An apparatus and method for treating oily sludge by supercritical water thermal desorption

Abstract

This invention discloses a supersubcritical hydrothermal desorption device and method for treating oily sludge. The device includes a main body, with its top and bottom sealed by an upper and lower end cover, respectively. Inside is a desorption chamber equipped with a guide plate. Its side walls are provided with a primary preheating water inlet, a desorption product outlet, a slag discharge port, and a temperature detection device, all communicating with the desorption chamber. An oily sludge inlet is located on the upper end cover, and a secondary preheating water inlet is located on the lower end cover. This device is compact, easy to operate and maintain, and can effectively achieve the desorption of oily sludge from supersubcritical water flowing against the temperature gradient, as well as the desorption of petroleum components as the temperature gradually increases. This achieves the goals of resource recovery, harmless treatment, and volume reduction of the oily sludge.

Description

Technical Field

[0001] This invention belongs to the field of oily sludge treatment technology, and relates to a device and method for supercritical hydrothermal desorption treatment of oily sludge. Background Technology

[0002] Supercritical water desorption technology refers to the technique of heating water above its critical point and utilizing the special properties of supercritical water for substance separation or treatment. Subcritical water, on the other hand, refers to heating water above its boiling point but below its critical point and controlling the system pressure to maintain the water in a liquid state.

[0003] Supercritical water desorption technology has broad application prospects in many fields. For example, in wastewater treatment, this technology can effectively remove pollutants such as organic matter and heavy metals from wastewater. Supercritical water desorption technology has many advantages over traditional desorption methods. It can operate at lower temperatures and pressures, thus saving energy and reducing costs. Simultaneously, due to the strong solubility of supercritical water, it can remove adsorbed substances more thoroughly, improving desorption efficiency.

[0004] Supercritical water desorption units are specialized equipment used to implement supercritical water desorption technology and have wide applications in many fields. However, it should be noted that supercritical water desorption technology places high demands on the reactor. Existing supercritical water desorption units are usually structurally complex, difficult to operate, and not conducive to later maintenance, thus increasing operating costs. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of the prior art mentioned above and to provide a device and method for supercritical hydrothermal desorption treatment of oily sludge.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A supercritical hydrothermal desorption device for treating oily sludge includes a main body 7. The main body 7 contains a desorption chamber, inside which are baffles. The baffles are staggered, with one end tightly connected to the side wall of the desorption device at an angle, and the other end spaced apart from the side wall to facilitate fluid flow. The side wall of the main body 7 is provided with a primary preheating water inlet pipe 2, a desorption product outlet pipe 5, and a slag discharge port 17 communicating with the desorption chamber. A heating device is provided on the outer wall of the main body 7. The top of the main body 7 has an oily sludge inlet pipe 1. The bottom of the main body 7 has a secondary preheating water inlet pipe 9. A high-temperature and high-pressure resistant sealing gasket is provided at the connection between the main body 7 and the upper end cover 12. A high-temperature and high-pressure resistant sealing gasket is also provided at the connection between the main body 7 and the lower end cover 8.

[0008] The main body 7 and the upper and lower end caps are made of high-temperature and corrosion-resistant metal through turning and welding processes, and a circular flow channel with a consistent inner diameter is formed inside the main body 7. The main body 7 and the upper and lower end caps are connected by high-temperature resistant metal bolts 10. The outer sides of the main body 7 and the upper and lower end caps are equipped with heat insulation cotton and metal shells.

[0009] The oily sludge inlet pipe 1 is located on the upper end cover 12 of the main body 7 of the device; the primary preheating water inlet pipe 2 is located on the upper part of the side wall of the main body 7 of the device; the desorption product outlet pipe 5 is located on the middle and lower part of the side wall of the desorption device; the slag discharge port 17 is located at the bottom of the side wall of the desorption device; and the secondary preheating water inlet pipe 9 is located on the lower end cover 8 of the desorption device.

[0010] Furthermore, a temperature detection device is provided on the side wall of the main body 7 of the device; the temperature detection device is evenly distributed between each of the guide plates.

[0011] Furthermore, all components of the super-subcritical hydrothermal desorption treatment device for oily sludge can withstand high temperatures of 500℃ and pressures of 30MPa.

[0012] A method for treating oily sludge by supercritical hydrothermal desorption includes the following steps:

[0013] S1, the preheating device body 7 reaches the predetermined temperature;

[0014] S2, subcritical water that has reached the predetermined temperature is introduced into the main body of the device 7 through the primary preheating water inlet pipe 2; oily sludge is introduced into the main body of the device 7 through the oily sludge inlet pipe 1; the oily sludge and subcritical water are mixed in the desorption chamber and flow from top to bottom, and the oil components are gradually heated and precipitated during the flow.

[0015] The precipitated oil components dissolve in supercritical water and flow out from the desorption product outlet pipe 5; the ash particles after oil component desorption slide to the bottom of the main body of the device 7 and are discharged from the slag discharge port 17.

[0016] S3, deionized water enters the main body 7 of the device through the secondary preheated water inlet pipe 9, and performs secondary extraction on the oily sludge particles to complete the desorption treatment.

[0017] Furthermore, the subcritical water is highly mineralized and can be recycled.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention discloses a supercritical subcritical hydrothermal desorption device for treating oily sludge. The device includes a main body; a desorption chamber inside the main body with a guide plate installed inside; a primary preheating water inlet pipe, a desorption product outlet, a slag discharge port, and a temperature detection device connected to the desorption chamber are provided on the side wall of the main body; an oily sludge inlet is provided on the upper end cover; a secondary preheater inlet pipe is provided on the lower end cover; and an axially adjustable heating device is provided on the outside of the main body. The oily sludge and primary preheating water are mixed and flow slowly through the guide plate, allowing for thorough mixing and desorption of the oil components. This invention, through the combined design of the guide plate, oily sludge inlet, preheating water inlet, and heating device, has a simple structure, requires minimal equipment investment, and only requires opening the heating device to introduce preheating water and oily sludge, making operation simple and facilitating subsequent maintenance. 。

[0020] Furthermore, this invention designs a two-stage extraction method, namely, after primary preheating with hot water, a secondary preheating with hot water is provided at the bottom for further treatment; this two-stage extraction method can more completely desorb the oil components in oily sludge, realizing the reduction of oily sludge volume; the desorption chamber of this invention is equipped with a guide plate inside and an axially adjustable heating device outside, so that the oily sludge and water mixture runs against the temperature gradient, effectively promoting the full reaction between the oily sludge and supercritical water, further improving the desorption effect of oily sludge.

[0021] Furthermore, when using supercritical hydrothermal desorption to treat oily sludge, this invention can use water with high mineralization, and the water resources can be recycled, saving a lot of water pretreatment equipment and reducing one-time investment and operating costs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a supercritical hydrothermal desorption device for treating oily sludge.

[0024] Wherein: 1-Oil-containing sludge inlet pipe; 2-Primary preheating water inlet pipe; 3-First temperature detection device; 4-Second temperature detection device; 5-Desorption product outlet pipe; 6-Third temperature detection device; 7-Main body of the device; 8-Lower end cover; 9-Secondary preheating water inlet pipe; 10-Bolt; 11-Nut; 12-Upper end cover; 13-First guide plate; 14-Second guide plate; 15-Outlet guide plate; 16-Third guide plate; 17-Slag discharge port. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings:

[0032] See Figure 1 This invention discloses a supercritical hydrothermal desorption device for treating oily sludge, comprising an upper end cover 12, a device body 7, a first guide plate 13, a second guide plate 14, an outlet guide plate 15, a third guide plate 16, a first temperature detection device 3, a second temperature detection device 4, a third temperature detection device 6, and a lower end cover 8; the upper end cover 12 and the lower end cover 8 are fixed to both ends of the device body 7 by bolts 10 and nuts 11; the device body 7 has a desorption chamber inside, and a certain number of [unspecified items] are placed inside the desorption chamber. A guide plate is provided; the upper part of the main body 7 is provided with a primary preheating water inlet pipe 2 that connects to the desorption chamber; the lower part of the main body 7 is provided with a desorption product outlet pipe 5 that connects to the desorption chamber; the bottom of the main body 7 is provided with a slag discharge port 17 that connects to the desorption chamber; the slag discharge port 17 is connected to a stepped cooling and depressurizing slag discharger, and the desorbed ash particles can be continuously discharged from the desorption device through the stepped cooling and depressurizing slag discharger connected to the slag discharge port 17; the upper end cover 12 is provided with an oily sludge inlet pipe 1; the lower end cover 8 is provided with a secondary preheating water inlet pipe 9.

[0033] All components of the super-subcritical hydrothermal desorption treatment device for oily sludge are resistant to high temperatures of 500℃ and pressures of 30MPa.

[0034] The supercritical hydrothermal desorption treatment device for oily sludge can directly use high-mineralized water, and the water resources can be recycled, saving a lot of water pretreatment equipment and reducing one-time investment and operating costs.

[0035] The supercritical hydrothermal desorption treatment device for oily sludge has wide material applicability and can treat oily sludge with different concentrations of ash, moisture and oil components, realizing the resource utilization, harmlessness and volume reduction of oily sludge.

[0036] The working process of this invention is as follows:

[0037] After the main body 7 of the device is heated to a predetermined temperature, subcritical water at the predetermined temperature (300°C) flows in from the primary preheating water inlet pipe 2. Unheated oily sludge (20°C) flows into the desorption chamber from the oily sludge inlet pipe 1 and mixes with the subcritical water (220°C). Due to the small distance between the first guide plate 13, the second guide plate 14, and the third guide plate 16 and the wall surface, the mixture of oily sludge and subcritical water can only flow from top to bottom. During the flow, the temperature gradually rises to 390°C. Simultaneously, the oil components and ash particles in the oily sludge desorb and diffuse into the supercritical water. The precipitated oil components dissolve in the supercritical water and flow out from the desorption product outlet pipe 5. The ash particles after desorption fall onto the surface of the guide plate 16 and slide to the bottom of the main body 7, where they are discharged from the slag discharge port 17. Deionized water flows from the bottom of the desorption unit through the secondary preheating water inlet pipe 9 to perform secondary extraction on the oily sludge particles, further realizing the resource utilization, harmlessness and volume reduction of the oily sludge.

[0038] This invention discloses a method for supercritical hydrothermal desorption treatment of oily sludge, comprising the following steps:

[0039] S1, the preheating device body 7 reaches the predetermined temperature;

[0040] S2, subcritical water that has reached the predetermined temperature is introduced into the main body of the device 7 through the primary preheating water inlet pipe 2; oily sludge is introduced into the main body of the device 7 through the oily sludge inlet pipe 1; the oily sludge and subcritical water are mixed in the desorption chamber and flow from top to bottom, and the oil components are gradually heated and precipitated during the flow.

[0041] The precipitated oil components dissolve in supercritical water and flow out from the desorption product outlet pipe 5; the ash particles after oil component desorption slide to the bottom of the main body of the device 7 and are discharged from the slag discharge port 17.

[0042] S3, deionized water enters the main body 7 of the device through the secondary preheated water inlet pipe 9, and performs secondary extraction on the oily sludge particles to complete the desorption treatment.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for treating oily sludge by super-subcritical hydrothermal desorption, comprising a super-subcritical hydrothermal desorption device for treating oily sludge, including the main body of the device (7). The device body (7) has a desorption chamber inside, and a guide plate is installed inside the desorption chamber. The guide plates inside the desorption chamber are staggered, with one end connected to the side wall of the device body (7) at an angle, and the other end spaced from the side wall of the device body (7) to facilitate fluid flow. The main body (7) of the device is provided with a primary preheating water inlet pipe (2), a desorption product outlet pipe (5) and a slag discharge port (17) connected to the desorption chamber. The outer wall of the main body (7) of the device is provided with a heating device; the top of the main body (7) of the device is provided with an oily sludge inlet pipe (1); the bottom of the main body (7) of the device is provided with a secondary preheating water inlet pipe (9); the oily sludge inlet pipe (1) is located on the upper end cover (12) above the main body (7); the primary preheating water inlet pipe (2) is located on the upper part of the side wall of the main body (7); the desorption product outlet pipe (5) is located on the middle and lower part of the side wall of the main body (7); the slag discharge port (17) is located on the bottom of the side wall of the main body (7); the secondary preheating water inlet pipe (9) is located on the lower end cover (8) below the main body (7); all components of the super subcritical hydrothermal desorption treatment device for oily sludge can withstand a high temperature of 500℃ and a pressure of 30MPa; Its features are, The method for supercritical hydrothermal desorption treatment of oily sludge includes the following steps: S1, the preheating device body (7) reaches the predetermined temperature; S2, subcritical water that has reached the predetermined temperature is introduced into the main body of the device (7) through the first-stage preheated water inlet pipe (2); oily sludge is introduced into the main body of the device (7) through the oily sludge inlet pipe (1); the oily sludge and subcritical water are mixed and flow from top to bottom in the desorption chamber, and the oil components are gradually heated and precipitated during the flow. The precipitated oil components dissolve in supercritical water and flow out from the desorption product outlet pipe (5); the oil-containing sludge particles after oil component desorption slide to the bottom of the main body of the device (7) and are discharged from the slag discharge port (17); S3, deionized water enters the main body (7) of the device through the secondary preheated water inlet pipe (9) to perform secondary extraction on the oily sludge particles and complete the desorption treatment.

2. The method for supercritical hydrothermal desorption treatment of oily sludge according to claim 1, characterized in that, The main body (7) and the upper and lower end caps are made of high temperature and corrosion resistant metal by turning and welding processes, and a circular flow channel with the same inner diameter is formed inside the main body (7); the main body (7) and the upper and lower end caps are connected by high temperature resistant metal bolts (10).

3. The method for supercritical hydrothermal desorption treatment of oily sludge according to claim 1, characterized in that, The main body (7) of the device is provided with a temperature detection device on its side wall; the temperature detection device is evenly distributed between each guide plate.

4. The method for supercritical hydrothermal desorption treatment of oily sludge according to claim 1, characterized in that, The connection between the main body (7) and the upper end cover (12) of the device is provided with a high temperature and high pressure resistant sealing gasket; the connection between the main body (7) and the lower end cover (8) of the device is provided with a high temperature and high pressure resistant sealing gasket.

5. The method for supercritical hydrothermal desorption treatment of oily sludge according to claim 1, characterized in that, The main body (7) of the device and the outer sides of the upper and lower end caps are provided with heat insulation cotton and metal shell.

6. The method for supercritical hydrothermal desorption treatment of oily sludge according to claim 1, characterized in that, The subcritical water is highly mineralized water.

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