CN118751175A - A shell and tube reactor with multi-layer insert microchannels - Google Patents

Abstract

The invention discloses a shell-and-tube reactor with multilayer inserted micro-channels, which comprises a cylinder body, an inlet end socket, an outlet end socket, a cooling water inlet, a cooling water outlet, a micro-reaction channel array and a baffle plate. The cylinder body is a cylindrical shell, and the inlet end socket and the outlet end socket are identical in structure and are both composed of flange plates. The shell-and-tube reactor with the multilayer inserted sheet micro-channels provided by the invention has the advantages that the micro-reaction channel unit for circulating reaction substances adopts the micro-channel design of the multilayer inserted sheet, the inserted sheet consists of S-shaped fins with the trunk and the two ends symmetrically and equidistantly distributed, the inserted sheets are stacked in a staggered way, the mixing degree of the reaction substances can be effectively improved, and meanwhile, the reactor has the advantages of small pressure drop and good heat exchange effect, and can be applied to a gas-liquid-solid heterogeneous catalytic cracking reactor.

Description

A shell and tube reactor with multi-layer insert microchannels

Technical Field

The invention relates to the field of chemical equipment design, in particular to a shell-and-tube reactor with multi-layer insert microchannels.

Background Art

Shell and tube reactor is a commonly used chemical equipment, widely used in various chemical reactions and heat exchange processes, especially in the fields of petrochemical, biopharmaceuticals, food processing, etc. Shell and tube reactor has the advantages of excellent thermal management ability, strong adaptability, and high processing capacity. Its main feature is that under the action of the heat exchange fluid in the shell side, the reaction fluid flows continuously through a certain shape of the tube side in the reactor. Since the size of the contact surface of the reaction substances in the reactor affects the efficiency of the reaction, the mixing degree of the reaction substances has a decisive influence on the reaction performance of the shell and tube reactor.

However, the tubes of traditional shell and tube reactors are mostly straight tubes, U-shaped tubes or threaded tubes, which cannot effectively achieve the mixing of reactants. This may cause the reactants to flow through the reaction area faster, thereby reducing the reaction efficiency. If the contact time of the reactants is increased by increasing the tube length of the traditional shell and tube reactor to improve the mixing degree, a large pressure drop will often occur. In addition, the momentum change stress generated by the significant change in the direction of the fluid will also cause premature aging or damage to the reactor.

Therefore, in order to improve the reaction efficiency and extend the service life of the shell and tube reactor, there must be a method or device that can make the reaction materials more mixed in the reactor, that is, a new shell and tube reactor design is needed, which can effectively achieve the mixing of reaction materials, improve reaction efficiency, and extend the service life of the equipment. The shell and tube reactor with multi-layer insert microchannels will be an ideal device to solve this problem.

Summary of the invention

Aiming at the shortcomings of the existing traditional shell and tube reactor, the present invention provides a shell and tube reactor with multi-layer insert microchannels, comprising a cylinder and a head; the head comprises an inlet head and an outlet head, and the inlet head and the outlet head are respectively arranged at the two ends of the cylinder; the cylinder is provided with a cooling water inlet and a cooling water outlet, and a micro-reaction channel array and a baffle are arranged inside the cylinder;

The micro-reaction channel array comprises a plurality of micro-reaction channel units; one end of the micro-reaction channel unit is connected to the inlet head, and the other end is connected to the outlet head; the micro-reaction channel unit comprises a square steel shell and a multi-layer insert arranged inside the square steel shell; the cross-section of the square steel shell is rectangular, and the insert comprises a trunk and a plurality of S-shaped fins arranged on both sides of the trunk, and the axial direction of the trunk is consistent with the extension direction of the square steel shell; the S-shaped fins on the same side of the trunk are arranged at equal intervals, and the S-shaped fins on both sides of the trunk are symmetrical about the trunk; the inserts arranged in the square steel shell are stacked, and the heads and tails of the adjacent two layers of inserts are opposite and 180 degrees symmetrical; the roots of the S-shaped fins are fixed on the trunk, and the middle parts and heads of the upper and lower fins closest to each other on the adjacent two layers of inserts fit each other; a plurality of the baffles are arranged inside the cylinder to support the tube bundle and change the flow direction of cooling water.

As a preferred embodiment of the present invention, the baffle is semicircular as a whole, with rectangular holes opened at corresponding positions where the micro-reaction channel units pass through, the baffles are arranged at equal intervals, and the arc edges of two adjacent baffles are staggered.

The present invention also provides a reaction method using the shell and tube reactor, comprising the following steps:

1) The cooling water is passed into the cooling water inlet, and the flow direction is continuously changed under the action of the baffle;

2) After the cooling water fills the cylinder and flows out from the cooling water outlet, the reaction fluid is introduced from the inlet head;

3) After the reaction fluid fills the cavity of the head, it enters the micro-reaction channel unit. The reaction fluid flows through each layer of inserts, and the S-shaped fins of each layer of inserts continuously change the direction of the reaction fluid, further enhancing the mixing and heat transfer effects;

4) The reaction fluid after passing through the micro-reaction channel unit converges into one stream at the outlet head and leaves from the outlet head.

As a preferred embodiment of the present invention, the arc opening in the S-shaped fin facing the direction of reaction fluid inflow is set as a concave part, and the arc opening in the S-shaped fin facing the direction of reaction fluid outflow is set as a convex part; during the flow of the reaction fluid in the micro-reaction channel unit, the reaction fluid is blocked by the convex part of the S-shaped fin, and a part of it converges to the concave part of this layer of S-shaped fin, and a part of it flows to the insert of the adjacent layer; after the reaction fluid flows to the concave part of the S-shaped fin, it is blocked again, and the reaction fluid flows to the insert of the adjacent layer; in the micro-reaction channel unit, the reaction fluid continuously flows in each layer of the insert, thereby improving the mixing and heat transfer effects.

Compared with the prior art, the present invention has the following beneficial effects:

1) Good mixing effect: by setting a multi-layer S-shaped insert microreactor on the reaction channel, the reaction fluid can be fully contacted in the microreaction channel, and has a good mixing effect.

2) High heat exchange efficiency. By setting baffles, the flow direction of cooling water is constantly changed, which shows countercurrent overall and cross-current locally, and can efficiently take away the heat generated by the reaction.

3) Simple processing and low cost. The micro-reaction channel is composed of an external square steel shell and multiple layers of identical S-shaped inserts stacked inside. The design is relatively simple, and the square steel shell and the S-shaped inserts can be machined.

4) Large flux and small pressure drop. By setting up multiple micro-reaction channels and realizing parallel amplification, the flow capacity of the reaction substances can be effectively improved, thereby realizing large-flux material transportation. In the interior of the traditional shell-and-tube reactor, due to the limitation of the tube bundle, while ensuring a good heat exchange effect, the pressure drop generated is often large. The shell-and-tube reactor with multi-layer insert microchannels of the present invention achieves a good mixing effect while not generating a large pressure drop, thereby reducing losses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural diagram of a shell-and-tube reactor having multi-layer insert microchannels.

FIG. 2 is a schematic diagram of an axial cross-section of a shell-and-tube reactor having multi-layer insert microchannels.

FIG. 3 is a schematic cross-sectional view of a shell-and-tube reactor having multi-layer insert microchannels.

FIG. 4 is a schematic diagram of a microchannel with multi-layer inserts.

FIG. 5 is a schematic diagram of an S-shaped insert.

FIG6 is a velocity vector diagram of a microchannel cross section.

In the figure: 1. inlet head; 2. cooling water outlet; 3. cylinder; 4. cooling water inlet; 5. outlet head; 6. inlet flange plate; 7. outlet flange plate; 8. micro-reaction channel array; 9. baffle; 10. micro-reaction channel unit; 11. square steel shell; 12. S-shaped fin; 13. insert.

DETAILED DESCRIPTION

The present invention is further described and illustrated below in conjunction with specific embodiments. The embodiments are merely exemplary of the present disclosure and do not define the scope of limitation. The technical features of each embodiment of the present invention may be combined accordingly without conflicting with each other.

As shown in Figures 1 and 2, the present invention provides a shell and tube reactor with multi-layer insert microchannels, including an inlet head 1, a cooling water outlet 2, a cylinder 3, a cooling water inlet 4, an outlet head 5, an inlet flange plate 6, and an outlet flange plate 7. In one embodiment of the present invention, the inlet head 1 and the outlet head 5 are connected to the cylinder 3 through flanges, the cooling water outlet 2 and the cooling water inlet 4 are connected to the inlet flange plate 6 and the outlet flange plate 7 by welding, respectively, and the inlet flange plate 6 and the outlet flange plate 7 are connected to the flanges welded to the cylinder by bolts.

The inlet end cap 1 and the outlet end cap 5 have the same structure and are respectively arranged at the two ends of the reactor cylinder. The end caps include a flange plate and a end cap flange. One end of the flange plate is connected to the cylinder by bolts, and the other end is welded to the inlet flange or the outlet flange. In a specific embodiment of the present invention, the end cap flange is a DN60 flat welding flange.

The cooling water inlet 4 and the cooling water outlet 2 have the same structure, both consisting of a circular steel pipe and a cooling water flange, and the circular steel pipe is connected to the cooling water flange by welding; the cooling water flange is a DN60 flat welding flange;

As shown in Figure 3, the baffle 9 is semicircular as a whole, with rectangular holes opened on it at the corresponding positions where the microchannels pass through. They are arranged at equal intervals from each other, and the arc edges of two adjacent baffles are staggered. When the cooling water flows in the cylinder, the flow direction will be changed by the baffle, forming a flow state that changes direction upward or downward, radially flushing the tube bundle to enhance convective heat exchange; in a specific embodiment of the present invention, there are 4 baffles in total, and the spacing between the baffles is 80mm.

As shown in Figures 2 and 4, the micro-reaction channel array 8 is composed of a plurality of micro-reaction channel units 10, both ends of which are welded to the cylinder; the micro-reaction channel unit 10 is composed of a square steel shell 11 and an internal multi-layer insert 13, which are staggered and mixed, and are regularly and symmetrically distributed in the cylinder, and the arrangement mode is that the narrow side is parallel to the cooling water inlet and outlet; the mixed insert is composed of a trunk and S-shaped fins 12, and the S-shaped fins are arranged at equal intervals and symmetrical about the trunk axis; the adjacent mixed inserts have opposite heads and tails; the root of the S-shaped fin is fixed on the trunk, and the middle part and the head of the two fins closest to the upper and lower fins fit each other, and the s-shaped projections of each layer of fins are arranged alternately, and the projections on the same plane overlap to form an "8" shape. The trunk axis is consistent with the extension direction of the square steel shell; in a specific embodiment of the present invention, the thickness of the insert is 0.5-5mm. The square steel shell is made of a steel plate with a thickness of 0.5-2mm, and the rectangular cross-section of the square steel shell is 15-24mm long and 5-8mm wide.

In order to further illustrate the effect of the shell and tube reactor of the present invention, a reaction method using the shell and tube reactor is also disclosed, comprising the following steps:

1) The cooling water is passed into the cooling water inlet, and the flow direction is continuously changed under the action of the baffle;

2) After the cooling water fills the cylinder and flows out from the cooling water outlet, the reaction fluid is introduced from the inlet head;

3) After the reaction fluid fills the cavity of the head, it enters the micro-reaction channel unit. The reaction fluid flows through each layer of inserts, and the S-shaped fins of each layer of inserts continuously change the direction of the reaction fluid, further enhancing the mixing and heat transfer effects. The arc openings in the S-shaped fins facing the inflow direction of the reaction fluid are set as concave parts, and the arc openings in the S-shaped fins facing the outflow direction of the reaction fluid are set as convex parts. During the flow of the reaction fluid in the micro-reaction channel unit, after the reaction fluid is blocked by the convex parts of the S-shaped fins, a part of it converges to the concave parts of this layer of S-shaped fins and generates vortices with the reaction fluid that originally flows to the concave parts of this layer of S-shaped fins, and a part of it flows to the inserts of the adjacent layer and generates vortices with the reaction fluid that originally flows to this layer. After the reaction fluid flows to the concave parts of the S-shaped fins, it is blocked again and flows to the inserts of the adjacent layer. In the micro-reaction channel unit, the reaction fluid continuously flows in the inserts of each layer, thereby improving the mixing and heat transfer effects.

4) The reaction fluid after passing through the micro-reaction channel unit converges into one stream at the outlet head and leaves from the outlet head.

As shown in Figure 6, the mixing performance of the micro-reaction channel was numerically simulated using Fluent software, and the motion trajectory of the fluid was analyzed by the velocity vector of the reaction substance, so as to obtain the motion characteristics and vortex structure inside the fluid to evaluate the mixing performance of the microchannel and the mixing degree of the reaction substance.

As shown in FIG5 , compared with the traditional shell and tube reactor in which the reaction fluid mainly flows along the extension direction of the pipeline, the reaction fluid of the reactor with multi-layer insert microchannels of the present invention also flows perpendicular to the extension direction of the pipeline and at a certain angle to each other, with excellent mixing effect, and the reaction channel can achieve high-throughput fluid transportation by parallel amplification.

The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims (8)

1. A shell-and-tube reactor with multilayer inserted micro-channels, which is characterized by comprising a cylinder (3) and a sealing head; the seal head comprises an inlet seal head (1) and an outlet seal head (5), and the inlet seal head (1) and the outlet seal head (5) are respectively arranged at two ends of the cylinder body (3); the cooling water inlet (4) and the cooling water outlet (2) are arranged on the cylinder body, and a micro-reaction channel array and a baffle plate (9) are arranged inside the cylinder body (3);

The micro-reaction channel array comprises a plurality of micro-reaction channel units; one end of the micro-reaction channel unit is communicated with the inlet end socket (1), and the other end of the micro-reaction channel unit is communicated with the outlet end socket (5); the micro-reaction channel unit comprises a square steel shell (11) and a plurality of layers of inserting sheets (13) arranged inside the square steel shell (11); the cross section of the square steel shell (11) is rectangular, the inserting piece (13) comprises a trunk and a plurality of S-shaped fins (12) arranged on two sides of the trunk, and the axial direction of the trunk is consistent with the extending direction of the square steel shell; s-shaped fins (12) on the same side of the trunk are arranged at equal intervals, and the S-shaped fins (12) on two sides of the trunk are symmetrical with respect to the trunk; the inserting sheets (13) arranged in the square rigid shell are stacked and arranged, and the heads and the tails of two adjacent layers of inserting sheets (13) are opposite and are symmetrical at 180 degrees; the root parts of the S-shaped fins are fixed on the trunk, and the middle parts and the head parts of the upper fins and the lower fins which are closest to each other on the adjacent two layers of inserting sheets are mutually attached; a plurality of baffles (9) are arranged inside the cylinder (3) for supporting the tube bundle and changing the flow direction of the cooling water.

2. The shell-and-tube reactor according to claim 1, wherein the baffle plates (9) are semicircular in shape as a whole, rectangular holes are formed in corresponding positions where the micro-reaction channel units pass through, the baffle plates (9) are arranged at equal intervals, and the circular arc sides of two adjacent baffle plates are staggered.

3. The shell-and-tube reactor according to claim 1, wherein the insert sheet has a thickness of 0.5-5mm.

4. Shell-and-tube reactor according to claim 1, characterized in that the square steel shell (11) is made of steel sheet with a thickness of 0.5-2mm, the rectangular cross-section of the square steel shell (11) being 15-24mm long and 5-8mm wide.

5. The shell-and-tube reactor according to claim 1, wherein the inlet end socket (1) and the outlet end socket (5) are respectively connected with an inlet flange plate (6) and an outlet flange plate (7) in a welding mode, and the inlet flange plate (6) and the outlet flange plate (7) are connected with flanges welded on the cylinder body through bolts.

6. Shell-and-tube reactor according to claim 1, characterized in that the cooling water inlet (4) and the cooling water outlet (2) have the same structure, each consisting of a circular steel tube and a flange, which circular steel tube is connected to the flange by means of welding.

7. A reaction process employing the shell-and-tube reactor of claim 1, comprising the steps of:

1) Cooling water is introduced into the cooling water inlet, and the flowing direction is continuously changed under the action of the baffle plate;

2) After the cooling water fills the cylinder and flows out from the cooling water outlet, introducing the reaction fluid from the inlet seal head;

3) The reaction fluid fills the cavity of the seal head and then enters the micro-reaction channel unit, the reaction fluid flows through each layer of inserting sheets, and the S-shaped fins of each layer of inserting sheets continuously change the direction of the reaction fluid; further enhancing the mixing and heat transfer effects;

4) The reaction fluid passing through the micro-reaction channel unit is converged into one strand at the outlet end socket and leaves from the outlet end socket.

8. The reaction method according to claim 7, wherein the arc opening in the S-shaped fin is set to be concave in the direction of inflow of the reaction fluid, and the arc opening in the S-shaped fin is set to be convex in the direction of outflow of the reaction fluid; in the process of flowing the reaction fluid in the micro-reaction channel unit, part of the reaction fluid is blocked by the S-shaped fin convex parts and then is converged to the S-shaped fin concave part of the layer, and the other part of the reaction fluid flows to the inserting sheet of the adjacent layer; the reaction fluid is blocked again after flowing to the S-shaped fin concave parts, and flows to the inserting sheets of the adjacent layers; the reaction fluid continuously flows in each layer of the inserting sheets in the micro-reaction channel unit, so that the mixing and heat transfer effects are improved.