Steam circulator

Boiler Design Issues Boiler design involves the interaction of many variables water-steam circulation, fuel characteristics, firing systems and heat input, and heat transfer. The furnace enclosure is one of the most critical components of a steam generator and must be conservatively designed to assure high boiler availability. The furnace... 

Most industrial installations have a boiler of some kind this boiler and its steam user form a circuit in which water and steam circulates. Loose use of nomenclature sometimes leads to confusion, and it is therefore useful to define the various waters in it ... 

Some boiler plant designs employ a vacuum pump CR system because this type of system requires less steam pressure to flow up a riser. Thus, greater steam circulation can be obtained, giving rise to an increased heat transfer rate. 

Also called hot air cure. A method of curing, mainly used for footwear. The articles are placed in a double-walled vulcaniser, the heat for curing being obtained from steam circulating between the double walls. Steam does not therefore come in contact with the articles in the vulcaniser itself. Dry Rubber Compound... 

The method of vulcanising those rubber products which do not require the precision of shape given by a mould. The heat for curing is supplied by steam circulating openly in an autoclave, the products being supported on mandrels or embedded in chalk. See Moulding. 

Several refineries in Europe employ the Pro-Abd refiner to upgrade whizzed naphthalene to phthalic-grade quality or to convert the latter into the purer chemical grade. The device consists of a rectangular tank fitted with a nest of coils through which either steam or water circulates. The tank is filled with the feedstock, which is crystallized by circulating cold water in the coils. When the contents of the tank have solidified, a tap at the base is opened and hot water is circulated until the temperature is just below the desired crystallizing point of the product. This condition is maintained until no more oil drains from the base. The bottom tap is then closed and the contents of the tank are melted by steam circulation and drained. 

In the corresponding calculation for Hj an alternative way has to be found to calculate the output of the steam circulator, since steam is highly imperfect. The steam is expanded isothermally at 25 °C, from standard pressure, 1 bar, saturated to standard partial pressure 0.0088 bar. A minor extrapolation of the Mollier chart gives G, = H-TS = 2590 - 2555.14 and Gf = 2590 - 2745.96. Hence AG = — 190.82kWskg and AG = 3.435kWsmoP (steam circulator). 

The stability of the main boiler steam cycle has been excellent. The large openings that were made for the low Btu gas burners have not caused any disturbances in the water/steam circulation system. Furthermore, as regards the operation of the product gas burners, the product gas combustion has been stable even though the moisture content of the solid fuel has been mostly high and the heating value of the gas very low. The stability of the main boiler coal burners has been normal despite the fact that the product gas burners were integrated very close to the... 

Three principal variants of steam treatment are (a) cyclical steam injection (steam soak or "huff and puff ) (b) steam circulation technique and (c) area steam injection (steam flooding) (see Fig. 18). 

Fig. 18. Three techniques of steam injection into the reservoir and bottomhole zone a -steam soak b-steam circulation c-steam flooding...

If such factors as heat loss and the difficulty of process control are ignored, it is theoretically possible to displace all of the crude oil from a "clean porous reservoir by continuous injection of steam. But in practice, in the oil fields with reservoirs of both micro- and macroporosity types, this process cannot be carried out to completion. The three principal limiting factors are the escape of heat through the reservoirs of macroporosity type, further large heat losses that occur in the well column, and the inability to strictly control the movement of the heat carrier. Under these conditions, the employment of conventional steam soak, steam circulation, or steam... 

In a plant, both the steam pressure and temperature may be reduced for process steam use. This is because the process equipment is not rated for the high pressure and temperature. Also, steam latent heat at lower pressure is higher so less steam circulation is required with lower pressure steam. The device for reducing pressure is the steam letdown valve. 

Water - steam circulation mode Forced convection... 

The core outlet temperature is set to 900°C, which is below what has been, or will be demonstrated, by the fuels in AVR (Arbeitsgemeinschaft Versuchs Reaktor), HTR-10, HTTR (High Temperature Test Reactor), etc. No safety hazard of water or steam ingress into the primary system exists, since all water and steam circulation is remotely located in the third loop. The nitrogen heater is essentially pressure balanced with a slightly higher secondary pressure to ensure that no fission products enter the secondary system in case of leaking tubes. 

The nitrobenzene is placed in a reducer, which is a vertical cylindrical vessel provided with cover, steam jacket, and agitator. The iron turnings, or powder, and a small amount of hydrochloric acid are added in small portions. A brisk reaction is maintained by means of steam circulated in the jacket of the reducer or blown directly into the charge. A condenser returns to the reducer any vapors that escape. After the nitrobenzene is completely converted to aniline, a strong current of live steam is passed into the charge a mixture of steam and aniline vapors passes to the condenser and is collected in storage tanks. The bulk of the aniline separates as a lower layer and is drawn off the water over... 

Fig. B.24 Diagram of SWPR for the versions with steam circulation by steam blowers (a) and by jet pumps (b) (Taken from ref. [3])...

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