Document 8VbZEoMwZDR8gD2RGd01d64ga

T A B L E 112. CUBIC IN C H ES OF A M M O N IA VAPOR TO BE C IR C U L A T E D TO PRODUCE ONE TON American Society of Heating and Ventilating Engineers Guide, 1924-25 mr-"O^OOO''3OaOO^TOjO,'0LcONQOtO/^iO0O0CO'OOO>NQ^O^.Oc0Q^Oa' ........................................... - 00 r- r JOOOOOOOOOOOOOO SfO-HCOOOOOO'H^HOOOiN^*^10 u'jiO'-d'Ttr^C'l*--'-O -- -- -- n ^ *3 to co 8u'>0vr.Q000000'>'r>< <oofOOO(*5ooOr4>oO'^`'-t2r' ? to > o vtC--tN>t"- aoOi/>jt-o? ^ to fO <) *OOOOOOl/>0OOOQOOQOO,>0^> cof'*-`'--r^e*S^,oo'OOCS*--e,'i'OC`>Jooioe'i ---------- - oor- io >o ^ fo to to 'OifliO^'^'fONM^OO `OOOOOOOOOOOtoOOQtOOOOOOtO t^^5o-'0oCttio0\'5`Oirf'^0>>0nt>--NM^o0o'0r''''O5'eooOo0^>'0N*fr'9--0O22Nj - - . ------- -oo oo to o to to to io to ^ to to cn *- -- o o i0*000O0i00*00OOOOO0OOOQ0O fOOOfOOOfOtOOO -- lOONO'OI,*00'HlO'f'V'"1 . - . - - 1 - - - - -oo oo t"- to o Tt* Tf to to to lOiO'ftl'fOtONH^OO OOOOOQOQOOOtoOO^JOOQOu^OQ lOr'fO',"^'OCo5N`0NOiNO>tOOOtO^`/) r*rtiO'-N'0'00^,0'00'^'0sOtnQN^^ - - - ------ -O0 f- *" to ^ 5* to to to imoTt'tfOtotN'-'-O trOgioO^OcMOTtotrO^--OQOO-- Or^uODOCOOCONO-HOO^O*ctsOtoQO-- lOTC^'^-tOOf,OOCtOs4NtO^O00Ot-00O0tOo0^0^'tO0^tOg^'3PJS^?tO'-- OOOOOOOOOOOtoOOOtoOOOOOO (O^ifn-TN*t<^rN>jOtoO^|Or>fjO^,t^-o--oC^Nitt^s>--t-s<--<0o'0^H0Oito0r~0'--ictNt)t0^-------- - - 00 *"* to ^ ^ to to to to tO to fO C'J CN -- O O gOOOtOOtoOtOOOOOOOOOOOQOO to5^t'tOtO'ON'f^^-'^*--N(tSW5"<-"OOOM r-lOO'OO'OOOr-lOOtOtO'O -- i'tOeOtOO'tOOlO ....................................................- 00*'" f'- O to O* O* to toto to tOTj-TttOtOM-'-OO 0000*0000000000to000000 0DMCt500OO*-OOlO'H<NTl'00lO>OiHrl00 OOfOOOtOOO^'t^-0^`CO^CM`OOfO^,^*C>IOOtOC^- ---- --- - -OOC- t-- to to<5* **tO CO fOC4 tt^fOtONN-^O 'OtOOi'0^`*-*00'0^`^|i^Ots,f>*fO^O>OOOMtO^ fONOOiWN^MOOO'O-N^O'O'-iN^'OO^ <OfOfOCMCNCNf'tC'*CS-i -- -* j | | -- es CN to o II I II II II 1 II (N t. M N N N r r- i-- t-- f-- . 220 American Society of Heating and Ventilating Engineers Guide, 1924-25 Some of the advantages of the double pipe condenser are that it may be placed near the other, apparatus and does not have to be placed out side as in the case of the atmospheric condenser. Further, on the double pipe condenser the cold water enters on the bottom and meets the liquid ammonia, sending the liquid ammonia away much cooler than in the case of the atmospheric condenser, where the hot water comes in contact with the liquid ammonia. When an atmospheric condenser is worn out it must be entirely scrapped, while in a double pipe condenser, the water pipes, which are the only pipes to deteriorate can easily be replaced. Another advantage of the double pipe type is that it is easily, cleaned by a spiral tube cleaner, while it is a much more tedious and uncertain job to clean the outside of the atmospheric condenser. The submerged condenser consisting of a tank containing water in which a coil conveying the ammonia is sub merged is seldom used now. Fig. 73. Relative Horse-Power Consumption at Various Back Pressures The capacity of an ammonia compressor is governed mostly by the pressure of the ammonia gas, or vapor entering it. The higher the pres sure the heavier the ammonia and consequently more pounds of am monia will be pumped through the system per stroke of the compressor. The refrigeration accomplished is directly proportioned to the pounds of ammonia circulated in a given time. The higher the suction or inlet pressure the greater will be the refrigerating capacity of that plant. Roughly about 0.43 lb. of ammonia must be circulated through the system per minute per ton of refrigeration. When cooling and holding products in a room, the temperature at which they must be held will be determined largely by the nature of the goods Tabje 116. The circulating ammonia must be several degrees lower in temperature than the room. Ammonia at any stated temperature has a relative pressure which would consequently be the pressure of the ammonia entering the compressor and would therefore govern the capacity of it. It is desirable, from the power consumption basis, to operate the compressor with the highest possible.back pressure, but this hardly ever exceeds 40-lb. gage pressure. Fig. 73 shows the relative horse-power consumption at various back pressures. This curve based upon averages and practical installations might deviate somewhat. 221,