Triple heat exchanger pipeline dredging device for styrene production

Abstract

The utility model relates to the technical field of styrene production, in particular to a triple heat exchanger pipeline dredging device for styrene production, which is characterized in that a guide spraying part is obliquely and downwards arranged on the side wall of a liquid collecting bag of a triple heat exchanger pipeline, and is subjected to heat preservation and anti-corrosion treatment, so that when the triple heat exchanger liquid collecting bag is overhauled and regularly maintained, the guide spraying part is prevented from being blocked; a valve at the bottom of the liquid collecting bag does not need to be opened, only the drainage part needs to be opened, the discharging amount and the descending liquid level of the liquid collecting bag are accurately controlled according to maintenance requirements, waste caused by discharging excessive materials is avoided, and pipeline dredging and maintenance are facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of styrene production, in particular to a triple heat exchanger pipeline dredging device for styrene production. Background Art

[0002] In a styrene production plant, a triple heat exchanger is a critical piece of equipment. It consists of three heat exchangers connected in series and welded together, hence the name. The equipment comprises a feed / discharge heat exchanger (TT-1202), a high-pressure steam generator (TT-1201), and a high-pressure steam generator (TT-1203). The triple heat exchanger process flows from top to bottom, through the feed / discharge heat exchanger (TT-1202), to the high-pressure steam generator (TT-1203), and then to the high-pressure steam generator (TT-1201). The material in the tubes is crude styrene, and the process principle is to cool the crude styrene.

[0003] As the triple heat exchanger ages, problems such as leakage and scaling will occur inside the triple heat exchanger pipeline, causing the polymer of the triple heat exchanger to clog the liquid collection bag, affecting the styrene production progress and reducing product quality. When inspecting and regularly maintaining the liquid collection bag of the existing triple heat exchanger, the bottom valve of the liquid collection bag can only be opened to discharge the material before inspection and maintenance can be carried out. The bottom valve of the liquid collection bag is difficult to operate due to the large material pressure it bears, and it is difficult to control the liquid level and discharge volume of the liquid collection bag, which easily leads to material waste and is inconvenient for dredging and maintenance. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a triple heat exchanger pipeline dredging device for styrene production. By setting a shower guide portion obliquely downward on the side wall of the liquid collecting bag, the liquid level and discharge volume of the liquid collecting bag can be accurately controlled according to maintenance requirements, making dredging and maintenance convenient.

[0005] The utility model provides the following specific technical solutions:

[0006] A triple heat exchanger pipeline dredging device for styrene production includes an inlet and outlet heat exchanger, the tail of the inlet and outlet heat exchanger is connected to a first high-pressure steam generator, the tail of the first high-pressure steam generator is connected to a second high-pressure steam generator, and the tail of the second high-pressure steam generator is connected to a connecting pipe, characterized in that a liquid collecting bag is provided at the bottom of the connecting pipe, and a shower guide is provided on the liquid collecting bag.

[0007] Preferably, the shower guide part includes a welding base, on which a shower guide pipe is welded, the shower guide pipe is connected to the side wall of the liquid collecting bag, a necked butt-welded flange is fixedly installed at the bottom end of the shower guide pipe, a gate valve is fixedly installed on the necked butt-welded flange, and a flange cover is fixedly installed at the end of the gate valve away from the necked butt-welded flange.

[0008] Preferably, the shower guide pipe includes an inner shower guide pipe, which is connected to the side wall of the liquid collecting bag. A protective sleeve is provided on the outer side of the inner shower guide pipe, which is fixedly connected to the welding base. An insulation layer is provided on the outer wall of the inner shower guide pipe, and several groups of binding belts are fixedly provided on the outer wall of the insulation layer.

[0009] Preferably, the inner drain pipe is a 20# carbon steel seamless pipe, and the spacing between the strapping strips is ≤200mm.

[0010] Preferably, the maximum working pressure of the inner drainage tube is 0.16 MPa and the working temperature is 124°C.

[0011] Preferably, the inner wall of the inner shower pipe is coated with a first anti-corrosion layer, and a second anti-corrosion layer is coated with fluorine on the first anti-corrosion layer.

[0012] Preferably, the first anti-corrosion layer is an inorganic zinc-rich primer with a layer thickness of 40 microns, and the second anti-corrosion layer is an organic silicon heat-resistant paint with a layer thickness of 25 microns.

[0013] Preferably, the shower guide portion is arranged obliquely downward on the side wall of the liquid collection bag.

[0014] Preferably, the shower guide is welded to the side wall of the liquid collecting bag by tungsten inert gas arc welding, and the welding material is nickel-based welding wire ERNiCr-3.

[0015] The utility model has the following technical effects:

[0016] The utility model sets a drain guide portion obliquely downward on the side wall of the liquid collecting bag, and performs insulation and anti-corrosion treatment on the drain guide portion. When the liquid collecting bag of the triple heat exchanger is inspected and regularly maintained, there is no need to open the bottom valve of the liquid collecting bag. Only the drain guide portion needs to be opened, and the liquid level and discharge amount of the liquid collecting bag can be accurately controlled according to the inspection and maintenance requirements, so as to avoid waste caused by discharging too much material and facilitate pipeline dredging and inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of an embodiment of the present utility model;

[0018] Figure 2 This is a structural diagram of the shower guide portion in one embodiment of the present utility model;

[0019] Figure 3 This is a structural diagram of the shower pipe in one embodiment of the present invention;

[0020] Figure 4 This is a cross-sectional view of the shower pipe in one embodiment of the present invention.

[0021] In the figure: 1-inlet and outlet heat exchanger; 2-first high-pressure steam generator; 3-second high-pressure steam generator; 4-connecting pipe; 5-liquid collecting bag; 6-shower guide; 61-welded base; 62-shower guide pipe; 621-shower guide inner pipe; 6211-insulation layer; 6212-first anti-corrosion layer; 6213-second anti-corrosion layer; 622-binding belt; 63-neck butt welding flange; 64-gate valve; 65-flange cover. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] like Figure 1 As shown, the utility model discloses a triple heat exchanger pipeline dredging device for styrene production, including an inlet and outlet heat exchanger 1, the tail of the inlet and outlet heat exchanger 1 is connected to a first high-pressure steam generator 2, the tail of the first high-pressure steam generator 2 is connected to a second high-pressure steam generator 3, and the tail of the second high-pressure steam generator 3 is connected to a connecting pipe 4, which is characterized in that a liquid collecting bag 5 is provided at the bottom of the connecting pipe 4, and a shower guide 6 is provided on the liquid collecting bag 5. The shower guide 6 is used to accurately control the liquid level and discharge amount of the liquid collecting bag according to maintenance requirements, so as to facilitate dredging and maintenance.

[0024] like Figure 2 As shown, in the embodiment disclosed in the present utility model, the shower guide part 6 includes a welding base 61, a shower guide pipe 62 is welded on the welding base 61, the shower guide pipe 62 is connected to the side wall of the liquid collecting bag 5, and a necked butt-welded flange 63 is fixedly installed at the bottom end of the shower guide pipe 62, a gate valve 64 is fixedly installed on the necked butt-welded flange 63, and a flange cover 65 is fixedly installed on the end of the gate valve 64 away from the necked butt-welded flange 63.

[0025] like Figure 3 As shown, in the embodiment disclosed in the present utility model, the shower guiding pipe 62 includes a shower guiding inner tube 621, which is connected to the side wall of the liquid collecting bag 5, and a protective sleeve is provided on the outer side of the shower guiding inner tube 621, which is fixedly connected to the welding base 61, and an insulation layer 6211 is fixedly provided on the outer wall of the shower guiding inner tube 621, and several groups of strapping belts 622 are fixedly provided on the outer wall of the insulation layer 6211.

[0026] The protective sleeve is used to protect the inner drainage tube 621 , and the protective sleeve may be a stainless steel sleeve. The thermal insulation layer 6211 is used to keep the inner drainage tube 621 warm.

[0027] The inner pipe 621 of the showerhead is a 20# carbon steel seamless pipe. The manufacturing standard is "Seamless Steel Pipe for Fluid Transportation" GB / T 8163-2018, and the outer diameter selection standard is "Petrochemical Steel Pipe Size Series" SH / T3405-2017.

[0028] After the assembly of the inner drainage pipe 621 is completed, a water pressure test is required with a test pressure of 0.26 MPa. The pipe is also required to undergo a gas leakage test, which shall comply with the following regulations:

[0029] a) Leakage test should be carried out after the pressure test is passed;

[0030] b) When the design pressure of the pipeline is ≤1.6MPaG, the test medium is air, and the test pressure is the smaller of the design pressure of the inner drainage pipe 621 or the test pressure of the equipment;

[0031] c) When the design pressure of the pipeline is greater than 1.6 MPaG, a sensitivity leak test shall be conducted. The test pressure shall be 105 kPa and the test method shall comply with GB / T 15823-2009 "Non-destructive Helium Leak Detection Method";

[0032] b) The inspection focus of the leakage test should be on the valve stuffing box, flange or threaded connection, vent valve, exhaust valve, drain valve, etc.

[0033] c) The test pressure of the leakage test should be increased slowly step by step. When the test pressure is reached, stabilize the pressure for 10 minutes, and then check all sealing points by applying a neutral foaming agent. The test is qualified if there is no leakage.

[0034] d) After the pipeline system passes the gas leakage test, the pressure should be released slowly and promptly, and the test record should be filled in.

[0035] Furthermore, the maximum working pressure of the shower pipe of the shower inner pipe 621 is 0.16 MPa, and the design pressure is 0.172 MPa / FV; the working temperature is 124°C, and the design temperature is 360°C.

[0036] Furthermore, the spacing between the strapping belts 622 is ≤200 mm, and the strapping belts 622 may be made of stainless steel wire.

[0037] like Figure 4 As shown, in the embodiment disclosed in the present utility model, the inner wall of the inner drain tube 621 is coated with a first anti-corrosion layer 6212 , and a second anti-corrosion layer 6213 is coated with fluorine on the first anti-corrosion layer 6212 .

[0038] Among them, the first anti-corrosion layer 6212 is an inorganic zinc-rich primer with a layer thickness of 40 microns, and the second anti-corrosion layer 6213 is an organic silicone heat-resistant paint with a layer thickness of 25 microns.

[0039] Before painting the inner wall of the shower guide inner pipe 621, it should be derusted first, and the rust removal level should meet the Sa2 1 / 2 level requirements in "Surface preparation of steel before painting - Visual assessment of surface cleanliness Part 1: Rust removal grades and treatment grades for uncoated steel surfaces and steel surfaces after thorough cleaning to remove the original coating" GB / T8923.1.

[0040] In the embodiment disclosed in the present invention, the shower guide portion 6 is arranged on the side wall of the liquid collection bag 5 at an angle downward, and the inclination angle is preferably 45 degrees.

[0041] The color and marking of the shower guide part 6 shall comply with the provisions of 8.2 and 8.3 of the "Design Regulations for External Corrosion Protection of Chemical Equipment and Pipelines" HG / T20679-2014.

[0042] In the embodiment disclosed in the present utility model, in order to ensure the welding quality, according to the recommendation of the ASME Boiler and Pressure Vessel Manual, the shower guide 6 is welded to the side wall of the liquid collecting bag 5 by tungsten inert gas arc welding, and the welding material is nickel-based welding wire ERNiCr-3 to ensure the high-temperature strength of the weld.

[0043] Weld inspection quality requirements must comply with the provisions of Chapter 7, "Evaluation and Quality Grading of Radiographic Testing Results of Fusion-Welded Circumferential Welded Joints of Pressure Equipment Pipes and Pressure Piping," in the currently effective industry standard, "Nondestructive Testing of Pressure Equipment Part 2: Radiographic Testing," NB / T 47013.2-2015. The pipeline inspection level for this project is Level I, and the weld quality acceptance standard must not be lower than Level II as specified in the current national standard, "Nondestructive Testing of Pressure Equipment Part 2: Radiographic Testing," NB / T 47013.2-2015. The weld quality acceptance standard for spot or local radiographic testing must not be lower than Level III as specified in 7.1.3.

[0044] For ordinary technicians in this field, based on the teachings of this utility model, without departing from the principles and spirit of this utility model, changes, modifications, substitutions and variations made to the implementation methods are still within the scope of protection of this utility model.

Claims

1. A triple heat exchanger pipeline dredging device for styrene production, comprising an inlet and outlet heat exchanger (1), wherein the tail of the inlet and outlet heat exchanger (1) is connected to a first high-pressure steam generator (2), the tail of the first high-pressure steam generator (2) is connected to a second high-pressure steam generator (3), and the tail of the second high-pressure steam generator (3) is connected to a connecting pipe (4), characterized in that: A liquid collecting bag (5) is provided at the bottom of the connecting pipe (4), and a shower guide (6) is provided on the liquid collecting bag (5).

2. The triple heat exchanger pipeline dredging device for styrene production according to claim 1, characterized in that: The shower guide portion (6) includes a welding base (61), a shower guide pipe (62) is welded to the welding base (61), the shower guide pipe (62) is communicated with the side wall of the liquid collecting bag (5), a neck butt-welding flange (63) is fixedly mounted on the bottom end of the shower guide pipe (62), a gate valve (64) is fixedly mounted on the neck butt-welding flange (63), and a flange cover (65) is fixedly mounted on the end of the gate valve (64) away from the neck butt-welding flange (63).

3. The triple heat exchanger pipeline dredging device for styrene production according to claim 2, characterized in that: The shower guide pipe (62) comprises a shower guide inner pipe (621), the shower guide inner pipe (621) being in communication with the side wall of the liquid collecting bag (5), a protective sleeve being provided on the outer side of the shower guide inner pipe (621), the protective sleeve being fixedly connected to the welding base (61), a heat-insulating layer (6211) being provided on the outer wall of the shower guide inner pipe (621), and a plurality of groups of binding belts (622) being fixedly provided on the outer wall of the heat-insulating layer (6211).

4. The triple heat exchanger pipeline dredging device for styrene production according to claim 3, characterized in that: The inner drainage pipe (621) is a 20# carbon steel seamless pipe, and the spacing between the binding belts (622) is ≤200 mm.

5. The triple heat exchanger pipeline dredging device for styrene production according to claim 3, characterized in that: The maximum working pressure of the inner drainage tube (621) is 0.16 MPa, and the working temperature is 124°C.

6. The triple heat exchanger pipeline dredging device for styrene production according to claim 3, characterized in that: The inner wall of the inner drainage tube (621) is coated with a first anti-corrosion layer (6212), and a second anti-corrosion layer (6213) is coated with fluorine on the first anti-corrosion layer (6212).

7. A triple heat exchanger pipeline dredging device for styrene production according to claim 6, characterized in that: The first anti-corrosion layer (6212) is an inorganic zinc-rich primer with a layer thickness of 40 microns, and the second anti-corrosion layer (6213) is an organic silicon heat-resistant paint with a layer thickness of 25 microns.

8. A triple heat exchanger pipeline dredging device for styrene production according to any one of claims 1 to 7, characterized in that: The shower guide portion (6) is arranged obliquely downward on the side wall of the liquid collection bag (5).

9. The triple heat exchanger pipeline dredging device for styrene production according to claim 8, characterized in that: The shower guide portion (6) is welded to the side wall of the liquid collecting bag (5) by tungsten inert gas arc welding, and the welding material is nickel-based welding wire ERNiCr-3.

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