Quenching gas distributor for dimethyl ether reactor
By designing a four-stage distribution structure and a cold-excitation gas distributor with conical spray holes, the problems of uneven distribution and uneven mixing of cold-excitation gas in the dimethyl ether reactor are solved, and the rapid and uniform mixing of cold-excitation gas and reaction gas is achieved, improving equipment safety and production efficiency.
Patent Information
- Application Number
- CN202422538640.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-10-21
AI Technical Summary
The existing cold-excited gas distributors have problems such as large temperature difference between the cold-excited gas and the reaction gas, uneven distribution, uneven mixing, poor equipment safety, and difficulty in maintenance in the dimethyl ether reactor.
The cold-exciting gas distributor adopts a four-stage distribution structure, including the inlet manifold, a semi-annular manifold and a fixed manifold, is designed with a conical spray hole and a sliding fixing device to achieve uniform distribution and rapid mixing of the cold-exciting gas.
It improves the mixing uniformity between cold-exciting gas and reaction gas, reduces thermal stress, reduces equipment height, facilitates maintenance and replacement, and improves equipment safety and production efficiency.
Smart Images
Figure CN223221462U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of gas distributors, in particular to a cold shock gas distributor for a dimethyl ether reactor. Background Art
[0002] Dimethyl ether, also known as methyl ether, abbreviated as DME, is an organic compound. Under standard conditions, it is a colorless, odorous, flammable gas or compressed liquid with a slight ether aroma.
[0003] Currently, dimethyl ether, as a new basic organic chemical raw material, has many unique applications in chemical industries such as medicine, fuel, and pesticides due to its excellent properties of easy compression, easy condensation, and easy gasification.
[0004] The most commonly used production process for dimethyl ether is the two-step process, namely the so-called methanol dehydration process, which includes gas phase process and liquid phase process, of which the most important is the gas phase process.
[0005] The vapor-phase dehydration of methanol to dimethyl ether (DME) is a solid-acid catalyzed reaction, with γ-Al₂O₃ and molecular sieves being commonly used. Because it is highly exothermic, the reaction temperature typically ranges from 250°C to 380°C. To prevent reactor overheating, a multi-stage adiabatic chill reactor is typically employed. This involves dividing the catalyst into multiple sections, with chill gas distributors positioned between each section. Unreacted, cooler chill gas is introduced for cooling. The chill gas temperature typically ranges from 130°C to 150°C. The temperature difference between the chill gas and the reactant gas can reach as high as 250°C, and the flow rate and composition vary significantly. Designing an efficient chill gas distributor to quickly and evenly distribute the chill gas and ensure rapid mixing of the chill gas and reactant gas is crucial to production capacity, product quality, and catalyst life.
[0006] The conventional design scheme of the existing general cold shock gas distributor is as follows: Figure 1 As shown, a main pipe is installed inside and outside the reactor shell. One end of the main pipe is fixed to the inner wall of the reactor shell. Multiple semicircular branches are installed on both sides of the main pipe inside the reactor shell. The semicircular branches are fixed to the main pipe via connecting flanges. Adjacent semicircular branches in different circles are spaced evenly and have the same diameter. Each semicircular branch has a number of nozzles of the same diameter, all located directly below the semicircular branches. Cold shock gas enters from one end of the main pipe, is distributed to the semicircular branches on both sides, and is then ejected through the nozzles.
[0007] The disadvantages of this solution are:
[0008] 1. There is a temperature difference of up to 250°C between the quenching gas and the reaction gas, which will generate large thermal stress in the main pipe, increase the stress on the reactor shell, and affect the safety of the equipment;
[0009] 2. The diameters of the semicircular branches are all the same, and the nozzles appear to be evenly distributed. However, the number of nozzles varies greatly, and the gas flow distance also varies greatly (the spacing between adjacent nozzles on the same semicircular branch is 60 mm, but the spacing between adjacent nozzles on different semicircular branches is 150 mm). In reality, the gas is unevenly distributed, resulting in a large temperature difference in the same plane within the catalyst bed.
[0010] 3. The radius of the outermost semicircular branch pipe can reach 2m, which is difficult to remove from the manhole. In fact, it can only be installed in the factory, which is difficult to repair and replace. In addition, it will vibrate and sag under the action of gravity and airflow, which can easily cause leakage of the connecting flange.
[0011] 4. The nozzle is located directly below the semicircular branch. The cold shock gas and the reaction gas flow in the same direction. Due to the blocking effect of the semicircular branch on the airflow, a vortex is generated, and the lateral diffusion is weak, resulting in the cold shock gas and the reaction gas not being able to mix quickly. It is necessary to increase the mixing space and increase the height of the equipment. Utility Model Content
[0012] The purpose of the utility model is to provide a cold shock gas distributor for a dimethyl ether reactor to solve the deficiencies of the prior art.
[0013] The utility model adopts the following technical solutions:
[0014] A cold shock gas distributor for a dimethyl ether reactor comprises an inlet manifold, two semi-annular manifolds and a fixed manifold;
[0015] One end of the inlet manifold is located inside the reactor shell, and the other end is located outside the reactor shell; a fixed manifold is located inside the reactor shell, and one end of the fixed manifold is fixed to the inner wall of the reactor shell; two semi-annular manifolds are located inside the reactor shell, one end of the two semi-annular manifolds is respectively fixed to the end of the inlet manifold located inside the reactor shell, the two semi-annular manifolds are connected to the inlet manifold, and the other ends are respectively fixed to the non-fixed end of the fixed manifold, the two semi-annular manifolds are connected to the fixed manifold, and the two semi-annular manifolds form an annular manifold;
[0016] A plurality of outer ring primary branches are radially arranged on the outer ring main pipe outer ring, the outer ring primary branches are connected to the annular main pipe, a plurality of outer ring secondary branches are vertically arranged on the outer ring primary branches, the outer ring secondary branches are connected to the outer ring primary branches, and a plurality of outer ring spray holes are arranged on the outer ring primary branches and the outer ring secondary branches; a plurality of inner ring primary branches are radially arranged on the inner ring main pipe inner ring, the inner ring primary branches are connected to the annular main pipe, a plurality of inner ring secondary branches are vertically arranged on the inner ring primary branches, the inner ring secondary branches are connected to the inner ring primary branches, and a plurality of inner ring spray holes are arranged on the inner ring primary branches and the inner ring secondary branches; a plurality of inlet main pipe secondary branches are vertically arranged on the inlet main pipe located in the reactor shell, the inlet main pipe secondary branches are connected to the inlet main pipe, a plurality of fixed main pipe secondary branches are vertically arranged on the fixed main pipe, the fixed main pipe secondary branches are connected to the fixed main pipe, and a plurality of main pipe secondary branch spray holes are evenly arranged on the inlet main pipe secondary branches and the fixed main pipe secondary branches;
[0017] The outer ring spray holes, inner ring spray holes and main pipe secondary branch spray holes are all located at the lower side of the corresponding pipeline. They are all conical spray holes with the outer opening larger than the inner opening.
[0018] Furthermore, the angles formed by the outer ring spray holes, the inner ring spray holes, the main pipe secondary branch pipe spray holes and the vertical center lines of the corresponding pipelines are 30° to 60°; the top angle of the conical spray holes is 20° to 40°.
[0019] Furthermore, one end of the fixed main pipe is fixed to the inner wall of the reactor shell by a sliding fixing device, the sliding fixing device includes an upper half of the guide pipe clamp, a lower half of the guide pipe clamp and an inner liner, the lower half of the guide pipe clamp is fixed to the support on the inner wall of the reactor shell, the inner liner is sleeved on one end of the fixed main pipe, the end of the fixed main pipe with the inner liner is arranged on the lower half of the guide pipe clamp, the upper half of the guide pipe clamp is arranged on the end of the fixed main pipe with the inner liner, and the upper half of the guide pipe clamp and the lower half of the guide pipe clamp are fixed by screws.
[0020] Furthermore, the center of the annular manifold is located on the vertical center line of the reactor shell, and the outer diameter of the annular manifold is 1 / 3-2 / 3 of the inner diameter of the reactor shell.
[0021] Furthermore, the outer diameter of the annular main pipe is 1 / 2 of the inner diameter of the reactor shell.
[0022] Furthermore, the widths of the outer ring secondary branch pipe, the inner ring secondary branch pipe, the inlet main pipe secondary branch pipe, and the fixed main pipe secondary branch pipe do not exceed the manhole width.
[0023] Furthermore, the diameters of the main pipe, the first-level branch pipe, and the second-level branch pipe are from large to small. The main pipe includes the inlet main pipe, the fixed main pipe, and the ring main pipe. The first-level branch pipes include the outer circle first-level branch pipe and the inner circle first-level branch pipe. The second-level branch pipes include the outer circle second-level branch pipe, the inner circle second-level branch pipe, the inlet main pipe second-level branch pipe, and the fixed main pipe second-level branch pipe.
[0024] Beneficial effects of the utility model:
[0025] 1. The utility model makes the cold shock gas flow distribution more uniform through the four-stage distribution of the main pipe - the first-level branch pipe - the second-level branch pipe - the nozzle hole, which is conducive to the rapid and uniform mixing of the cold shock gas and the reaction gas.
[0026] 2. The outer ring spray holes, inner ring spray holes, and secondary branch nozzles of the main pipe are all located below the corresponding pipe sides. The quenching gas is injected into the reactant gas at a certain angle, generating strong lateral diffusion, effectively reducing the vortex effect of the pipe on the airflow, and promoting rapid and uniform mixing of the quenching gas and the reactant gas. The tapered nozzle design not only reduces the possibility of catalyst dust entering the nozzle hole and clogging it, but also increases the jet diffusion angle, which promotes jet diffusion and mixing, and also facilitates rapid and uniform mixing of the quenching gas and the reactant gas.
[0027] 3. The spray holes of the utility model are set on the primary branch pipe and the secondary branch pipe, and no spray holes are set on the main pipe, which effectively prevents uneven distribution of cold shock gas.
[0028] 4. The utility model can quickly and evenly mix the cold shock gas and the reaction gas, and the reserved mixing height between the cold shock gas distributor and the catalyst bed of the next section of reaction gas can be reduced, saving equipment space and allowing more catalyst to be filled.
[0029] 5. The utility model adopts two semi-annular main pipes to form an annular main pipe, which plays the role of an expansion joint and can greatly reduce the thermal stress caused by the temperature difference between the cold shock gas and the reaction gas.
[0030] 6. One end of the fixed main pipe of the utility model is fixed to the inner wall of the reactor shell by a sliding fixture. The fixed main pipe can slide slightly between the sliding fixtures, which is beneficial to reduce the thermal stress caused by the temperature difference between the cold shock gas and the reaction gas, and will not generate excessive force pulling the reactor shell inward.
[0031] 7. The outer ring primary branch pipe and the inner ring primary branch pipe of the utility model are respectively longitudinally arranged on the outer ring and inner ring of the annular main pipe, the outer ring secondary branch pipe and the outer ring secondary branch pipe are respectively vertically arranged on the outer ring primary branch pipe and the inner ring primary branch pipe, the inlet main pipe secondary branch pipe and the fixed main pipe secondary branch pipe are respectively vertically arranged on the inlet main pipe and the fixed main pipe, the width of the outer ring secondary branch pipe, the inner ring secondary branch pipe, the inlet main pipe secondary branch pipe and the fixed main pipe secondary branch pipe does not exceed the manhole width. Most components of the utility model can be taken out through the manhole, which is easy to inspect and replace. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 This is a schematic diagram of the structure of an existing general cold shock gas distributor.
[0033] Figure 2 This is a schematic diagram of the structure of the cold shock gas distributor of the utility model.
[0034] Figure 3 This is a schematic diagram of the spray hole structure of the cold shock gas distributor of the utility model.
[0035] Figure 4 This is a schematic structural diagram of the sliding fixing device of the cold shock gas distributor of the utility model.
[0036] Reactor shell 1, manhole 2, inlet connecting pipe 3, inlet main pipe 4, inlet main pipe secondary branch 41, main pipe secondary branch spray hole 42, connecting flange 43, semi-annular main pipe 5, outer ring primary branch 6, outer ring secondary branch 61, outer ring spray hole 62, connecting flange 63, inner ring primary branch 7, inner ring secondary branch 71, inner ring spray hole 72, connecting flange 73, fixed main pipe 8, sliding fixing device 81, fixed main pipe secondary branch 82, guide pipe clamp upper part 83, guide pipe clamp lower part 84, screw 85, lining 86, support 87, type A outer ring branch 6a, type B outer ring branch 6b, type A inner ring branch 7a, type B inner ring branch 7b. DETAILED DESCRIPTION
[0037] The following examples and accompanying drawings are used to further explain the present invention. The following examples are only used to illustrate the present invention, but are not intended to limit the scope of implementation of the present invention.
[0038] A cold shock gas distributor for a dimethyl ether reactor, such as Figure 2-4 As shown, it includes an inlet manifold 4, two semi-annular manifolds 5 and a fixed manifold 8;
[0039] One end of the inlet manifold 4 is located inside the reactor shell 1, and the other end is located outside the reactor shell 1; the fixed manifold 8 is arranged inside the reactor shell 1, and one end of the fixed manifold 8 is fixed to the inner wall of the reactor shell 1. Preferably, one end of the fixed manifold 8 is fixed to the inner wall of the reactor shell 1 by a sliding fixing device 81. The sliding fixing device 81 includes an upper half 83 of the guide pipe clamp, a lower half 84 of the guide pipe clamp and an inner liner 86. The lower half 84 of the guide pipe clamp is fixed to the support 87 on the inner wall of the reactor shell 1. The inner liner 86 is sleeved on one end of the fixed manifold 8, and the end of the fixed manifold 8 with the inner liner 86 is arranged on the lower half 84 of the guide pipe clamp. The upper half 83 of the guide pipe clamp is arranged on the end of the fixed manifold 8 with the inner liner 86. The upper half 83 of the guide pipe clamp and the lower half 84 of the guide pipe clamp are fixed by screws 85; two semi-annular manifolds 5 are arranged in the reactor shell 1, one end of the two semi-annular manifolds 5 is respectively fixed to the end of the inlet manifold 4 located in the reactor shell 1, the two semi-annular manifolds 5 are connected to the inlet manifold 4, and the other ends are respectively fixed to the non-fixed ends of the fixed manifold 8, the two semi-annular manifolds 5 are connected to the fixed manifold 8, and the two semi-annular manifolds 5 form an annular manifold; preferably, the center of the annular manifold is located on the vertical center line of the reactor shell 1, and the outer diameter of the annular manifold is 1 / 3-2 / 3 of the inner diameter of the reactor shell 1; more preferably, the outer diameter of the annular manifold is 1 / 2 of the inner diameter of the reactor shell 1;
[0040] The outer ring of the annular main pipe is provided with a plurality of outer ring primary branch pipes 6 in a radial direction, the outer ring primary branch pipe 6 is connected to the annular main pipe, a plurality of outer ring secondary branch pipes 61 are vertically provided on the outer ring primary branch pipe 6, the outer ring secondary branch pipe 61 is connected to the outer ring primary branch pipe 6, and a plurality of outer ring spray holes 62 are provided on the outer ring primary branch pipe 6 and the outer ring secondary branch pipe 61; the inner ring of the annular main pipe is provided with a plurality of inner ring primary branch pipes 7 in a radial direction, the inner ring primary branch pipe 7 is connected to the annular main pipe, a plurality of inner ring secondary branch pipes 71 are vertically provided on the inner ring primary branch pipe 7, the inner ring secondary branch pipe 71 is connected to the inner ring primary branch pipe 7, and a plurality of inner ring spray holes 62 are provided on the inner ring primary branch pipe 7 and the inner ring secondary branch pipe 71 hole 72; the inlet manifold 4 located in the reactor shell 1 is vertically provided with a plurality of inlet manifold secondary branches 41, the inlet manifold secondary branches 41 are connected to the inlet manifold 4, the fixed manifold 8 is vertically provided with a plurality of fixed manifold secondary branches 82, the fixed manifold secondary branches 82 are connected to the fixed manifold 8, and a plurality of manifold secondary branch nozzle holes 42 are evenly arranged on the inlet manifold secondary branches 41 and the fixed manifold secondary branches 82; preferably, the width of the outer ring secondary branch 61, the inner ring secondary branch 71, the inlet manifold secondary branch 41, and the fixed manifold secondary branch 82 does not exceed the width of the manhole 2 to facilitate removal for inspection and replacement;
[0041] The outer ring spray holes 62, the inner ring spray holes 72, and the main pipe secondary branch spray holes 42 are all located below the corresponding pipeline side, preferably, the angle formed with the vertical center line of the corresponding pipeline ( Figure 3b) is 30° to 60°, which are all conical nozzles. The outer opening of the conical nozzle is larger than the inner opening. Preferably, the top angle of the conical nozzle ( Figure 3 The angle a) in the figure is 20° to 40°. The dimensions and number of the outer ring spray holes 62, inner ring spray holes 72, and manifold secondary branch spray holes 42 are designed as follows: the total spray hole area is calculated based on the actual flow rate of the quenching gas required by the reactor design and the design injection velocity. The desired number of spray holes is then determined by selecting an appropriate nozzle diameter.
[0042] Preferably, the diameters of the main pipes (inlet main pipe 4, fixed main pipe 8, and annular main pipe), primary branches (outer ring primary branch 6 and inner ring primary branch 7), and secondary branches (outer ring secondary branch 61, inner ring secondary branch 71, inlet main pipe secondary branch 41, and fixed main pipe secondary branch 82) are arranged from largest to smallest. In some embodiments, the inner diameter of the main pipe is 250 mm, the inner diameter of the primary branches is 50 mm, and the inner diameter of the secondary branches is 25 mm.
[0043] Preferably, in order to avoid space conflicts and improve space utilization, there are at least two types of outer ring branches (outer ring primary branch 6 and outer ring secondary branch 61). In some embodiments, two types of outer ring branches, type A 6a and type B 6b, can be set. The difference between type A outer ring branch 6a and type B outer ring branch 6b mainly lies in the distance between the corresponding secondary branch and the annular main pipe; there are also at least two types of inner ring branches (inner ring primary branch 7 and inner ring secondary branch 71). In some embodiments, there are two types of inner ring branches, type A 7a and type B inner ring branch 7b, which can be set. The difference between type A inner ring branch 7a and type B inner ring branch 7b mainly lies in the distance between the corresponding secondary branch and the annular main pipe.
[0044] The two semi-annular main pipes 5 and the inlet main pipe 4, the two semi-annular main pipes 5 and the fixed main pipe 8, the outer ring primary branch pipe 6 and the annular main pipe, and the inner ring primary branch pipe 7 and the annular main pipe can be connected by connecting flanges, clamps, threads, etc.
[0045] The working process of the present invention is as follows: the reaction gas after a period of reaction flows from top to bottom in the reactor shell 1 and passes vertically through the cold shock gas distributor. The cold shock gas is introduced into the cold shock gas distributor from the inlet pipe 3, and a small part is distributed to the inlet main pipe secondary branch 41 through the inlet main pipe 4, and most of it is distributed to the two semi-annular main pipes 5, and then distributed to the outer circle primary branch 6, the inner circle primary branch 7, and the fixed main pipe 8, and then distributed to the outer circle secondary branch 61, the inner circle secondary branch 71 and the fixed main pipe secondary branch 82, and finally sprayed into the reaction gas at a certain angle b through the nozzles of each pipeline, and quickly mixed evenly with the reaction gas.
Claims
1. A cold shock gas distributor for a dimethyl ether reactor, characterized in that: It includes an inlet main pipe, two semi-annular main pipes and a fixed main pipe; One end of the inlet manifold is located inside the reactor shell, and the other end is located outside the reactor shell; a fixed manifold is located inside the reactor shell, and one end of the fixed manifold is fixed to the inner wall of the reactor shell; two semi-annular manifolds are located inside the reactor shell, one end of the two semi-annular manifolds is respectively fixed to the end of the inlet manifold located inside the reactor shell, the two semi-annular manifolds are connected to the inlet manifold, and the other ends are respectively fixed to the non-fixed end of the fixed manifold, the two semi-annular manifolds are connected to the fixed manifold, and the two semi-annular manifolds form an annular manifold; A plurality of outer ring primary branches are radially arranged on the outer ring main pipe outer ring, the outer ring primary branches are connected to the annular main pipe, a plurality of outer ring secondary branches are vertically arranged on the outer ring primary branches, the outer ring secondary branches are connected to the outer ring primary branches, and a plurality of outer ring spray holes are arranged on the outer ring primary branches and the outer ring secondary branches; a plurality of inner ring primary branches are radially arranged on the inner ring main pipe inner ring, the inner ring primary branches are connected to the annular main pipe, a plurality of inner ring secondary branches are vertically arranged on the inner ring primary branches, the inner ring secondary branches are connected to the inner ring primary branches, and a plurality of inner ring spray holes are arranged on the inner ring primary branches and the inner ring secondary branches; a plurality of inlet main pipe secondary branches are vertically arranged on the inlet main pipe located in the reactor shell, the inlet main pipe secondary branches are connected to the inlet main pipe, a plurality of fixed main pipe secondary branches are vertically arranged on the fixed main pipe, the fixed main pipe secondary branches are connected to the fixed main pipe, and a plurality of main pipe secondary branch spray holes are evenly arranged on the inlet main pipe secondary branches and the fixed main pipe secondary branches; The outer ring spray holes, inner ring spray holes and main pipe secondary branch spray holes are all located at the lower side of the corresponding pipeline. They are all conical spray holes with the outer opening larger than the inner opening.
2. The cold shock gas distributor for a dimethyl ether reactor according to claim 1, characterized in that: The angle formed by the outer ring spray holes, the inner ring spray holes, the secondary branch pipe spray holes of the main pipe and the vertical center line of the corresponding pipeline is 30° to 60°; the top angle of the conical spray hole is 20° to 40°.
3. The cold shock gas distributor for a dimethyl ether reactor according to claim 1, characterized in that: One end of the fixed main pipe is fixed to the inner wall of the reactor shell by a sliding fixing device. The sliding fixing device includes an upper half of the guide pipe clamp, a lower half of the guide pipe clamp and an inner liner. The lower half of the guide pipe clamp is fixed to the support on the inner wall of the reactor shell. The inner liner is sleeved on one end of the fixed main pipe. The end of the fixed main pipe with the inner liner is arranged on the lower half of the guide pipe clamp. The upper half of the guide pipe clamp is arranged on the end of the fixed main pipe with the inner liner. The upper half of the guide pipe clamp and the lower half of the guide pipe clamp are fixed by screws.
4. The cold shock gas distributor for a dimethyl ether reactor according to claim 1, characterized in that: The center of the annular main pipe is located on the vertical center line of the reactor shell, and the outer diameter of the annular main pipe is 1 / 3-2 / 3 of the inner diameter of the reactor shell.
5. The cold shock gas distributor for a dimethyl ether reactor according to claim 4, characterized in that: The outer diameter of the annular main pipe is 1 / 2 of the inner diameter of the reactor shell.
6. The cold shock gas distributor for a dimethyl ether reactor according to claim 1, characterized in that: The width of the outer circle secondary branch pipe, the inner circle secondary branch pipe, the inlet main pipe secondary branch pipe, and the fixed main pipe secondary branch pipe shall not exceed the manhole width.
7. The cold shock gas distributor for a dimethyl ether reactor according to claim 1, characterized in that: The diameters of the main pipe, first-level branch pipe and second-level branch pipe are from large to small. The main pipe includes the inlet main pipe, fixed main pipe and ring main pipe. The first-level branch pipes include the outer circle first-level branch pipe and the inner circle first-level branch pipe. The second-level branch pipes include the outer circle second-level branch pipe, the inner circle second-level branch pipe, the inlet main pipe second-level branch and the fixed main pipe second-level branch.