Document N2JBzXBgowXxMGO8w60Z2px8y

H*oi exchanger lor generoitng sloom (2 io ISO pslg) from high-temp woter 5 Piping layout lor a typtcol vertical direct-contact cas cade heater lor o hlgh-temperoture water-heating tyitem. Consider High-Temperature Water foi Your Process and Space-Heating Jobs \\ Tick off the plants that can use hlgh-temperature water in process and heating systems and you'll have an impressive list. Here's a quick review of latest design thinking of importance to all future users By ALEXANDER KUll, Inghmr American District 5t*om Co. Inc Urcause they outlike principles of a system not yet widely accepted in Americs, Owen IJeberg's articles on high pressure high - temperature hot water were moil welcome (Power. Muy and June 1952). European engineers have obtained excellent results with this system (or many years, but only in the last 25 years have American engineers given it much thought. Origins. H-p h-t hot water is not a completely new idea. Its forerunner, the Perkins heating system, was used in England and on the Continent more than 100 years ago. This system was closed hut had no circulating pump, the heart Aram "r**-- of the modern h-p h-t installation. Man of the early English systems are it! running today. Advantages. Good points of h-p h systems of interest to all engineers b elude: (1) Completely elosed pipla, system of simple design does not aea condensate-return equipment or pres Mire reducers. (2) Negligible mskeoj reduces amount of water treatment .needed. (3) Boilers are scale-free, haw high efficiency. (4) In space heatias output ia easily controlled. (S) Piping system has small temperature dropobout 3 F per mile. (6) There is as pipe corrosion. (7) Maintenance con SectIan A-A Ivr limple piping snd valves is low. [>' (8) Pipeline is easy to install because i . it follows ground contour*. (9) System , has large heat-storage capacity that redaces peak loads on boilers, equalises heat`demand and production. (10) There is no water hammer. Chief advantages are fuel and main' lenance sa.vioga together with productive I ity inereue from more exact tempera. lure control These are important in j.'. plywood,-rubber, plastics, textile, fond processing and other Industries. Fuel savings of 25 to 40% ore recorded in many plants in Germany, Switzerloml, Aastria, Italy, France end other Euro> pean countries where steam-heating aysl terns were converted to h-p h-t water. th'Numbcrg s large electric company Fis presently converting from steam to h-p h-t water end has saved 43% in fuel by eliminating the condensate re ! turn line. What Is It? High-temperature water is water betted to above 212 F, the bull ing point at atmospheric pressure. Its pressure corresponds to the saturation value at the given temperature. Though called by a number of differ ent names, including high-pressure hot water, high-pressure high-temperature water, superheated water, high-temperalure hot water and high-temperature (h-t) ureter, [ believe the last it the best and briefest name. We will use it throughout the remainder of the article. Conversions. Many engineers ac knowledge that this system is the njost economical and efficient for new plants but object to converting on existing steam system to h-t water because of high cost. Though labor costs more in America than In Europe, while fuel it cheaper, no plant should overlook a fuel saving of 30% or more. This is just what h-t water offers. H-t water lowers production costs. Conversion from steam to h-t water docs not have to be dune overnight; it can be carried out gradually. Eighty per cent of h-t woter installations replace former steam systems. Usually conversion was gradually made. Unila like that in Fig. 5 help in aystem conversion. Cascodo Heaters. These, Fig. 4 and 5, use live or bled steam to generate h-t water. An expansion vessel with waterlevel control, it has a aeries of waterdispersing units called coscndes or trays. These expose a Inrge surface of the water for fast, efficient heat absorption. Steam enters heater top, filling vessel to waler level. Water entering heater side comes in direct contact with steam, condensing it. Level of water U auto matically controlled, surplus water being discharged through condensate return main to the boiler. Surplus water Is usually taken from heater return line. Fig. S. Water el this point is the coldest in the system. Circulating pump below heeler forces F-* Avan i i i j This it one way of hooking up a high-temperature woter accumulator. Control may be either manual or automatic 7High-presture iteel radiotori or* widely used In Europe for hooting 9tloioge copoclty ol h-t woter system Heat exchanger using h-t woter re places boiler in hot-water heating Hookup ro generoto steam trom h-t woter tn o tubular heot exchonger 96 ENGINEERING AND MANAGEMENT SECTION ENGINEERING ANp MANAGEMENT SECTION 97