Manufacturing process of special polyester reactor

Abstract

The invention discloses a manufacturing process of a special polyester reactor, which belongs to the field of reactor manufacturing, and comprises the following steps of: forging a carbon steel forge piece, performing heat treatment processing on the forge piece, adopting the carbon steel forge piece as a cylinder body and an end socket material, and manufacturing the cylinder body and the end socket through a stainless steel welding material surfacing process, the corrosion resistance of the reactor is guaranteed under the hydrogen-related working condition, meanwhile, the temperature-resistant and compression-resistant strength requirements of the reactor are guaranteed, and the manufacturing cost of the reactor can be greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of reactor manufacturing, in particular to a manufacturing process of a special polyester reactor. Background Art

[0002] Polyester is a general term for polymers obtained by polycondensation of polyols and polyacids. It mainly refers to polyethylene terephthalate (PET), PTT (PTA+PDO), PBT, PBAT, and PETG. Polyester is a type of engineering plastic with excellent performance and wide applications. Special polyester is a polyester material made through special processes and formulas. Its performance is improved compared to ordinary polyester or it has specific functions.

[0003] At present, the material of special polyester reactors is all stainless steel; combined with the temperature and pressure calculation of the reactor, the wall thickness of the main material of the equipment is greater than 100mm. If it is made of composite plates, the bonding degree of the composite plates cannot reach 100%. The thick wall is easy to damage the composite layer during the rolling process, and it is easy to crack and leak, and the leakage point is difficult to find; if thick-walled plates are used, there are no suppliers in China and only imported materials can be used, with a long procurement cycle, high prices, and high manufacturing costs. Moreover, the reactor is used in hydrogen-related working conditions. If the reactor is made of plates, the defects of the plates caused by the plate production process are very likely to cause defects such as bulging and cracking under the working conditions of this project, which will cause safety hazards.

[0004] In the production process of specialty polyester, the reactor as a core equipment needs to meet the requirements of corrosion resistance and high temperature resistance. The selection of its material is directly related to the quality of the product, the safety of production and the manufacturing cost. With the continuous advancement of technology in the petrochemical industry at home and abroad, high temperature and high pressure hydrogenation reaction technology has been widely used and has achieved remarkable results in many fields. However, for the reactor of specialty polyester raw materials, the selection of its material and manufacturing process are still a key issue in reducing the manufacturing cost of the reactor while ensuring safety and reliability. Summary of the invention

[0005] The purpose of the present invention is to reduce the manufacturing cost of the reactor while ensuring the safe and stable operation of the special polyester reactor. In order to solve the above technical problems, the present invention is solved by the following technical solutions.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A manufacturing process for a special polyester reactor includes: carbon steel forgings, which are processed by forging and heat treatment, and the cylinder and the head are made of carbon steel forgings, and the cylinder and the head are processed by stainless steel welding material surfacing process.

[0007] Preferably, the S and P contents in the welding material are controlled at S ≤ 0.005%, P ≤ 0.008%.

[0008] Preferably, the straight section of the cylinder adopts the forging + butt welding process.

[0009] Preferably, the base material with a head diameter greater than 2000 mm is welded by forging plates, pressed and then surfacing, and the base material with a head diameter less than 2000 mm is integrally pressed by bowl forging and then surfacing.

[0010] Preferably, the cladding is performed successively through a transition welding process and two cladding welding processes, so that the thickness of the thick cladding pure stainless steel after forming and processing is ≥3m.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The special arc-shaped structure of the reactor head adopts the forging and surfacing processing technology, which effectively avoids the defects of tensile stress generated by plate stamping in the prior art and large thickness reduction caused by bending of the head; Compared with the existing process, the present application ensures the corrosion resistance of the reactor under hydrogen-related working conditions while ensuring the temperature and pressure resistance strength requirements of the reactor, is safe and reliable, and also reduces the manufacturing cost of the reactor. DETAILED DESCRIPTION

[0013] The present invention is described in further detail below.

[0014] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be used for other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0015] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate directions or positions are only for the convenience of describing the simplified description of the present invention, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the above terms should not be understood as limiting the present invention.

[0016] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0017] The present invention adopts the following process, a manufacturing process of a special polyester reactor, including: carbon steel forgings, the forgings are forged, heat treated, the forgings are forged, heat treated, etc., the strength and toughness are good, the defects are few, the corrosion resistance of the reactor is ensured, and the temperature and pressure resistance requirements of the reactor are ensured. The barrel and the head are made of carbon steel forgings, and the processing of the barrel and the head is manufactured by the stainless steel welding material surfacing process. The carbon steel forgings are used as the base layer to play the role of pressure resistance and temperature resistance, and the surfacing stainless steel layer plays the role of corrosion resistance and hydrogen embrittlement, which solves the problem that the traditional process uses plates or composite plates as the main materials of the reactor, and the plates are easy to damage the composite layer during the rolling process, and are prone to cracking, leakage, etc., and the leakage point is difficult to find, which is prone to safety hazards. The arc-shaped special structure of the reactor head adopts the forging plus surfacing processing technology, which effectively avoids the defects of the prior art that the plate stamping forming will produce tensile stress, and the head bending causes a large amount of thickness reduction.

[0018] The S and P contents in the welding materials are controlled at S ≤ 0.005% and P ≤ 0.008%, so that the welding performance is good and the temper brittleness of the welding materials is small, which is beneficial for the reactor to be in hydrogen-related working conditions.

[0019] The straight section of the cylinder adopts the forging + butt welding process. The base material with head diameter > 2000mm is welded with forging plates and then pressed and surfacing. The base material with head diameter ≤ 2000mm is pressed as a whole by bowl forging and then surfacing.

[0020] Taking hydrogen corrosion and other factors into consideration, the cladding process is carried out through a transition welding and two cladding processes, so that the thickness of the thick cladding pure stainless steel is ≥3m after forming and processing.

[0021] Compared with the existing process, the present application ensures the corrosion resistance of the reactor under hydrogen-related working conditions while ensuring the temperature and pressure resistance strength requirements of the reactor, is safe and reliable, and also reduces the manufacturing cost of the reactor.

[0022] Those skilled in the art should understand that the embodiments of the present invention shown in the above description are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A manufacturing process for a special polyester reactor, characterized in that: include: Carbon steel forgings are processed by forging and heat treatment. The cylinder and head materials are made of carbon steel forgings. The cylinder and head are processed by stainless steel welding process.

2. The manufacturing process of a special polyester reactor according to claim 1, characterized in that: The S and P contents in welding materials are controlled at S ≤ 0.005%, P ≤ 0.008%.

3. The manufacturing process of a special polyester reactor according to claim 1, characterized in that: The straight section of the cylinder adopts forging + butt welding process.

4. The manufacturing process of a special polyester reactor according to claim 1, characterized in that: For head diameters greater than 2000mm, the base material is welded with forging plates, pressed and then surfacing welded; for head diameters ≤ 2000mm, the base material is integrally pressed with bowl-shaped forging and then surfacing welded.

5. The manufacturing process of a special polyester reactor according to claim 1, characterized in that: The cladding process is carried out through a transition welding and two cladding processes, so that the thickness of the thick cladding pure stainless steel is ≥3m after forming and processing.