, a breathing valve is provided on the zero-level tank, and both the dirty oil chamber and the sewage chamber are provided with liquid level gauges.

[0010] Preferably, the bottom of the dirty oil chamber, the bottom of the sewage chamber, the first sewage pipe, the first connecting pipe and the second connecting pipe are respectively provided with a first vent pipe, a second vent pipe, a third vent pipe, a fourth vent pipe and a fifth vent pipe.

[0011] Preferably, the first sewage pipe and the first drainage pipe are connected to the first steam purge pipe and the second steam purge pipe respectively, and the first steam purge pipe and the second steam purge pipe are provided with a first purge valve and a second purge valve respectively.

[0012] Preferably, the first drain pipe is connected to the return pipe and the second connecting pipe through the third connecting pipe, and the return pipe inlet is arranged at the bottom of the sewage chamber.

[0013] Preferably, the bottom of the dirty oil chamber is connected to the first sewage pipe through a fourth connecting pipe.

[0014] Preferably, the second connecting pipe is connected to the second sewage well through a fifth connecting pipe.

[0015] Preferably, the edge of the partition is sealed and connected to the inner wall of the zero-level tank, a flow port is opened on the upper part of the partition, the dirty oil chamber and the sewage chamber are connected through the flow port, a flow regulating valve is provided on the flow port, a water meter is provided on the upper part of the sewage chamber, and the detection probe of the water meter extends below the lowest point of the flow port.

[0016] As another embodiment of the utility model, the height of the partition is smaller than the height inside the zero-level tank, the upper edge of the partition is not connected to the upper inner wall of the zero-level tank, and the dirty oil chamber and the sewage chamber are connected through the gap between the upper edge of the partition and the inner wall of the zero-level tank.

[0017] Valves can be installed on the pipeline according to control needs, and the flow of materials in the corresponding pipeline can be conveniently controlled and adjusted by opening and closing the valves.

[0018] When the utility model is in use, the dehydration tank controls the heating to separate the oil and water by gravity, and then discharges the water in the lower layer to the second sewage well through the dehydration pipe and the second sewage pipe. During the drainage, the drainage water measuring instrument installed on the first connecting pipe determines that the water has been drained to the oil-water stratification by detecting changes in comprehensive parameters such as the viscosity and density of the medium, and then controls the drainage solenoid valve to open, and most of the oil (mixed with a small amount of water) in the upper layer of the dehydration tank enters the sewage chamber of the zero-level tank. After the secondary oil and water are separated by gravity at the bottom of the sewage chamber, the secondary dehydrated oil in the zero-level tank can be recovered or the oil and water can be separated again.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] 1. The utility model has a reasonable and compact structure and is easy to operate. By detecting the changes in the comprehensive parameters of the medium through the sewage water meter and the drainage water meter, the oil-water boundary can be judged more accurately, which reduces the difficulty of oily sewage treatment and saves labor costs;

[0021] 2. The utility model improves the oil recovery rate, reduces environmental pollution, and is completely suitable for dehydrating heavy oil storage tanks with high water content. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the utility model;

[0023] Figure 2 This is a schematic diagram of the structure of the zero-position tank of Embodiment 2 of the present utility model;

[0024] Figure 3 This is a schematic diagram of the structure of the zero-position tank in Embodiment 3 of the present utility model;

[0025] In the figure: 1, zero-level tank; 2, dehydration tank; 3, auxiliary tank; 4, partition; 5, dirty oil chamber; 6, sewage chamber; 7, outlet pipe; 8, first sewage pipe; 9, first sewage well; 10, sewage water meter; 11, dehydration pipe; 12, first connecting pipe; 13, second sewage pipe; 14, first drainage pipe; 15, second sewage well; 16, drainage water meter; 17, second drainage pipe; 18, liquid inlet pipe; 19, second connecting pipe; 20, oil inlet pipe; 21, pump; 22, drainage Solenoid valve; 23. Sewage solenoid valve; 24. Breathing valve; 25. Liquid level gauge; 26. First vent pipe; 27. Second vent pipe; 28. Third vent pipe; 29. ​​Fourth vent pipe; 30. Fifth vent pipe; 31. First steam purge pipe; 32. Second steam purge pipe; 33. First purge valve; 34. Second purge valve; 35. Third connecting pipe; 36. Reflux pipe; 37. Fourth connecting pipe; 38. Fifth connecting pipe; 39. Circulation regulating valve; 40. Upper water measuring instrument. DETAILED DESCRIPTION

[0026] The present invention will be described clearly and completely below with reference to the accompanying drawings.

[0027] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation for the convenience of expression and do not represent a sequential relationship.

[0028] Example 1

[0029] like Figure 1As shown, the oil tank closed dehydration system of the utility model comprises a zero-level tank 1 arranged underground, a dehydration tank 2 and an auxiliary tank 3 arranged above the zero-level tank 1, the internal cavity of the zero-level tank 1 is divided into a dirty oil cavity 5 and a sewage cavity 6 by a vertically arranged partition 4, the dirty oil cavity 5 and the sewage cavity 6 are interconnected at the top, the sewage cavity 6 is connected to a water outlet pipe 7 at the bottom, the water outlet pipe 7 is connected to a first sewage well 9 through a first sewage pipe 8, and a sewage water meter 10 is arranged on the first sewage pipe 8; the bottom of the dehydration tank 2 is connected to a dehydration pipe 11, and the dehydration pipe 12 is connected to the first sewage well 9 through a first sewage pipe 8. 11 connects the second sewage pipe 13 and the first drainage pipe 14 through the first connecting pipe 12, the second sewage pipe 13 is connected to the second sewage well 15, a drainage water meter 16 is installed on the first connecting pipe 12, the first drainage pipe 14 is connected to the second drainage pipe 17, and the outlet of the second drainage pipe 17 is arranged at the bottom of the sewage chamber 6; the bottom of the auxiliary tank 3 is connected to the liquid inlet pipe 18, the liquid inlet pipe 18 is connected to the oil inlet pipe 20 through the second connecting pipe 19, the inlet of the oil inlet pipe 20 is arranged at the bottom of the dirty oil chamber 5, and a pump 21 is arranged on the second connecting pipe 19;

[0030] The first sewage pipe 8 is provided with a sewage solenoid valve 23 , the first connecting pipe 12 is provided with a drainage solenoid valve 22 , the sewage water meter 10 is electrically connected to the sewage solenoid valve 23 , and the drainage water meter 16 is electrically connected to the drainage solenoid valve 22 .

[0031] There are two drainage water measuring instruments 16 and two sewage water measuring instruments 10.

[0032] A breathing valve 24 is provided on the zero-level tank 1 , and both the dirty oil chamber 5 and the dirty water chamber 6 are provided with liquid level gauges 25 .

[0033] The bottom of the dirty oil chamber 5, the bottom of the sewage chamber 6, the first sewage pipe 8, the first connecting pipe 12 and the second connecting pipe 19 are respectively provided with a first drain pipe 26, a second drain pipe 27, a third drain pipe 28, a fourth drain pipe 29 and a fifth drain pipe 30.

[0034] The first sewage pipe 8 and the first drainage pipe 14 are connected to the first steam purge pipe 31 and the second steam purge pipe 32 respectively. The first steam purge pipe 31 and the second steam purge pipe 32 are provided with a first purge valve 33 and a second purge valve 34 respectively.

[0035] The first drain pipe 14 is connected to the return pipe 36 and the second connecting pipe 19 through the third connecting pipe 35 , and the inlet of the return pipe 36 is arranged at the bottom of the sewage chamber 6 .

[0036] The bottom of the dirty oil chamber 5 is connected to the first sewage pipe 8 through a fourth connecting pipe 37 .

[0037] The second connecting pipe 19 is connected to the second sewage well 15 through the fifth connecting pipe 38 .

[0038] The working process is as follows: after the dehydration tank 2 controls the heating and uses the gravity separation of oil and water, the water in the lower layer is discharged to the second sewage well 15 through the dehydration pipe 11 and the second sewage pipe 13. During the drainage, the two drainage water measuring instruments 16 installed on the first connecting pipe 12 both detect the changes in the viscosity and density of the medium and judge that the water has been drained to the oil-water stratification point, and control the drainage solenoid valve 22 to open, and most of the oil in the upper layer of the dehydration tank 2 mixed with a small amount of water enters the sewage chamber of the zero-level tank 1, and the secondary gravity separation of oil and water will be carried out in the sewage chamber 6. There are the following working conditions:

[0039] 1) The liquid entering the bottom of the sewage chamber 6 from the second drainage pipe 17 is separated into oil and water due to different densities. The oil with low density enters the upper layer, and the water with high density enters the lower layer. As the liquid level in the sewage chamber 6 rises, when the liquid level is higher than the connection between the dirty oil chamber 5 and the upper part of the sewage chamber 6, the oil in the upper layer flows into the dirty oil chamber 5, and as the second drainage pipe 17 delivers liquid, the oil is continuously discharged into the dirty oil chamber 5;

[0040] The oil in the dirty oil chamber 5 is checked through the first vent pipe 26. If the oil discharged from the bottom of the dirty oil chamber 5 is oil, it proves that the oil entering the dirty oil chamber 5 has a high purity and can be directly recovered. The machine pump 21 is turned on and the oil enters the auxiliary tank 3 through the oil inlet pipe 20, the second connecting pipe 19 and the liquid inlet pipe 18; if the water discharged from the bottom of the dirty oil chamber 5 is water, it proves that the oil entering the dirty oil chamber 5 is mixed with a lot of water and still needs to be further separated. The machine pump 21 can be turned on, and the water at the bottom of the dirty oil chamber 5 enters the second sewage well 15 through the oil inlet pipe 20, the second connecting pipe 19 and the fifth connecting pipe 38. During this period, the degree of water-oil separation can be judged through the fifth vent pipe 30; if the water discharged from the bottom of the dirty oil chamber 5 is water, it can also be discharged into the first sewage well 9 through the fourth connecting pipe 37 and the first sewage pipe 8, and the viscosity and density changes of the water are detected by two sewage water measuring instruments 10 to judge the degree of dehydration, so as to control the on and off of the sewage solenoid valve 23.

[0041] 2) Dehydrating the liquid in the sewage chamber 6 separately, controlling the sewage solenoid valve 23 to start dehydration, and discharging the water in the lower layer into the first sewage well 9 through the outlet pipe 7 and the first sewage pipe 8. During the drainage, the changes in the viscosity and density parameters of the medium are detected by the sewage water meter 10 to determine that the water has been drained to the oil-water stratification point, and the oil condition at the bottom of the sewage chamber 6 is checked through the second vent pipe 27. If there is still a lot of water, dehydration can be continued. If the oil purity is high, it can be directly recovered;

[0042] To dehydrate the sewage chamber 6 , the pump 21 can be turned on to sequentially flow the water through the reflux pipe 36 , the second connecting pipe 19 and the liquid inlet pipe 18 into the auxiliary tank 3 .

[0043] 3) If the drainage water detector 16 is abnormal, the fourth vent pipe 29 can be used to vent and check whether there is water in the dehydration tank 2, and the probe can be cleaned by steam purging through the second steam purge pipe 32, or the probe can be steam purged regularly by setting the second purge valve 34;

[0044] If the sewage water meter 10 is abnormal, the third vent pipe 28 can be used to vent and check the situation, and the probe can be cleaned by steam purging through the first steam purge pipe 31. The probe can also be steam purged regularly by setting the first purge valve 33.

[0045] Example 2

[0046] On the basis of Example 1, Figure 2 As shown, the edge of the partition 4 is sealed and connected to the inner wall of the zero-level tank 1, a flow port is opened on the upper part of the partition 4, the dirty oil chamber 5 and the sewage chamber 6 are connected through the flow port, a flow regulating valve 39 is provided on the flow port, and an upper water meter 40 is provided on the upper part of the sewage chamber 6, and the detection probe of the upper water meter 40 extends below the lowest point of the flow port.

[0047] When the oil-water mixture in the zero-level tank 1 reaches the circulation port as the liquid level rises, the liquid level meter 25 detects the liquid level, opens the circulation regulating valve 39, and the upper layer of oil enters the dirty oil chamber 5 from the circulation port. As the second drain pipe 17 continuously delivers liquid, the upper layer of oil is continuously discharged to the dirty oil chamber 5; when the detection signal of the upper water measuring instrument 40 changes, it indicates that the oil-water separation interface has reached the circulation port, and the circulation regulating valve 39 is closed.

[0048] Example 3

[0049] On the basis of Example 1, Figure 3 As shown, the height of the partition 4 is less than the inner height of the zero-level tank 1 , the upper edge of the partition 4 is not connected to the upper inner wall of the zero-level tank 1 , and the dirty oil chamber 5 and the sewage chamber 6 are connected through the gap between the upper edge of the partition 4 and the inner wall of the zero-level tank 1 .

[0050] When the oil-water mixture in the zero-level tank 1 reaches the flow port as the liquid level rises, the upper layer of oil in the sewage chamber 6 can directly overflow the partition plate 4 and enter the dirty oil chamber 5 as the second drainage pipe 17 delivers liquid.

Claims

1. A closed dehydration system for oil tanks, characterized in that: The invention comprises a zero-level tank (1) arranged underground, and a dehydration tank (2) and an auxiliary tank (3) arranged above the zero-level tank (1). The internal cavity of the zero-level tank (1) is divided into a dirty oil cavity (5) and a sewage cavity (6) by a vertically arranged partition plate (4). The upper parts of the dirty oil cavity (5) and the sewage cavity (6) are interconnected. The bottom of the sewage cavity (6) is connected to a water outlet pipe (7). The water outlet pipe (7) is connected to a first sewage well (9) through a first sewage pipe (8). A sewage water meter (10) is arranged on the first sewage pipe (8). The bottom of the dehydration tank (2) is connected to a dehydration pipe (11). The dehydration pipe (11) is connected to a first sewage well (9) through a first connecting pipe ( 12) connects the second sewage pipe (13) and the first drainage pipe (14), the second sewage pipe (13) is connected to the second sewage well (15), a drainage water meter (16) is installed on the first connecting pipe (12), the first drainage pipe (14) is connected to the second drainage pipe (17), the outlet of the second drainage pipe (17) is arranged at the bottom of the sewage chamber (6); the bottom of the auxiliary tank (3) is connected to the liquid inlet pipe (18), the liquid inlet pipe (18) is connected to the oil inlet pipe (20) through the second connecting pipe (19), the inlet of the oil inlet pipe (20) is arranged at the bottom of the dirty oil chamber (5), and a pump (21) is arranged on the second connecting pipe (19); The first sewage pipe (8) is provided with a sewage electromagnetic valve (23), the first connecting pipe (12) is provided with a drainage electromagnetic valve (22), the sewage water meter (10) and the sewage electromagnetic valve (23), and the drainage water meter (16) and the drainage electromagnetic valve (22) are respectively electrically connected.

2. The closed dehydration system for oil tanks according to claim 1 is characterized in that: There are at least two drainage water measuring instruments (16) and sewage water measuring instruments (10).

3. The closed dehydration system for oil tanks according to claim 1 is characterized in that: The zero-level tank (1) is provided with a breathing valve (24), and the dirty oil chamber (5) and the dirty water chamber (6) are both provided with liquid level gauges (25).

4. The closed dehydration system for oil tanks according to claim 1 is characterized in that: The bottom of the dirty oil chamber (5), the bottom of the sewage chamber (6), the first sewage pipe (8), the first connecting pipe (12) and the second connecting pipe (19) are respectively provided with a first vent pipe (26), a second vent pipe (27), a third vent pipe (28), a fourth vent pipe (29) and a fifth vent pipe (30).

5. The closed dehydration system for oil tanks according to claim 1 is characterized in that: The first sewage pipe (8) and the first drainage pipe (14) are respectively connected to a first steam purge pipe (31) and a second steam purge pipe (32), and the first steam purge pipe (31) and the second steam purge pipe (32) are respectively provided with a first purge valve (33) and a second purge valve (34).

6. The oil tank closed dehydration system according to claim 1, characterized in that: The first drainage pipe (14) is connected to the return pipe (36) and the second connecting pipe (19) via the third connecting pipe (35), and the inlet of the return pipe (36) is arranged at the bottom of the sewage chamber (6).

7. The closed dehydration system for oil tanks according to claim 1 is characterized in that: The bottom of the dirty oil chamber (5) is connected to the first sewage pipe (8) via a fourth connecting pipe (37).

8. The closed dehydration system for oil tanks according to claim 1 is characterized in that: The second connecting pipe (19) is connected to the second sewage well (15) via a fifth connecting pipe (38).

9. The closed dehydration system for oil tanks according to claim 1, characterized in that: The edge of the partition (4) is sealedly connected to the inner wall of the zero-position tank (1), a flow port is opened on the upper part of the partition (4), the dirty oil chamber (5) and the sewage chamber (6) are connected through the flow port, a flow regulating valve (39) is provided on the flow port, an upper water meter (40) is provided on the upper part of the sewage chamber (6), and a detection probe of the upper water meter (40) extends below the lowest point of the flow port.

10. The oil tank closed dehydration system according to claim 1, characterized in that: The height of the partition (4) is smaller than the inner height of the zero-level tank (1); the upper edge of the partition (4) is not connected to the upper inner wall of the zero-level tank (1); the dirty oil chamber (5) and the dirty water chamber (6) are connected through the gap between the upper edge of the partition (4) and the inner wall of the zero-level tank (1).

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