Subatmospheric pressure development

A plant producing 2 kg of B per year by equilibrium distillation of the complex of BF3 and diethyl ether, BF3 (CjHj)jO, was operated by 20th Century Electronics, Ltd., in New Addington, England [El]. The process, developed by the U.K. Atomic Energy Authority (UKAEA), is generally similar to the U.S. process using the dimethyl ether complex. Both plants ate operated at subatmospheric pressure, to minimize ineversible decomposition of the complex. 

The vapor is drawn into a steam jet (discussed in Chap. 16). The steam condensate flows into the boot or hot well. The water in the boot is slightly subcooled. This is accomplished by a pair of baffles that create a small zone of condensate backup. The subcooled condensate, cooled to perhaps 10°F below its boiling or bubbling point, is easier to pump. As the pressure in the hot well is subatmospheric, the hot-well pump typically develops a AP of at least 30 to 50 psi. 

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