Bayonet heaters

Bayonet Heaters A bayonet-tube element consists of an outer and an inner tube. These elements are inserted into tanks and process vessels for heating and cooling purposes. Often the outer tube is of expensive alloy or nonmetalhc (e.g., glass, impeivdous graphite), while the inner tube is of carbon steel. In glass construction, elements with 50.8- or 76.2-mm (2- or 3-in) glass pipe [with lengths to 2.7 m (9 ft)] are in contact with the external fluid, with an inner tube of metal. 

About one half of the tantalum used in the chemical industry is employed on sulphuric acid duties, mainly in the form of multiple-tube bayonet heaters. 

Halogens (except Chlorine, bromine. Bayonet Heaters, coils, condensers. 

Hydrobromic acid Generation Bayonet heaters, coils, condensers, synthetic HBr plants... 

Hydrochloric acid Production, purification, recovery, processing Bayonet heaters, heat exchangers, coils, condensers, HCl absorbers, synthetic HCl plants, acid coolers, gas coolers, chlorine burners, strippers, thermometer wells... 

The first alternative simplifies the heat integration of the chemical process, and the second simplifies the interface between the chemical process and the secondary loop. CEA (Leybros, 2009) has designed their S-I process for the first alternative, as the requirements for the reactor expected to be used are most suitable for it. GA has developed flow sheets for both alternatives. Sandia National Laboratories (SNL) is a partner of both CEA and GA in the operation of a demonstration loop for the S-I cycle. SNL is charged with design and operation of the sulphuric acid decomposition section. They have developed a bayonet-heater design for the decomposer which incorporates internal heat recovery. As a result, the outlet temperature of the bayonet heat modules is too low to use in the HI decomposition section. Thus, helium is utilised in the HI decomposition section, as in the CEA flow sheets. 

The vacuum sulphuric acid concentrator consists of a single stage evaporator. The vacuum is maintained by a two-stage steam ejector system utilizing shell and tube inter-and after-condensers. Most of the heat required to reconcentrate the sulphuric acid is recovered as sensible heat from the reaction and is contained in the spent acid. The balance is added through a tantalum bayonet heater immersed in the evaporator body. 

Most caustic storage systems require some form of freeze protection, and the normal approach uses steam coils or bayonet heaters. The steam is regulated with a self-contained temperature control valve with a capillary system and sensing bulb in a nickel thermowell. 

Amino acids Digesting proteins in hydrochloric acid Bayonet heaters, condaisers ... 

Aqua regia Ore dissolving, pickling Bayonet heaters, pickling tank coils ... 

Ethyl ether Heating alcohol reactor Bayonet heaters ... 

Fuming nitric acid Distillation Multiple bayonet heaters, condensers ... 

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