Welded plate heat exchanger

Other types of plate-and-frame heat exchangers are double-wall-plate exchangers, welded-plate exchangers, wide-gap-plate exchangers, and brazed-plate exchangers. Each type is briefly described below. 

B. Omberg and P. Crook, F Neir NickelFlloir and a New Semi-Welded Plate Heat Exchanger The State of theFrtfor Tomorrow s Fcid Coolers, Sulphur 94 (British Sulphur Conference), Tampa, Fla., Nov. 1994. 

U-Tube Heat Excbajiger (Fig. 11-36J) The tube bundle consists of a stationaiy tube sheet, U tubes (or hairpin tubes), baffles or support plates, and appropriate tie rods and spacers. The tube bundle can be removed from the heat-exchanger shell. A tube-side header (stationary head) and a shell with integr shell cover, which is welded to the shell, are provided. Each tube is free to expand or contract without any limitation being placed upon it by the other tubes. 

There are two major types gasketed and welded-plate heat exchangers. Each shall be discussed individually. 

It is very difficult to estimate the magnitude of the contact conductance G. Normally the total conductance of the heat exchanger is determined, and G - is calculated from Eq. (9.48). Only in the case that rhe plate fins are welded to the pipes with a metallurgical contact is the contact conductance infinite, leading to zero contact resistance, that is 1 /G,. = 0. 

Figure 10-7C. The patented COMPABLOG welded plate heat exchanger is technologically advanced, compact, and efficient. The fully welded design (but totally accessible on both sides) combines the best in performance, safety maintenance, and capital/maintenance costs. (Used by permission Vicarb Inc., Canada, publication VNT-3110 1997.)...

The shell of a heat exchanger is commonly made of carbon steel and standard pipes are used for the smaller sizes and rolled welded plate for the larger sizes (say 0.4-1.0 m). 

G. Effluent exchanger channel welds, plate, and heat-affected zone, isolated areas damaged postweld heat treatment. 

Another type is the shell- and tube-arrangement. In Fig. 4.3-23 an example with a combined inlet- and outlet chamber is shown, which is designed as a high-pressure vessel. One end of this vessel is the tube plate into which the hair-pin tubes are welded. The lower-pressure side could be connected to a low-pressure heating or cooling system. A further apparatus is the multi-tube hair-pin heat exchanger presented in Fig. 4.3-24. 

Figure 7 Various welded plate heat exchangers.

Aluminum plate-hn heat exchangers are often used as condensers in distillation and separation processes, but they require nonfouling and noncorrosive fluids. In the chemical industry, stainless steel or welded-plate heat exchangers have been used as top condensers of distillation columns, because they can be either directly installed inside the column or closely integrated outside (Figure 39),... 

Welded plate heat exchanger (courtesy of Barriquand)... 

Takeda et al. [141] described the conditions applied for the diffusion bonding of nickel-based alloys (Hastelloy). A test piece of a plate and fin heat exchanger (dimensions 40 mm x 40 mm x 3 mm, channel dimensions 1000 pm x 1000 pm) was first cleaned with a 1% solution of nitric acid and hydrogen fluoride to remove the oxidation layer. A pressure as low as 6 mPa was necessary to run the process. For NiCrFe and other materials, other authors claim that an even lower pressure of 1 pPa is required. A welding temperature of 1 150 °C and a contact pressure of... 

Figure 4.112 Monolithic counter-current heat exchanger manufactured from a stack of micro structured plates and sealed by laser welding (source IMM).

The band width in this study was limited to 150 mm but could exceed 1000 mm, thus opening a route to large-scale micro structured plate-like reactors comparable to the large-scale micro (or mini) structured heat exchangers from Heatric [96], These are manufactured by diffusion welding of stacked plates (Figure 4.114). 

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