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Noncondensing operation

Separation of mixtures of condensable and non-condensable components. If a fluid mixture contains both condensable and noncondensable components, then a partial condensation followed by a simple phase separator often can give a food separation. This is essentially a single-stage distillation operation. It is a special case that deserves attention in some detail later. [Pg.75]

In this condenser, part of the stripper off-gases are condensed (the heat of condensation is used to generate low pressure steam). The carbamate formed and noncondensed NH and CO2 are put into the reactor bottom and conversion of the carbamate into urea takes place. The reactor is sized to allow enough residence time for the reaction to approach equiUbrium. The heat required for the urea reaction and for heating the solution is suppHed by additional condensation of NH and CO2. The reactor which is lined with 316 L stainless steel, contains sieve trays to provide good contact between the gas and Hquid phases and to prevent back-mixing. The stripper tubes are 25-22-2 stainless steel. Some strippers are still in service after almost 30 years of operation. [Pg.304]

I eon—Helium Separation and Purification. As indicated eadier, neon, heHum, and hydrogen do not Hquefy in the high pressure (nitrogen) column because these condense at much lower temperatures than nitrogen. As withdrawn, the noncondensable stream has a neon—helium content that varies 1—12% in nitrogen, depending on the rate of withdrawal and elements of condenser design and plant operation. [Pg.11]

Enerco, Inc. (Yardley, Pennsylvania) has a 600 tine/d demonstration pyrolysis plant located in Indiana, Pennsylvania. The faciUty operated 8 h/d, 5 d/wk for six months. The process involves pyrolysis in a 5.4 t/d batch-operated retort chamber. The heated tines are broken down to cmde oil, noncondensable gases, pyrolytic filter, steel (qv), and fabric waste. In this process, hot gases are fed direcdy to the mbber rather than using indirect heating as in most other pyrolyses. The pyrolysis plant was not operating as of early 1996. [Pg.15]

Favor condensation (a simple and cheap unit operation) for removal of high boilers from noncondensable gases when cooling water can be used as the condensing medium. [Pg.458]

Process Description. Reactors used in the vapor-phase synthesis of thiophene and aLkylthiophenes are all multitubular, fixed-bed catalytic reactors operating at atmospheric pressure, or up to 10 kPa and with hot-air circulation on the shell, or salt bath heating, maintaining reaction temperatures in the range of 400—500°C. The feedstocks, in the appropriate molar ratio, are vaporized and passed through the catalyst bed. Condensation gives the cmde product mixture noncondensable vapors are vented to the incinerator. [Pg.20]

Offset design gives ready access along the axis of the hot 2one. This design permits routine operation and cycling of the furnace without sacrificing control of containination, access, and speed for condensables or noncondensables. [Pg.377]

Drying is an operation in which volatile Hquids are separated by vaporization from soHds, slurries, and solutions to yield soHd products. In dehydration, vegetable and animal materials are dried to less than their natural moisture contents, or water of crystallization is removed from hydrates. In freeze drying (lyophilization), wet material is cooled to freeze the Hquid vaporization occurs by sublimation. Gas drying is the separation of condensable vapors from noncondensable gases by cooling, adsorption (qv), or absorption (qv) (see also Adsorption, gas separation). Evaporation (qv) differs from drying in that feed and product are both pumpable fluids. [Pg.237]

Table 29-4 lists several applications of condensers currently in use. For most operations listed, air and noncondensable gases should be kept to a minimum, as they tend to reduce condenser capacity. [Pg.480]

For a steam coil to operate efficiently, it must have all the latent heat in the steam. This is achieved by the use of a steam trap. The correct trap type must be selected for the particular application in order to prevent waterlogging. All condensate, air, or other noncondensable must be removed from the system without delay otherwise,... [Pg.712]

Most steam turbines operate in the condensing (of steam on exhaust from turbine) mode or noncondensing or backpressure mode. (Steam is exhausted or extracted from the turbine at preselected exhaust pressure for other uses.) See Figures 14-17A-C, 14-18A, 14-18B, 14-19A, 14-19B, 14-20A, and 14-20B. [Pg.662]

The steam turbine is operated noncondensing when the exhaust steam is not condensed but passes into a low-pressure distribution system for additional use and heat recovery, Figure 14-18B. [Pg.662]

The turbine applied to driving mechanical equipment is not operated (very often) with extraction or bleed streams. Here again, this depends upon the plant steam balance, and this is one of the fine features of steam turbine drive. The flexibility of design and application allow it to be set in the proper place for the economic balance of a system. The decision as to condensing or noncondensing should not be... [Pg.662]

The efficiency of the condenser is reduced by poor air removal (and the presence of other noncondensable gases), so surface condensers usually are equipped with vacuum pumps but also may incorporate older style, single or multistage multielement, steam-jet air ejectors. Under most normal operations, the residual oxygen level is below 20 to 40 ppb 02. [Pg.117]

The pressure in condenser A is greater than that in the surface condenser, and less than that in the final condenser (condenser B). This means that condenser A is operating at vacuum conditions. This prevents the condensed steam formed in condenser A from draining out to atmospheric pressure, unless the condenser is elevated by 10 to 15 ft. To avoid this problem, the condensate is drained back to the lower-pressure surface condenser. To prevent blowing the noncondensable vapors back to the surface condenser as well, a loop seal is required. The height of this loop seal must be greater than the difference in pressure (expressed in ft of water) between the surface condenser and the primary jet discharge condenser (condenser A). [Pg.222]

Finally, the receiver will accumulate any noncondensable (or hard-to-condense) components that have accidentally entered the system. Air left in the vessels on start-up is one such example. Traces of methane and ethane in a propane refrigerant system is another. These light vapors may be vented from the top of the receiver during normal operations. [Pg.294]

Details on pumps, manometers, vacuum gauges, special apparatus, and leak testing are given in Chapters 6-10. It is the purpose of the remainder of this chapter to describe the transfer of condensable and noncondensable gases, trap-to-trap fractional separation of volatiles, and the use of vapor pressure in the characterization of volatile compounds. These operations are basic to practically all chemical vacuum line work. [Pg.57]


See other pages where Noncondensing operation is mentioned: [Pg.268]    [Pg.268]    [Pg.141]    [Pg.266]    [Pg.10]    [Pg.10]    [Pg.11]    [Pg.14]    [Pg.103]    [Pg.167]    [Pg.475]    [Pg.478]    [Pg.478]    [Pg.1147]    [Pg.1193]    [Pg.2299]    [Pg.515]    [Pg.241]    [Pg.100]    [Pg.143]    [Pg.141]    [Pg.177]    [Pg.156]    [Pg.89]    [Pg.955]    [Pg.180]    [Pg.14]    [Pg.266]    [Pg.164]    [Pg.204]    [Pg.141]   
See also in sourсe #XX -- [ Pg.268 ]




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