Document NNrKbRLq3b8XBzjp9ZZODj88

FILE NAME: Power Generation (POW) DATE: 1946 DOC#: POW019 DOCUMENT DESCRIPTION: Excerpt - Article Trade Journal y # ' - ' 'I.! -/ Uikttt-- Frndt C. Smith Euf W 0 `pri<j feofiru/ Editori Huntar R. Hugh*, Jr. 1' Mjr. ; W. Ji Cooler .- H u N s i n e lor : BL Y f, O'Brien | mmm Aopwootafirog L 1* BoJtHL 18 S u l d S ti U t. w aSUMx --IptKboHb.o,Mpoiw*VuBrt-twaITs, nuli K. Hoffnun. SB Bovdelo i' n u w r d U D u r u m , 7 C ooing, " lo t hood. B a tto lo 1 , U. T.-- iti- m u . AO dM tlt 0312. i l l C- Bb UO. 3 M A u d ito riu m r m i iato. C l e r d u d I d , OUis j i * 1--m u , C k e r r j T ia a . Ojftf*.' 0K---.-l--e-U.--iu*Jia_t_ia-B_-v_Q--i_aw_.. cM- u'lcuBia a 1u, I f i l l --ffcau, Control d i i , rfSif aciuWp pdtnt .3At0udBitto,riUumu BAJiQd*e.-, . ,t t a r d i l i . -- n u m i, Tuckir M W * H iu k il, J r ,, 1841 Ufa. "T 'oSrntrur-O^ltUwai,filOilwo . tndDTj d*lUu ,. mini juOHripUuB--fiI.oo 6r W. (L C. SMITH NIUSHIN CO. faa> *Uo ut: Collo, JtUo- m I. Bard tow, tort#* AMmaJ. L d i, ftwiiMat ; B. P. IWcullTl Ylco-lTMltkat j huUUstir, Vl6-Pieldit ; wC. iBZitL VJo* P raidut; m l Vl5-PraU*ntT O. A. Tr*u*r*r ; A- . Btb- m! fn o d ir O t/ifU NT BUILDING A GEORGIA ^ l n ^ r y , by Hwqtff.EUhjflgb Jf*-.-T. . 5? f t p * - i- 'b * ? I* e p ^ ; / v v R --'tfoamijfi R*f .QD909, by Laonord A. J^ajdar 5*. - Y >.: 2 y } v " ^*rir5j ^ M^*fvaac, by R- C, R*jH^ar,4 -.......- .......*....... W IS- Jn Fornitura M*nui*styri*3(iby W. H. Hkb4........M ** " 1v- HP*!**... ..........v ..... m 7bf $rMd't*rpf of Gaffing Ahaad, by Horry C. Walfcar... .........62 -V4>tnri :... ............ 92 U iw t S y ste m (Continued from page 05) indicator an d ,a hole large enough to receive the staff is made in the side wail of the duct. The staff is inserted to the centerline of the pipe, the staff being marked off in inches and fractions for conven ience in locating the j e t Head ings, taken for each inch of radius of the pipe are added and divided by the number of readings to ob tain an average velocity. Table 11 shows velocities in fpm corresponding velocity ' pressure and the volume of air carried bypipes of different diameters. Sup pose the average of our readings was 3,7|S0 fpm and the diameter of the air duct was, by measurement 6". Going down the column of figures below the 3,750 fpm head ing to the fl" die. pipe line we find that the volume handled is 730 c fm . This is within 14 e f m o f the design. But suppose the velocity read only 3,000 fpm--under the 3000 fpm heading we find 580 cfm as the volume flowing in a 8" pipeDividing this by 4.31 sq ft as found to be the hood opening above, we have an inlet velocity of 138 fpm or a reduction of 2244% and to return the inlet velocity to the original design amount of 175 fpm we must close off at opening No. 6 to 1.4 sq ft. The alternative would be to go through the. system and determine the cuse of the re duction in velocity and correct the trouble at its source. This latter course is the logical one since other vent points must be affected in a similar manner. Check When dealing with a system which has been in service .for a considerable period of time and trouble of this character is dis covered the next logical step would FIB. 4. CKHAUtT FAN O ftlV t INSTALLATION. CMTlwiyAasKVTMf^ndry Xqulfl, Cu. be to take a resistance test semes',, the dust collector. The resistance'! of dust collectors varies in differ' ent makes. The resistance of ihe* dry type collector varies from to 3" water gauge, and in a wot'j type collector the resistance from; inlet to outlet is approximately 3*' water gauge. The standard resist-' ance for a given type and make collector should be obtained from the manufacturer. To measure the resistance across the collector, regardless Of type and make, static readings should be made at point 1 on the dkty s ir . side of the unit as shown in Fig. 3 and a t 2 on the dean air side of the unit, There may be a alight; difference in the velocity at the i respective points but for the pres ent purpose this may be ignored. Subtract the pressure reading at 1 from the pressure reading at 2 if the fan is beyond 2 or on the dean air side. The difference in total pressure thus obtained is the ap proximate resistance of die unit. If a pitot tube is being used take the RP at the two points and make the subtraction to obtain the re- ' sisianee of the unit. If the fan is on the dirty air aide of the collector and 3 blowing through use the static tube as shown in Fig. 9 and subtract reading NO. 2 from NO. 1 to obtain the resistance Of the unit. Compare this with the manufac turer's standard and if it is high it indicates that a plug is forming, or has formed in some part of the collector. Perhaps it merely needs cleaning. Filter type collectors will increase in resistance when used without periodic shaking but will reduce in resistance when worn out or contain damaged cloth or bags. Exhaust Fan Drives Exhaust fan drives give consid erable trouble from slipping par ticularly when the motor is mount ied wrong and the pull of the belt is on the tap stands instead Of the bottom for wide center drives. Fig. 4 is an excellent drive design- One improvement could have been made by lowering the motor some what as the angle drive has some desirable features. The motor is on the discharge side of the fan and the bottom strand of belt is 84 SOUTHERN POWER ft INDUSTRY for APRIL, If46 TABUS li- A ir Votesn e te P I ntm- A*. il 2 .0218 3 jMfil 4 -873 5 .1384 6 .1964 7 073 *8 .3491 a ,.4416 10 .5454 h .6800 12 ,785 13 218 14 1.06B0 13 1.2373 18 1.3883 17 1.5703 ia 1.7671 19 1.8800 29 2.1817 ai 8.4063 88 8.6891 33 3.8853 24 3.1416 23 3.4088 28 3.6870 27 3.0731 28 4.2781 2B 4.586 SO 4.S0S7 3000'V 0-56 VP 05 147 262 409 589 802 1047 1325 1636 I960 2356 2705 3207 3082 41B0 4729 6301 6007 6545 7316 7819 8868 9425 10228 11081 11928 12826 13781 14728 Specific Veloci V P = (V /4006)* 3500'V 0.7 VP 76 172 300 477 3750' V OJIVP B2 184 327 512 4800* V 11.897 VP 97 196 349 546 687 736 786 936 1002 1069 12Z2 1306 1396 1546 1652 1787 1909 2048 2102 2310 475 2040 2749 2918 3142 3220 3507 3887 3742 4009 4270 4295 4802 4909 4887 5238 6585 5517 6911 8305 6185 8627 7089 6892 7304 7878 7638 8132 8727 8419 9899 10090 lOBsa 11931 9030 9890 10020 11781 12783 seat 10580 11541 12500 13035 12905 13918 14988 18054 17180 13027 14910 18035 17151 1840B 14748 15904 17104 10348 18835 4588' V UB VP 98 S 614 884 1203 1571 1968 2454 2970 3534 4148 4811 5522 8383 7093 7052 8881 9818 10836 11879 12983 14137 15340 16592 17892 18242 20041 22089 IV .F . 5000'V 1.51 VP as 437 6S2 9B2 1337 ' 1746 2209 2727 3300 ' 3927 4009 5345 8138 8982 7882 8838 9845 10008 13037 10188 14428 1S708 17044 18435 16880 213U 22935 24544 under tension when power is en while the top strand may lay down thus increasing the angle of con tact. 'The drive is nearly a ratio 1:1 and is protected by a heavy sheet metal shield. The motor is provided with a take-up bane. A desired feature of belt guards is an opening opposite the shaft ends so that shaft speeds may be taken without the necessity for removal of the guard. Knowing the design speed for the fan and having the name plate speed of the motor it is a simple matter to check the slip page by aid of a revolution counter. t Reconstruction of Italy's Utilities (Continued from pop 07) In Sicily,-Sardinia, and Southern Italy, the Germans did compara tively little damage to the power systems. There was little heavy industry in this part of Italy, hence they did not see the necessity of demolishing power facilities, and the war was moving so rapidly that they had no time to plan ex tensive demolition. Then, too, they thought that they would soon be back and would need this equip ment However, things could hardly be said to have been left undisturbed. In order to obtain conductors to repair a 70,000 v trunk line in Sicily, it was necessary to recover and use much of the overhead trolley-wire of the street-car sys tem of wrecked Messena. A group of Hydro-electric plants in Calabria (the part of Southern Italy so well known to the readers of Norman Douglas) with a capaci ty of 170,000 kw was left practical- Toronto, pari, and Before the WWji service, the dty w a s supplied bor, Naples' (normally a standby), which considerably damaged, was paired by the Hoyal Navy, and H| three 15,000 kw units went M*; operation in May, August, and No*' vember of 1944, Central Italy Conditions were quite different in central Italy. By this time th lighting was moving forward slow ly, the Germans ^were angry with the Italians for quitting, and they began to see that there was little likelihood of their regaining much lost territory, w ith the* thing* ip mind, the Gofjmaipi did * thor ough job of dempiltien, destroying 93% of $U power generating ca pacity between Naples and FIor- : ence. The effective generating ca pacity in this area bad- amounted to about one million kw, but after the Germans left, only 57,000 kw were in operating condition. Of this, 30,000 kw were in two old standby steam plants in Home. The Electrical Division and other Allied Military Units went to work immediately and within six months had increased the plant capacity to 170,000 kw and then added an other 170,000 in the following year. This was accomplished primarily by rebuilding wrecked machinery without the import of new parts- ' Construction materials, as well as food, were in the black market, and in 1949-44 it took six months to receive an order from the states. Major overhaul jobs were under taken and completed in the field that would have been considered impossible under most favorable peace-time conditions. For exam ple, the main casting for a 12.000 kw, 3000 rpm steam turbine was. cast, machined, and assembled without blueprints (the factory in Northern Italy being in German hands) a n d with only the broken and scattered pieces of the demol ished casting to use as ^pattern. Sheet mica lor insulating com mutator bars and generator coils 86 SOUTHERN PO W ER & INDUSTRY fo r APRIL, .194*.