
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, June 8, 1990                   TAG: 9006080729
SECTION: EDITORIAL                    PAGE: A6   EDITION: METRO 
SOURCE: 
DATELINE:                                 LENGTH: Short

SOME FACTS ABOUT STEAM GENERATION

THE WRITER of a recent letter about steam generation in Buena Vista seems to need more basic engineering facts about power plants.

First, no commercial, industrial or utility boilers manufactured in the last 50 years were designed to waste unneeded steam. A 100,000 lb./hr. boiler will produce only that amount which the load or "end user" requires. Automated controls allow the boiler to produce only what is needed by the consumer.

Venting or condensing unused steam would be prohibitively costly. Water used for steam is highly purified before using. The return of all used steam or "condensate" to be reused is one of the most important parts of efficiency in power plants.

As for cooling towers, they are not used to condense waste steam, but rather to cool liquids used in process operations.

Most steam boilers and associate turbo-generators return all water back to rivers from which they were pumped for condensed cooling, not cooling towers. If all steam produced in a modern boiler was condensed back to water and returned to the river from which it came, it would be many times purer and only slightly higher in temperature. A quick call to Virginia Tech's engineering department will most probably get you a pamphlet on steam generation.

\ B.J. MARTIN\ ROCKY MOUNT

by CNB