Plate heat-exchanger

Fig. 10. Plate-—coil heat exchangers. Plate—coil is a very efficient and versatile prime surface-type heat exchanger.

Heat exchanger, plate A heat exchanger in which the fluids are separated by a thin plate as opposed to a tube. 

For those condensing duties where permissible pressure loss is less than 0.07kpf/cm there is no doubt but that the tubular unit is most efficient. Under such pressure-drop conditions only a portion of the length of a plate heat exchanger plate would be used and a substantial surface area would be wasted. However, when less restrictive pressure drops are available the plate heat exchanger becomes an excellent condenser, since very high heat transfer coefficients are obtained and the condensation can be carried out in a single pass across the plate. 

For new components, the nickel coating is usually 25-250 im thick. Normally, the deposits are not machined. Applications include pump bodies, laundry plates, heat exchanger plates, evaporator tubes, alkaline battery cases and food-handling equipment of various sorts. 

Heat exchange plate material Copper Temperature stability Up to 180 °C... 

The micro bubble column comprises internal cooling via heat conduction from the reaction zone to a mini channel heat exchanger [3, 9, 10], Either two such heat exchange plates can encompass the reaction plate, or only one. In the latter case, the free position is occupied by an inspection window which allows direct observation of the quality of the flow patterns. 

A typical evaporative recovery system consists of an evaporator, a feed pump, and a heat exchanger. Plating solution or rinsewater containing dilute plating chemicals is circulated through the evaporator. The water evaporates and concentrates the plating chemicals for reuse. In open evaporator systems, the water evaporates and mixes with air and is released to the atmosphere. It may be necessary to vent the contaminated airstream to a ventilation/scrubber treatment system prior to release. In enclosed evaporators the water is condensed from the air and can be reused in rinses, which further increases savings. Water reuse is preferred whenever possible. 

For applications where viscosities or product concentrations are high, APV have developed the Paravap evaporator in which corrugated-plate heat exchanger plates are... 

A bench-scale evaporator was built first, consisting of the nickel foam monolith and heat exchanger plates 5.7 cm wide and 7 cm long. The stainless-steel channels fabricated by EDM were 254 pm deep and the vapor channel depth was varied from aspect ratios of 4 to 18, the latter being the optimum value determined by experiments. 

Tonkovich and coworkers [42—47] used packed bed microreactors for the production of hydrogen. The authors constructed a reactor consisting of stacked stainless steel plates for the partial oxidation of methane [42]. The microchannels (which were 254 pm wide, 1500 pm deep, and 35 mm long) were filled with mesoporous silica that was impregnated with rhodium. The reactor plates were sandwiched between two integrated heat exchanger plates. 

In addition to the individual polymer electrolyte membrane fuel cells and their bipolar plates, special heat-exchanger plates must also be included in the battery stack. Cooling fluid is circulated through these plates in order to eliminate the heat produced during battery operation. At least one such plate must be provided for any two cells when the battery is to be operated with high current densities. These plates could also be used to warm up the battery for a cold start-up. 

Continuous Cooling tower, electric heater, fired heater, heat exchanger, heat exchanger plate, heat exchanger shell and tube, refrigeration unit... 

Alternative designs are very similar to plate heat exchangers, in which the supported membrane replaces the heat-exchanger plates. These modules may be open or closed to the outside on the permeate side, with internal ducts for feed and retentate and, when closed, for permeate removal. It has been proposed to integrate plate heat exchangers as preheaters and permeate condenser into such modules. 

Figure 5.11 Channel structure of a microreactor plate between two heat exchanger plates [17]. (Adapted with permission from Elsevier.)...

McGeorge, H. D. Marine Auxiliary Machinery. 7th ed. Burlington, Mass. Butterworth-Heinemann, 1995. Excellent descriptions of shell-and-tube heat exchangers, plate heat exchangers, and deaerators are provided in very readable form, including a simple presentation of heat exchanger theory. 

Type of heat exchanger Plate and frame (gaskets) Fully welded plate (Alfarex) Brazed plate Spiral Brazed plate-fin Diffusion- bonded plate-fin Printed circuit Polymer (e.g. channel- plate) Chart-flo... 

Figure 4.10 Polymer film cross-flow heat exchanger plates.

HEAT EXCHANGING PLATES SURROUND THE KILN (ABSORBER)... 

The absorber consists of 12 individual level heat exchanging plates. These are so-called thermo-plates plates which are joined together and subsequently expanded hydraulically. On the side facing the kiln they are painted with black absorber varnish and are equipped with weatherproof thermal insulation on the rear side. 

In addition to the individual cells and their bipolar plates, special heat-exchanger plates must be included in the battery stack. Cooling fluid is circulated... 

The traditional structure of a fuel battery is that of a vertical stack of alternating bipolar plates, MEAs, and heat-exchange plates that is compressed with the aid of massive end plates and tie bolts. This structure is poorly adapted for building mini-fuel plants. Particularly for the applications mentioned, special small fuel cells are needed that have design principles different from those of their large cousins. 

Hay, M. G., Baron, J. J., and Moffat, T. A., 1996, Elastomer Induced Crevice Cmrosirm and Stress Corrosion Cracking of Stainless Steel Heat Exchanger Plates in Sour Amine Service, paper presented at Corrosion 96, The NACE International Aimual Conference and Exposition, Paper No. 389, Denver, CO, March 24-29. 

Recuperative systems use conventional shell-and-tube or plate-type heat exchangers. Plate-type units are reported to be more economical for low to moderate temperature service (to about 1,000°F), while shell and tube are preferable for higher temperatures (van der Vaart et al., 1990). Because of the temperature limitations of conventional heat exchangers, recuperative systems are normally designed to heat the feed gas to no more than l,200°F. A conventional. shell-and-tube recuperative system can typically recover 60 to 80% of the available energy. 

A number of heat exchanger configurations were reviewed within the gas cooler scoping phase. These configurations consisted of a variety of compact heat exchangers (plate/fin, chemically etched, and hybrid designs), and shell-and-tube designs. 

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