CN211814283U

CN211814283U - Refinery sump oil and scum decompression dewatering device

Info

Publication number: CN211814283U
Application number: CN202020367471.7U
Authority: CN
Inventors: 齐广建
Original assignee: Shandong Huifeng Petrochemical Group Co ltd
Current assignee: Shandong Huifeng Petrochemical Group Co ltd
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2020-10-30
Anticipated expiration: 2030-03-20

Abstract

The utility model belongs to the technical field of the useless dregs of fat of oil processing, concretely relates to refinery sump oil and dross dehydration device that reduces pressure. The refinery sump oil and scum decompression dehydration device comprises a sump oil intermediate tank, wherein the sump oil intermediate tank is connected with a decompression tower through a heat exchanger, the top of the decompression tower is connected with a separator through a water ring vacuum pump, the heat exchanger is connected with the separator through a condenser, and the bottom of the decompression tower is connected with a normal decompression device. The utility model discloses the production continuity is strong, the handling capacity is big, can satisfy a large amount of refinery continuous processing demands, and the oil moisture after the separation can fall to 0.3-1%, aquatic oil content < 100ppm, the oil after the separation can directly get into atmospheric pressure relief device and refine back, can utilize the small-size atmospheric pressure relief device relief apparatus of old and useless to process, the investment is little, can carry out the heat union with other devices of refinery, the energy consumption is lower, only produce the electric energy consumption, compromise the dross that handles sewage treatment and produce simultaneously, retrieve the sump oil in the dross.

Description

Refinery sump oil and scum decompression dewatering device

Technical Field

The utility model belongs to the technical field of the useless dregs of fat of oil processing, concretely relates to refinery sump oil and dross dehydration device that reduces pressure.

Background

The dirty oil of the oil refinery generally comes from the start-up and shut-down of each device and back flushing of the dirty oil, coking and emptying of the dirty oil, an atmospheric and vacuum crude oil desalting and dehydrating unit and an oil separation tank unit of a sewage treatment plant. Little dirty oil is also generated in the cleaning of crude oil tanks or finished oil tanks, the inspection and maintenance of equipment or pipelines. The dirty oil has different sources, complex composition and unstable property, and the main components of the dirty oil consist of oil, silt, organic sludge, surface active substances and a large amount of water. The dirty oil gathered together from different units contains colloid, asphaltene and other impurities, has the characteristics of strong emulsifying capacity, serious aging degree, high impurity content, stable emulsion structure and high water content, and generally exists in an oil-in-water or water-in-oil emulsifying form at normal temperature, and also has partial free water. The density of the oil phase is similar to that of the water phase, and tiny water drops are difficult to aggregate, so that the dehydration is difficult, and the difficulty in processing each device of a refinery is high. How to improve the recycling amount of the heavy dirty oil, reduce the processing loss of crude oil in a refinery and improve the economic benefit is a common problem faced by petrochemical enterprises.

At present, the domestic common sump oil dehydration methods mainly comprise two types, namely a process dehydration technology and an equipment dehydration technology. The process dehydration technology is mainly a thermal gravity settling method. The equipment dehydration techniques include ultrasonic method, centrifugal method, electric field dehydration method, etc.

1. Method of dewatering plant

The equipment dehydration method is the most effective method for treating the dirty oil in various large oil refineries at present, in particular to the dirty oil and scum at the bottom of a tank. The current advanced equipment dehydration method adopts a multi-stage circulating treatment process, which comprises a pretreatment device, a first-stage separation device and a second-stage separation device. The dirty oil is collected to a dirty oil intermediate tank from each unit, after heat exchange and temperature rise, a demulsifier and a flocculating agent are added to enter a dirty oil storage tank for sedimentation, then the dirty oil is sent to a primary separation device for solid-liquid separation, solid residues are discharged, and oil water enters a secondary separation device. And the secondary separation device is used for oil-water separation, and oil is conveyed to the buffer tank and finally conveyed to the crude oil or residual oil storage tank for recycling. The water is conveyed to a sewage treatment device for treatment.

2. Thermal gravity dewatering process

The thermal gravity dehydration method is a traditional method for processing dirty oil in various large oil refineries at present. And collecting the sump oil from each unit to a sump oil intermediate tank, heating through heat exchange, adding a demulsifier, allowing the mixture to enter a sump oil storage tank for sedimentation, allowing part of water to settle at the bottom of the sump oil tank, removing the dehydrated water at regular intervals, and allowing the rest to be the dehydrated sump oil. The method has the following disadvantages: due to different dirty oil sources and complex components, a large amount of emulsified dirty oil cannot be effectively dehydrated and occupies a limited storage tank. The water content of the sump oil is still high after the sump oil is primarily dehydrated through gravity settling, and is usually more than 10%. The method for recycling the dirty oil of the oil refinery comprises the following steps; after the dirty oil is dewatered, the dirty oil is mixed with crude oil in a normal and reduced pressure workshop according to a certain proportion, and the mixture is mixed with a coking tower which is seriously emulsified and contains much silt.

3. Comparison of the two protocols

The equipment dehydration technology utilizes an oil-water-solid three-phase centrifugal machine to separate, and has the advantage of realizing thorough separation of oil, mud and water. The water content of the separated oil can be reduced to 0.3-2%, the solid content can be reduced to 0.1-2%, and the oil content in the water is only 5-300 ppm. The separated oil can directly enter an atmospheric and vacuum device for refining. The disadvantages are that: firstly, the investment is large, a special post is needed for continuous operation, the continuous processing capacity of the equipment is limited, and the equipment is generally 5-10 t/h; second, the treatment cost is high, and the market price for the third party to treat is about 1000 yuan/ton at present.

The advantages of the thermal gravity settling method are that the oil and water can be primarily separated to achieve the blending condition, and the dirty oil treatment cost is low. The disadvantages are that the salt content in the recovered oil is still high, and the recovered oil contains more organic sludge and can not become a high-quality raw material for atmospheric and vacuum pressure.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: overcomes the defects in the prior art, provides a refinery dirty oil and scum decompression dehydration device, can realize oil-water separation without adding medicaments, and has the advantages of strong production continuity, large treatment capacity, simple structure, small investment and low energy consumption.

The utility model discloses an adopt following technical scheme to realize:

the refinery sump oil and scum decompression dehydration device comprises a sump oil intermediate tank, wherein the sump oil intermediate tank is connected with a decompression tower through a heat exchanger, the top of the decompression tower is connected with a separator through a water ring vacuum pump, the heat exchanger is connected with the separator through a condenser, and the bottom of the decompression tower is connected with a normal decompression device.

And the non-condensable gas outlet at the top of the separator is connected with a flare system.

And a light dirty oil outlet at the bottom of the separator is connected with the crude oil tank.

And a sewage outlet at the bottom of the separator is connected with a sewage treatment device.

The working principle and the process are as follows:

dirty oil and scum are collected to a dirty oil intermediate tank from each unit of the device, then heat exchange and temperature rise are carried out on the dirty oil intermediate tank through a heat exchanger, a heat source is thermally combined with other devices, so that the steam consumption is reduced, the temperature rises to 160 ℃ plus, the dirty oil can generate gas after being heated by the heat exchanger, the gas can be condensed by a condenser from the heat exchanger and directly enters a separator, the heated dirty oil enters a decompression tower (the vacuum degree is between-80 and-95 kPa) for oil, water and gas separation, the top of the decompression tower is pumped by a water ring vacuum pump for vacuum cooling and then enters the separator, a small amount of non-condensable gas in the separator enters a torch system, the separated light dirty oil can be periodically sent to a crude oil tank, and the separated sewage is sent to a sewage treatment device for treatment. The sump oil dehydrated at the bottom of the vacuum tower can be directly sent to an atmospheric and vacuum device or a coking device for recycling.

Compared with the prior art, the beneficial effects of the utility model are as follows:

1. the utility model discloses can realize oil, water thorough separation without adding the medicament, and the oil moisture after the separation can be reduced to 0.3-1%, and aquatic oil content < 100ppm, and the oil after the separation can directly get into atmospheric and vacuum distillation plant and refine again.

2. The utility model has strong production continuity and large treatment capacity, and can meet the continuous treatment requirements of a large number of refineries.

3. The utility model discloses can make use of small-size atmospheric and vacuum distillation plant relief device of old and process, the investment is little, can carry out the heat with other devices of refinery and unite, and the energy consumption is lower, only produces the electric energy consumption.

4. The utility model discloses can compromise the dross that handles sewage treatment production simultaneously, retrieve the sump oil in the dross.

Drawings

Fig. 1 is a schematic structural view of the present invention;

in the figure: 1. a dirty oil intermediate tank; 2. a heat exchanger; 3. a vacuum tower; 4. a water ring vacuum pump; 5. a condenser; 6. a separator; 7. a flare system; 8. a crude oil tank; 9. a sewage treatment device; 10. an atmospheric and vacuum device.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, the refinery sump oil and scum decompression dehydration device comprises a sump oil intermediate tank 1, wherein the sump oil intermediate tank 1 is connected with a decompression tower 3 through a heat exchanger 2, the top of the decompression tower 3 is connected with a separator 6 through a water ring vacuum pump 4, the heat exchanger 2 is connected with the separator 6 through a condenser 5, and the bottom of the decompression tower 3 is connected with an atmospheric and vacuum device 10.

The top of the separator 6 is connected with a non-condensable gas outlet and a flare system 7.

And a light dirty oil outlet at the bottom of the separator 6 is connected with a crude oil tank 8.

And a sewage outlet at the bottom of the separator 6 is connected with a sewage treatment device 9.

When in work, dirty oil and scum are collected to the dirty oil intermediate tank 1 from each unit of the device, then heat exchange and temperature rise are carried out on the dirty oil intermediate tank 1 through the heat exchanger 2, a heat source is thermally combined with other devices, therefore, the steam consumption is reduced, the temperature is increased to 160 ℃ and the dirty oil can generate gas after being heated by the heat exchanger 2, the gas can be condensed by the condenser 5 from the heat exchanger 2 and then directly enters the separator 6, the heated dirty oil enters the vacuum tower 3 (the vacuum degree is-80 to-95 kPa) for oil, water and gas separation, the top of the vacuum tower 3 is vacuumized and cooled by the water ring vacuum pump 4 and then enters the separator 6, a small amount of non-condensable gas in the separator 6 enters the torch system 7, the light dirty oil separated by the separator 6 can be periodically sent to the crude oil tank 8 from the light dirty oil outlet at the bottom of the separator 6, and the sewage separated by the separator 6 is sent to the sewage treatment device 9 from the sewage outlet at the bottom of the separator 6 for treatment. The dewatered sump oil at the bottom of the vacuum tower 3 can be directly sent to an atmospheric and vacuum device 10 for recycling.

Of course, the above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and the technical field of the present invention is equivalent to the changes and improvements made in the actual range of the present invention, which should be attributed to the patent coverage of the present invention.

Claims

1. The utility model provides a refinery sump oil and dross decompression dewatering device, includes sump oil pans (1), its characterized in that: dirty oil pans (1) are connected with vacuum tower (3) through heat exchanger (2), the top of the vacuum tower (3) is connected with separator (6) through water ring vacuum pump (4), heat exchanger (2) are connected with separator (6) through condenser (5), the bottom of the vacuum tower (3) is connected with atmospheric pressure device (10).

2. The refinery sump oil and scum decompression and dehydration apparatus according to claim 1, wherein: the top of the separator (6) is provided with a non-condensable gas outlet which is connected with a flare system (7).

3. The refinery sump oil and scum decompression and dehydration apparatus according to claim 1, wherein: and a light dirty oil outlet at the bottom of the separator (6) is connected with a crude oil tank (8).

4. The refinery sump oil and scum decompression and dehydration apparatus according to claim 1, wherein: and a sewage outlet at the bottom of the separator (6) is connected with a sewage treatment device (9).