facts you should know about dryers...
HOW TO BENEFIT THROUGH USE OF A STEAM TUBE DRYER For over 55 years, Louisville Dryers have been solving industry's drying problems and effecting marked economies. This experience can often be applied to provide unusual benefits in specific cases, possibly yours, for example . . .
Q. Since avoiding dust loss and contamination by furnace gases indicates the choice of an indirect heat rotary dryer for my material, what type of indirect dryer would you recommend? A. Unless there are abnormal conditions, we would recommend a steam tube dryer, especially if the material is heat sensitive. Q. What advantages does the steam tube dryer offer in comparison with indirect fire types? A. There are many advantages. One is ease of operation and low maintenance costs due to the definite moderate temperature (established by steam pressure) imposed on both
the material being dried and on the dryer itself. Another advantage is that there is no furnace refractory maintenance. Still another advantage is quick "warm u p " and "cool off". In many cases where the drying operation is intermittent, there is no need to shut off the steam supply or stop rotation when the wet material feed is interrupted since steam is condensed in quantity only when wet material is fed. Q. Isn't steam supposed to be an expensive drying medium? A. That depends on how the steam is used. It is true that a low overall efficiency results (often as low as 25%) when steam is used to heat air for low temperature drying. However, t h e Louisville S t e a m T u b e Dryer normally utilizes 85% or more of the available heat in the steam. By combining this with a reasonable minimum efficiency of 80% in modern
small steam generators (and higher in large boiler plants), you get an overall efficiency close to 70%. This compares with indirect fire dryers which develop an efficiency seldom higher than 50% and generally less. Q. Does material insulate the tubes by sticking to them or by clogging the spaces between tubes? A. Very few materials have this tendency to any serious extent and most of these, when properly conditioned before feeding, handle without difficulty. For the balance, no dryer using heated surfaces for heating the material is a proper application. Q. How can I be sure a Steam Tube Dryer will handle and dry my material satisfactorily? A. The General American dryer pilot plant is at your service. No charge for routine tests and demonstrations. N o obligation, either. W r i t e for test date.
PROCESS EQUIPMENT DIVISION
GENERAL
LOUISVILLE DRYING MACHINERY UNIT TRADE
MARK
GENERAL AMERICAN T R A N S P O R T A T I O N
CORPORATION
Dryer General Sales Office: 139 So. Fourth Street, Louisville 2, Kentucky Eastern Sales Office: 380 Madison Avenue, New York 17, New York In Canada: Canadian Locomotive Company, Ltd., Kingston, Ontario, Canada General Offices: 135 S. La Salle Street, Chicago 90, Illinois VOL. 50, NO. I
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JANUARY 1958
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