Foam heat exchangers

In 1972 the chemical industry was producing about 700,000 metric tons (about 1.5 billion pounds) of chlorofluorocarbons (CFCs) per year, compounds composed entirely of carbon, chlorine, and fluorine. Most of the CFCs produced in the early 70s were either CFC-11, which is CFCI3, or CFC-12, which is CF2CI2. The development of these chemicals was considered a major triumph for the industry because they seemed to be perfect for use as aerosol propellants, solvents, expansion gases in foams, heat-exchanging fluids in air conditioners, and temperature-reducing fluids in refrigerators. 

Foam heat exchanger Foam produced from a metal-coated polymer foam Aerospace, micro-power generation, compact and micro-reactors 3,4... 

Fig. 1. Rigid bun foam line 1, material tank with agitators 2, metering pump 3, heat exchanger 4, bottom paper roU 5, conveyor 6, mixing head 7, traverse assembly 8, rising foam 9, side paper 10, adjustable side panels 11, top paper roU 12, top panels with adjustable height 13, cutoff saw...

Fig. 2. Rigid foam laminating line 1, material tank 2, agitator 3, metering pump 4, heat exchanger 5, bottom facet toU 6, bottom facet alignment device 7, top facet toU 8, top facet alignment device 9, mixing head 10, traverse assembly 11, top nip toU 12, bottom nip toU 13, take-up conveyor top belt with adjustable height 14, take-up conveyor bottom belt 15, curing oven 16, laminate 17, side-trim saws 18, cutoff saw (traversing) 19, laminated-panel stack...

Oil Expressed as oil or chloroform extractable matter, ppmw Scale, sludge and foaming in boilers impedes heat exchange undesirable In most processes Baffle separators, strainers, coagulation and filtration, diatomaceous earth filtration... 

Standard components for a bioreactor comprise the vessel, the agitator and impeller, heat exchangers, seals, and valves. Other components include utilities such as clean-in-place (CIP), and steam-in-place (SIP) systems, auxiliary tanks, pH and foam control, inlet tubes,... 

The first application of a rhodium-ligand system was realized in the LPO-process (low pressure oxo Fig. 18). Huge stirred tank reactors are used, equipped with internal heat exchangers to control the heat of reaction. The solution of the catalyst recycle is simple but efficient. The catalyst remains in the reactor, products and unconverted propene are stripped by a huge excess of synthesis gas. Because of strong foaming, only a part of the reaction volume is used. After the gas has left the reactor, the products are removed by condensing, the big part of synthesis gas is separated from the liquid products and recycled via compressors. The liquid effluent of the gas-liquid separator... 

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. 

The foam structure can be fixed by fast freezing of low expansion ratio foams. The equation of Stephan [117,118] is employed to estimate the rate of foam freezing when there is a heat exchange at its surface... 

However, since most of the plastic foams now produced commercially have a cell size below this value, the contribution of the convective heat exchange to the total heat... 

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