Heat transfer agent

CUCI2 on phenyl magnesium halides also provide reasonable quantities of diphenyl. Uses include its action as a fungistat during shipment of apples and oranges, and as a heat transfer agent (dowtherms) mixed with diphenyl ether and terphenyls. 

An alloy of sodium with potassium, NaK, is also an important heat transfer agent. 

In a suspension polymerisation monomer is suspended in water as 0.1—5-mm droplets, stabilised by protective coUoids or suspending agents. Polymerisation is initiated by a monomer-soluble initiator and takes place within the monomer droplets. The water serves as both the dispersion medium and a heat-transfer agent. Particle sise is controlled primarily by the rate of agitation and the concentration and type of suspending aids. The polymer is obtained as small beads about 0.1—5 mm in diameter, which are isolated by filtration or centrifugation. 

Fried, J. R, Heat-Transfer Agents for High-Temperature Systems, Chem. Eng, May 28 (1973) p. 89. 

In solution polymerization, monomers mix and react while dissolved in a suitable solvent or a liquid monomer under high pressure (as in the case of the manufacture of polypropylene). The solvent dilutes the monomers which helps control the polymerization rate through concentration effects. The solvent also acts as a heat sink and heat transfer agent which helps cool the locale in which polymerization occurs. A drawback to solution processes is that the solvent can sometimes be incorporated into the growing chain if it participates in a chain transfer reaction. Polymer engineers optimize the solvent to avoid this effect. An example of a polymer made via solution polymerization is poly(tetrafluoroethylene), which is better knoivn by its trade name Teflon . This commonly used commercial polymer utilizes water as the solvent during the polymerization process,... 

Uses Preparation of phenol, 4-chlorophenol, chloronitrobenzene, aniline, 2-, 3-, and 4-nitro-chlorobenzenes carrier solvent for methylene diisocyanate and pesticides solvent for paints insecticide, pesticide, and dyestuffs intermediate heat transfer agent. 

Uses. Heat transfer agent fungistat for citrus fruits in organic synthesis... 

Thermally stable fluorinated ethers have been considered for use as replacing CFCs and HCFCs in such applications as cleaning of engineering and electronic components, and working fluids and heat transfer agents. 

Thus liquid metals in nucleate boiling are excellent heat transfer agents, being superior even to water. Water in turn is definitely superior to the other common nonmetallic liquids. 

Copper appears to function only as a surface heat transfer agent. Broken pieces of porous plate, for example, may also be used. 

The fluidized-bed drier is a welded square chamber accommodating meshes and separated by two vertical partitions into three sections having individual inputs suited to receive a heat-transfer agent. T wo of the sections are used for drying granules and the third one is a cooling section. The granules are loaded and unloaded by sluice feeders. 

Heat transfer agents. Carbon dioxide gas is used for transferring heat in some nuclear power stations. 

This is used to carry out the gas/liquid reaction at the start of the process. Further along the backbone, a large cylindrical residence-time module is visible in the background. The macro-scale residence-time module consists of a wound tube heated by a heat-transfer agent. The last reactor seen at the end of the backbone on the right-hand side is the reactor where the final hydration step takes place. The entire set-up has been tested for leak tightness up to 5 bar, the pressure limit for glass reactors. 

Sodium is used as a heat transfer agent in cooling nuclear reactors. It has a relatively high specific heat and an acceptable fiquid range for the purpose. (It melts just below 100°C.)... 

According to the literature survey of Sundstrom and Hutzinger [11], there have been many patents for PCDEs and desired applications have included use as hydraulic fluids, electric insulators, flame retardants, lubricants, and plasticizers. Ethers have had wide use in industry and they appear in heat transfer agents like a mixture of diphenyl ether (73.5%) and biphenyl (26.5%), Dowtherm A [12]. Lower chlorinated PCDEs, mono- and dichlorinated, have... 

Glycerol is a polyhydric alcohol that finds wide uses in several areas of applications. These include as solvent or drugs carrier in pharmaceutical products as humectants in cosmetics and tobacco as ingredients for the production of explosives as plasticizer/stabilizer for less polar polymers as antifreeze or heat transfer agent as hydraulic fluid for the production of polyesters that can be used in grease and/or lubricants and for polyols and polyurethanes and mono and diglycerides, which are useful food emulsifiers. 

The vapor pressure of PCB can vary within a wide range. The more volatile PCBs have a vapor pressure around 40-75 mbar, which is similar to the vapor pressure of some organo-chlorine pesticides. Our own lab deodorization trials showed that PCBs and dioxins can be stripped from fish oil without degradation of the 00-3 fatty acids (eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA) provided that the deodorization pressure is very low (>2 mbar) (Table 10). Other studies showed that deodorization at 230°C and 5 mbar was insufficient to remove a PCB heat-transfer agent from contaminated rice bran oil (28). 

Some efforts have been made to design nuclear reactors in which liquid metals are used as heat transfer agents. Liquid sodium is the metal most often suggested. Liquid sodium has many attractive properties as a heat transfer agent, but it has one serious drawback. It reacts violently with water and great care must be taken, therefore, to make sure that the two materials do not come into contact with each other. 

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