Nominal steam

Recommended nominal steam rates at 60 m/s exit velocity for a typical flare tip are shown in Figure 2. At lower velocities, higher steam ratios are required. Typical steam control consists of a flow ratio controller with adjustable ratio set point, related to flare gas flow. The ratio adjustment, located in the control house, provides for the higher steam ratios necessary at low flaring rates. 

Figure 2. Nominal steam requirement for a typical flare tip.

Boiler controls have already been described in Section 2.2, so their discussion here will be limited and oriented toward power generation. The level control of the steam drum of an HRSG is very similar to that of fired boilers, except that up to 30% of nominal steam flow, a single-element controller is usually used. Above 30%, the loop is bumplessly transferred to a three-element control (Figure 2.116). 

The second heat removal system is an independent cooling system (ICS), which includes, besides a part of primary and secondary circuit equipment, a loop separator-cooling condenser with natural circulation. Via this loop the heat is removed to the intermediate circuit water. This system ensures independent (from the turbine generator systems) reactor cooling and independent reactor plant operation at a constant power level up to 6 % N om at the nominal steam pressure. In case of total RI de-energizig the system ensures cooling of the reactor over several days. Connection/disconnection of ICS is realized with no operator action and without using external power supply systems. 

A "full-capacity" steam bypass system is also provided to enable dumping the full nominal steam flow directly to the main turbine condenser in the event of certain disturbances, in order to avoid pressure surges, and corresponding power peaks, in the reactor. 

These systems, commercially known as Tberminol VP or Dowtherm A, differ from steam in some key areas which can result in operating problems unless handled properly in design (14). The low pressure—high temperature operation means that the AT/AP ratio at saturation is quite high for example, at 315°C the ratio is 25 times that of steam. This means that a pressure drop that would be nominal in a steam system (10 kPa (0.1 atm)), can not be tolerated if precise temperature control is needed. 

The drum is provided with a drawoff boot of nominal 6(X) mm diameter by 900 mm in height, with a separate steam coil fabricated from 25 mm pipe. Normally it is not necessary to withdraw hydrocarbon and water separately, and the pumpout pump takes suction from the bottom of the boot. The LL(CO)A is located as close as possible to the top of the boot to ensure that the pump is shutdown before losing suction. 

Unfired steam boilers, i.e., nominally termed waste beat boilers or, heat exchangers, which generate steam by heat interchange with other fluids (See ASME code [1] Par. U-... 

Nominal tonnage capacities range from 60-1,700 tons of refrigeration producing chilled water at 45°F. One unique feature of this system is the use of low pressure steam for the operation of the generator. 

The single-stage, single-valve turbine is the simplest option. Such a machine is suitable for applications requiring powers up to 300 kW, steam conditions up to a nominal 115 bar, 530°C and rotational speeds... 

The limitation of solvent evaporation could be avoided by working at high temperature with water vapor in the presence of a solid electrolyte (steam electrolysis). Nominally, at about 4000°C, at which AG = 0, electroless thermal water splitting would be realized. In practice, problems of material stability, necessary... 

CEI produced the Sulphlex-233/ in 7.5 ton (6.8 tonne) batches the reaction vessel has a nominal 9 ton (8.2 tonne) capacity, is steam heated, and is equipped with a wet scrubber system to control potential hydrogen sulfide emissions. Since no cooling capability was available, the reaction exotherm was controlled by the rate at which the preblended chemical modifiers were added to the reaction mass. 

The bulk of the samples for this study came from TVA s Allen Steam Plant at Memphis, Tenn. The sampling points (Figure 4) included inlet air, coal, bottom ash, precipitator inlet, and outlet at the 268-ft stack level. During the 2-week sampling period the unit was operated under steady state conditions at 240 MW (12) with a uniform coal supply so that a mass balance might be established for a number of elements. All the coal from southern Illinois was washed and crushed so that 90% was less than 4 mesh. Nominal coal analysis indicated the following composition 9.5% moisture, 34% volatiles, 43% fixed carbon, 13% ash, and 3.4% sulfur. 

Cu. 99.90% minimum P. 0.025% nominal density 8.94 g/cm. KC. 80-90% Industrial condensers, evaporators, beat-exchangers, dairy tubes, fractionating columns, keitles. pulp and paper piping, steam and water piping, tanks... 

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