Feed distributor for small tubular reactor

Abstract

A feed distributor for a small tubular reactor, comprising sintered metal microporous tubes (1) arranged in reactor tubes (3), wherein the tube opening of each sintered metal microporous tube (1) is higher than the tube opening of the corresponding reactor tube (3), and a sealing packing (2) is arranged between the tube openings of the sintered metal microporous tube (1) and the reactor tube (3).

Description

Small tubular reactor feed distributor Technical Field

[0001] This utility model relates to a small tubular reactor feed distributor, belonging to the field of tubular reactor technology. Background Technology

[0002] In the design of small fixed-bed tubular reactors, the uniform distribution of feed in each channel is crucial to the accuracy of the reaction results. Because the catalyst loading in each reaction tube is the same, uneven flow rates of reactants entering each reactor tube will cause inconsistent reaction processes on the catalyst bed, resulting in different final products. Under low flow rate conditions, such distribution errors have a significant impact on the experimental results.

[0003] Currently, the feed distribution in small fixed-bed tubular reactors typically employs a method where the number of flow controllers corresponds to the number of tubes. While this ensures uniform feed in each channel, the flow controllers are expensive. To save costs, most small tubular reactors do not use flow controllers to control the feed. Instead, they rely on ensuring consistent catalyst particle size and packing density to achieve similar resistance in each channel, thus ensuring a uniform distribution of material flowing through each channel.

[0004] However, the uniformity of catalyst particle size and the compaction during loading are both manually controlled, which is much less accurate than the flow controller. Moreover, the loading personnel are different each time, and the cumulative operational errors make it difficult to achieve uniformity of feed in each small channel.

[0005] In industrial plants, the catalysts used in tubular reactors are mostly large-particle, and each reactor consists of hundreds to thousands of tube bundles. With long tube bundles (6 meters), catalyst resistance can effectively regulate the uniform distribution of the feed. Furthermore, due to the large feed volume, the percentage of feed passing through each channel is extremely small. Therefore, slight distribution errors have a relatively limited impact on the quality of the resulting product. Also, in industrial plants, because the production capacity is fixed, the feed volume for the tubular reactor is essentially constant, unlike experimental setups which require a wider range of feed volume adjustments.

[0006] Because small-scale tubular reactors have a relatively small feed volume (100-200 mL), the number of tubes is limited. Furthermore, the catalyst particles used are essentially the same as those used in industrial plants. Therefore, the diameter of each channel cannot be made too small. Consequently, fewer channels and shorter lengths are characteristic of small-scale tubular reactors. Fewer channels mean that the proportion of material flowing through each channel is relatively high, making the uniformity of material flow in each channel crucial and significantly impacting the reaction results. Short lengths mean minimal resistance from the tubes. Therefore, small-scale tubular reactors cannot rely solely on the resistance of the catalyst bed itself to achieve uniform feed distribution, as is the case in industrial plants (Note: Industrial tubular reactors can have a height-to-diameter ratio of around 200 or greater, while the experimental setup is only around 50). Furthermore, since small tubular reactors are used in laboratory settings, various conditions (such as reaction pressure and flow range) need to be explored and adjusted during the experiment. If a flow controller is used, the flexibility during the experiment will be constrained (because the flow range of the flow controller is related to the reaction system pressure, the type of metering medium, etc.). When the test conditions exceed the range of the flow controller, or cannot meet the requirements, or when a new specification flow controller needs to be replaced according to the test conditions, the increased cost and the constraint on flexibility will become more apparent.

[0007] Therefore, in order to meet the requirements of uniform feeding in each channel while maintaining flexibility, and to achieve uniform feeding distribution without relying on a mass flow controller, a different approach is needed. Summary of the Invention

[0008] The technical problem to be solved by this invention is the uneven distribution of catalyst bed resistance to feed in each channel of a small tubular reactor.

[0009] To address the aforementioned problems, this utility model provides a small-scale tubular reactor feed distributor, which includes a sintered metal microporous tube disposed within the reactor tubes. The opening of the sintered metal microporous tube is higher than the opening of the reactor tubes, and a sealing packing is provided between the sintered metal microporous tube and the opening of the reactor tubes.

[0010] Preferably, the sintered metal microporous tube has a microporous structure with micropores of 0.5 to 140 micrometers.

[0011] Preferably, the sintered metal microporous tube is fixed by a microporous tube mounting plate.

[0012] This invention artificially creates a resistance in each channel by installing sintered metal microporous tubes. This resistance negligibles the inherent resistance of the catalyst bed, ensuring uniform distribution of the small-flow feed from the main inlet of the tubular reactor across each channel. Compared to existing technologies, this invention offers the following advantages:

[0013] 1. Suitable for uniform distribution of small-flow feed in each channel of a small tubular reactor;

[0014] 2. Depending on the flow rate and medium properties, sintered metal microporous tubes with different micropore sizes can be flexibly selected;

[0015] 3. The distributor is threaded to the mounting plate, which facilitates the replacement of sintered metal microporous tubes of different specifications;

[0016] 4. It can replace the feed flow controller, expand the range of experimental feed flow rates, and greatly save costs. Attached Figure Description

[0017] Figure 1 is a structural schematic diagram of the small tubular reactor feed distributor provided by this utility model;

[0018] Figure 2 is a schematic diagram of sintered metal microporous tubes;

[0019] Figure 3 is a schematic diagram of the installation position of this utility model. Detailed Implementation

[0020] To make this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0021] Example

[0022] As shown in Figures 1-3, this utility model provides a small-scale tubular reactor feed distributor, which includes a sintered metal microporous tube 1 disposed within the reactor tube 3. The opening of the sintered metal microporous tube 1 is higher than the opening of the reactor tube 3, and a sealing packing 2 is provided between the sintered metal microporous tube 1 and the opening of the reactor tube 3. The sintered metal microporous tube 1 is fixed by a microporous tube mounting plate 5. The sintered metal microporous tube 1 has a microporous structure with micropores of 0.5 to 140 micrometers.

[0023] Sintered metal microporous tubes are commonly used as filter elements or gas distributors. They are made from fine metal powder, and under specific process conditions, microporous devices with different specifications can be sintered. The micropore size can be selected from 0.5 to 140 micrometers, making them very suitable for low-flow dampers. Through calculations matching the feed rate, they can be used as low-flow feed distributors under specific conditions, and can be replaced according to different operating conditions, without being limited by pressure or temperature.

[0024] After the feed flow rate enters the reactor through the feed inlet 4, a constant resistance is formed between the reactor head and the sintered metal microporous tube 1. Under the flow restriction of the sintered metal microporous tube 1, the feed is evenly distributed. That is, the sum of the total feed flow rate of all the arranged metal sintered microporous tubes 1 is slightly less than the total feed rate. Therefore, there is a corresponding constant pressure difference between the microchannel inlet and the outlet after passing through the sintered metal microporous tube. The existence of the pressure difference is a prerequisite for ensuring uniform feed distribution.

Claims

1. A feed distributor for a small tubular reactor, characterized in that, It includes a sintered metal microporous tube (1) installed in the reactor tube (3), the opening of the sintered metal microporous tube (1) is higher than the opening of the reactor tube (3), and a sealing packing (2) is provided between the sintered metal microporous tube (1) and the opening of the reactor tube (3).

2. The feed distributor for a small tubular reactor as described in claim 1, characterized in that, The sintered metal microporous tube (1) has a microporous structure with micropores of 0.5 to 140 micrometers.

3. The small-scale tubular reactor feed distributor as described in claim 1, characterized in that, The sintered metal microporous tube (1) is fixed by the microporous tube mounting plate (5).

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