Plate heat exchangers selection

The authors provide selection criteria, by which the suitability of a process for a distributed production can be assessed [139]. These are explicitly given for the categories of feedstock, processes, customer products, and waste products. This is completed by a list of suitable device types for distributed production such as plate heat exchangers, pressure and temperature swing units, electrostatic dispersers, and membrane units. The various operations often rely on the use of electricity and therefore are said to be particularly suited for operation at the mini scale. 

Description The spiral-plate heat exchanger (SHE) may be one exchanger selected primarily on its virtues and not on its initial cost. SHEs offer high reliability and on-line performance in many severely fouling services such as slurries. 

TABLE 17.3 A Guide for Selection of Plate Heat Exchangers [6]... 

Reuse et al. [16] combined endothermic methanol steam reforming with exothermic methanol combustion in a plate heat exchanger reactor, which was composed of a stack of 40 foils (Figure 24.5). Each foil carried 34 S-shaped channels. Cu/ZnO catalyst from Siid-Chemie (G-66MR) was coated into the channel system for the steam reforming reaction. Cobalt oxide catalyst served for the combustion reaction. The reactor was operated in co-current mode. The steam reformer was operated at a S/C ratio of 1.2. At reaction temperatures between 250 and 260 °C, more than 95% conversion and more than 95% carbon dioxide selectivity were achieved. 

Heat exchangers used in gas production facilities are shell-and-tube, double-pipe, plate-and-frame, bath-type, forced-air, or direct-fired. In this chapter we will discuss the basic concepts for sizing and selecting heat exchangers. This is just a brief overview of this complex subject and is meant to provide the reader with a basis upon which to discuss specific sizing and selection details with heat exchange experts in engineering companies and with vendors. 

In forming a comparison between plate and tubular heat exchangers there are a number of guidelines which will generally assist in the selection of the optimum exchanger for any application. In summary, these are ... 

The table below offers several generalized comparisons to aid in selecting among shell-and-tube, plate, and spiral heat exchangers. 

The type of heat exchanger to be selected depends primarily on the type of fluids involved, the size and weight limitations, and the presence of any phase-change pmetsses, For example, a heat exchanger is suitable to cool a liquid by a gas it the surface area on the gas side is many limes that on the liquid side. On tile other hand, a plate or shell-and-tube heat exchanger is very suitable for cooling a liquid by another liquid. 

The heat recovery heat exchanger is of flat-plate type Fig. 9). This construction was selected because of the low investment costs. Primary flow is moist, nearly saturated exhaust air from the drying silo, The secondary flow is outdoor air, which is used as combustion air and drying air. 

For the precooler, the helical coil type heat exchanger which has proven results for various machine type has been selected and the low-fin tube has been employed to reduce the height. If a plate-firmed or fin-and-tube type heat exchanger is employed for the precooler, it can reduce the installation space for the precooler. This subject will be dealt Avith in the next stage of our research work. 

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