Fixed bed reactor for negative pressure pyrolytic reaction
By using a horizontally positioned tank and a medium heat exchange heating device, combined with a negative pressure conveying system, the problems of uneven heating of raw materials and unsuitability for continuous production in existing fixed-bed reactors have been solved, achieving efficient and environmentally friendly continuous production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HARBIN INST OF TECH ZHENGZHOU RES INST
- Filing Date
- 2025-06-03
- Publication Date
- 2026-05-12
AI Technical Summary
Existing fixed-bed reactors suffer from problems such as uneven heating of raw materials, unsuitability for introducing carrier gas, and inability to produce continuously.
The system employs a horizontally arranged tank, a medium heat exchange heating device, and a negative pressure conveying system. The tank contains a catalyst and a porous block carrier material. The medium heat exchange tube is heated by a high-temperature medium, and the outlet pipe is connected to the negative pressure conveying system to achieve continuous production.
It achieves uniform heating of raw materials, high pyrolysis rate, no need for carrier gas, reversible reaction to reduce temperature, and suitability for continuous production, thereby improving production efficiency and environmental friendliness.
Smart Images
Figure CN224221303U_ABST
Abstract
Description
Technical Field
[0001] This utility model is specifically a fixed-bed reactor for negative pressure pyrolysis reaction, and relates to the field of chemical equipment technology. Background Technology
[0002] A fixed-bed pyrolysis reactor is a device that decomposes organic matter through heating. Its working principle involves a catalyst piled inside the reactor. After the raw material enters the reactor, catalytic pyrolysis occurs, and the pyrolysis gas is carried out of the reactor by a carrier gas (usually nitrogen). For the production of certain chemical products, existing fixed-bed reactors have the following problems:
[0003] 1. Existing fixed-bed reactors typically use electric heating, gas heating, or furnace heating, which can easily cause uneven heating of the raw materials and affect the pyrolysis reaction;
[0004] 2. Existing fixed-bed reactors are usually set vertically, which results in insufficient contact between the raw materials and the catalyst, and also limits the space for the release of pyrolysis gases, which is not conducive to the pyrolysis reaction.
[0005] 3. Existing fixed-bed reactors are suitable for batch production, but not for continuous production;
[0006] 4. The production process is not suitable for introducing carrier gas. Utility Model Content
[0007] To overcome the shortcomings of the prior art, this utility model discloses a fixed-bed reactor for negative pressure pyrolysis reaction, adopting the following technical solution:
[0008] A fixed-bed reactor for negative pressure pyrolysis reaction includes a horizontally arranged tank, a catalyst and a medium heat exchange heating device are arranged inside the tank, and a feed pipe and a gas outlet pipe are arranged at the upper part of the tank; wherein, the gas outlet pipe is connected to a negative pressure conveying system for pumping the decomposition gas to downstream equipment.
[0009] Further improvements to the technical solution: The tank is elongated, with a circular or rectangular cross-section, a viewing window on the tank, and an insulation layer on the outside of the tank.
[0010] Further improved technical solution: The catalyst is attached to the surface of a porous blocky carrier material, and the blocky carrier material is filled into the tank.
[0011] Further improvements to the technical solution: The medium heat exchange heating device mainly consists of heat exchange tubes, end tube sheets and support tube sheets. The end tube sheets are set at both ends of the tank, and the support tube sheets are set in the middle of the tank. High-temperature medium is introduced into the heat exchange tubes.
[0012] Further improve the technical solution: multiple heat exchange tubes are connected between a pair of end tube sheets, with a medium inlet chamber and a medium outlet chamber provided on one end tube sheet, and a medium return chamber provided on the other end tube sheet.
[0013] Further improve the technical solution: The support tube sheet divides the tank into multiple interconnected compartments. Each compartment has an inspection chamber and an exhaust manifold at the top, and each exhaust manifold is connected to an exhaust pipe.
[0014] Further improve the technical solution: provide flow gaps on the support tube sheet, and arrange the flow gaps on each support tube sheet in an alternating manner.
[0015] Further improvements to the technical solution: The negative pressure delivery system consists of a vacuum pump, a negative pressure tank, and connecting pipes.
[0016] Further improve the technical solution: install a residue discharge pipe at the bottom of the tank.
[0017] Further improve the technical solution: The feed pipe is partially horizontally located inside the tank and has multiple drip holes; the feed pipe is connected to the negative pressure conveying system through the vent pipe to draw raw materials from upstream equipment into the tank.
[0018] After implementing the above technical solution, the beneficial effects of this utility model compared to the prior art are:
[0019] 1. This fixed-bed reactor adopts a medium heat exchange heating method, which has the advantages of constant heating temperature, large heat exchange area, and uniform heating of raw materials;
[0020] 2. The fixed-bed reactor is horizontally designed, which allows the liquid feedstock to fully contact the heat exchange tubes and catalyst, thereby improving the pyrolysis rate; and it also provides a sufficiently large space to facilitate the reaction in the direction of pyrolysis.
[0021] 3. This fixed-bed reactor adopts a negative pressure delivery method. First, it eliminates the need for carrier gas, which meets the requirements of the production process. Second, it eliminates the crystallization and blockage problems caused by using pumps to transport liquid raw materials. Third, the negative pressure environment can reduce the pyrolysis temperature of the liquid raw materials and is conducive to the reaction proceeding in the direction of pyrolysis.
[0022] 4. This fixed-bed reactor can achieve continuous production, is energy-saving and environmentally friendly, and has high efficiency. Attached Figure Description
[0023] Appendix Figure 1 The diagram shown is a schematic representation of the overall structure of this fixed-bed reactor.
[0024] Appendix Figure 2 The diagram shown is a structural schematic of the tank.
[0025] Appendix Figure 3The diagram shown is a schematic of a medium-heat exchange heating device.
[0026] Appendix Figure 4 The attached image shows the attached image. Figure 3 Cross-sectional view of AA.
[0027] Appendix Figure 5 The attached image shows the attached image. Figure 3 Cross-sectional view of BB in the middle.
[0028] Appendix Figure 6 The attached image shows the attached image. Figure 3 Cross-sectional view of CC.
[0029] Appendix Figure 7 The diagram shown illustrates the working principle of this fixed-bed reactor.
[0030] In the attached image:
[0031] 1. Tank body; 1.1 Feed pipe; 1.2 Vent manifold; 1.3 Vent pipe; 1.4 Residue discharge pipe; 1.5 Inspection compartment; 1.6 Insulation layer; 1.7 Support legs;
[0032] 2. Medium heat exchange heating device; 2.1 Heat exchange tubes; 2.2 End tube sheet; 2.3 Support tube sheet; 2.4 Medium inlet chamber; 2.5 Medium reflux chamber; 2.6 Medium outlet chamber;
[0033] 3. Block carrier material;
[0034] 4. Raw materials. Detailed Implementation
[0035] The preferred embodiments of this utility model are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of this utility model and are not intended to limit the scope of protection of this utility model. It should be noted that in the description of this utility model, terms such as "front," "rear," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation and positional relationship, and therefore should not be construed as a limitation of this utility model. It should also be noted that in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0036] A fixed-bed reactor for negative pressure pyrolysis reactions, relating to the field of chemical equipment technology, is mainly used to solve problems in existing technologies such as uneven heating of raw materials, unsuitability for introducing carrier gas, and inability to produce continuously. The composition, structure, and working principle of this fixed-bed reactor are described in detail below.
[0037] See attached document Figure 1 This fixed-bed reactor includes a horizontally positioned tank 1, within which a catalyst and a medium heat exchange heating device 2 are installed. The catalyst is attached to the surface of a porous, blocky support material 3, which fills the tank 1.
[0038] See attached document Figure 2 , attached Figure 2 The diagram shown is a structural schematic of tank 1. (See attached diagram.) Figure 2 As can be seen, the tank 1 is elongated and has a viewing window (not shown in the figure) on it. An insulation layer 1.6 is provided on the outside of the tank 1. The cross-sectional shape of the tank 1 can be circular or rectangular. In this embodiment, the tank 1 is circular.
[0039] Support legs 1.7 are installed at the lower part of tank body 1, and a residue discharge pipe 1.4 is installed at the lower right part of tank body 1. A feed pipe 1.1 is installed at the upper left part of tank body 1, and the portion of feed pipe 1.1 inside tank body 1 is horizontally positioned with multiple drip holes. Three maintenance chambers 1.5, three exhaust manifolds 1.2, and one exhaust pipe 1.3 are located in the upper middle part of tank body 1. Pyrolysis gases inside the tank can flow into the exhaust pipe 1.3 through the maintenance chambers 1.5 and exhaust manifolds 1.2. For ease of inspection and maintenance, the maintenance chambers 1.5 are detachably connected to tank body 1 by bolts. The exhaust pipe 1.3 is connected to a negative pressure conveying system, which consists of a vacuum pump, a negative pressure tank, and connecting pipes, used to pump pyrolysis gases to downstream equipment.
[0040] See attached document Figure 3 , attached Figure 3 The diagram shows the structure of the medium heat exchange heating device 2. The medium heat exchange heating device 2 mainly consists of heat exchange tubes 2.1, end tube sheets 2.2, and support tube sheets 2.3. A pair of end tube sheets 2.2 are set at both ends of the tank body 1, and two support tube sheets 2.3 are set in the middle of the tank body 1. A high-temperature medium is introduced into the heat exchange tubes 2.1. The high-temperature medium can be heat transfer oil or other heat transfer media.
[0041] Twenty-six heat exchange tubes 2.1 are connected between a pair of end tube sheets 2.2. A medium inlet chamber 2.4 and a medium outlet chamber 2.6 are provided on the left end tube sheet 2.2, and a medium reflux chamber 2.5 is provided on the right end tube sheet 2.2. The high-temperature medium enters the upper 11 heat exchange tubes 2.1 through the medium inlet chamber 2.4, then enters the lower 15 heat exchange tubes 2.1 through the medium reflux chamber 2.5, and finally flows out from the medium outlet chamber 2.6.
[0042] See attached document Figure 4-6 The end tube sheet 2.2 is a complete circular tube sheet, while the support tube sheet 2.3 has a flow gap, and the flow gaps on the two support tube sheets 2.3 are staggered.
[0043] Please refer to the appendix again. Figure 1 Two support tube plates 2.3 divide the tank body 1 into three compartments, which are connected in an S-shape by staggered flow gaps. Each compartment corresponds to a maintenance chamber 1.5 and an exhaust manifold 1.2, facilitating the entry of pyrolysis gas from the compartment into the exhaust manifold 1.3.
[0044] Working principle:
[0045] See attached document Figure 7 During operation, raw material 4 enters tank 1 from upstream equipment through feed pipe 1.1. After being heated by the medium heat exchange heating device 2 and catalytically pyrolyzed by the catalyst, it is converted into gas. The pyrolysis gas flows through maintenance chamber 1.5 and outlet manifold 1.2 into outlet pipe 1.3, and is then pumped to downstream equipment under negative pressure. Unpyrolyzed residues are deposited at the bottom of tank 1 and periodically discharged from residue outlet pipe 1.4.
[0046] Similarly, liquid raw material 4 can also be pumped from upstream equipment into tank 1 using a negative pressure conveying method. This negative pressure conveying method can solve at least three problems: first, it eliminates the need for carrier gas, which meets the requirements of the production process; second, it eliminates the crystallization and blockage problems caused by using pumps to transport liquid raw materials; and third, since the pyrolysis reaction is a reversible reaction, the negative pressure environment can lower the pyrolysis temperature of the liquid raw material and promote the reaction to proceed in the direction of pyrolysis.
[0047] Compared to electric heating, gas heating, or furnace heating, the medium heat exchange heating device 2 has the advantages of constant temperature, large heat exchange area, and uniform heating of raw materials.
[0048] Compared to a vertically arranged fixed-bed reactor, firstly, the horizontally arranged tank 1 allows the liquid raw material 4 to fully contact the heat exchange tube 2.1 and the catalyst, thereby improving the pyrolysis rate; secondly, the maintenance chamber 1.5 and the gas outlet manifold 1.2 have sufficiently large spaces, which is conducive to the reaction proceeding in the direction of pyrolysis.
[0049] Compared to existing fixed-bed reactors, this fixed-bed reactor can achieve continuous production, is energy-saving and environmentally friendly, and has high efficiency.
[0050] It is worth noting that the content not described in detail in the above embodiments is prior art. It is also worth noting that any additions, subtractions, substitutions, and improvements made by those skilled in the art based on the structure and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A fixed-bed reactor for negative pressure pyrolysis reaction, characterized in that: It includes a horizontally positioned tank, which contains a catalyst and a medium heat exchange heating device. The upper part of the tank has a feed pipe and an exhaust pipe. The exhaust pipe is connected to a negative pressure conveying system to pump the decomposed gas to downstream equipment.
2. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 1, characterized in that: The tank is elongated and has a circular or rectangular cross-section. It has a viewing window and an insulation layer on the outside.
3. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 1, characterized in that: The catalyst is attached to the surface of a porous blocky carrier material, which is filled into the tank.
4. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 1, characterized in that: The medium heat exchange heating device mainly consists of heat exchange tubes, end tube sheets and support tube sheets. The end tube sheets are located at both ends of the tank, and the support tube sheets are located in the middle of the tank. High-temperature medium is introduced into the heat exchange tubes.
5. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 4, characterized in that: Multiple heat exchange tubes are connected between a pair of end tube sheets. One end tube sheet is provided with a medium inlet chamber and a medium outlet chamber, and the other end tube sheet is provided with a medium return chamber.
6. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 4, characterized in that: The support tube sheet divides the tank into multiple interconnected compartments. Each compartment has an inspection chamber and an exhaust manifold at its upper part, and each exhaust manifold is connected to an exhaust pipe.
7. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 6, characterized in that: The support tube sheet has flow gaps, and the flow gaps on each support tube sheet are staggered.
8. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 1, characterized in that: The negative pressure delivery system consists of a vacuum pump, a negative pressure tank, and connecting pipes.
9. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 1, characterized in that: A residue discharge pipe is installed at the bottom of the tank.
10. A fixed-bed reactor for negative pressure pyrolysis reaction as described in claim 1, characterized in that: The feed pipe is partially horizontally positioned inside the tank and has multiple drip holes. The feed pipe is connected to the negative pressure conveying system via an outlet pipe, which is used to pump raw materials from upstream equipment into the tank.