Gas distributor and radial fixed bed reactor
By designing the gas distributor in the reactor, the static hybrid and the heat storage body are used to preheat the reactive gas, which solves the problem of low reaction gas import temperature, reduces the side reaction, and improves the chemical reaction efficiency of the reactor.
Patent Information
- Application Number
- CN202420958680.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-07
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-05-07
AI Technical Summary
In the existing radial fixed bed reactor, the inlet temperature of the reaction gas is low, resulting in an increase in the side reaction when the reaction gas is initially in contact with the catalyst, reducing the overall reaction efficiency of the reactor.
A gas distributor is designed, including external pipes, internal pipes, and branches. The static mixture and heat storage body in the branch tube are used for preheating gas to ensure that the reaction gas is fully preheated before entering the catalyst bed.
Through effective preheating, the temperature of the reaction gas enters the catalyst bed, reduce the side reaction between the reaction gas and the catalyst, and improve the chemical reaction efficiency of the reactor.
Smart Images
Figure CN222401400U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a chemical device, in particular to a distributor and a reactor used for synthesizing methanol, specifically a gas distributor and a radial fixed bed reactor. Background Art
[0002] Fixed bed chemical reactor is one of the core equipment of chemical production, widely used in chemical industry, oil refining, metallurgy and other fields. The advanced level of its technology has an important impact on chemical production, directly affecting the investment scale and production cost of the device. Fixed bed reactor refers to a reactor filled with granular solid catalyst or solid reactant to form a stacked bed layer of a certain height, so that gas or liquid materials can flow through the gap between particles through the static fixed bed layer, realizing a heterogeneous reaction process.
[0003] At present, in the field of large-scale methanol synthesis, radial fixed bed reactors are widely used in the market. The reactor is provided with a central tube, which is vertically arranged in the catalyst bed, with its upper end closed and a vent hole on its side wall. Its lower end extends downward from the cylinder body and is connected to the reaction gas, so that the reaction gas flows into the central tube, flows out from the vent hole, and flows radially through the catalyst bed to react with the catalyst.
[0004] However, this type of reactor has the following defects: the reaction gas inlet temperature is much lower than the temperature inside the reactor (the reaction gas inlet temperature is about 220°C, and the temperature inside the reactor is about 250°C), which leads to an increase in side reactions during the initial contact between the reaction gas and the catalyst, thereby reducing the overall reaction efficiency of the reactor.
[0005] Therefore, improvements are needed to increase the chemical reaction efficiency of the reactor. Utility Model Content
[0006] The utility model aims to provide a gas distributor and a radial fixed bed reactor to address the deficiencies of the prior art, which can fully utilize the waste heat in the reactor, solve the problem of low inlet temperature of the reaction gas, reduce the side reactions between the reaction gas and the catalyst, and improve the chemical reaction efficiency of the reactor.
[0007] The technical solution of the utility model is:
[0008] A gas distributor comprises an outer tube, an inner tube and a branch tube; the outer tube is cylindrical and its side wall is hollow; the diameter of the inner tube is smaller than the inner diameter of the outer tube, its length is equivalent to the length of the outer tube, its upper end is open and its lower end is closed; the inner tube is concentrically arranged in the outer tube; the branch tube is arranged between the outer tube and the inner tube, and its two ends are respectively connected to the side wall of the outer tube and the inner tube; there are multiple branch tubes, which are radially distributed with the center of the inner tube as the center; a reaction gas inlet is arranged on the side wall of the outer tube.
[0009] Furthermore, the branch pipes are evenly distributed along the axial direction of the outer pipe.
[0010] Furthermore, a static mixer is provided in the branch pipe.
[0011] Furthermore, the reaction gas inlet is located at the bottom of the side wall of the outer tube.
[0012] A radial fixed bed reactor comprises a barrel and a distributor, wherein the barrel is a vertical cylinder with open ends, and an upper head and a lower head connected thereto are respectively provided at its upper and lower ends, and a catalyst layer is provided therein; the upper head is provided with a reaction gas outlet; the lower head is provided with a discharge port, which is filled with a heat storage body; the outer tube of the distributor is arranged outside the lower head, the inner tube is arranged inside the lower head, and the branch tube is passed through the lower head; a center tube is also included; the center tube is a long straight tube, which is vertically and centrally arranged in the catalyst layer, the upper end of which is closed, and the lower end of which is communicated with the upper end of the inner tube, and the side wall of the center tube is provided with a plurality of air holes that pass through the inside and outside.
[0013] Furthermore, the upper head and the lower head have the same shape, both are hemispherical shells, and their openings face the interior of the cylinder.
[0014] Furthermore, the reaction gas outlet and the discharge port are both centrally arranged.
[0015] Beneficial effects of the utility model:
[0016] The utility model has reasonable design, simple structure and is easy to use. It can make full use of the waste heat in the reactor to effectively preheat the reaction gas before entering the catalyst bed, effectively solving the problem of low reaction gas temperature, reducing the side reactions between the reaction gas and the catalyst, and improving the chemical reaction efficiency of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a top view of the distributor of the utility model.
[0018] Figure 2 yes Figure 1 Middle AA section view.
[0019] Figure 3 It is a structural schematic diagram of the reactor of the utility model.
[0020] Among them: 1-upper head; 2-catalyst layer bed; 3-cylinder; 4-central tube; 5-distributor; 6-lower head; 7-discharging port; 8-heat storage body; 9-reaction gas outlet; 51-outer tube; 52-inner tube; 53-branch pipe; 54-static mixer; 55-reaction gas inlet. DETAILED DESCRIPTION
[0021] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0022] like Figure 1 and 2 As shown, the utility model provides a gas distributor, which includes an outer tube 51 , an inner tube 52 and a branch tube 53 .
[0023] The outer tube 51 is cylindrical, and its side wall is hollow. A reaction gas inlet 55 is provided at the bottom of the side wall of the outer tube 51. The diameter of the inner tube 52 is smaller than the inner diameter of the outer tube 51, and its length is equivalent to the length of the outer tube. Its upper end is open and its lower end is closed. The inner tube 52 is concentrically arranged inside the outer tube 51.
[0024] The branch pipe 53 is a straight pipe, disposed between the outer pipe 51 and the inner pipe 52, and its two ends are respectively connected to the side wall of the outer pipe 51 and the inner pipe 52. There are multiple branch pipes 53, which are distributed in a multi-layer structure along the axial direction of the outer pipe 51. The branch pipes in each layer are radially distributed with the center of the inner pipe as the center.
[0025] Furthermore, a static mixer 54 is provided in the branch pipe 53. The static mixer 54 is a conventionally purchased product, and is composed of a series of short sheet elements twisted 180° left and right, which can make the gas flowing through uniformly radially mixed by repeated segmentation and rotation in positive and negative directions. The outer diameter of the static mixer 54 matches the inner diameter of the branch pipe 53, which is easy to install. At the same time, the aperture of the connection between the branch pipe 53 and the inner pipe 52 is slightly smaller than the outer diameter of the static mixer 54, so as to prevent the static mixer from entering the inner pipe.
[0026] like Figure 3 As shown, the utility model is a radial fixed bed reactor, comprising a cylinder 3, a central tube 4 and the distributor 5.
[0027] The cylinder 3 is a vertical cylinder with two open ends, and an upper end cap 1 and a lower end cap 6 are respectively provided at the upper and lower ends thereof to seal the two ends. A catalyst is provided in the cylinder 3 to form a catalyst layer bed 2.
[0028] The upper end cap 1 and the lower end cap 6 have the same shape, both of which are hemispherical shells, and their openings face the interior of the cylinder 3 to facilitate fluid convergence. A reaction gas outlet 9 is provided in the center of the upper end cap 1 to facilitate the outflow of the gas after the reaction. The lower end cap 6 is filled with a heat storage body 8, which can form a support body for the upper catalyst. At the same time, a discharge port 7 is provided in the center of the lower end cap 6 to facilitate the removal of the heat storage body and the catalyst.
[0029] The outer tube of the distributor 5 is arranged outside the lower head 6, the inner tube thereof is arranged inside the lower head 6, and the branch pipes thereof are passed through the lower head 6 so that most of the branch pipes are buried in the heat storage body.
[0030] The central tube 4 is a long straight tube, and its diameter is equivalent to that of the inner tube. The central tube 4 is vertically and centrally arranged in the catalyst layer bed 2, its upper end is closed, and its lower end is connected to the upper end of the inner tube. Its side wall is provided with a plurality of pores that penetrate inside and outside, so that after the reaction gas flowing through the distributor enters the central tube, it can flow out from the pores and radially flow to the catalyst layer bed, contact with the catalyst and react.
[0031] The working process of the utility model is:
[0032] First, the central tube is connected and assembled with the distributor and then installed in the reactor so that the distributor is located in the lower head.
[0033] Then, the heat storage body is loaded into the reactor through the reaction gas outlet until the lower head is filled. The heat storage body includes but is not limited to aluminum oxide, mullite, etc., which can support the catalyst bed but will not react chemically with the reaction gas.
[0034] After the heat storage body is filled, the catalyst is loaded into the reactor through the reaction gas outlet to complete the assembly of the catalyst bed and bury the central tube completely in the catalyst.
[0035] During production, the reaction gas enters the distributor through the reaction gas inlet, passes through the outer tube, branch tube and inner tube, enters the central tube, is ejected through the air holes, flows radially toward the catalyst layer, contacts with the catalyst and reacts before being discharged from the reaction gas outlet.
[0036] Since the reaction gas releases heat when reacting with the catalyst, this part of heat will increase the temperature of the catalyst layer, and under the action of heat conduction, the heat storage body in the lower head 9 will be heated up, and finally the temperature of the heat storage body and the catalyst will tend to be consistent.
[0037] When the reaction gas flows through the branch pipe of the distributor, it can exchange heat with the heat storage body and increase its temperature, effectively increasing the temperature of the reaction gas when it enters the catalyst layer, creating favorable conditions for improving the reaction efficiency. In addition, the layered arrangement of the branch pipe allows more reaction gas to participate in the heat exchange and improve the heat exchange efficiency. At the same time, under the action of the static mixer in the branch pipe, the reaction gas flowing through can be fully radially mixed, making the gas temperature more balanced and enhancing the heat exchange effect.
[0038] The utility model can make full use of the waste heat in the reactor by adding a gas distributor in the reactor, so that the reaction gas can be effectively preheated before entering the catalyst bed, effectively solving the problem of low reaction gas temperature, reducing the side reaction between the reaction gas and the catalyst, and improving the chemical reaction efficiency of the reactor.
[0039] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.
Claims
1. A gas distributor, characterized in that: It comprises an outer tube, an inner tube and a branch tube; the outer tube is cylindrical and its side wall is hollow; the diameter of the inner tube is smaller than the inner diameter of the outer tube, its length is equivalent to the length of the outer tube, its upper end is open and its lower end is closed; the inner tube is concentrically arranged in the outer tube; the branch tube is arranged between the outer tube and the inner tube, and its two ends are respectively connected with the side wall of the outer tube and the inner tube; there are multiple branch tubes, which are radially distributed with the center of the inner tube as the center; a reaction gas inlet is arranged on the side wall of the outer tube.
2. The gas distributor according to claim 1, characterized in that: The branch pipes are evenly distributed along the axial direction of the outer pipe.
3. The gas distributor according to claim 1, characterized in that: A static mixer is arranged in the branch pipe.
4. The gas distributor according to claim 1, characterized in that: The reaction gas inlet is located at the bottom of the side wall of the outer tube.
5. A radial fixed bed reactor, comprising a barrel and a distributor according to any one of claims 1 to 4, characterized in that: The cylinder body is a vertical cylinder with open ends, and its upper and lower ends are respectively provided with an upper head and a lower head connected to it, and a catalyst layer is arranged inside it; the upper head is provided with a reaction gas outlet; the lower head is provided with a discharge port, which is filled with a heat storage body; the outer tube of the distributor is arranged outside the lower head, the inner tube is arranged inside the lower head, and the branch pipe is passed through the lower head; it also includes a center tube; the center tube is a long straight tube, which is vertically and centrally arranged in the catalyst layer, the upper end of which is closed, and the lower end is connected to the upper end of the inner tube, and the side wall is provided with a plurality of air holes that pass through the inside and outside.
6. The radial fixed bed reactor according to claim 5, characterized in that: The upper head and the lower head have the same shape, both of which are hemispherical shells, and their openings face the interior of the cylinder.
7. The radial fixed bed reactor according to claim 5, characterized in that: The reaction gas outlet and the discharge port are both centrally arranged.