Vacuum condensing point

V band spect Absorption bands that appear in the ultraviolet part of the spectrum due to color centers produced in potassium bromide by exposure of the crystal at temperature of liquid nitrogen (81 K) to intense penetrating x-rays. ve. band ( vcp See vacuum condensing point. 

Fig. 9.11. The vapor-pressure thermometer. The manometer is filled as described in the caption to Fig. 7.1. The manometer is then evacuated and outgassed through a joint attached at point A. A pure compound is condensed into the probe, and the apparatus is sealed off under vacuum at point A. For thermometric compounds which boil below room temperature, care must be taken not to overfill the apparatus.

The difference of temperature between the shelves and the condenser results in a vapor pressure difference above the ice, also called driving force, which is an essential factor in the sublimation rate. The colder is the ice condenser, the higher is the driving force for the same shelf temperature and pressure (vacuum) set point. This also means that for an identical shelf temperature profile and pressure (vacuum) set point, the sublimation rate can vary in relation to the condenser temperature. 

P-2.1 Recommendations for Medical-Surgical Vacuum Systems in Health Care Facilities. Applies to piped vacuum systems in hospitals but not to systems used for vacuum cleaning or as a vacuum condensate return. Covers requirements for central vacuum supply systems with control equipment, piping system to points in the hospital where suction may be required, and suitable outlet valves at point of use. (8 pages)... 

The process operates at 1 kPa (10 mbars) and 450 kW of power. When the condenser temperature reaches 580°C, the power is reduced to 350 kW. Cooling water is appHed to the condenser, throughout distillation, by means of sprays. Normally distillation takes 10—12 hours and the end point is signified by an increase in furnace temperature and a decrease in vapor temperature to 500—520°C. At this point the power is turned off and the vacuum pump is shut down. Nitrogen is then bled into the system to prevent oxidation of 2inc. 

In filter operation, it is essential that the gas be kept above its dew point to avoid water-vapor condensation on the bags and resiilting plugging of the bag pores. However, fabric filters have been used successfully in steam atmospheres, such as those encountered in vacuum diyers. In such cases, the housing is generally steam-traced. 

One of the most important operations in a refinery is the initial distillation of the crude oil into its various boiling point fractions. Distillation involves the heating, vaporization, fractionation, condensation, and cooling of feedstocks. This subsection discusses the atmospheric and vacuum distillation processes which when used in sequence result in lower costs and higher efficiencies. This subsection also discusses the important first step of desalting the crude oil prior to distillation. 

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