Oily sludge extraction device and oily sludge extraction method

Abstract

The invention discloses an oil-containing sludge extraction device, which relates to the technical field of environmental protection, and comprises a supply module for providing supercritical carbon dioxide, a roller extractor for extracting oil-containing sludge, and a post-treatment module for separating an extraction product and recovering the separation product, the output end of the supply module is communicated with the input end of the roller extractor, the output end of the roller extractor is communicated with the input end of the post-treatment module, spiral protrusions and stirring blades are arranged in the roller extractor, the spiral protrusions are arranged on the inner wall of the roller extractor, the stirring blades are arranged on a rotating shaft located in a cavity of the roller extractor, and the stirring blades are arranged on the rotating shaft. The extraction process of the supercritical carbon dioxide is carried out in the rolling roller extractor, the spiral protrusions and the stirring blades are arranged in the roller extractor so that the contact effect and efficiency of the supercritical carbon dioxide and the oily sludge can be improved, and the rolling of the roller extractor can also achieve a more positive stirring effect; the extraction efficiency of the supercritical carbon dioxide is higher, and the extraction is more thorough.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection technology, and in particular to an oily sludge extraction device and an oily sludge extraction method, aiming to significantly improve extraction efficiency, shorten processing time, and reduce energy consumption. Background Art

[0002] Oily sludge refers to sludge mixed with crude oil, various finished oils, residual oil and other heavy oils. As a typical industrial waste, it is widely derived from multiple industries such as oil extraction, refining, and mechanical processing. Improper treatment not only occupies a large amount of land resources, but also causes serious pollution to water and soil, threatening ecological security. The current oily sludge treatment technologies mainly include chemical flocculation, pyrolysis, biological treatment, and supercritical fluid extraction. The summary of each technology is as follows:

[0003] Chemical flocculation method: a technology that uses flocculants to flocculate organic components and separate the products from sand and soil. Although conventional chemical flocculation technology can initially separate oil sludge, it often requires the addition of a large amount of chemical agents, which not only increases the treatment cost, but also the subsequent treatment of chemical residues is also a major problem, causing secondary pollution to the environment.

[0004] Pyrolysis: Pyrolysis technology uses high-temperature cracking of organic matter in oily sludge to produce various gaseous or liquid products such as alkanes, cycloalkanes, aromatic hydrocarbons, olefins, gums and asphaltene. Although some energy can be recovered, high-temperature operations consume huge amounts of energy and may produce harmful gases during the process, requiring expensive tail gas treatment facilities.

[0005] Biological treatment method: Use microorganisms to degrade petroleum hydrocarbons in oily sludge into harmless soil components. Although it is environmentally friendly, the treatment cycle is long and is greatly affected by factors such as microbial activity, temperature, and pH value. It is difficult to adapt to the needs of large-scale rapid treatment.

[0006] Supercritical fluid extraction: Supercritical carbon dioxide has a special dissolving effect on certain special natural products to extract organic pollutants from oily sludge. In recent years, supercritical CO2 extraction has attracted much attention due to its high efficiency and environmental protection. However, most existing supercritical extraction equipment uses static containers or simple stirring devices, resulting in the extraction efficiency being limited by the limited mass transfer surface area, and the efficient dissolving capacity of supercritical CO2 cannot be fully utilized. In addition, efficient supercritical extraction is often accompanied by high energy consumption requirements. How to reduce energy consumption while ensuring the treatment effect, achieve the requirements of rapid treatment of large amounts of oily sludge, and form industrial-scale applications is a problem that needs to be solved urgently. Summary of the invention

[0007] The purpose of the present invention is to provide an oily sludge extraction device to solve the problems existing in the above-mentioned prior art, so that the extraction process of supercritical carbon dioxide is carried out in a rolling drum extractor. The spiral protrusions and stirring blades inside the drum extractor can increase the contact efficiency between supercritical carbon dioxide and oily sludge. The overall rolling of the drum extractor can also play a more active stirring effect, so that the extraction efficiency of supercritical carbon dioxide is higher and the extraction is more thorough.

[0008] The present invention also provides a method for extracting oily sludge. Based on the above device, the extraction efficiency of oily sludge using supercritical carbon dioxide is higher and the extraction is more thorough.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] The present invention provides an oily sludge extraction device, comprising a supply module for providing supercritical carbon dioxide, a drum extractor for performing extraction operations on the oily sludge, and a post-processing module for separating the extraction product and recovering the separation product;

[0011] The output end of the supply module is connected to the input end of the drum extractor, and the output end of the drum extractor is connected to the input end of the post-processing module;

[0012] A spiral protrusion and a stirring blade are arranged in the drum extractor, wherein the spiral protrusion is arranged on the inner wall of the drum extractor, and the stirring blade is arranged on a rotating shaft located in the cavity of the drum extractor.

[0013] Preferably, the mathematical model of the spiral protrusion is z=α·r, wherein z is the spiral height, α is the inclination angle of the spiral, and r is the radial coordinate of the spiral protrusion in the drum extractor;

[0014] The surface profile of the stirring blade is a parabola.

[0015] Preferably, the supply module comprises a carbon dioxide supply module for providing carbon dioxide gas, a pretreatment module for generating supercritical carbon dioxide gas, and a delivery module for delivering supercritical carbon dioxide gas to the drum extractor;

[0016] The output end of the carbon dioxide supply module is connected to the input end of the pretreatment module, the output end of the pretreatment module is connected to the conveying module, and the output end of the conveying module is connected to the input end of the drum extractor.

[0017] Preferably, the carbon dioxide supply module is a carbon dioxide storage device.

[0018] Preferably, the pretreatment module includes a heating module for increasing the temperature of the carbon dioxide gas and a pressurizing module for increasing the pressure of the carbon dioxide gas;

[0019] The input end of the heating module is connected to the output end of the carbon dioxide supply module, the output end of the heating module is connected to the input end of the pressurizing module, and the input end of the pressurizing module is connected to the input end of the conveying module.

[0020] Preferably, the conveying module comprises a heat-insulating and pressure-maintaining conveying pipe and a flow controller for adjusting the conveying flow in the heat-insulating and pressure-maintaining conveying pipe, and the flow controller is arranged on the heat-insulating and pressure-maintaining conveying pipe;

[0021] The input end of the heat-insulating and pressure-maintaining conveying pipe is connected to the output end of the pretreatment module, and the output end of the heat-insulating and pressure-maintaining conveying pipe is connected to the input end of the drum extractor.

[0022] Preferably, the post-processing module includes a centrifugal separation module for separating the extract from the solid residue, a low-temperature solidification stratification module for obtaining the extract, and a purification recovery module for recovering carbon dioxide gas;

[0023] The input end of the centrifugal separation unit is connected to the output end of the drum extractor, the output end of the centrifugal separation unit is connected to the input end of the low-temperature solidification stratification module, and the input end of the low-temperature solidification stratification module is connected to the purification and recovery module.

[0024] The present invention also provides a method for extracting oily sludge, based on the above-mentioned oily sludge extraction device, comprising the following steps:

[0025] S1. preparing supercritical carbon dioxide: heating and pressurizing carbon dioxide gas until supercritical carbon dioxide is obtained;

[0026] S2, injecting oily sludge: injecting the oily sludge into the drum extractor;

[0027] S3, injecting supercritical carbon dioxide and performing extraction: injecting the supercritical carbon dioxide obtained in S1 into the drum extractor, starting the drum extractor, mixing the oily sludge and the supercritical carbon dioxide in the drum extractor, and allowing the supercritical carbon dioxide to extract organic matter in the oily sludge;

[0028] S4, separating the extract and recovering carbon dioxide: separating the mixture obtained in S3, firstly performing primary separation of the liquid phase substance and the solid phase substance, and then performing secondary separation on the liquid phase substance obtained by the primary separation to obtain an organic extract.

[0029] Preferably, in step S3, supercritical carbon dioxide is continuously injected.

[0030] Preferably, in step S4, the primary separation method is centrifugal separation, and the secondary separation method is cryogenic solidification separation.

[0031] Compared with the prior art, the present invention has achieved the following technical effects:

[0032] The present invention provides an oily sludge extraction device, which enables the extraction process of supercritical carbon dioxide to be carried out in a rolling drum extractor. The drum extractor is provided with spiral protrusions and stirring blades to increase the contact efficiency between the supercritical carbon dioxide and the oily sludge. The overall rolling of the drum extractor can also play a more active stirring effect, so that the extraction efficiency of the supercritical carbon dioxide is higher and the extraction is more thorough.

[0033] The present invention also provides a method for extracting oily sludge. Based on the above device, the extraction efficiency of oily sludge using supercritical carbon dioxide is higher and the extraction is more thorough.

[0034] Compared with the prior art, the present invention also achieves the following technical effects:

[0035] In the present invention, the drum extractor is provided with specially shaped spiral protrusions and stirring blades, which can specifically improve the contact effect in the drum extractor. Compared with traditional stirring technology, it has obvious improvements in removal rate, processing speed, energy consumption and reduced environmental impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0038] Figure 2 It is a schematic diagram of the composition structure of the supply module in the present invention;

[0039] Figure 3 It is a schematic diagram of the internal structure of the drum extractor in the present invention;

[0040] Figure 4 The figure is a flow chart of the extraction method of the present invention.

[0041] Among them, 1. supply module; 11. carbon dioxide supply module; 12. pretreatment module; 13. transportation module; 2. drum extractor; 21. spiral protrusion; 22. stirring blade; 3. post-treatment module. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The purpose of the present invention is to provide an oily sludge extraction device to solve the problems existing in the above-mentioned prior art, so that the extraction process of supercritical carbon dioxide is carried out in a rolling drum extractor. The spiral protrusions and stirring blades inside the drum extractor can increase the contact efficiency between supercritical carbon dioxide and oily sludge. The overall rolling of the drum extractor can also play a more active stirring effect, so that the extraction efficiency of supercritical carbon dioxide is higher and the extraction is more thorough.

[0044] The present invention also provides a method for extracting oily sludge. Based on the above device, the extraction efficiency of oily sludge using supercritical carbon dioxide is higher and the extraction is more thorough.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] like Figure 1 and 2 As shown, the present invention provides an oily sludge extraction device, comprising a supply module 1 for providing supercritical carbon dioxide, a drum extractor 2 for performing extraction operations on the oily sludge, and a post-processing module 3 for separating the extraction products and recovering the separation products. The output end of the supply module 1 is connected to the input end of the drum extractor 2, and the output end of the drum extractor 2 is connected to the input end of the post-processing module 3. During extraction, the sludge and supercritical carbon dioxide are successively introduced into the drum extractor 2 for extraction.

[0047] like Figure 3 As shown, a spiral protrusion 21 and a stirring blade 22 are provided in the drum extractor 2. The spiral protrusion 21 is provided inside the drum extractor 2, and the stirring blade 22 is provided on a rotating shaft 23 located in the cavity of the drum extractor 2. In one embodiment, the mathematical model of the spiral protrusion 21 is z=α·r, wherein z is the spiral height, α is the inclination angle of the spiral, and r is the radial coordinate of the spiral protrusion in the drum extractor 2. The surface profile of the stirring blade 22 is a parabola, and its mathematical model is y=ax 2+bx+c, wherein a, b, and c are optimization parameters, and the values ​​of a, b, and c are determined to ensure that the aspect ratio of the blade profile of the stirring blade 22 is 1:0.618, the length of the blade profile is the vertical distance from the vertex of the stirring blade 22 to the rotating shaft 23, the width of the blade profile is the contact length between the stirring blade 22 and the rotating shaft 23, and the drum extractor 2 is a cylindrical drum, and the ratio of the bottom diameter to the height of the cylindrical drum is 1:2.

[0048] like Figure 1 As shown, the supply module 1 includes a carbon dioxide supply module 11 for providing carbon dioxide gas, a pretreatment module 12 for generating supercritical carbon dioxide gas and a delivery module 13 for delivering supercritical carbon dioxide gas to the drum extractor 2, the output end of the carbon dioxide supply module 11 is connected to the input end of the pretreatment module 12, the output end of the pretreatment module 12 is connected to the delivery module 13, the output end of the delivery module 13 is connected to the input end of the drum extractor 2, and the carbon dioxide gas is converted into supercritical carbon dioxide that can be used for extraction in the supply module 1. In one embodiment, the carbon dioxide supply module 11 is a carbon dioxide storage device, which can output and maintain the gas when supercritical carbon dioxide needs to be prepared. The carbon dioxide supply module 11 can also be a carbon dioxide manufacturing machine or a detachable carbon dioxide cylinder.

[0049] In one embodiment, the pretreatment module 12 includes a heating module for increasing the temperature of carbon dioxide gas and a pressurizing module for increasing the pressure of carbon dioxide gas. The input end of the heating module is connected to the output end of the carbon dioxide supply module 11, the output end of the heating module is connected to the input end of the pressurizing module, and the input end of the pressurizing module is connected to the input end of the conveying module 13. According to the generation conditions of supercritical carbon dioxide, the heating temperature is at least 31.1°C and the pressurizing pressure is at least 7.38MPa. The pretreatment module 12 can also be a reaction device with both heating and pressurizing functions.

[0050] In one embodiment, the conveying module 13 includes a heat-insulating and pressure-maintaining conveying pipe and a flow controller for adjusting the conveying flow in the heat-insulating and pressure-maintaining conveying pipe. The flow controller is arranged on the heat-insulating and pressure-maintaining conveying pipe. The input end of the heat-insulating and pressure-maintaining conveying pipe is connected to the output end of the pretreatment module 12, and the output end of the heat-insulating and pressure-maintaining conveying pipe is connected to the input end of the drum extractor 2. The flow controller can adjust the flow of supercritical carbon dioxide to be in a reasonable state at all times, and the heat-insulating and pressure-maintaining conveying pipe can keep the physical state of supercritical carbon dioxide unchanged, thereby ensuring the extraction effect.

[0051] In one embodiment, the post-processing module 3 includes a centrifugal separation module for separating the extract from the solid residue, a low-temperature solidification stratification module for obtaining the extract, and a purification and recovery module for recovering the carbon dioxide gas. The input end of the centrifugal separation unit is connected to the output end of the drum extractor 2, the output end of the centrifugal separation unit is connected to the input end of the low-temperature solidification stratification module, the input end of the low-temperature solidification stratification module is connected to the purification and recovery module, the centrifugal separation module can separate the liquid extract containing the extract and the solid particulate matter, and the low-temperature solidification stratification module uses the different properties of different liquid solidification points to perform liquid phase separation.

[0052] The present invention is also provided with a PLC control device, which can automatically control and adjust the working states of the supply module 1, the drum extractor 2 and the post-processing module 3. The PLC control device can realize the functions of error reporting and automatic shutdown.

[0053] The present invention also provides a method for extracting oily sludge, based on the above-mentioned oily sludge extraction device, such as Figure 4 As shown, the following steps are included:

[0054] S1. preparing supercritical carbon dioxide: heating and pressurizing carbon dioxide gas until supercritical carbon dioxide is obtained;

[0055] S2, injecting oily sludge: injecting the oily sludge into the drum extractor 1;

[0056] S3, injecting supercritical carbon dioxide and performing extraction: injecting the supercritical carbon dioxide obtained in S1 into the drum extractor 1, starting the drum extractor 1, mixing the oily sludge and the supercritical carbon dioxide in the drum extractor 1, and allowing the supercritical carbon dioxide to extract organic matter in the oily sludge;

[0057] S4, separating the extract and recovering carbon dioxide: separating the mixture obtained in S3, firstly performing primary separation of the liquid phase substance and the solid phase substance, and then performing secondary separation on the liquid phase substance obtained by the primary separation to obtain an organic extract.

[0058] In step S3, supercritical carbon dioxide is continuously injected to maintain the temperature and pressure of the drum extractor 1. In step S4, the primary separation method is centrifugal separation, and the secondary separation method is cryogenic solidification separation.

[0059] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An oily sludge extraction device, characterized in that: It comprises a supply module (1) for providing supercritical carbon dioxide, a drum extractor (2) for extracting oily sludge, and a post-processing module (3) for separating the extraction product and recovering the separation product; The output end of the supply module (1) is connected to the input end of the drum extractor (2), and the output end of the drum extractor (2) is connected to the input end of the post-processing module (3); A spiral protrusion (21) and a stirring blade (22) are arranged in the drum extractor (2); the spiral protrusion (21) is arranged on the inner wall of the drum extractor (2); and the stirring blade (22) is arranged on a rotating shaft (23) located in the cavity of the drum extractor (2).

2. The oily sludge extraction device according to claim 1, characterized in that: The mathematical model of the spiral protrusion (21) is z=α·r, wherein z is the spiral height, α is the inclination angle of the spiral, and r is the radial coordinate of the spiral protrusion in the drum extractor (2); The surface profile of the stirring blade (22) is a parabola.

3. The oily sludge extraction device according to claim 1, characterized in that: The supply module (1) comprises a carbon dioxide supply module (11) for providing carbon dioxide gas, a pretreatment module (12) for generating supercritical carbon dioxide gas, and a delivery module (13) for delivering supercritical carbon dioxide gas to the drum extractor (2); The output end of the carbon dioxide supply module (11) is connected to the input end of the pretreatment module (12), the output end of the pretreatment module (12) is connected to the conveying module (13), and the output end of the conveying module (13) is connected to the input end of the drum extractor (2).

4. The oily sludge extraction device according to claim 3, characterized in that: The carbon dioxide supply module (11) is a carbon dioxide storage device.

5. The oily sludge extraction device according to claim 3, characterized in that: The pretreatment module (12) comprises a heating module for increasing the temperature of the carbon dioxide gas and a pressurizing module for increasing the pressure of the carbon dioxide gas; The input end of the heating module is connected to the output end of the carbon dioxide supply module (11), the output end of the heating module is connected to the input end of the pressurizing module, and the input end of the pressurizing module is connected to the input end of the conveying module (13).

6. The oily sludge extraction device according to claim 3, characterized in that: The conveying module (13) comprises a heat-insulating and pressure-maintaining conveying pipe and a flow controller for adjusting the conveying flow in the heat-insulating and pressure-maintaining conveying pipe, wherein the flow controller is arranged on the heat-insulating and pressure-maintaining conveying pipe; The input end of the heat-insulating and pressure-maintaining conveying pipe is connected to the output end of the pretreatment module (12), and the output end of the heat-insulating and pressure-maintaining conveying pipe is connected to the input end of the drum extractor (2).

7. The oily sludge extraction device according to claim 1, characterized in that: The post-processing module (3) comprises a centrifugal separation module for separating the extract from the solid residue, a low-temperature solidification stratification module for obtaining the extract, and a purification recovery module for recovering carbon dioxide gas; The input end of the centrifugal separation unit is connected to the output end of the drum extractor (2), the output end of the centrifugal separation unit is connected to the input end of the low-temperature solidification stratification module, and the input end of the low-temperature solidification stratification module is connected to the purification and recovery module.

8. A method for extracting oily sludge, characterized in that: The oily sludge extraction device according to any one of claims 1 to 7 comprises the following steps: S1. preparing supercritical carbon dioxide: heating and pressurizing carbon dioxide gas until supercritical carbon dioxide is obtained; S2, injecting oily sludge: injecting the oily sludge into the drum extractor (1); S3, injecting supercritical carbon dioxide and performing extraction: injecting the supercritical carbon dioxide obtained in S1 into the drum extractor (1), starting the drum extractor (1), mixing the oily sludge and the supercritical carbon dioxide in the drum extractor (1), and allowing the supercritical carbon dioxide to extract organic matter from the oily sludge; S4, separating the extract and recovering carbon dioxide: separating the mixture obtained in S3, firstly performing a primary separation of the liquid phase substance and the solid phase substance, and then performing a secondary separation on the liquid phase substance obtained by the primary separation to obtain an organic extract.

9. The method for extracting oily sludge according to claim 8, characterized in that: In step S3, supercritical carbon dioxide is continuously injected.

10. The method for extracting oily sludge according to claim 8, characterized in that: In step S4, the primary separation method is centrifugal separation, and the secondary separation method is low-temperature coagulation separation.

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