Production process and production line for continuous stainless steel coil

Abstract

The invention relates to the machining for a stainless steel coil of a heat exchanging pipe. A production process for a continuous stainless steel coil comprises a pipe making step, a pipe bending step and a cutting step which adopt continuous on-line machining, wherein the first pipe making step comprises the following step: using a steel band as a raw material to perform on-line continuous pipe making; the second pipe bending step comprises the following steps: conveying an obtained steel pipe into a pipe bending machine; conveying a bent pipe to a second pipe bending position to bend the bent pipe for a second time; continuously bending the pipe in turn until the steel pipe is bent and assumes a single continuous bent pipe; and the third cutting step comprises the following step: sizing the single continuous bent pipe and cutting pipe end excess materials to obtain a single coil single pipe with a length of between 15 and 133 meters without a radial weld joint. The production process has the advantages of low cost, continuous pipe making and pipe bending and convenient machining, assembling and transportation. The obtained stainless steel coil has few or no radial welding spot, strong corrosion resistance without stress corrosion or corrosive pitting phenomenon, stable mechanical strength and relatively better heat exchanging efficiency.

Description

technical field [0001] The invention relates to the field of heat exchange equipment, in particular to the production process of heat exchange stainless steel coils. In addition, the invention also relates to its production line. Background technique [0002] There are two types of serpentine coils currently used for heat exchange equipment: carbon steel pipes and stainless steel pipes. Carbon steel pipe: the appearance is usually treated by hot-dip galvanizing. However, it will inevitably be oxidized and discolored during long-term use. Corrosion in wet conditions will produce zinc white rust or red rust, which is inferior to stainless steel in terms of aesthetics. Scale resistance: Due to the hot-dip galvanizing process of carbon steel pipes and the continuous corrosion of the zinc layer during use, the surface roughness increases, and impurities, biological bacteria, and dirt in the water are easier to adhere to and deposit, and the induction period for scaling is shorter...

AI Technical Summary

Problems solved by technology

[0003] The current stainless steel serpentine coils are all serpentine single-piece coils formed by radial butt welding of straight pipes and elbow pipes, such as figure 1 As shown, the production process is formed by cutting steel pipe-bending pipe-butt welding pressure test. The process steps are complicated, and the raw steel pipe is generally up to 7 meters long. The cutting size is designed on the premise of meeting the requirements and minimizing the waste of raw materials. , after cutting, bend the single pipe, align the bent pipes, adjust the gap between the single pipes, and perform welding and pressure testing to form a single piece of stainless steel serpentine coil. Radial welds affect the quality and performance of finished products: Affected by the quality of welding points, stress corrosion or pitting is prone to occur at the welding points; mechanical strength is related to welding quality and technology, normal welding points will not affect the mechanical strength, but there will be welding The frequency of defects; there are many welding points, and the welding meat in the tube is easy to form a bulge, which increases the flow resistance of the working medium in the tube, hinders the gravity flow process of the condensate, leads to poor drainage, increases the thermal resistance of the liquid film, and slightly reduces the heat transfer efficiency ; There are many butt welding spots on the appearance, which affect the appearance

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