阅读说明：本技术 一种油洗除尘罐及热脱附高温尾气除尘冷凝系统及方法 (Oil washing dust removal tank and thermal desorption high-temperature tail gas dust removal and condensation system and method ) 是由 邵志国 聂凡 许毓 孙静文 于 2020-05-19 设计创作，主要内容包括：本发明提供了一种油洗除尘罐及热脱附高温尾气除尘冷凝系统及方法,所述油洗除尘罐包括油洗除尘罐罐体,罐体底部设置有清洗油储存区,用于储存清洗油,清洗油储存区设置有清洗油出口；罐体中于清洗油储存区上设置有两端开口的填料筒,填料筒的顶部与罐体之间设置有封堵端板并通过封堵端板于所述罐体顶部形成净化后脱附气区；填料筒的底部设置有填料床层,填料筒的顶端开口处设置有除雾器,填料床层与除雾器之间设置有喷油器,清洗油出口通过管路经由循环油泵与所述喷油器相连通；填料筒的外侧壁与罐体内侧壁之间形成环形通道；罐体的上部设置有进气管,以将待处理高温脱附尾气送入所述环形通道；所述罐体的顶部于净化后脱附气区设置有排气管。(The invention provides an oil washing dust removal tank and a thermal desorption high-temperature tail gas dust removal condensation system and method, wherein the oil washing dust removal tank comprises an oil washing dust removal tank body, the bottom of the tank body is provided with a cleaning oil storage area for storing cleaning oil, and the cleaning oil storage area is provided with a cleaning oil outlet; a filling cylinder with two open ends is arranged in the tank body on the cleaning oil storage area, a plugging end plate is arranged between the top of the filling cylinder and the tank body, and a purified desorption gas area is formed at the top of the tank body through the plugging end plate; a filler bed layer is arranged at the bottom of the filler cylinder, a demister is arranged at an opening at the top end of the filler cylinder, an oil injector is arranged between the filler bed layer and the demister, and a cleaning oil outlet is communicated with the oil injector through a circulating oil pump through a pipeline; an annular channel is formed between the outer side wall of the filling cylinder and the inner side wall of the tank body; an air inlet pipe is arranged at the upper part of the tank body so as to send the high-temperature desorption tail gas to be treated into the annular channel; the top of the tank body is provided with an exhaust pipe in a purified desorption gas area.)

1. The oil washing dust removal tank is characterized by comprising a tank body of the oil washing dust removal tank, wherein a cleaning oil storage area is arranged at the bottom of the tank body and used for storing cleaning oil, and a cleaning oil outlet is formed in the cleaning oil storage area;

a filling cylinder with two open ends is arranged on the cleaning oil storage area in the tank body, a plugging end plate is arranged between the top of the filling cylinder and the tank body, and a purified desorption gas area is formed at the top of the tank body through the plugging end plate; a filler bed layer is arranged at the bottom of the filler cylinder, a demister is arranged at an opening at the top end of the filler cylinder, an oil injector is arranged between the filler bed layer and the demister, and a cleaning oil outlet is communicated with the oil injector through a circulating oil pump through a pipeline;

an annular channel is formed between the outer side wall of the filling cylinder and the inner side wall of the tank body;

an air inlet pipe is arranged at the upper part of the tank body so as to send the high-temperature desorption tail gas to be treated into the annular channel; the top of the tank body is provided with an exhaust pipe in a purified desorption gas area.

2. The oil-washing dust removing tank of claim 1, wherein the air inlet pipe is arranged at the upper part of the tank body along the tangential direction of the tank body.

3. The oil wash dust tank of claim 1, wherein the wash oil outlet is provided with a filter.

4. The oil wash dust tank of claim 1, wherein the wash oil storage area is provided with a heating coil.

5. The oil-washing dust removing tank of claim 1 or 4, wherein a circulating cooling water sleeve is arranged on the outlet pipeline of the circulating oil pump.

6. The oil-washing dust removal tank of claim 1, wherein a plurality of spiral guide plates are arranged on the inner side wall of the tank body in the annular channel, so that the high-temperature desorption tail gas to be treated flows downwards in the annular channel in a spiral manner after entering the tank body.

7. The oil-washing dust-removing tank of claim 6, wherein a plurality of the spiral guide plates are arranged in parallel and obliquely downwards on the inner side wall of the tank body in the annular channel, the angle formed by any spiral guide plate and the horizontal direction is 30-60 degrees, and the distance between adjacent spiral guide plates is 10-30 cm.

8. The oil-washing dust removal tank of claim 1, wherein a bottom opening of the filling cylinder is provided with a diversion flap plate, so that the high-temperature desorption tail gas to be treated enters the filling cylinder along the diversion flap plate.

9. The oil wash dust tank of claim 8, wherein the deflector is disposed at the bottom end opening of the stuffing cylinder at an angle offset from 20-45 ° into the stuffing cylinder.

10. The oil-washing dust removal tank of claim 1, further comprising a first thermometer and a second thermometer, wherein thermocouples of the first thermometer and the second thermometer are respectively arranged at the inlet of the air inlet pipe and below the liquid level of the cleaning oil in the cleaning oil storage area, so as to monitor the temperature of the high-temperature desorption tail gas to be treated and the temperature of the cleaning oil at the inlet in real time.

11. The oil-washing dust removing tank according to claim 1 or 10, further comprising a differential pressure gauge, wherein pressure detection probes of the differential pressure gauge are respectively arranged above and below the packing bed layer to monitor the pressure of the high-temperature desorption tail gas flowing through the packing.

12. The oil wash dust tank of claim 1 or 11, characterized in that the height of the packing bed is 1/3-1/2 of the height of the packing cylinder.

13. The utility model provides a thermal desorption high temperature tail gas dust removal condensing system which characterized in that, thermal desorption high temperature tail gas dust removal condensing system includes:

the oil washing dust removal device comprises a cyclone dust removal device, a plurality of oil washing dust removal tanks and a heat exchange condensing device, wherein the oil washing dust removal tanks are arranged in series, a gas outlet of the cyclone dust removal device is connected with an air inlet pipe of a first oil washing dust removal tank in the oil washing dust removal tanks through a pipeline, and an exhaust pipe of a last oil washing dust removal tank in the oil washing dust removal tanks is connected with the heat exchange condensing device.

14. The system of claim 13, further comprising a tail gas treatment unit and a sewage treatment unit, wherein the dry gas outlet and the oily sewage outlet of the heat exchange condensing device are respectively connected with the tail gas treatment unit and the sewage treatment unit through pipelines.

15. The system of claim 13, wherein the cleaning oil outlet of the oil cleaning dust tank positioned at the back of the plurality of serially connected oil cleaning dust tanks is connected with the cleaning oil inlet of the oil cleaning dust tank positioned at the front by a pipeline.

16. The system of any one of claims 13-15, wherein the number of oil wash dust tanks is 2.

17. A thermal desorption high-temperature tail gas dedusting and condensing method, which is implemented by using the thermal desorption high-temperature tail gas dedusting and condensing system of any one of claims 13 to 16, and comprises the following steps:

(1) cyclone dust removal is carried out on the high-temperature desorption tail gas generated by the thermal desorption device so as to remove most of dust in the tail gas;

(2) sequentially carrying out multi-stage oil washing dust removal on the tail gas subjected to cyclone dust removal in the step (1) in a plurality of serially connected oil washing dust removal tanks according to any one of claims 1 to 9;

(3) and (3) carrying out heat exchange on the tail gas subjected to the multistage oil washing and dust removal in the step (2) and a cooling medium to condense and remove water vapor in the tail gas, so as to obtain dry gas and oily sewage.

18. The method as claimed in claim 17, wherein when there are two oil-washing dust-removing tanks, the temperature of the cleaning oil used in the primary oil-washing dust-removing tank is 200-350 ℃, and the temperature of the cleaning oil used in the secondary oil-washing dust-removing tank is 120-180 ℃.

19. The method according to claim 17 or 18, wherein when the number of the oil-washing dust-removing tanks is two, the residence time of the tail gas in the primary oil-washing dust-removing tank and the secondary oil-washing dust-removing tank is 10-60 min.

20. The method according to claim 17 or 18, wherein in the step (3), the condensate temperature is controlled to be 40-60 ℃ during the heat exchange process.

21. The method of claim 17 or 18, further comprising subjecting the dry gas to incineration or activated carbon adsorption.

Technical Field

The invention relates to an oil washing dust removal tank, a thermal desorption high-temperature tail gas dust removal and condensation system and a method, and belongs to the technical field of oil-containing solid waste recycling treatment in the petrochemical industry.

Background

In the exploration, exploitation, storage and transportation and refining processes of petroleum, a large amount of oily solid waste is generated, the oily solid waste generally comprises two types of oil-based drilling cuttings and oily sludge, and the oily solid waste contains a large amount of petroleum hydrocarbons, solid suspended matters, bacteria, salts, flocculating agents, corrosion inhibitors, scale inhibitors and other chemical agents, is a definite dangerous waste in China and needs to be subjected to appropriate harmless treatment.

The thermal desorption technology is originally applied to the dry distillation and petroleum cracking process of coal and wood, and is applied to the fields of oil-containing solid waste treatment and high-concentration organic contaminated soil remediation. In the process of thermal desorption of the oil-containing solid waste, distillation and thermal decomposition exist at the same time, and the oil-containing solid waste is heated to a certain temperature under the anaerobic condition to decompose hydrocarbons and organic matters, so that the oil-containing solid waste is converted into three phase substances: the gas phase is non-condensable gas such as methane, carbon monoxide and the like; the liquid phase mainly comprises thermal desorption oil and water; the solid phase is inorganic mineral matter and carbon residue. Generally speaking, the thermal desorption process mainly comprises a material storage unit, a thermal desorption reaction device, a tail gas dedusting unit, a tail gas condensing unit, a non-condensable gas treatment unit, an oil-water separation unit and a sewage treatment unit. The method can be divided into electric heating, electromagnetic heating, fuel oil, fuel gas, heat conducting oil and high-temperature flue gas heating according to different heat sources; direct heating, indirect heating, direct-indirect combination and direct flame heating can be classified according to the heating mode; according to different feeding materials, the method can be divided into continuous feeding and intermittent feeding; the method can be divided into a rotary kiln type desorption furnace, a spiral propulsion type desorption furnace, a vertical desorption tower and a fluidized bed type desorption furnace according to the structure of a furnace body; the device arrangement can be divided into a single-layer arrangement, a double-layer arrangement and the like. The thermal desorption treatment engineering project of oil sludge is built in Daqing oil fields, Xinjiang oil fields and other fields, and the thermal desorption technology is adopted in the demonstration projects of polycyclic aromatic hydrocarbon and petroleum soil remediation of Chongqing chemical plants, polycyclic aromatic hydrocarbon and benzene series organic pollution site remediation of Shanghai Baoshan chemical plants, chromium pollution soil remediation of Hubei and the like.

However, in practical application, coking and blockage of the oil gas condensation system and the matched pipeline are main factors limiting continuous and stable operation of the thermal desorption process. Because the oily solid waste contains a certain amount of moisture, high-temperature oil gas, water vapor and entrained dust generated in the thermal desorption process are pumped into a condensing unit by a fan to carry out oil-water-solid three-phase separation. At present, the separation mode commonly adopted in China is a high-temperature flue gas dust removal and low-temperature condensation process route, and the separation mode is divided into a direct condensation process and an indirect condensation process according to whether a cooling medium is in contact with desorption gas, wherein the direct condensation process mostly adopts water spray cooling, and the indirect condensation process mostly adopts a tubular water-cooling heat exchanger. The direct water spraying cooling mode has the advantages of good cooling effect, and the water spraying can further elute dust in the flue gas, so that pure non-condensable gas components can be obtained. But the consumption of cooling water is increased, a large amount of oily sewage is generated, oil and water are deeply emulsified in the circulating spraying process, and the subsequent sewage treatment difficulty is increased. The tubular water-cooling heat exchange process reduces the consumption of cooling water, avoids the generation of a large amount of oily sewage, and because the temperature of desorption gas generated in the thermal desorption process is generally above 300 ℃, a bag type dust collector with higher dust removal efficiency cannot be adopted, the dust removal efficiency of the currently and commonly adopted cyclone dust collector is generally about 60%, and the flue gas after dust removal of the dust collector still contains a large amount of dust, so that a subsequent condenser and matched pipelines are easily blocked, and the continuous operation of the system is difficult. In addition, heavy tar in the desorption gas is easily adsorbed on the surface of dust, and the dust is used as an inner core to form a coke body which is attached to an elbow and a valve of the pipeline, so that the coke body is accumulated for a long time to block the pipeline, and the normal work of the valve body is influenced.

Therefore, finding a high-efficiency and reliable thermal desorption tail gas dedusting and condensing measure is a favorable guarantee for realizing long-term stable operation of the thermal desorption system.

Disclosure of Invention

To address the above-described shortcomings and drawbacks, it is an object of the present invention to provide an oil wash dust tank.

The invention also aims to provide a thermal desorption high-temperature tail gas dedusting and condensing system.

The invention also aims to provide a dust removal and condensation method for the thermal desorption high-temperature tail gas. The technical scheme provided by the invention integrates oil washing dust removal and step-by-step condensation processes, realizes dust removal and purification of the oil-containing solid waste thermal desorption gas and step-by-step recovery of the condensate, and improves the dust removal and condensation effects.

To achieve the above object, in one aspect, the present invention provides an oil wash dust tank, wherein the oil wash dust tank comprises:

the bottom of the oil washing dust removal tank is provided with a washing oil storage area for storing washing oil, and the washing oil storage area is provided with a washing oil outlet;

a filling cylinder with two open ends is arranged on the cleaning oil storage area in the tank body, a plugging end plate is arranged between the top of the filling cylinder and the tank body, and a purified desorption gas area is formed at the top of the tank body through the plugging end plate; a filler bed layer is arranged at the bottom of the filler cylinder, a demister is arranged at an opening at the top end of the filler cylinder, an oil injector is arranged between the filler bed layer and the demister, and a cleaning oil outlet is communicated with the oil injector through a circulating oil pump through a pipeline;

an annular channel is formed between the outer side wall of the filling cylinder and the inner side wall of the tank body;

an air inlet pipe is arranged at the upper part of the tank body so as to send the high-temperature desorption tail gas to be treated into the annular channel; the top of the tank body is provided with an exhaust pipe in a purified desorption gas area.

In the oil-washing dust-removing tank described above, the demister is used to remove oil mist carried in the air flow.

In the oil-washing dust removing tank, preferably, the air inlet pipe is arranged at the upper part of the tank body along the tangential direction of the tank body. Wherein, set up the intake pipe along the tangential direction of the jar body, make use of the gas to advance jar velocity of flow.

In the oil wash dust tank described above, preferably, the wash oil outlet is provided with a filter. Wherein, the filter can avoid the sediment in the cleaning oil that the cleaning oil storage area was stored to get into the circulating oil pump.

In the oil wash dust tank described above, preferably, the wash oil storage area is provided with a heating coil.

Wherein, heating coil can heat the cleaning oil that the cleaning oil storage area was stored to the controller temperature, heating coil's heat source can be conventional energy such as steam, electricity, or adopt other industrially usable companion's heat mode.

In the oil-washing dust removing tank, preferably, a circulating cooling water sleeve is arranged on the outlet pipeline of the circulating oil pump.

The cooling water quantity and the temperature in the circulating cooling water sleeve are adjustable, and the circulating cooling water sleeve and the heating coil at the bottom of the dust removal tank can be used for cooperatively controlling the temperature of the cleaning oil according to the process requirements.

In the oil-washing dust removal tank, preferably, a plurality of spiral guide plates are arranged on the inner side wall of the tank body in the annular channel, so that the high-temperature desorption tail gas to be treated flows downwards in the annular channel in a spiral manner after entering the tank body.

In the oil-washing dust removal tank, preferably, the spiral guide plates are parallel to each other and obliquely arranged on the inner side wall of the tank body in the annular channel, the angle formed by any spiral guide plate and the horizontal direction is 30-60 degrees, and the distance between adjacent spiral guide plates is 10-30 cm.

In the oil-washing dust removal tank, preferably, a diversion flap plate is arranged at the bottom opening of the filling cylinder, so that the high-temperature desorption tail gas to be treated enters the filling cylinder along the diversion flap plate.

In the oil-washing dust removing tank, preferably, the diversion flap is arranged at the bottom end opening of the filling cylinder at an angle deviating from 20 to 45 degrees towards the inside of the filling cylinder (namely, an acute angle formed by the diversion flap and the vertical direction is 20 to 45 degrees).

Preferably, the oil washing dust removal tank further comprises a first thermometer and a second thermometer, wherein thermocouples of the first thermometer and the second thermometer are respectively arranged at the inlet of the air inlet pipe and below the liquid level of the washing oil in the washing oil storage area so as to monitor the temperature of the inlet to-be-treated high-temperature desorption tail gas and the temperature of the washing oil in real time.

Preferably, the oil-washing dust removal tank further comprises a differential pressure gauge, and pressure detection probes of the differential pressure gauge are respectively arranged above and below the packing bed layer to monitor the pressure of the high-temperature desorption tail gas flowing through the packing.

In the oil-washing dust removing tank, the height of the packing bed layer is 1/3-1/2 of the height of the packing cylinder.

In the oil washing dust removal tank, the filler bed layer can be a filler bed layer composed of Raschig rings or pall rings and the like, so that the contact area of the cleaning oil and the tail gas can be increased; in the operation process, the high-temperature cleaning oil is sprayed downwards from the top and is in reverse contact with tail gas from bottom to top so as to elute dust and soluble heavy oil components carried in the tail gas.

On the other hand, the invention also provides a thermal desorption high-temperature tail gas dedusting and condensing system, wherein the thermal desorption high-temperature tail gas dedusting and condensing system comprises:

cyclone, a plurality of above oil wash dust removal jar and heat transfer condensing equipment, it is a plurality of oil wash dust removal jar is established ties and is set up, and cyclone's gas outlet passes through the pipeline and is a plurality of the intake pipe of the first oil wash dust removal jar in the oil wash dust removal jar links to each other, and is a plurality of the blast pipe of the last oil wash dust removal jar in the oil wash dust removal jar with heat transfer condensing equipment links to each other.

Preferably, the system further comprises a tail gas treatment unit and a sewage treatment unit, and the dry gas outlet and the oily sewage outlet of the heat exchange condensing device are respectively connected with the tail gas treatment unit and the sewage treatment unit through pipelines.

In the system, preferably, the cleaning oil outlets of the oil washing dust removing tanks which are arranged in series and are positioned at the back of the oil washing dust removing tanks are connected with the cleaning oil inlets of the oil washing dust removing tanks which are positioned at the front of the oil washing dust removing tanks through pipelines.

Furthermore, a cleaning oil outlet of an oil washing dust removal tank which is arranged in series and is positioned at the back of the oil washing dust removal tanks is connected with a cleaning oil inlet of an oil washing dust removal tank which is positioned at the front of the oil washing dust removal tanks through a heat exchanger by a pipeline, so that oil products condensed in the oil washing dust removal tank which is positioned at the back of the oil washing dust removal tanks are recycled as cleaning oil used in the oil washing dust removal tank which is positioned at the front of the oil washing dust removal tanks.

In the system described above, preferably, the number of the oil wash dust tanks is 2.

In another aspect, the present invention further provides a thermal desorption high temperature tail gas dust removal and condensation method, wherein the thermal desorption high temperature tail gas dust removal and condensation method is implemented by using the thermal desorption high temperature tail gas dust removal and condensation system described above, and includes:

(1) cyclone dust removal is carried out on the high-temperature desorption tail gas generated by the thermal desorption device so as to remove most of dust in the tail gas;

(2) sequentially carrying out multistage oil washing dust removal on the tail gas subjected to cyclone dust removal in the step (1) in a plurality of oil washing dust removal tanks connected in series;

(3) and (3) carrying out heat exchange on the tail gas subjected to the multistage oil washing and dust removal in the step (2) and a cooling medium to condense and remove water vapor in the tail gas, so as to obtain dry gas and oily sewage.

In the above-mentioned method, in the step (1), the cyclone dust removal is performed in a cyclone dust removal device (e.g., a cyclone dust remover), and the cyclone dust removal device needs to periodically discharge dust to the ash yard as the cyclone dust removal is performed.

In the above method, the properties of different oil-containing solid wastes are different, and the properties such as the composition of the high-temperature desorption tail gas generated by thermal desorption are also different, so that a person skilled in the art can adjust the temperature of the cleaning oil used in the oil-washing dust-removing tank according to the thermal desorption process and the different properties of the oil-containing solid waste raw material; the kind of the cleaning oil can be selected by the technicians in the field according to different components of the high-temperature desorption tail gas, and the diesel oil can be generally adopted for spray washing; the types of the adopted cleaning oil, different temperature control strategies and the arrangement stages of the oil cleaning dust removal tank are all the deformation of the process and are within the protection range of the patent;

preferably, when the number of the oil-washing dust-removing tanks is two, the temperature of the cleaning oil used in the primary oil-washing dust-removing tank is 200-350 ℃, and the temperature of the cleaning oil used in the secondary oil-washing dust-removing tank is 120-180 ℃.

The method provided by the invention integrates cyclone dust removal and high-temperature oil washing dust removal, and can realize high-efficiency removal of dust particles in desorption gas;

the method integrates oil washing dust removal and step-by-step condensation processes, realizes the step-by-step condensation removal of oil and water vapor in the desorption gas by controlling the temperature of the cleaning oil, avoids oil-water mixing caused by primary condensation, improves the quality of recovered oil, and reduces the difficulty of oil-water separation of condensed water.

The temperature of the cleaning oil used in the first-stage oil washing dust removal tank is higher, the heavy oil with a higher boiling point is mainly condensed in the first-stage oil washing dust removal tank and the dust in the gas is eluted (the dust is basically removed in the first-stage oil washing dust removal tank), the temperature of the cleaning oil used in the second-stage oil washing dust removal tank is lower, the oil with a low and medium boiling point is mainly condensed in the second-stage oil washing dust removal tank, and the oil gas is recovered to the maximum extent on the premise of not generating condensed water.

In the above method, the skilled person can adjust the residence time of the tail gas in the oil washing dust removing tank and the heat exchange condensing device used in the heat exchange process according to the components and yield of the tail gas;

preferably, when the number of the oil washing dust removal tanks is two, the residence time of the tail gas in the first-stage oil washing dust removal tank and the second-stage oil washing dust removal tank is 10-60 min.

In the above-mentioned method, preferably, in the step (3), the temperature of the condensate (oily sewage) is controlled to be 40-60 ℃ during the heat exchange process.

In the method, further, the flow rate of the high-temperature desorption tail gas generated by the thermal desorption device in the annular channel is 2-8m/s, and the flow rate of the high-temperature desorption tail gas entering the packing cylinder is controlled to be 0.5-1 m/s.

In the method, further, in the multi-stage oil washing dust removal process, the spraying strength of the oil sprayer is 1.5-8L/s.m²。

In the above method, further, the height of the cleaning oil in the cleaning oil storage area is 200-400 mm.

In the above-described method, further, the concentration of the suspended matter in the cleaning oil is controlled to be 60 to 200 mg/L.

Preferably, the method further comprises the step of carrying out incineration or activated carbon adsorption treatment on the dry gas.

In the method, all solid dust and most easily condensed heavy oil gas components are removed from the desorbed tail gas after two-stage oil washing and condensation, the treated tail gas is pumped into a heat exchange condensing device through a draught fan, the heat exchange condensing device can adopt a conventional plate heat exchanger or a tubular heat exchanger, the temperature is controlled to be 40-60 ℃, water vapor in the tail gas is condensed and removed to obtain cleaner dry gas, the obtained dry gas enters a tail gas treatment device for harmless treatment, and the tail gas treatment device can adopt a common burning method or an active carbon adsorption process and the like in the field to treat the tail gas.

Most of oil gas components are removed at the front section, so that the oil content of condensate discharged by the heat exchange condensing device is low, the condensate is not severely disturbed, the emulsification degree is low, and the condensate is discharged to the oil-containing treatment unit, so that the standard treatment can be realized.

In the method, when the solid content in the cleaning oil exceeds a certain limit value, the oily ash at the bottom of the cleaning oil can be discharged to a feed hopper of the thermal desorption device, and the oily ash and the oily solid are mixed and then enter the thermal desorption device for thermal desorption treatment.

The thermal desorption high-temperature tail gas dedusting and condensing system and method provided by the invention integrate oil washing dedusting and step-by-step condensing processes (when in specific implementation, cyclone dedusting, first-stage oil washing dedusting, second-stage oil washing condensing and third-stage heat exchange are sequentially carried out on the thermal desorption high-temperature tail gas), so that dust, heavy oil and water are respectively removed step by step in different devices, and the purification of desorption gas and the efficient recovery of desorption oil are realized; the problems of low desorption gas dust removal efficiency, incomplete condensation, blockage of a condenser and coking of matched pipelines, large amount of condensate liquid and difficult oil-water separation of the existing thermal desorption system for the oily solid waste are solved, the operation stability and reliability of the thermal desorption process are improved, the quality of recovered oil is improved, the generation amount of secondary pollutants such as oily sewage is reduced, and the further popularization and application of the thermal desorption process in the field of oily solid waste treatment are facilitated.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an oil-washing dust removal tank provided in embodiment 1 of the present invention.

Fig. 2 is a top view of the oil scrubbing tank provided in example 1 of the present invention.

Fig. 3 is a schematic structural diagram of a thermal desorption high-temperature tail gas dedusting and condensing system provided in embodiment 2 of the present invention.

Fig. 4 is a flowchart of a thermal desorption high-temperature tail gas dedusting and condensing method provided in embodiments 3 to 5 of the present invention.

The main reference numbers illustrate:

1. an air inlet pipe;

2. an annular channel;

3. a packing bed layer;

4. an oil injector;

5. a demister;

6. a tank body of the oil washing dust removal tank;

7. an exhaust pipe;

8. a heating coil;

9. a filter;

10. a circulating oil pump;

11. a first thermometer;

12. a differential pressure gauge;

13. a first pressure probe;

14. a first thermocouple;

15. a packing cylinder;

16. a diversion folded plate;

17. plugging the end plate;

18. circulating cooling water sleeve;

19. a spiral deflector;

20. a second thermometer;

21. a second thermocouple;

22. a second pressure probe;

100. a cyclone dust removal device;

200. a first-stage oil washing dust removal tank;

300. a secondary oil washing dust removal tank;

400. a heat exchange condensing unit;

500. a tail gas treatment unit;

600. a sewage treatment unit;

700. a thermal desorption device.

Detailed Description

In order to clearly understand the technical features, objects and advantages of the present invention, the following detailed description of the technical solutions of the present invention will be made with reference to the following specific examples, which should not be construed as limiting the implementable scope of the present invention.

It should be noted that the term "comprises/comprising" and any variations thereof in the description and claims of this invention and the above-described drawings is intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps, components, or elements does not have to be limited to those steps, components, or elements expressly listed but may include other steps, components, or elements not expressly listed or inherent to such process, method, system, article, or apparatus.

In the present invention, the terms "upper", "lower", "middle", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the invention and its embodiments and are not intended to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation.

Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meanings of these terms in the present invention can be understood by those skilled in the art as appropriate.

Furthermore, the terms "disposed" and "connected" should be interpreted broadly. The specific meanings of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.

Example 1

The embodiment provides an oil-washing dust-removing tank, the structural schematic diagram of which is shown in fig. 1-2, and as can be seen from fig. 1-2, the oil-washing dust-removing tank comprises: the device comprises an oil washing dust removal tank body 6, wherein a washing oil storage area is arranged at the bottom of the tank body 6 and used for storing washing oil, a heating coil 8 is arranged below the liquid level of the stored washing oil in the washing oil storage area, a washing oil outlet is arranged in the washing oil storage area, and a filter 9 is arranged at the washing oil outlet;

a filler cylinder 15 with two open ends is arranged in the tank body 6 on the cleaning oil storage area, a plugging end plate 17 is arranged between the top of the filler cylinder 15 and the tank body 6, and a purified desorption gas area is formed at the top of the tank body 6 through the plugging end plate 17; the bottom of the packing cylinder 15 is provided with a packing bed layer 3, the height of the packing bed layer 3 is 1/3-1/2 of the height of the packing cylinder 15, the packing bed layer 3 is a packing bed layer composed of Raschig rings or pall rings and other packing materials, the contact area of cleaning oil and tail gas can be increased, a demister 5 is arranged at an opening at the top end of the packing cylinder 15, and an oil sprayer 4 is arranged between the packing bed layer 3 and the demister 5; a diversion folded plate 16 is arranged at an opening at the bottom end of the filling cylinder 15, so that the high-temperature desorption tail gas to be treated enters the filling cylinder 15 along the diversion folded plate 16;

the diversion folded plate 16 is arranged at the bottom end opening of the filling cylinder 15 at an angle which is deviated from 20-45 degrees inwards to the filling cylinder 15;

the cleaning oil outlet is communicated with the oil injector 4 through a circulating oil pump 10 through a pipeline; a circulating cooling water sleeve 18 is arranged on an outlet pipeline of the circulating oil pump 10;

an annular channel 2 is formed between the outer side wall of the packing cylinder 15 and the inner side wall of the tank body 6, and a plurality of spiral guide plates 19 are arranged on the inner side wall of the tank body 6 in the annular channel 2, so that the high-temperature desorption tail gas to be treated flows downwards in the annular channel 2 in a spiral manner after entering the tank body 6;

the spiral guide plates 19 are mutually parallel and are obliquely and downwards arranged on the inner side wall of the tank body 6 in the annular channel, the angle formed by any spiral guide plate 19 and the horizontal direction is 30-60 degrees, and the distance between every two adjacent spiral guide plates 19 is 10-30 cm;

an air inlet pipe 1 is arranged at the upper part of the tank body 6, and the air inlet pipe 1 is arranged at the upper part of the tank body 6 along the tangential direction of the tank body 6 so as to send the high-temperature desorption tail gas to be treated into the annular channel 2; an exhaust pipe 7 is arranged at the top of the tank body 6 in the purified desorption gas area;

the oil washing dust removal tank further comprises a first thermometer 11 and a second thermometer 20, wherein a first thermocouple 14 and a second thermocouple 21 of the first thermometer 11 and the second thermometer 20 are respectively arranged at the inlet of the air inlet pipe 1 and below the liquid level of the washing oil in the washing oil storage area so as to monitor the temperature of the high-temperature desorption tail gas to be treated at the inlet and the temperature of the washing oil in real time;

the oil washing dust removal tank further comprises a differential pressure gauge 12, and a first pressure detection probe 13 and a second pressure detection probe 22 of the differential pressure gauge 12 are respectively arranged above the packing bed layer 3 and below the packing bed layer 3 so as to monitor the pressure of the high-temperature desorption tail gas flowing through the packing.

Example 2

This embodiment provides a thermal desorption high temperature tail gas dust removal condensing system, its schematic structure is shown in fig. 3, can see from fig. 3, the system includes:

the system comprises a cyclone dust removal device 100, two oil washing dust removal tanks provided by the embodiment 1, which are respectively marked as a primary oil washing dust removal tank 200, a secondary oil washing dust removal tank 300, a heat exchange condensing device 400, a tail gas treatment unit 500 and a sewage treatment unit 600, wherein a gas outlet of the cyclone dust removal device 100 is connected with an air inlet pipe of the primary oil washing dust removal tank 200 through a pipeline, an air outlet pipe of the primary oil washing dust removal tank 200 is connected with an air inlet pipe of the secondary oil washing dust removal tank 300, and an air outlet pipe of the secondary oil washing dust removal tank 300 is connected with the heat exchange condensing device 400;

a dry gas outlet of the heat exchange condensing device 400 is connected with the tail gas treatment unit 500 through a pipeline by an induced draft fan, and an oily sewage outlet of the heat exchange condensing device 400 is connected with the sewage treatment unit 600 through a pipeline;

the circulating oil pump of the secondary oil-washing dust-removing tank 300 is also connected to a washing oil inlet (not shown in the figure, which is disposed at the middle-lower portion of the sidewall of the primary oil-washing dust-removing tank 200) of the primary oil-washing dust-removing tank 200 through a pipeline, so as to recycle the oil condensed in the secondary oil-washing dust-removing tank 300 as the washing oil used in the primary oil-washing dust-removing tank 200.

In this embodiment, the cyclone dust collector 100 is a cyclone dust collector, and the heat exchange condenser is a heat exchange condenser.

Example 3

The embodiment provides a thermal desorption high-temperature tail gas dedusting and condensing method which is realized by using the system provided by the embodiment 2, in a primary oil washing dedusting tank and a secondary oil washing dedusting tank used by the system, a plurality of spiral guide plates are parallel to each other and are obliquely and downwards arranged on the inner side wall of a tank body in an annular channel, the angle formed by any spiral guide plate and the horizontal direction is 40 degrees, and the distance between every two adjacent spiral guide plates is 20 cm; the diversion folded plate is arranged at the bottom opening of the filling cylinder at an angle deviating from 20-45 degrees towards the inside of the filling cylinder (namely, an acute angle formed by the diversion folded plate and the vertical direction is 20-45 degrees); the height of the packing bed layer is 1/3 of the height of the packing cylinder, the process flow chart of the method is shown in figure 4, and as can be seen from figure 4, the method comprises the following specific steps:

(1) cyclone dust removal is carried out on high-temperature desorption tail gas generated by a thermal desorption device 700 (the thermal desorption raw material is oil-based drilling cuttings, and the properties of the thermal desorption raw material are shown in the following table 1) in a cyclone dust collector so as to remove most of dust in the tail gas;

TABLE 1

Properties of	Oil content (wt%)	Water content (wt%)	Solid content (wt%)
				Oil-based drill cuttings	14.75	5.10	80.15

(2) Enabling the tail gas subjected to cyclone dust removal in the step (1) to enter a primary oil washing dust removal tank 200 at the flow speed of 6-12m/s, controlling the temperature of cleaning oil (washing oil) used by the primary oil washing dust removal tank 200 at 250 ℃ and staying in the primary oil washing dust removal tank 200 for about 10-30 min; the tail gas after cyclone dust removal enters the tank body from the air inlet pipe of the primary oil washing dust removal tank 200 and then flows downwards in the annular channel in a spiral manner along the spiral guide plate, and dust carried in the gas impacts the tank wall to be separated from the tail gas and slides down to the bottom along the tank wall; the cleaning oil used by the first-stage oil cleaning dust removing tank 200 is diesel oil;

the tail gas flows to the bottom of the first-stage oil washing dust removal tank 200, and turns back after impacting the liquid level of the bottom washing oil, the flow speed of the tail gas is reduced after the tail gas is reversed, so that the wrapped dust is favorably removed from the tail gas, the tail gas enters the packing cylinder along the diversion folded plate, flows through the packing bed layer, and is in reverse contact with the sprayed washing oil, and the dust in the tail gas is further eluted; then the oil mist is removed through a demister, and is discharged out of the primary oil washing dust removing tank 200 through an exhaust pipe and enters the secondary oil washing dust removing tank 300;

(3) the tail gas treated by the primary oil washing dust removal tank 200 enters the secondary oil washing dust removal tank 300 from the air inlet pipe of the secondary oil washing dust removal tank 300, the temperature of the cleaning oil (cleaning oil) used by the secondary oil washing dust removal tank 300 is controlled at 120 ℃ plus 150 ℃, the retention time is 10-20min, the tail gas undergoes the same treatment process in the primary oil washing dust removal tank 200 in the secondary oil washing dust removal tank 300, and the tail gas is discharged through the exhaust pipe of the secondary oil washing dust removal tank 300 after the treatment is finished and enters a heat exchange condenser; the cleaning oil used by the secondary oil cleaning dust removing tank 300 is also diesel oil;

in the embodiment, the flow velocity of the high-temperature desorption tail gas generated by the thermal desorption device in the annular channel is 2-4m/s, and the flow velocity of the high-temperature desorption tail gas entering the packing cylinder is controlled to be 0.5-0.8 m/s;

in the process of oil washing and dust removal, the spraying strength of the oil sprayer is 1.5-2L/s.m²；

The height of the cleaning oil in the cleaning oil storage area is 300mm, and the concentration of suspended matters in the cleaning oil is controlled to be 120 mg/L;

(4) the tail gas treated by the secondary oil washing dust removal tank 300 is discharged from an exhaust pipe of the secondary oil washing dust removal tank 300, enters a heat exchange condenser, the temperature of condensate is controlled to be 40-50 ℃, condensation and separation of water vapor are realized, the condensate (oily sewage) is discharged into a sewage treatment unit, oil-water separation is realized after static precipitation, and the eluted noncondensable gas (clean dry gas) enters a subsequent tail gas treatment unit and is subjected to incineration treatment or activated carbon adsorption treatment;

the ash slag containing oil is periodically discharged from the first-stage oil washing dust removal tank 200 and returns to the thermal desorption device 700 for treatment; the cleaning oil in the first-stage oil washing dust removal tank 200 is periodically supplemented by the second-stage oil washing dust removal tank 300, and the redundant condensed oil is recovered.

Example 4

The embodiment provides a thermal desorption high-temperature tail gas dedusting and condensing method which is realized by using the system provided by the embodiment 2, in a primary oil washing dedusting tank and a secondary oil washing dedusting tank used by the system, a plurality of spiral guide plates are parallel to each other and are obliquely and downwards arranged on the inner side wall of a tank body in an annular channel, the angle formed by any spiral guide plate and the horizontal direction is 40 degrees, and the distance between every two adjacent spiral guide plates is 20 cm; the diversion folded plate is arranged at the bottom opening of the filling cylinder at an angle deviating from 20-45 degrees towards the inside of the filling cylinder (namely, an acute angle formed by the diversion folded plate and the vertical direction is 20-45 degrees); the height of the packing bed layer is 1/3 of the height of the packing cylinder, the process flow chart of the method is shown in figure 4, and as can be seen from figure 4, the method comprises the following specific steps:

(1) cyclone dust removal is carried out on the high-temperature desorption tail gas generated by the thermal desorption device 700 (the thermal desorption raw material is petroleum-polluted soil, and the properties of the high-temperature desorption tail gas are shown in the following table 2) in a cyclone dust collector so as to remove most of dust in the tail gas;

TABLE 2

Properties of	Oil content (wt%)	Water content (wt%)	Solid content (wt%)
				Oil contaminated soil	9.38	26.24	64.38

(2) Enabling the tail gas subjected to cyclone dust removal in the step (1) to enter a primary oil washing dust removal tank 200 at the flow speed of 6-12m/s, controlling the temperature of cleaning oil (washing oil) used by the primary oil washing dust removal tank 200 at 240-280 ℃, and staying in the primary oil washing dust removal tank 200 for about 20-40 min; the tail gas after cyclone dust removal enters the tank body from the air inlet pipe of the primary oil washing dust removal tank 200 and then flows downwards in the annular channel in a spiral manner along the spiral guide plate, and dust carried in the gas impacts the tank wall to be separated from the tail gas and slides down to the bottom along the tank wall; the cleaning oil used by the first-stage oil cleaning dust removing tank 200 is diesel oil;

the tail gas flows to the bottom of the first-stage oil washing dust removal tank 200, and turns back after impacting the liquid level of the bottom washing oil, the flow speed of the tail gas is reduced after the tail gas is reversed, so that the wrapped dust is favorably removed from the tail gas, the tail gas enters the packing cylinder along the diversion folded plate, flows through the packing bed layer, and is in reverse contact with the sprayed washing oil, and the dust in the tail gas is further eluted; then the oil mist is removed through a demister, and is discharged out of the primary oil washing dust removing tank 200 through an exhaust pipe and enters the secondary oil washing dust removing tank 300;

(3) the tail gas treated by the primary oil washing dust removal tank 200 enters the secondary oil washing dust removal tank 300 from the air inlet pipe of the secondary oil washing dust removal tank 300, the temperature of the cleaning oil (cleaning oil) used by the secondary oil washing dust removal tank 300 is controlled at 120 ℃ plus 150 ℃, the retention time is 20-30min, the tail gas undergoes the same treatment process in the primary oil washing dust removal tank 200 in the secondary oil washing dust removal tank 300, and the tail gas is discharged through the exhaust pipe of the secondary oil washing dust removal tank 300 after the treatment is finished and enters a heat exchange condenser; the cleaning oil used by the secondary oil cleaning dust removing tank 300 is also diesel oil;

in the embodiment, the flow velocity of the high-temperature desorption tail gas generated by the thermal desorption device in the annular channel is 2-4m/s, and the flow velocity of the high-temperature desorption tail gas entering the packing cylinder is controlled to be 0.5-0.8 m/s;

in the process of oil washing and dust removal, the spraying strength of the oil sprayer is 1.5-2L/s.m²；

The height of the cleaning oil in the cleaning oil storage area is 300mm, and the concentration of suspended matters in the cleaning oil is controlled to be 120 mg/L;

(4) the tail gas treated by the secondary oil washing dust removal tank 300 is discharged from an exhaust pipe of the secondary oil washing dust removal tank 300, enters a heat exchange condenser, the temperature of condensate is controlled to be 40-50 ℃, condensation and separation of water vapor are realized, the condensate (oily sewage) is discharged into a sewage treatment unit, oil-water separation is realized after static precipitation, and the eluted noncondensable gas (clean dry gas) enters a subsequent tail gas treatment unit and is subjected to incineration treatment or activated carbon adsorption treatment;

the ash slag containing oil is periodically discharged from the first-stage oil washing dust removal tank 200 and returns to the thermal desorption device 700 for treatment; the cleaning oil in the first-stage oil washing dust removal tank 200 is periodically supplemented by the second-stage oil washing dust removal tank 300, and the redundant condensed oil is recovered.

Example 5

The embodiment provides a thermal desorption high-temperature tail gas dedusting and condensing method which is realized by using the system provided by the embodiment 2, in a primary oil washing dedusting tank and a secondary oil washing dedusting tank used by the system, a plurality of spiral guide plates are parallel to each other and are obliquely and downwards arranged on the inner side wall of a tank body in an annular channel, the angle formed by any spiral guide plate and the horizontal direction is 40 degrees, and the distance between every two adjacent spiral guide plates is 20 cm; the diversion folded plate is arranged at the bottom end opening of the filling cylinder at an angle deviating from the filling cylinder by 20-45 degrees (namely, an acute angle formed by the diversion folded plate and the vertical direction is 20-45 degrees); the height of the packing bed layer is 1/3 of the height of the packing cylinder, the process flow chart of the method is shown in figure 4, and as can be seen from figure 4, the method comprises the following specific steps:

(1) cyclone dust removal is carried out on high-temperature desorption tail gas generated by a thermal desorption device 700 (the thermal desorption raw material is oily sludge, and the properties of the thermal desorption raw material are shown in the following table 3) in a cyclone dust collector so as to remove most of dust in the tail gas;

TABLE 3

Properties of	Oil content (wt%)	Water content (wt%)	Solid content (wt%)
				Oily sludge	15.74	35.33	48.93

(2) Enabling the tail gas subjected to cyclone dust removal in the step (1) to enter a primary oil washing dust removal tank 200 at the flow speed of 6-12m/s, controlling the temperature of cleaning oil (washing oil) used by the primary oil washing dust removal tank 200 at 320-350 ℃, and staying in the primary oil washing dust removal tank 200 for about 30-50 min; the tail gas after cyclone dust removal enters the tank body from the air inlet pipe of the primary oil washing dust removal tank 200 and then flows downwards in the annular channel in a spiral manner along the spiral guide plate, and dust carried in the gas impacts the tank wall to be separated from the tail gas and slides down to the bottom along the tank wall; the cleaning oil used by the first-stage oil cleaning dust removing tank 200 is diesel oil;

the tail gas flows to the bottom of the first-stage oil washing dust removal tank 200, and turns back after impacting the liquid level of the bottom washing oil, the flow speed of the tail gas is reduced after the tail gas is reversed, so that the wrapped dust is favorably removed from the tail gas, the tail gas enters the packing cylinder along the diversion folded plate, flows through the packing bed layer, and is in reverse contact with the sprayed washing oil, and the dust in the tail gas is further eluted; then the oil mist is removed through a demister, and is discharged out of the primary oil washing dust removing tank 200 through an exhaust pipe and enters the secondary oil washing dust removing tank 300;

(3) the tail gas treated by the primary oil washing dust removal tank 200 enters the secondary oil washing dust removal tank 300 from the air inlet pipe of the secondary oil washing dust removal tank 300, the temperature of the cleaning oil (cleaning oil) used by the secondary oil washing dust removal tank 300 is controlled at 120 ℃ plus 150 ℃, the retention time is 30-40min, the tail gas undergoes the same treatment process in the primary oil washing dust removal tank 200 in the secondary oil washing dust removal tank 300, and the tail gas is discharged through the exhaust pipe of the secondary oil washing dust removal tank 300 after the treatment is finished and enters a heat exchange condenser; the cleaning oil used by the secondary oil cleaning dust removing tank 300 is also diesel oil;

in the embodiment, the flow velocity of the high-temperature desorption tail gas generated by the thermal desorption device in the annular channel is 3-6m/s, and the flow velocity of the high-temperature desorption tail gas entering the packing cylinder is controlled to be 0.8-1 m/s;

in the process of oil washing and dust removal, the spraying strength of the oil sprayer is 1.5-2L/s.m²；

The height of the cleaning oil in the cleaning oil storage area is 300mm, and the concentration of suspended matters in the cleaning oil is controlled to be 120 mg/L;

(4) the tail gas treated by the secondary oil washing dust removal tank 300 is discharged from an exhaust pipe of the secondary oil washing dust removal tank 300, enters a heat exchange condenser, the temperature of condensate is controlled to be 40-50 ℃, condensation and separation of water vapor are realized, the condensate (oily sewage) is discharged into a sewage treatment unit, oil-water separation is realized after static precipitation, and the eluted noncondensable gas (clean dry gas) enters a subsequent tail gas treatment unit and is subjected to incineration treatment or activated carbon adsorption treatment;

the ash slag containing oil is periodically discharged from the first-stage oil washing dust removal tank 200 and returns to the thermal desorption device 700 for treatment; the cleaning oil in the first-stage oil washing dust removal tank 200 is periodically supplemented by the second-stage oil washing dust removal tank 300, and the redundant condensed oil is recovered.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

compared with the existing oil-containing solid waste thermal desorption gas condensation system, the technical scheme provided by the embodiment of the invention adopts an oil washing dust removal and step-by-step condensation process, the process has the characteristics of high direct condensation dust removal efficiency, low indirect condensation cooling consumption and small oil-containing sewage production capacity, can thoroughly solve the problems of blockage and coking of a condenser and a matched pipeline, large amount of condensate liquid and difficulty in oil-water separation in the existing desorption gas condensation process, and has strong innovation and practical application prospect.

In particular, the following advantages are provided:

firstly, the oil-injection gas scrubbing is utilized to strengthen the dust removal effect of the thermal desorption gas, and absorb organic components in the desorption gas, so that the oil-injection gas scrubbing device has a good removing effect on heavy oil components with low condensation point, realizes the function of synchronously removing suspended matters and coking precursors, and avoids the coking blockage problem of subsequent condensing equipment and matched pipelines.

Secondly, the temperature of the cleaning oil is controlled, so that the oil and the water in the desorption tail gas are removed step by step, a large amount of oily sewage generated by once cooling and condensing oil-water mixing is avoided, and the difficulty of rear-end sewage treatment is reduced.

Thirdly, by utilizing the principle of 'similarity and compatibility', the cleaning oil can remove heavy organic components with long carbon chains in the desorption tail gas, purify the tail gas and greatly reduce the treatment difficulty and cost of subsequent non-condensable gas; meanwhile, the water content of the condensed oil is reduced, and the quality of the recovered oil is improved.

Fourthly, the temperature of the first-stage oil washing dust removal tank is mainly maintained by the temperature of the desorption gas, an external heating source and a refrigeration system are not needed in the operation, part of organic components in the desorption gas are washed and removed, the gas quantity entering a subsequent condensation system is reduced, and the construction scale and the operation cost of the subsequent condensation system are reduced.

Fifthly, the condensed oil generated by the system supplements the cleaning oil, the generated dirty oil with high dust content and dissolved organic matters enters the heating system of the thermal desorption device again for incineration treatment, the system internal circulation of the cleaning oil is realized, and secondary pollutants such as waste oil and the like are not generated.

The above description is only exemplary of the invention and should not be taken as limiting the scope of the invention, so that the invention is intended to cover all modifications and equivalents of the embodiments described herein. In addition, the technical features and the technical inventions of the present invention, the technical features and the technical inventions, and the technical inventions can be freely combined and used.