Material mixing device for acrylic acid production

Abstract

The utility model provides a material mixing device for acrylic acid production, relates to the technical field of acrylic acid production equipment, and aims to solve the problem of non-uniform mixing caused by the fact that steam is directly introduced into a premixer through a pipeline in the prior art. The material mixing device for acrylic acid production comprises a premixer body, a steam main pipeline, a steam branch pipeline and a circulating tail gas conveying pipe, and the steam main pipeline and the circulating tail gas conveying pipe are connected with different parts of the premixer body respectively. One end of the steam branch pipeline is connected with the steam main pipeline, and the other end of the steam branch pipeline is connected with the circulating tail gas conveying pipe. According to the material mixing device for acrylic acid production, the flow of each strand of feed is stable, the mixing is uniform, and the operation stability of the device is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of acrylic acid production equipment, in particular to a material mixing device used in acrylic acid production. Background Art

[0002] Acrylic acid is an important organic synthetic raw material and synthetic resin monomer. It is a vinyl monomer with a very fast polymerization rate. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group and a carboxyl group. It is miscible with water, alcohol, ether and chloroform, and is prepared from propylene obtained from refineries. Most of it is used to make acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and hydroxyethyl acrylate. Acrylic acid and acrylic esters can be homopolymerized and copolymerized, and their polymers are used in synthetic resins, synthetic fibers, highly absorbent resins, building materials, coatings and other industrial sectors.

[0003] In the process of producing acrylic acid by propane one-step oxidation, propane and oxygen are mainly used as raw materials, and a gas phase oxidation reaction occurs under catalyst conditions. In the acrylic acid production device, the feeds to the propylene oxidation reactor mainly include air, steam, circulating tail gas, etc. These three materials need to be mixed in the premixer, and the feed flow of each stream needs to be controlled. The patent application document with application number 201320197589.X discloses a control system for a propane one-step acrylic acid reactor, which is equipped with a propane feed flow automatic control system, a steam flow automatic control system, a nitrogen feed flow automatic control system, an oxygen feed flow automatic control system, a circulating tail gas flow automatic control system, an oxygen content analyzer, and a C3 content analyzer. The detection signals of the above two analyzers are input into the DCS to participate in the ratio calculation, which can more accurately adjust the amount of steam, oxygen, nitrogen, and circulating tail gas entering, and the calculation results can better reflect the actual ratio relationship. Among them, the steam is directly introduced into the premixer through a pipeline. This mixing method easily leads to uneven mixing of various materials, and there are problems such as poor pressure matching and large flow fluctuations. Utility Model Content

[0004] The purpose of the utility model is to provide a material mixing device for acrylic acid production to solve the problem of uneven mixing caused by steam directly passing through a pipeline into a premixer in the prior art. The material mixing device for acrylic acid production of the utility model has stable feed flow rates of various streams and is mixed evenly, which effectively improves the stability of device operation.

[0005] The utility model provides a material mixing device for acrylic acid production, comprising a premixer body, a steam main line, a steam branch line and a circulating tail gas transmission pipe, wherein the steam main line and the circulating tail gas transmission pipe are respectively connected to different parts of the premixer body, one end of the steam branch line is connected to the steam main line and the other end is connected to the circulating tail gas transmission pipe.

[0006] As a preferred solution of the utility model, the angle α between the steam branch line and the circulating tail gas transmission pipe is 30°-60°.

[0007] As a preferred solution of the utility model, the angle α between the steam branch line and the circulating tail gas transmission pipe is 45°.

[0008] As a preferred solution of the utility model, a first control valve is arranged on the steam main line; the steam branch line is connected to the steam main line at the rear end of the first control valve, and a second control valve capable of controlling the steam flow is arranged on the steam branch line.

[0009] As a preferred solution of the present invention, the premixer body includes a first mixing body and a second mixing body, and the center line of the first mixing body is arranged perpendicular to the center line of the second mixing body.

[0010] As a preferred solution of the utility model, the circulating exhaust gas pipeline is connected to one end of the first mixing body, the steam main line is connected to the side wall of the first mixing body, and one end of the first mixing body away from the circulating exhaust gas pipeline is connected to the side wall of the second mixing body.

[0011] As a preferred solution of the utility model, it also includes an air intake pipe, which is connected to one end of the second mixing body, and the other end of the second mixing body is connected to a main line leading to the reactor.

[0012] As a preferred solution of the present invention, both the first mixing body and the second mixing body are cylindrical tubular structures.

[0013] Compared with the prior art, the utility model has the following positive effects:

[0014] The material mixing device for acrylic acid production provided by the utility model comprises a premixer body, a steam main line, a steam branch line and a circulating tail gas pipeline, wherein the steam main line and the circulating tail gas pipeline are respectively connected to different parts of the premixer body, one end of the steam branch line is connected to the steam main line and the other end is connected to the circulating tail gas pipeline. When the material mixing device for acrylic acid production of the utility model is in operation, the first part of the steam is first mixed with the circulating tail gas in the circulating tail gas pipeline through the steam branch line to form a primary mixed gas, and then introduced into the premixer body, the second part of the steam is directly transported to the premixer body through the steam main line, and then the second part of the steam is mixed with the primary mixed gas in the premixer body for a second time to form a secondary mixed gas, the steam enters the premixer body in two streams and is mixed with the circulating tail gas twice, so that the steam can be fully mixed with the circulating tail gas, compared with the existing steam mixing method, the improved feed flow rate of each stream is stable and mixed evenly, which effectively improves the stability of the device operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 The utility model is a schematic structural diagram of a material mixing device used in acrylic acid production.

[0017] In the figure: 1, premixer body; 11, first mixing body; 12, second mixing body; 2, circulating exhaust gas transmission pipe; 3, steam main line; 31, reducer; 32, first control valve; 4, steam branch line; 41, second control valve; 5, air intake pipe; 6, main line. DETAILED DESCRIPTION

[0018] In the description of the present utility model, it should be noted that, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "front end", "back end", "head", "tail" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present utility model and simplification, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0019] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0020] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings.

[0021] Embodiment 1:

[0022] This embodiment provides a material mixing device for acrylic acid production, such as Figure 1 As shown, it includes a premixer body 1, a steam main line 3, a steam branch line 4 and a circulating tail gas pipeline 2. The steam main line 3 and the circulating tail gas pipeline 2 are respectively connected to different parts of the premixer body 1, and one end of the steam branch line 4 is connected to the steam main line 3 and the other end is connected to the circulating tail gas pipeline 2. The premixer body 1 is used to premix a variety of materials before entering the reactor. The circulating tail gas pipeline 2 is used to transport circulating gas to the premixer body 1, and return the reaction tail gas containing propane to the reactor after compression to continue to participate in the oxidation reaction, thereby improving the utilization rate of propane and saving resources. The steam main line 3 and the steam branch line 4 are both used to transport steam to the premixer body 1. The steam branch line 4 can be obliquely connected to the circulating tail gas pipeline 2, that is, the steam branch line 4 and the circulating tail gas pipeline 2 are not vertically connected.

[0023] When the material mixing device for acrylic acid production provided in this embodiment is in operation, the first part of the steam is first mixed with the circulating tail gas in the circulating tail gas transmission pipe 2 through the steam branch line 4 to form a primary mixed gas, and then introduced into the premixer body 1, the second part of the steam is directly transported to the premixer body 1 through the steam main line 3, and then the second part of the steam is mixed with the primary mixed gas for a second time in the premixer body 1 to form a secondary mixed gas, the steam enters the premixer body 1 in two streams and is mixed with the circulating tail gas twice, so that the steam can be fully mixed with the circulating tail gas. Compared with the existing steam mixing method, the improved feed flow rate of each stream is stable and the mixing is uniform, which effectively improves the stability of the device operation.

[0024] As a preferred implementation mode, Figure 1 As shown, the angle α between the steam branch line 4 and the circulating tail gas transmission pipe 2 is 30°-60°. α can be 30°, 45°, or 60°.

[0025] The steam branch line 4 is connected at an angle relative to the circulating exhaust gas transmission pipe 2. On the one hand, it can enable the incoming steam flow to impact the circulating exhaust gas in the circulating exhaust gas transmission pipe 2, so that the steam and the circulating exhaust gas are mixed. On the other hand, it can reduce the resistance of the steam to the circulating exhaust gas, so that the steam flow can flow along the flow direction of the circulating exhaust gas to the premixer body 1.

[0026] As a preferred implementation mode, Figure 1 As shown, the angle α between the steam branch line 4 and the circulating tail gas transmission pipe 2 is 45°. When α is 45°, the steam can be fully mixed with the circulating tail gas while reducing the impact on the flow of the circulating tail gas, so that the primary mixed gas after mixing can maintain a stable flow rate.

[0027] As a preferred embodiment, a first control valve 32 is provided on the steam main line 3, and the first control valve 32 is used to adjust the total flow rate of steam on the steam main line 3. The steam branch line 4 is connected to the steam main line 3 at the rear end of the first control valve 32, that is, the steam branch line 4 is connected between the first control valve 32 and the premixer body 1. A part of the steam after passing through the first control valve 32 continues to flow along the steam main line 3 to the steam branch line 4, and the other part is mixed with the circulating exhaust gas in the circulating exhaust gas transmission pipe 2 through the steam branch line 4 and then flows into the premixer body 1.

[0028] A second control valve 41 capable of controlling the steam flow is provided on the steam branch line 4, and the second control valve 41 is used to regulate the steam flow in the steam branch line 4. The steam flow in the rear end of the steam main line 3 between the steam branch line 4 and the premixer body 1 is regulated by the first control valve 32 and the second control valve 41. That is, when the total steam flow at the front end of the steam main line 3 is constant, the greater the steam flow in the steam branch line 4 regulated by the second control valve 41, the smaller the steam flow at the rear end of the steam main line 3.

[0029] Specifically, a reducer 31 is provided on the steam main line 3 between the steam branch line 4 and the premixer body 1, so that the diameter of the rear end of the steam main line 3 is smaller than the diameter of the front end of the steam main line 3, so that the steam flow rate in the rear end of the steam main line 3 after the steam flow is diverted through the steam branch line 4 changes less, thereby improving the stability of operation.

[0030] As a preferred embodiment, the premixer body 1 includes a first mixing body 11 and a second mixing body 12 , and the center line of the first mixing body 11 is perpendicular to the center line of the second mixing body 12 .

[0031] The premixer body 1 is provided with the first mixing body 11 and the second mixing body 12 so that the first mixing body 11 and the second mixing body 12 can mix different materials in steps to make the mixing more uniform and the subsequent reaction more complete.

[0032] As a preferred embodiment, the circulating tail gas pipeline 2 is connected to one end of the first mixing body 11, the steam main line 3 is connected to the side wall of the first mixing body 11, and the end of the first mixing body 11 away from the circulating tail gas pipeline 2 is connected to the side wall of the second mixing body 12. The rear end of the steam main line 3 is vertically connected to the side wall of the first mixing body 11, so that the steam entering through the steam main line 3 is perpendicular to the entry direction of the primary mixed gas entering through the circulating tail gas pipeline 2.

[0033] Specifically, Figure 1 As shown, the circulating exhaust gas enters from the upper part of the first mixing body 11, and the steam enters in two streams, one stream enters the circulating exhaust gas pipeline 2 at an angle of 45°, and the other stream is fed perpendicularly to the feeding direction of the primary mixed gas, so that the primary mixed gas and the steam are fully mixed in the first mixing body 11 to form a secondary mixed gas.

[0034] Specifically, the steam in the steam main line 3 and the primary mixed gas in the circulating tail gas transmission pipe 2 are both sprayed into the first mixing body 11 through the nozzle to increase the contact area and fully mix.

[0035] As a preferred embodiment, the material mixing device for acrylic acid production provided in this embodiment also includes an air inlet pipe 5, which is connected to one end of the second mixing body 12, and the other end of the second mixing body 12 is connected to the main line 6 leading to the reactor.

[0036] The circulating exhaust gas and steam are fully mixed in the first mixing body 11 to form a secondary mixed gas, and the secondary mixed gas is transmitted to the second mixing body 12 through the bottom end of the first mixing body 11, and the intake direction of the secondary mixed gas is perpendicular to the direction of air entering the air intake pipe 5, so that the secondary mixed gas can be fully mixed with the air.

[0037] Specifically, the bottom end of the first mixing body 11 is in a constricted shape and is connected to the side wall of the second mixing body 12 through the constricted portion. The first mixing body 11 and air can be sprayed into the second mixing body 12 through a nozzle to increase the contact area between the first mixing body 11 and the air so that the two are fully mixed. The tertiary mixed gas formed after mixing flows toward the reactor through the main line 6.

[0038] As a preferred embodiment, the first mixing body 11 and the second mixing body 12 are both cylindrical tubular structures, so that the mixed gases can be fully mixed and flowed.

[0039] Specifically, the inner diameter of the first mixing body 11 is smaller than the inner diameter of the second mixing body 12. Since the mixed gas in the first mixing body 11 needs to flow into the second mixing body 12 to mix with the air again, the amount of gas in the first mixing body 11 is smaller than the amount of gas in the second mixing body 12. In order to maintain the stability of the air pressure in the two mixing bodies, the volume of the second mixing body 12 is made larger than the volume of the first mixing body 11.

[0040] The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make several modifications and improvements without departing from the creative concept of the present invention, which should be included in the protection scope of the present invention.

Claims

1. A material mixing device for acrylic acid production, characterized in that: The invention comprises a premixer body (1), a steam main line (3), a steam branch line (4) and a circulating exhaust gas transmission pipe (2), wherein the steam main line (3) and the circulating exhaust gas transmission pipe (2) are respectively connected to different parts of the premixer body (1), and one end of the steam branch line (4) is connected to the steam main line (3) and the other end is connected to the circulating exhaust gas transmission pipe (2).

2. A material mixing device for acrylic acid production according to claim 1, characterized in that: The angle α between the steam branch line (4) and the circulating tail gas transmission pipe (2) is 30°-60°.

3. A material mixing device for acrylic acid production according to claim 2, characterized in that: The angle α between the steam branch line (4) and the circulating tail gas transmission pipe (2) is 45°.

4. A material mixing device for acrylic acid production according to claim 1, characterized in that: A first control valve (32) is provided on the main steam line (3); the steam branch line (4) is connected to the main steam line (3) at the rear end of the first control valve (32); and a second control valve (41) capable of controlling the steam flow rate is provided on the steam branch line (4).

5. A material mixing device for acrylic acid production according to claim 1, characterized in that: The premixer body (1) comprises a first mixing body (11) and a second mixing body (12), wherein a center line of the first mixing body (11) is arranged perpendicular to a center line of the second mixing body (12).

6. A material mixing device for acrylic acid production according to claim 5, characterized in that: The circulating exhaust gas pipeline (2) is connected to one end of the first mixing body (11), the steam main line (3) is connected to the side wall of the first mixing body (11), and the end of the first mixing body (11) away from the circulating exhaust gas pipeline (2) is connected to the side wall of the second mixing body (12).

7. A material mixing device for acrylic acid production according to claim 6, characterized in that: It also includes an air inlet pipe (5), wherein the air inlet pipe (5) is connected to one end of the second mixing body (12), and the other end of the second mixing body (12) is connected to a main line leading to the reactor.

8. The material mixing device for acrylic acid production according to claim 5, characterized in that: The first mixing body (11) and the second mixing body (12) are both cylindrical tubular structures.

Images