Hofmann (Beijing) Engineering Technology Co.,Ltd
Add:6F, East International Building, No.2 DongZhiMen Outside Street, DongCheng District, Beijing
US Brown has launched Twisted-tube heat exchanger originating from the Swedish Llares Company and made improvements. The manufacturing process of the spiral flat tube includes ‘flattening’ and ‘heat distortion’.
The improved twisted-tube heat exchanger is as simple as the traditional shell-and-tube type, but it improves heat transfer, reduces the scaling and the countercurrent, reduces the cost, eliminates vibration, saves space and there is no folding component.
The unique structure of the tube makes the shell and the tube simultaneously in a spiral motion, which promotes the turbulence. Its overall heat transfer coefficient is higher than the conventional by 40% while the pressure drop is almost equal. The heat exchanger can be assembled by combining the twisted pipe and the light pipe. The heat exchanger is manufactured in accordance with ASME Standard and can take the place of the shell-and-tube heat exchanger and the traditional device. It can achieve the best value that the ordinary shell-and-tube type and the plate-and-frame type achieved, estimated that it has a wide application prospect in chemical and petrochemical industry.
A new product developed by UK Calgavin ltd., adopted the twined coil insert called Hitanmatrixelements that can make the fluid generate three-dimensional complex flow superimposed by radial displacement and spiral flow at low speed, increase the induced turbulence, enhance the fluid disturbance along the direction of the temperature gradient and increase the heat transfer coefficient without adding resistance. The insert can promote the turbulent flow in the pipe, enlarge heat transfer area and improve the heat transfer efficiency. Currently, the insert mainly includes twist iron, helix, spiral tie, spiral piece or the insert with gap on the stroke, made by twisting or winding various metal strip, belt, sheet and wire.
UK CalGavin developed an insert called Heatex, consisting of a set of round cores extending to the pipe wall and improving the heat efficiency of the pipe side by 2~15 times. The company also developed a kind of wire insert called Hitran, which can increase the heat transfer efficiency of the shell-and-tube heat exchanger by 25 times in liquid working conditions and 5 times in gas working conditions, and meanwhile improve anti-scaling ability of the heat exchange pipe by 8~10 times compared with the normal flow velocity.
It is a new type developed in Japan recent years, combining both advantages of the plate type and the shell-and-tube type and overcoming the weakness of the plate type which is limited by sealing problem. Thus, it has a promising future. Since 20C90s, the rapid development of the heat exchanger technology has greatly improved energy efficiency. The development and application of various new-type and high-efficiency heat exchangers have brought great social and economic benefits.
Now, the industrial developed countries have manufactured plate heat exchanger and sold the products all over the world. The most famous are UK APV, Swedish ALFA-LAVAL, Germany GEA, USA Omexel and Japan Hisaka, etc. which we will talk about tomorrow.