CN106215843A - A kind of overcritical water oxidization reactor - Google Patents

Abstract

The invention provides a supercritical water oxidation reactor. Wherein the supercritical water oxidation reactor includes: a shell, an inner cylinder and a baffle; wherein, the top of the shell is provided with a material input port, and the bottom of the shell is provided with a product output port; the inner cylinder is sleeved on the shell In the body, the material input port is connected to the inner cylinder through a pipe, the bottom of the inner cylinder is the material output port, and there is a preset distance between the material output port and the bottom of the shell; The plate is placed in the annular space and connected with the outer wall of the inner cylinder; the side wall of the casing is provided with a first quenching water inlet. In the present invention, the side wall of the reactor housing is provided with a first quenching water inlet, and the outer wall of the inner cylinder of the reactor is provided with a baffle, so that the quenching water input from the first quenching water inlet flows continuously along the baffle and the outer wall of the inner cylinder , uniformly surrounds the inner cylinder of the reactor, enhances the cooling effect on the inner cylinder, and effectively alleviates the corrosion problem of the material of the inner cylinder of the reactor under high temperature conditions.

Description

A supercritical water oxidation reactor

technical field

The invention relates to the technical field of supercritical oxidation, in particular to a supercritical water oxidation reactor.

Background technique

Supercritical water oxidation technology refers to the "combustion" of organic waste with supercritical water as the medium and air or oxygen as the oxidant under high temperature and high pressure conditions exceeding the critical point of water (T=374°C, P=22.1MPa). "Method of Oxidation. Since supercritical water has a liquid-like density, solubility and good fluidity, it is a non-polar solvent, and it also has a gas-like diffusion coefficient and low viscosity. In supercritical water, the gas-liquid two-phase interface disappears, organic matter and _O2 are completely soluble in supercritical water, forming a homogeneous system, and the reaction speed is greatly accelerated. In the reaction residence time of less than 1min or even a few seconds, more than 99.9% of the organic matter is rapidly burned and oxidized into non-toxic and harmless terminal products such as CO ₂ , H ₂ O and inorganic salts, and a large amount of oxygen will be released during the oxidation reaction. Thermal energy can be recycled efficiently.

However, under supercritical conditions, high temperature, high pressure, and high concentration of dissolved oxygen will cause oxidation and corrosion to the materials inside the reactor. The existing supercritical water oxidation reactor is generally mainly composed of a shell and an inner cylinder. The inner cylinder is placed in the shell, and the inlet is usually set on the top of the shell, and the outlet is set on the bottom of the shell. When the chilled water flows from top to bottom in the shell, it flows through the inner cylinder, exchanges heat with the material in the inner cylinder, and then is discharged from the outlet. The chilled water entering from the inlet of the shell will flow directly downward in the shell under its own gravity, and the residence time in the shell is short, resulting in a short heat exchange time with the reaction materials in the inner cylinder, and even some shocks The cold water is discharged from the outlet without exchanging heat with the reaction materials in the inner cylinder. This structure makes the contact time between the chilled water and the inner cylinder shorter, and cannot fully cool down the inner cylinder, resulting in the inner cylinder being too high in temperature and oxidized by high-temperature dissolved oxygen. .

Contents of the invention

In view of this, the present invention proposes a supercritical water oxidation reactor, aiming to solve the problem of material corrosion inside the reactor caused by poor cooling effect in the chilling zone in the structure of the existing supercritical water oxidation reactor.

In one aspect, the present invention provides a supercritical water oxidation reactor, the supercritical water oxidation reactor includes: a shell, an inner cylinder and a baffle; wherein, the top of the shell is provided with a material input port, the The bottom of the housing is provided with a product output port; the inner cylinder is sleeved in the housing, the material input port communicates with the inner cylinder through a pipeline, and the bottom of the inner cylinder is a material output port. There is a preset distance between the material output port and the bottom of the housing; the inner cylinder and the inner wall of the housing form an annular space, and the baffle is placed in the annular space and connected to the inner The outer wall of the cylinder is connected; the side wall of the shell is provided with a first quenching water inlet.

Further, in the above-mentioned supercritical water oxidation reactor, the area surrounded by the inner cylinder is a reaction zone, and the reaction zone includes: a jet flow zone, a reflux zone and a pipe flow zone, the jet flow zone, the reflux zone and The pipe flow area is distributed according to a preset volume, so that the aspect ratio of the reaction area is a preset value.

Further, in the above-mentioned supercritical water oxidation reactor, the material inlet is provided with a nozzle, and the setting of the nozzle matches the height-to-diameter ratio of the reaction zone so that the value range of the atomization angle α of the nozzle is 30 °～60°.

Further, in the above supercritical water oxidation reactor, the baffle is spirally wound outside the inner cylinder.

Further, in the above supercritical water oxidation reactor, the helically wound baffles have the same pitch.

Further, in the above supercritical water oxidation reactor, the first chilled water inlet is placed above the baffle.

Further, in the above supercritical water oxidation reactor, a second quenching water inlet is opened on the side wall of the shell, and the second quenching water inlet is arranged close to the material output port of the inner cylinder.

Further, in the above supercritical water oxidation reactor, there are at least two second quenching water inlets, and each of the second quenching water inlets is distributed along the circumferential direction of the housing.

Further, in the above supercritical water oxidation reactor, each of the second quenching water inlets is evenly distributed along the circumference of the shell, and the setting of the second quenching water inlets makes the incident direction of the quenching water along the shell The direction of the tangent to the circumference of the body side wall.

Further, the above supercritical water oxidation reactor further includes: a lock bucket; wherein, the lock bucket is connected to the product output port of the housing.

In the present invention, the first quenching water inlet is arranged on the side wall of the reactor shell, and the baffle plate is arranged on the outer wall of the inner cylinder of the reactor, so that the quenching water input from the first quenching water inlet can pass along the inner cylinder of the baffle plate. The outer wall flows continuously from top to bottom, thereby evenly surrounding the inner cylinder of the reactor, enhancing the cooling effect on the inner cylinder of the reactor, and effectively alleviating the corrosion problem of the material of the inner cylinder of the reactor under high temperature conditions.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating a preferred embodiment and are not to be considered as limiting the invention. Also throughout the drawings, the same reference numerals are used to designate the same components. In the attached picture:

Fig. 1 is the structural representation of the supercritical water oxidation reactor that the embodiment of the present invention provides;

Fig. 2 is a schematic diagram of the distribution of reaction zones of the supercritical water oxidation reactor provided by the embodiment of the present invention.

detailed description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

Referring to Fig. 1, the preferred structure of the supercritical water oxidation reactor provided in this embodiment is shown in the figure. The supercritical water oxidation reactor includes: a shell 1 , an inner cylinder 2 and a baffle 4 . Wherein, the top of the housing 1 is provided with a material input port 11, and the bottom of the housing 1 is provided with a product output port 14, and the housing 1 can be a hollow cylindrical body with one end open; the inner cylinder 2 is sleeved in the housing 1, namely : The top of the inner cylinder 2 is connected to the top of the shell through a pipeline, and is suspended inside the shell 1; the material input port 11 is connected to the inner cylinder 2 through a pipeline, and the bottom of the inner cylinder 2 is the material output port 21, and the material output port 21 There is a preset distance from the bottom of the shell 1. The preset distance means that there is a gap between the bottom of the inner cylinder and the bottom of the shell. The size of the distance can be determined according to the specific requirements of the reaction. The inner cylinder 2 and the inner wall of the shell 1 form an annular space. The baffle 4 is placed in the annular space and connected with the outer wall of the inner cylinder 2. The baffle 4 is a plate used to change the flow direction of the fluid. The properties of the medium, the flow rate and the size of the reactor are selected; the side wall of the shell 1 is provided with a first quenching water inlet 3, and the first quenching water inlet 3 can be set at the upper part of the side wall of the shell 1 near the top of the inner cylinder 2 , can also be arranged at the lower part of the side wall of the housing 1 near the outlet at the bottom of the inner cylinder.

Those skilled in the art should understand that the volume of the reaction zone can be determined according to the residence time of the materials participating in the reaction and the corresponding gas volume flow rate under specific temperature and pressure conditions; the height diameter of the reaction zone can be determined according to the distribution of the flow field in the reaction zone Compare.

In this embodiment, the annular area surrounded by the inner cylinder 2 and the inner wall of the housing 1 is a chilling zone 13, and the chilling zone 13 is used to reduce the wall temperature of the inner cylinder 2 and the housing 1; the material output port 21 and the housing 1. The area surrounded by the bottom is the mixing area 12. The basic process of the supercritical water oxidation reaction is: the material to be treated is sprayed into the reactor from the input port 11 at the top of the shell 1 to carry out the supercritical water oxidation reaction in the reaction zone 22, and the high-temperature reaction product after the reaction is discharged from the material at the bottom of the inner cylinder 2 The output port 21 is discharged into the mixing area 12, and at the same time, the quenching water is input from the first quenching water inlet 3, flows along the wall surface of the inner cylinder 2 from top to bottom along the baffle plate 4, and is discharged from the gap between the inner cylinder 2 and the shell 1 The mixing zone 12 realizes the mixing of high-temperature reaction products and chilled water.

In the above embodiment, the first chilled water inlet 3 is placed above the baffle plate 4, so that the chilled water flows continuously along the wall of the inner cylinder 2 directly under the guidance of the baffle plate 4 after entering the interior of the housing 1, extending the The residence time of chilled water on the wall enhances the cooling effect on the wall of the inner cylinder; in addition, gravity can be used to make the chilled water flow from the top of the inner cylinder 2 to the bottom with less resistance, without using equipment with a high pressure level The flow of chilled water on the wall surface of the inner cylinder 2 is realized, and the equipment cost is reduced.

Preferably, the baffle plate 4 is spirally wound on the side wall of the inner cylinder 2, and since the fluid circulation channel of the spiral baffle plate is continuous, the quenching water input from the first quenching water inlet 3 can be continuous. The spiral flow ensures that the quenching water can fill the gap between the reactor wall and the inner cylinder, so that the quenching zone can evenly surround the inner cylinder 2 of the reactor. On the one hand, the temperature of the outer wall of the reactor inner cylinder 2 is reduced, and the high temperature is relieved. Oxidative corrosion of the outer wall of the inner cylinder 2 of the reactor under certain conditions; on the other hand, the temperature of the reactor shell 1 is reduced, the heat dissipation loss is reduced, and the material selection standard of the reactor shell 1 is lowered, which can greatly reduce the manufacturing cost of the reactor .

Further preferably, the helically wound baffles 4 have equal pitches. When the screw pitch is too large, the flow rate of quenching water will decrease accordingly, resulting in poor heat transfer effect between the quenching zone and the reaction zone, which will easily lead to overheating of the outer wall; if the screw pitch is too small, the flow rate of quenching water will increase correspondingly, which will easily cause reaction The temperature in the zone decreases, making it difficult to maintain the temperature required for the supercritical water oxidation reaction. In the specific reaction process, it is advisable to control the temperature in the reaction zone above 550°C and the temperature of the reactor shell below 300°C. The choice of the pitch of the baffle plate needs to be determined according to the quenching water flow rate and the requirements of the reaction zone and shell temperature. .

In this embodiment, the first quenching water inlet 3 is set on the side wall of the reactor shell 1, and the baffle plate 4 is set on the outer wall of the reactor inner cylinder 2, so that the quenching water imported from the first quenching water inlet 3 can be The baffles 4 flow continuously from top to bottom on the outer wall of the inner cylinder 2, so as to evenly surround the inner cylinder 2 of the reactor, enhance the cooling effect on the wall of the inner cylinder 2 of the reactor, and effectively alleviate the temperature of the inner cylinder 2 of the reactor under high temperature conditions. Corrosion of materials.

In the above embodiment, the area surrounded by the inner cylinder 2 is the reaction zone 22. After the materials with high calorific value and low ignition point are heated up, they are mixed with oxygen and enter the reaction zone 22 to release a large amount of heat, providing high temperature and high pressure conditions for the reaction zone 22. , so that the reaction zone 22 reaches a supercritical state, which can ensure the supercritical water oxidation reaction of the raw material to be treated. Wherein, the reaction zone 22 includes: a jet flow zone 221, a reflux zone 222 and a pipe flow zone 223; the reflux zone 222 has a smaller volume and is located at the top of the reaction zone 22, and the jet flow zone 221 has a larger volume and is located in the middle of the reaction zone 22 in a conical distribution. Zone 223 is located in the lower part of reaction zone 22 . It should be noted that the jet flow zone 221 is a gasification reaction zone for carbonaceous substances; the medium in the recirculation zone 222 is the combustion product residual carbon, water vapor and a small amount of oxygen from the jet flow zone under the action of convective entrainment; the tube flow zone The reactions carried out by 223 are mainly the heterogeneous gasification reaction of carbon, methane and water vapor conversion reaction, reverse conversion reaction, etc. The jet flow zone 221 , the reflux zone 222 and the pipe flow zone 223 are distributed according to preset volumes so that the aspect ratio of the reaction zone 22 is a preset value. Specifically, the preset value of the aspect ratio can be determined according to the volume size distribution requirements of each area in the reaction zone 22, and the volume of the reaction zone 22 is determined according to the residence time of the materials. Generally speaking, the jet flow zone 221 has a large volume, is located in the middle of the reaction zone 22 and is distributed in a conical shape, and the tube flow zone 223 is located at the lower part of the reaction zone 22, and its volume is greatly affected by the height-to-diameter ratio. The flow area 223 is larger.

In the above-mentioned embodiment, the material inlet 11 is provided with a nozzle 111, and the arrangement of the nozzle 111 matches the height-to-diameter ratio of the reaction zone 22 so that the atomization angle α of the nozzle 111 ranges from 30° to 60°. Specifically, after the aspect ratio is determined, the position of the nozzle 111 can be determined, so that the value range of the atomization angle α is 30° to 60°, thereby ensuring that the flow rate of the gas phase material in the material is above 80 m/s, and finally making the The material can react more fully.

In this embodiment, the proportion of water in the material to be treated is relatively large, and the remaining ingredients are a small amount of solid particles and inorganic salts. The water in the reaction zone 22 is supercritical water, and inorganic salts will be precipitated in supercritical water and will be separated from the material. The output port 21 is discharged to the mixing zone 12, and the high-temperature reaction product and the chilled water imported from the first chilled water inlet 3 are mixed in the mixing zone 12 and cooled, so that the water in the mixing zone 12 can be reduced to a subcritical state, and the product in the The precipitated inorganic salts will dissolve in subcritical water.

In the above embodiment, the side wall of the housing 1 is provided with a second quenching water inlet 31, and the second quenching water inlet 31 is arranged close to the material output port 21 of the inner cylinder 2, that is, the second quenching water inlet 31 and the mixing zone 21 The corresponding setting can ensure that the chilled water input from the second chilled water inlet 31 directly enters the mixing zone 12, and cooperates with the chilled water input from the first chilled water inlet 3 to cool the high-temperature reaction product in the mixing zone 12, so that the product The supercritical water in the mixing zone is gradually converted into subcritical water, and at the same time, the materials in the mixing zone 12 are disturbed to a certain extent, so that the inorganic salts precipitated in the product are gradually dissolved in the subcritical water.

Preferably, there are at least two second chilled water inlets 31, and each second chilled water inlet 31 is distributed along the circumferential direction of the housing 1. Referring to FIG. 1, a third chilled water inlet 32 can also be provided on the side wall of the housing 1 , wherein, the second quenching water inlet 31 and the third quenching water inlet 32 are arranged oppositely, forming the form of opposite spraying, cooling the high-temperature reaction product to make the water in the product reach a subcritical state, and strengthening the cooling of the mixing zone 12 The disturbance of the material accelerates the dissolution of the inorganic salt precipitated in the product in the subcritical water.

Further preferably, each second quenching water inlet 31 is evenly distributed along the circumferential direction of the housing 1, that is, a plurality of second quenching water inlets 31 are arranged symmetrically along the circumferential direction of the housing 1, so that the second quenching water inlets form a plurality of pairs spray form. The degree of disturbance of the material in the mixing zone 12 is made more severe, so as to ensure that a small amount of particles therein are discharged into the shell 1 along with the main flow of the product without being blocked at the bottom of the shell 1 .

Even more preferably, each second quenching water inlet 31 is set so that the incident direction of the quenching water is along the tangential direction of the circumference of the side wall of the casing 1, that is, the jetted quenching water forms a swirl shape, which further strengthens the mixing zone 12 The disturbance makes the inorganic salts in the material dissolve in the subcritical water in the mixing zone 12 faster and more completely, and the solid particles entrained in the material are also continuously disturbed, and are discharged from the product outlet along with the reaction product without deposition. At the bottom of the shell 1, the problem of blockage of the outlet of the reactor is effectively solved.

In the above-mentioned embodiment, it also includes: a lock hopper; wherein, the lock hopper is connected to the product output port 14 of the housing 1, and the solid particles and a part of the analyzed inorganic salts in the reactor can be discharged from the reaction through the intermittent operation of the lock hopper. device, thereby avoiding the clogging of the reactor outlet.

To sum up, by connecting the baffle plate on the inner cylinder of the reactor, and setting the quenching water inlet at the position above the baffle plate on the side wall of the shell, it is ensured that the quenching water evenly surrounds the inner cylinder of the reactor, and the temperature of the inner cylinder wall surface is controlled. The control of the shell temperature relieves the oxidative corrosion of the reactor material; at the same time, a second quenching water inlet is provided on the shell side wall close to the material output port of the inner cylinder to form a disturbance to the product fluid, so that the particles in the product And the inorganic salt discharge system solves the problem of blockage of the shell outlet.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. A supercritical water oxidation reactor, comprising: the device comprises a shell (1), an inner cylinder (2) and a baffle plate (4); wherein,

a material input port (11) is formed in the top of the shell (1), and a product output port (14) is formed in the bottom of the shell (1);

the inner cylinder (2) is sleeved in the shell (1), the material inlet (11) is communicated with the inner cylinder (2) through a pipeline, the bottom of the inner cylinder (2) is provided with a material outlet (21), and a preset distance is reserved between the material outlet (21) and the bottom of the shell (1);

the inner cylinder (2) and the inner wall of the shell (1) enclose an annular space, and the baffle plate (4) is arranged in the annular space and connected with the outer wall of the inner cylinder (2);

the side wall of the shell (1) is provided with a first chilling water inlet (3).

2. Supercritical water oxidation reactor according to claim 1, characterized in that the area enclosed by the inner drum (2) is a reaction zone (22), the reaction zone (22) comprising: a jet flow zone (221), a reflux zone (222) and a pipe flow zone (223), wherein the jet flow zone (221), the reflux zone (222) and the pipe flow zone (223) are distributed according to preset volumes, so that the height-diameter ratio of the reaction zone (22) is a preset value.

3. Supercritical water oxidation reactor according to claim 2, characterized in that the material inlet (11) is provided with a nozzle (111), and the nozzle (111) is arranged in cooperation with the height-diameter ratio of the reaction zone (22) such that the atomization angle α of the nozzle (111) ranges from 30 ° to 60 °.

4. The supercritical water oxidation reactor according to claim 1, characterized in that the baffle plate (4) is spirally wound outside the inner cylinder (2).

5. Supercritical water oxidation reactor according to claim 4, characterized in that the spiral pitch of the baffles (4) wound in a spiral shape is equal.

6. Supercritical water oxidation reactor according to claim 1, characterized in that the first quench water inlet (3) is placed above the baffles (4).

7. Supercritical water oxidation reactor according to claim 1, characterized in that the housing (1) side wall is opened with a second quench water inlet (31), and the second quench water inlet (31) is arranged close to the material outlet (21) of the inner drum (2).

8. Supercritical water oxidation reactor according to claim 7, characterized in that the number of second quench water inlets (31) is at least two and that each of the second quench water inlets (31) is distributed along the circumference of the shell (1).

9. Supercritical water oxidation reactor according to claim 8, characterized in that the secondary quench water inlets (31) are evenly distributed along the circumference of the shell (1), the secondary quench water inlets (31) being arranged such that the direction of incidence of the quench water is tangential to the circumference of the shell (1) side wall.

10. The supercritical water oxidation reactor of claim 1 further comprising: locking the bucket; wherein the lock hopper is connected to a product outlet (14) of the housing (1).