Shell-and-tube heat exchangers are also known as tube-and-tube heat exchangers. It is a partition wall heat exchanger with the wall surface of the tube bundle enclosed in the shell as the heat transfer surface. The heat exchanger has a simple structure, low cost, a wide circulation cross section, and is easy to clean scale. However, the heat exchanger has a low heat transfer coefficient and a large footprint. It can be manufactured with various structural materials and can be used under high temperature and high pressure. Shell-and-tube heat exchangers include fixed tube-plate steam-water heat exchangers, tube-shell steam-water heat exchangers with expansion joints, floating head steam-water heat exchangers, and U-shaped shell-and-tube steam-water heat exchangers. , Node-type shell-and-tube steam-water heat exchanger, segmented water-water heat exchanger. The main control parameters of the shell-and-tube heat exchanger are heating area, hot water flow, heat exchange capacity, and heat medium parameters. So what are the welding skills of the heat exchanger?
(1) Before welding, the shell and tube heat exchanger should be maintained once, and only a layer of chlorate brazing flux can be applied to the welding place after maintenance.
(2) Before welding, fill the inside of the shell and tube heat exchanger with water, and use a damp cloth to wrap around the welding place to prevent the temperature formed during the welding process from being transmitted to the periphery of the welding place. Its melting or its welding quality is affected.
(3) The silver-based electrode used in the welding of shell-and-tube heat exchangers has a silver content of at least 45% and a temperature of less than 650°C during welding to prevent affecting the welding quality.
(4) When welding the shell and tube heat exchanger, it is necessary to limit the continuous welding time to not be too long, which can reduce the influence of temperature.