Document 9L0d2EKnKVVvkj2pY7Q9B3b35

More PLANT PROBLEMS. AUI!>-'-.. MERS WATER-CONDITIONING SERVICE EVAPORATIVE ofl*rcoolr mount* on th roof, doe* good |ob ABSORBENT liquid In this drier takes moisture out of * R^re Answers to Problem Mo. 2 from August 1952 INSTRUMENT-AIR DRTINO is a critical used. Operation may be made fully the. cooler surface* at regular interval problem toda'y because so much pro automatic if you desire it. Photo, above right, ahowa a typical duction and manufacturing depends on } K Cubic unit using a moisture-absorbent liquid) pneumatically controlled devices. These Pittsburgh Lectrodryer Corp, It removes moisture from air as o sep- instruments must perform right every Pittsburgh, Pa. arale function from eooling or heatist rainuie of the year. Moisture that may gives precise control at all limes. Thii cause freeze-ups, rusting or poor opera is classified under type 1, above. tion of instruments must be removed. TWO OTHER METHODS of removing Either refrigeration or adsorption moisture from atmospheric air are: (1) D K Ward Niagara Blower Co, Chicago, IU.'%\ drying can be used for Instrument air. drying air with a liquid absorbent--a Bot refrigeration has definite economic continuous process (2) evaporolive cool limitations besides needing some care ing in apparatus especially designed for MOST MOISTURE causing trouble in fe'l for operation and maintenance. ' compressed-air or gas aftercooling. Air, when leaving a refrigerated Method 2 is preferable (or compressed cooler, has less moisture than when air used in tools and instruments. atrumenia can be removed with a piptfl line-type separator installed In eatfj pressor discharge line aheod of receiver^ entering, and its temperature is lower. Evaporative aflercooler, photo above, Assuming intake air is saturated it- Unleas reheated, it is 100% saturated. left, in discharge line between compres-' 70 F, it contains 1.2 lb of water per l If It passes through areas at a lower sor and receiver does a good job. High-' 1000 cu ft. Compressing this sir to 1ft WATER HARDNESS CUT TO ZERO temperature, some moisture will con temperature air passes through a cool psi and cooling to 70 F in the after-* dense in the air lines. Cooling air to s ing coil in a watertight casing through cooler reduces moisture content to 0.08 40-F dewpoint isn't too difficult but which a blower forces outside sir. Water lb per 1000 cu ft. This is only 7% cf at record rate of 240,000 gallons per hour! below this the capacity needed rises sharply. Adsorption drying reduces dewpoint of air without changing its tempera ture. At all limes the air is far from a saturated condition and no reheat is needed. Positive protection ogainst con densation of moisture at different tem perature extremes is assured. Highly saturated air leaving a re frigerated cooler con corrode and scale interior of compressed-air lines even though there is no condensation. Scale is sprayed continuously over the eoil, cooling the compressed air by,evapora* tion of moisture. In this setup the compressed air is tlways cooled to within a few degrees of the atmospheric wet-bulb tempera ture. This is tower than the dry-bulb temperature of the atmosphere. No ad ditional cooling uket place in the air lines, nor is there any further condensa tion. In winter, automatic control o( amount of air entering spray chamber the Incoming moisture; $. 'As average-aftercoolers reduce lea*'J hing-me, outdoor water-soften- ing air temperature to within 12 lo 1^ ^-,i*itgusigyssytsetemm wwaass rreecteennutlyy iinhsitaaullecduubyy F of entering water temperature, [Alli^Chslmers to meet the special Ing shown above can be accomplUbedj Voeeds of a leading midwest oil refinery, with water ai 55-56 F. About 2 "" - It fumiiha four high-pressure boilers of water is needed. '.with filtered treated water at the extraor- Cooling air to 40 F only reduces moi*] idinary rate of 240,000 gallons per lure lo 0.025 lb per 1000 cu fl. Slig^M .how -- the largest water-softening sys- additional moisture removal isn't usoanj .stem ever insulted in a.refinery power ly warranted and may be quite exp^i plt site t( h involves using refrigeration. * 1 Extremely tugged and designed for Dual-adsorption units cost four t<l JTW'fwnd operation outdoors, this Allis-Chalmers system has been in ser vice about four years. There have been no breakdowns, and maintenance costs have been practically nil. Water Conditioning service For over 30 years Allis-Chalmers has been building power generation equip ment. This experience is invaluable in providing our water conditioning spe cialists with the extensive background needed today to recommend correct equipment, chemicals and service. An expert representative is available, ready to recommend proper chemicals or help select the right process for your power plant requirements. For complete information, contact your nearby AffisChalmers District Office, or write Allis-Chalmers, Milwaukee 1, Wis. A.3VU may flake off and be carried to the in prevents freezing. Control element also five times ss much os an eftercoolefyj struments. With odsorption drying the air is at such a low relative humidity corrosion doesn't occur. activates a heating element, when neces sary. Experience with e large number of With an aftercooler you can lemo*93%' of the moisturo from the air wil^| low first cost, and low installation *n^ ALLIS-CHALMERS Adsorption dryers have fewer moving installations shows this method of mois- maintenance costs. Efficiency is goodjij ni- ;parts, need less maintenance. For con lure removal has low first cost. Only JFCiuic, Jr. OINIRAl MACHINERY DIVISION tinuous service s 'dual Installation is maintenance needed is the cleaning of PLANT OPERATION AND MAINTENANCE SECTION Worthington Corp, Harrison, N. / $1 Wll, mm PITTItUIOM, VF**..--NOt WOOD, OMIO-aOIIOM, RUSS.-Mil* MAUTi, tND. - MONTRIA1, P. O.-ll. TMOItAA ONI. * JANUARY 1953 135