The manufacturing process of 90° shrimp bend of Venturi tube

Abstract

The present invention discloses a manufacturing process of a 90° shrimp bend of a venturi tube, comprising the following steps: A. using three-dimensional software to perform the first lofting to obtain n elbow piece processing drawings; B. processing according to the drawings to obtain n elbow pieces; C. rolling and welding the n elbow pieces respectively; D. measuring the angle of the shrimp bend after welding; and comparing the angle with 90 degrees to obtain an error value ±X; E. dividing the error value ±X equally according to the number of elbow pieces to obtain the correction amount of each elbow piece, i.e. ±X / n; F. obtaining the size data of n elbow pieces by the first lofting, and correcting them according to the correction amount, so as to obtain a 90° shrimp bend of a venturi tube that meets the design requirements. The 90° shrimp bend of a venturi tube processed by the present invention can meet the 90° high-precision requirements, has a low scrap rate, reduces the processing cost, and improves the corrosion resistance of the weld.

Description

Technical Field

[0001] The invention relates to a process for manufacturing a shrimp bend, in particular to a process for manufacturing a 90° shrimp bend of a Venturi tube. Background Art

[0002] The rapid development of the shipping industry has brought convenience to trade and transportation, but it has also brought tremendous pressure on improving regional air quality. Research results show that in coastal and riverine areas such as the Yangtze River Delta, the Pearl River Delta, the Bohai Rim and the Yangtze River, ship port emissions have become one of the important sources of air pollution.

[0003] Research results show that sulfur oxides (SOx) produced when ship propulsion units use high-sulfur fuel oil as fuel are the cause of environmental pollution phenomena such as acid mist, acid rain and chemical smog, which seriously pollute the atmosphere.

[0004] The use of a scrubbing tower to desulfurize the sulfur-hydrogen compounds produced during the combustion of ship power is a common purification process on ships. The 90° shrimp bend of the venturi tube of the scrubbing tower is a very critical desulfurization component. The 90° shrimp bend of the venturi tube is coordinated and connected with the external pipe. Since the venturi tube material used in the scrubbing tower is AL6XN super austenitic stainless steel, the outer dimensions are large, the price is high, and the procurement cycle is long, the processing accuracy of the 90° shrimp bend of the venturi tube is very high. If the shrimp bend is 89 degrees or 91 degrees, the flange surface will be tilted and not tightly matched with the external pipe. The existing welding processing technology is difficult to meet this requirement, with a high scrap rate and high processing cost. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a process for manufacturing a 90° shrimp bend of a Venturi tube, so as to solve the problem in the prior art that the 90° shrimp bend of the Venturi tube is difficult to meet the 90° high precision requirement.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] The manufacturing process of the 90° shrimp bend of the Venturi tube is characterized by comprising the following steps:

[0008] A. Use 3D software to carry out the first lofting according to the design requirements to obtain n elbow piece processing drawings;

[0009] B. Processing the elbow piece according to the size data of the elbow piece drawing to obtain n elbow pieces;

[0010] C. Roll the n elbow pieces respectively, and weld the rolled n elbow pieces together according to the designed sequence;

[0011] D. Measure the angle of the shrimp bend after welding; compare the angle with 90 degrees to obtain an error value ±X;

[0012] E. Divide the error value ±X equally according to the number of elbow pieces to obtain the correction amount of each elbow piece, that is, ±X / n;

[0013] F. Based on the n elbow piece size data obtained in the first layout, re-enter the layout software according to the above correction amount to obtain n elbow piece size data that meet the requirements, and then repeat steps B and C to obtain the 90° shrimp bend of the Venturi tube that meets the design requirements.

[0014] In a preferred embodiment of the present invention, n is equal to 3.

[0015] In the preferred embodiment of the present invention, when the n elbow pieces are welded and assembled after rolling, the last cover weld is all arranged on the inner side in contact with the medium to avoid repeated heating of the inner weld when welding the outer weld, thereby improving the medium corrosion resistance of the inner weld.

[0016] The present invention first obtains data from the simulated sample of the shrimp bend, and when assembling the formal product 90° shrimp bend, appropriate advance anti-deformation is used for lofting and assembly to achieve the 90° shrimp bend required by the drawing after welding. The 90° shrimp bend of the venturi tube processed by the present invention can meet the 90° high-precision requirements, with a low scrap rate, reduced processing costs, and improved weld corrosion resistance.

[0017] The features of the present invention can be clearly understood by referring to the detailed description of the preferred embodiments of the present invention. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.

[0019] The manufacturing process of the 90° shrimp bend of the Venturi tube includes the following steps:

[0020] A. Use 3D software to perform the first lofting according to the design requirements to obtain processing drawings (with dimensional data) of 3 elbow pieces (or other elbow pieces);

[0021] B. Process the elbow piece according to the size data of the elbow piece drawing to obtain 3 elbow pieces;

[0022] C. Roll the three elbow pieces separately, and weld the rolled elbow pieces together according to the design sequence; when welding and assembling, the last cover weld is all arranged on the inner side in contact with the medium to avoid repeated heating of the inner weld when welding the outer weld, thereby improving the corrosion resistance of the inner weld to the medium;

[0023] D. Measure the angle of the shrimp bend after welding; compare the angle with 90 degrees to obtain an error value ±X;

[0024] E. Divide the error value ±X equally according to the number of elbow pieces to obtain the correction amount of each elbow piece, that is, ±X / n; for example, if the measured angle is 91 degrees, the error value is 91-90=1 degree, and the correction amount of each elbow piece is 0.33; if the measured angle is 88 degrees, the error value is 88-90=-2 degrees, and the correction amount of each elbow piece is -0.67;

[0025] F. Based on the 3 elbow piece size data obtained from the first layout, re-enter the layout software according to the above correction amount to obtain the 3 elbow piece size data that meet the requirements, and then repeat steps B and C to obtain the 90° shrimp bend of the Venturi tube that meets the design requirements.

[0026] The present invention first obtains data from a simulated sample of the shrimp bend, and when assembling the formal product 90° shrimp bend, uses appropriate advance anti-deformation to perform layout and assembly to achieve the 90° shrimp bend required by the drawing after welding.

[0027] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. The manufacturing process of 90° shrimp bend of Venturi tube is characterized by: The following steps are involved: A. Use 3D software to carry out the first lofting according to the design requirements to obtain n elbow piece processing drawings; B. Processing the elbow piece according to the size data of the elbow piece drawing to obtain n elbow pieces; C. Roll the n elbow pieces respectively, and weld the rolled n elbow pieces together according to the designed sequence; D. Measure the angle of the shrimp bend after welding; compare the angle with 90 degrees to obtain an error value ±X; E. Divide the error value ±X equally according to the number of elbow pieces to obtain the correction amount of each elbow piece, that is, ±X / n; F. Based on the n elbow piece size data obtained in the first layout, re-enter the layout software according to the above correction amount to obtain n elbow piece size data that meet the requirements, and then repeat steps B and C to obtain the 90° shrimp bend of the Venturi tube that meets the design requirements.

2. The process for making a 90° shrimp bend of a Venturi tube according to claim 1, characterized in that: Said n is equal to 3.

3. The process for making a 90° shrimp bend of a Venturi tube according to claim 1, characterized in that: When the n elbow pieces are welded and assembled after being rolled, the last cover weld is all arranged on the inner side in contact with the medium.