Condensing capacity

Debye-Hiickel equation Debye-length Condenser capacity... 

For the actual systems, compressor work will be higher than for ideal for the isentropic efficiency and other losses. In the case of hermetic or accessible compressors where an elec trical motor is cooled by the refrigerant, condenser capacity should be ... 

If the process-steam demand is high and steac, then the exhaust size can be reduced, because not much condensing capacity is required. The choice would be to save cost by a smaller exhaust which would terminate the zero-extraction hne at C, while the total-extraction line would extend to B for rated capability. 

The dry ice condenser used with the apparatus should have sufficient condensing capacity to prevent the loss of significant amounts of methyl... 

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. 

The influence of a particular dielectric on the capacitance of a condenser is conveniently assessed by the dielectric constant, also known as the relative permittivity or rarely specific inductive capacity. This is defined as the ratio of the relative condenser capacity, using the given material as a dielectric, to the capacity of the same condenser, without dielectric, in a vacuum (or for all practical intents and purposes, air). 

Noncondensable gases at condenser temperature blanket the condenser surface and reduce the condenser capacity. 

Loss of Heat in Series Fractionation System - In series fractionation, i.e., where the bottoms from the first column feeds into the second column and the bottoms from the second feeds into the third, it is possible for the loss of heat input to a column to overpressure the following column. Loss of heat results in some of the light ends remaining with the bottoms and being transferred to the next column as feed. Under this circumstance, the overhead load of the second column may consist of its normal vapor load, plus the light ends from the first column. If the second column does not have the condensing capacity for the additional vapor load, excessive pressure could occur. 

Dividing the British thermal units per hour hy 3412 to get kilowatts, and multiplying the shaft horsepower hy 0.746, also to get kilowatts, and then adding, we get the condenser capacity ... 

Fig. 2.42 Condensation capacity of the condenser (surface area avaiiabie to condensation 1 rrf) as a function of intake pressure pp, of the water vapor. Curve a Cooling water temperature 12°C. Curve b Temperature 25 X. Consumption in both cases 1 mVh at 3 bar overpressure.

As a precaution, therefore, a Roots pump should always be inserted in front of the condenser at low inlet pressures so that the condensation capacity is essentially enhanced. The condensation capacity does not depend only on the vapor pressure, but also on the refrigerant temperature. At low vapor pressures, therefore, effective condensation can be obtained only if the refrigerant temperature is correspondingly low. At vapor pressures below 6.5 mbar, for example, the insertion of a condenser is sensible only if the refrigerant temperature is less than 0 °C. Often at low pressures a gas -vapor mixture with unsaturated water vapor is pumped (for further details, see Section 2.1.5). In general, then, one can dispense with the condenser. 

Most of the lines in the are spectrum are easily reversed. In order to differentiate the arc and spark spectra Buffam and Ireton 5 used an under-water oscillatory condenser discharge with a suitable condenser capacity in the circuit the spectra were produced between poles of metallic arsenic in a vessel through which water circulated continuously, and were photographed by means of Hilger spectrographs. The arc lines were inverted on a dark continuous background, while the spark lines were not. 

Naturally, we do not want to overpressure the tower, and pop open the safety relief valve. Alternatively, if the tower pressure gets too low, we could not condense the reflux. Then, the liquid level in the reflux drum would fall and the reflux pump would lose suction and cavitate. But assuming that we have plenty of condensing capacity, and are operating well below the relief valve set pressure, why do we attempt to fix the tower pressure Further, how do we know what pressure target to select ... 

Another reason to raise tower pressure is to permit higher reflux rates. If the pressure controller in Fig. 3.1 is set too low, then during hot weather, when condenser capacity becomes marginal, the level in the reflux drum will be lost. If we then raise the pressure set point, the drum will refill—but why ... 

One common error made in monitoring the performance of surface condensers is the practice of considering the hot-well temperatures, as if it were the true condensing temperature. It is the vapor outlet temperature, which is the real surface condenser temperature. A decrease in the hot-well temperature, resulting from a high hot-well water level, is not an indication of improved condenser performance. It is a sign of reduced condenser capacity. 

Once a liquid level reappears in the reflux drum, the condenser capacity has been exceeded. The level in the condenser will continue falling, until the drum empties, and the reflux pump begins to cavitate. 

A vapor trap having a wide-bore inlet tube and the appropriate condensate capacity is used. The checkers used a 4.8 cm. x 30.0 cm. trap having a 2,0 cm. x 18.0 cm. inlet tube. Best results are obtained when the trap is connected directly to the flask or the adapter (see Note 2) by a wide-bore tube. Ground-glass joints should be used throughout the apparatus. 

Shelf heating rate Shelf cooling rate Shelf temperature control Condenser cooling System evacuation rate Pressure control Leak test Sublimation rate Condenser capacity... 

Run 1 rsh = 20 °C, controlled operation pressure pc = 0.2 mbar, Tke measured e.g. -32 °C. In this test three things can happen (1) the test runs as planned (2) a pc of 0.2 mbar cannot be maintained and the pressure rises to e.g. 0.4 mbar the amount of water vapor produced under these conditions cannot be transported to the condenser, as 0.4 mbar is needed (the reason could also be the condenser capacity, which can be identified by a rising condenser temperature) (3) pc = 0.2 mbar cannot be reached the surface of the shelves or the heat transfer from the brine to the subli-... 

A cooled solution of 60 g. (1.365 moles) of freshly distilled acetaldehyde in 200 ml. of dry ether (Note 4) is added through the dropping funnel during 2-3.5 hours, as rapidly as the condenser capacity permits. The mixture is stirred and heated under reflux for 1 hour after the addition is completed. 

On the other hand, there is the question of the close relationship between coke formation (catalyst stability) and aromatics cyclization (catalyst selectivity) over the acid sites present in the zeolites. On naphtha reforming, coke formation is a bifunctional reaction requiring the dehydrogenation capacity of the metallic function and the condensation capacity of the acidic function. Therefore, it is interesting to... 

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