Three-stage supercritical water oxidation apparatus

Abstract

The present application belongs to the field of environmental protection and chemical technology, and proposes a three-stage supercritical water oxidation device, which comprises a reactor, the reactor comprises reaction kettle A, reaction kettle B and reaction kettle C which are vertically connected in sequence from top to bottom, the end of reaction kettle C away from reaction kettle B is provided with a settling kettle which is vertically connected thereto, the reaction kettle B is provided with a pollutant inlet, the reaction kettle A, the reaction kettle B and the reaction kettle C are all provided with an oxidant inlet, and the reaction kettle A is provided with a reactor outlet. The three-stage supercritical water oxidation device can solve the problems of insufficient residence time of solid-liquid mixture reactant and difficulty in continuous reaction in the existing supercritical water oxidation technology.

Description

Technical Field

[0001] The present invention belongs to the field of environmental protection and chemical technology, and specifically relates to a three-stage supercritical water oxidation device, which is suitable for treating organic wastewater and powdered hazardous waste using supercritical water oxidation technology. Background Art

[0002] With rapid economic development and accelerated industrialization, environmental issues have become a major global concern facing society today. Supercritical water oxidation, proposed in the early 1980s, is one of the most promising technologies for treating pollutants, particularly suitable for treating high-concentration organic wastewater, including printing and dyeing wastewater, oily wastewater, and landfill leachate. Compared with traditional treatment processes, supercritical water oxidation offers thorough treatment, short reaction times, zero secondary pollution, and high controllability.

[0003] The supercritical state of water refers to a state reached when the temperature exceeds 374°C and the pressure exceeds 22 MPa. Under supercritical conditions, the density and dielectric constant of water undergo significant changes, and water becomes a non-polar solvent. The solubility of organic matter and oxygen in supercritical water increases significantly, and they can even completely mix to form a homogeneous phase. Oxidants can undergo a strong oxidation reaction with organic matter in supercritical water, rapidly degrading the organic matter into harmless inorganic substances. Hydrocarbons are oxidized into CO2 and H2O, nitrogen is oxidized into N2, and sulfur and halogens precipitate as inorganic salts of acid ions.

[0004] However, large-scale application of supercritical water oxidation technology is difficult due to the following major issues: material corrosion under high temperature and pressure, inorganic salt clogging under supercritical conditions, and insufficient reaction time. Over more than 30 years, various supercritical water oxidation reactors have been developed both domestically and internationally, including vertical, horizontal, and tilted configurations. However, none of them effectively address the issues of insufficient reaction time and discontinuous reactions when the reactants are solid-liquid mixtures. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a three-stage supercritical water oxidation device, aiming to solve the problems of insufficient residence time of solid-liquid mixture reaction materials and difficulty in continuous reaction in existing supercritical water oxidation technology.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention provides a reactor device, which includes a reactor A, a reactor B and a reactor C vertically connected in sequence from top to bottom. The end of the reactor C facing away from the reactor B is provided with a sedimentation kettle vertically connected thereto. The reactor B is provided with a pollutant inlet, the reactors A, the reactor B and the reactor C are all provided with an oxidant inlet, and the reactor A is provided with a reactor outlet.

[0008] Furthermore, reactor A, reactor B, reactor C and sedimentation reactor are provided with connecting flanges and sealing members at their respective adjacent connections.

[0009] Furthermore, the reactor A, the reactor B, the reactor C and the sedimentation reactor all adopt a straight tube structure. In order to save space, the straight tube may also have a certain curvature.

[0010] Furthermore, the outer wall of the reactor is provided with a heater which is heated by steam, electricity or oil.

[0011] Furthermore, a heat-insulating layer is provided outside the heater.

[0012] Furthermore, the reactor A is provided with a head by means of bolts, and the reactor outlet and the thermocouple sleeve inserted into the reactor are provided on the head.

[0013] Furthermore, the height of the reactor is an adjustable structure.

[0014] Furthermore, a level meter is provided in the settling kettle.

[0015] The advantages of the present invention are as follows: the three-stage supercritical water oxidation reaction device mentioned in the present invention effectively increases the residence time of the reaction materials and the sufficiency of the reaction by allowing the reaction materials to flow from bottom to top and injecting oxygen into the three-stage reactors; and a sedimentation tank is provided under the reactor, so that the inorganic salt can be deposited in the sedimentation tank by its own gravity, which helps to solve the problem of reactor blockage and ensure the continuous reaction of the reaction materials.

[0016] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0018] Figure 1 This is a schematic diagram of the structure of the three-stage supercritical water oxidation device;

[0019] Figure numerals: 1. Thermocouple sleeve; 2. Reactor outlet; 3. Head; 4. Bolt; 5. Reactor A; 6. Oxidant inlet; 7. Insulation layer; 8. Pollutant inlet; 9. Connecting flange; 10. Heater; 11. Reactor B; 12. Reactor C; 13. Settling kettle. DETAILED DESCRIPTION

[0020] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0021] like Figure 1As shown, the three-section supercritical water oxidation device mentioned in the embodiment includes a reactor, which includes reaction kettle A5, reaction kettle B11 and reaction kettle C12 connected vertically from top to bottom, and the reaction kettle C12 is provided with a settling kettle 13 connected vertically at the end away from the reaction kettle B11. The reaction kettle B11 is provided with a pollutant inlet 8 for receiving reaction materials. The reaction kettle A5, the reaction kettle B11 and the reaction kettle C12 are all provided with an oxidant inlet 6 for receiving oxygen. The reaction kettle A5 is provided with a reactor outlet 2 for discharging the reacted reaction materials, and the settling kettle 13 is used for settling inorganic salt solids. In this way, the reactor is divided into a three-section reaction kettle and a settling kettle structure. The three-section reaction kettle includes the reaction kettle A5, the reaction kettle B11 and the reaction kettle C12, which are internally connected. The reason for arranging the three-section reaction kettle is to increase the residence time of the materials in the kettle, so that the materials can be fully reacted. Oxygen is injected into each section of the reaction kettle, and the oxygen and the materials are fully contacted. The mixed and uniform materials are injected into the middle of the reaction kettle A5 and the reaction kettle B11 or the upper part of the reaction kettle B11. A part of the liquid is gasified at high temperature, mainly in the reaction kettle A5. A part of the liquid and solid powder that is not gasified is mainly reacted in the reaction kettle B11 and the reaction kettle C12 under the influence of gravity. The reaction kettle C12 and the settling kettle 13 are connected, and the solid powder generated in the reaction kettle C12 and a small amount of liquid that is not evaporated are affected by gravity and enter the settling kettle 13 and are further settled. The gas in the reactor flows out of the reactor outlet 2 above the reaction kettle A5 and enters the subsequent cooling and separation. During the high-temperature and high-pressure reaction process, most of the liquid is evaporated into a gaseous state, which causes the solid powder in the reaction materials and the reaction products to precipitate. As the reaction proceeds, the solid powder increases, which may cause blockage of the reaction system, especially the pipeline, affecting the continuous reaction. However, the device provided with the settling kettle 13 can collect the solid powder, reduce the blockage of the pipeline and ensure the continuous reaction.

[0022] The reaction kettle A5, the reaction kettle B11 and the reaction kettle C12 in the embodiment are the main bodies of the reactor, which are all tubular structures and are connected by the connecting flanges 9. Each connecting flange 9 is provided with a sealing element, and the reaction materials flow in the tubes.

[0023] The outer wall of the reactor in the embodiment is provided with a heater 10, which can be electric heating or oil heating. The heater 10 is provided with a heat preservation layer 7 to ensure that the temperature in the reactor reaches the set temperature (above the supercritical point of water).

[0024] In this embodiment, the reactor A5 is provided with a head 3 via bolts 4. The head 3 is provided with a reactor outlet 2 and a thermocouple sleeve 1 inserted into the reactor. The thermocouple sleeve 1 is provided in the reactor for inserting a thermocouple for temperature measurement. At the same time, a pressure sensor (not shown) is also provided on the head 3 for measuring the pressure inside the reactor.

[0025] In this embodiment, the pollutant inlet 8 is located on one side or both sides of the reactor, and the reactor outlet 2 is located above the reactor. The gas in the reactor flows from bottom to top, and the inorganic salts settle from top to bottom under the action of their own gravity. The oxygen gas flow rate needs to be controlled to ensure that most of the inorganic salts can settle; the reaction material to be treated enters the reactor through the pollutant inlet 8. The reaction material to be treated can be a liquid material or a solid-liquid mixture, and the solid-liquid mixture needs to be stirred evenly before being injected into the reactor; the three-stage reactor is provided with an oxidant inlet 6, and the oxidant is generally a gas, which can be oxygen or air, and the gas flow rate of each gas injection port can be adjusted; in addition, the reaction material and the oxidant should generally be preheated before being injected into the reactor, which is beneficial to improving the reaction efficiency.

[0026] The height of the reactor in this embodiment is an adjustable structure, that is, the height of each section of the three-section reactor can be adjusted according to the characteristics of the reaction materials and the oxidant to be processed.

[0027] In this embodiment, the settling vessel 13 is provided with a material level meter. When the settling vessel 13 is full of inorganic salt, the reaction should be stopped and the inorganic salt should be taken out after disassembly. Alternatively, the inorganic salt can be sucked out by suction.

[0028] In this embodiment, the reactor and the settling tank 13 are made of high temperature resistant and corrosion resistant materials, such as inconel625.

[0029] Adopt this three-stage supercritical water oxidation device of above scheme to have following characteristics: one, three sections of three-stage reactor all spray into oxygen, make the interior oxygen of reactor fully contact with material, improve reaction efficiency, simultaneously the gaseous state of incomplete reaction and solid-state can react in reactor A or reactor C; Two, in the reactor device, gas flows from bottom to top, and solid utilizes gravity to deposit from top to bottom, is conducive to increasing solid residence time in reactor, and it is fully reacted; Three, three sections of reactor are all provided with oxygen inlet, can form certain turbulence at its entrance, have utilization extension material residence time in reactor; Four, be provided with sedimentation still, be inorganic salt storage space, ensure that reaction unit can be operated continuously; Five, reactor device and sedimentation still UNICOM, inorganic salt can utilize gravity to be settled in sedimentation still below, is conducive to solving inorganic salt blocking problem.

[0030] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It is apparent that various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the present invention. Thus, the present invention is intended to encompass such modifications and variations as long as they fall within the scope of the claims and their equivalents.

Claims

1. A three-stage supercritical water oxidation device, comprising a reactor, characterized in that: The reactor comprises a reactor A (5), a reactor B (11) and a reactor C (12) which are vertically connected in sequence from top to bottom. The end of the reactor C which is away from the reactor B is provided with a sedimentation tank (13) which is vertically connected thereto. The reactor B is provided with a pollutant inlet (8). The reactors A, B and C are all provided with an oxidant inlet (6). The reactor A is provided with a reactor outlet (2). The height of the reactor is set to an adjustable structure according to the characteristics of the reaction materials to be processed and the characteristics of the oxidant.

2. The three-stage supercritical water oxidation device according to claim 1, characterized in that: The reactor A, reactor B, reactor C and sedimentation reactor are provided with connecting flanges (9) and sealing members at their respective adjacent connection locations.

3. The three-stage supercritical water oxidation device according to claim 1, characterized in that: The reactor A, reactor B, reactor C and sedimentation reactor all adopt a straight tube structure.

4. The three-stage supercritical water oxidation device according to claim 1, characterized in that: The outer wall of the reactor is provided with a heater (10), and the heater is heated by steam, electricity or oil.

5. The three-stage supercritical water oxidation device according to claim 4, characterized in that: A heat-insulating layer (7) is provided outside the heater.

6. The three-stage supercritical water oxidation device according to claim 1, characterized in that: The reactor A is provided with a head (3) via bolts (4), and the reactor outlet and a thermocouple sleeve (1) inserted into the reactor are provided on the head.

7. The three-stage supercritical water oxidation device according to claim 1, characterized in that: A material level meter is arranged in the settling kettle.

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