Document NGjEZN40OLqgxgYZ7BXo88exV

1 HOW DIFFICULT IS YOUR PROBLEM OF Flvy-asn COLLECTION? You call a doctor when you're lick--why riot call upon engineering specialists to determine --and solee--your dust-collection problem? In the past 10 year*, the Buell Engineering Company ha* designed and Installed , thousands of dust-collection systems, each planned to solve an individual problem. Each situation was different, because a broad range of industrial uses was covered. The'engineering know-how behind Buell' design successfully meets difficult conditions Imposed by size and shape of available space, unusual dust compositions, and widely varied gas volumes. Furthermore, the Buell van Tongeren design eliminates plugging. It's all In the new 32-page catalog--wrltei Buell Engineering Co., 10 Cedar Street, New York 5. N. Y. V-- Engineered Efficiency In DUST COLLECTION 180 (2S$b) ary resistance for tion motors 1st ? J j. _ . B- J rm " 1.73 X I. X (-fr - o .ioV Where. i. tho ettein.l ..,.,1* l*r ph.se of Iho Y. in ohms- gS lacked secondary volts; I, ih'full'iSa secondary current; T, th, tomJ; * .doped on first point 0| the eapressed in percent of lu]|-l0,j Based on this formula, reiJ?wl values are obtained that BW0 JJJjgl acceleration up to the last polm * controller. Secondary resistors f4T $ ting motors ere usually Y*conneetiL although the delta connection used to reduce the current handled 'S' the contact fingers. 1! the resistors i delta-con'nccted, determine the pm, value for Y-conneeted resistors tad ew vert to an equivalent delta. E J KsOni Kansas City, Missouri. Qrld-Reslstor Values In Tenna of Slip Rotor grid resistors for slipring o . tori are designed for starting only j well as starting and speed regulation^ Both types are generally designed ( starting under various loads. It appears that HIV's resistor is i signed for a larger starting load this*! actually exists. If his motor is lirgera than necessary, the rotor current ejdijL. the slip will be smaller then calcoliteijBjl The rotor*eontrol equipment will nrtjT" work properly unless designed for lie! lighter load. This Is especially imporj^ tent where regulation is required. Let the resistance per phase of rotorJ winding equal X ohms. Slip it fuflj load is: BOlLtRS foe LEVEL DRUM! to A75 ft n h. 75000#Per Hr. 450** installation at Fremont, Nebraska. (3 repeat orders since 1929) Slip for %, Vi and V4 load can b*| determined from the motor's circladh* agram if available; it con he approxi'5 mated as directly proportional to thefl load for sero to full load. fa Hence, slip at % and *4 ^0I*.2 equals 0.031, 0.021 and 0.010, rapeo-3|| lively. Total resistance per phase ball the rotor circuit, including the eiislbljjp* resistance X, is Number of steps in the rheostat is and in this esse 12, The* slip el U*|| first step is given by & - mVJ - 0.77. Since ' MURRAY TYPE A Straight Tube Boiler arranged .for maximum super* hod. Builf in sizes from 30,000 to 150,000*per hour. Its flexible construction, together with good circulation, enables this boiler to be operated at high ratings without undue stress or strain* Readily adapted to any type of stoker, liquid or gaseous fuel. FOR ABOVE AND OTHER TYPE BOILERS WRITS MURRAY IRON WORKS CO. BURLINGTON, IOWA . MANUfACTURERS Of BOILERS CONTINUOUSLY SINCE -1870 then R, = 24 X ohma. Value of eJ^.i POWER April |W| SjOWER April lilt i "'"ts` ffl&TL i m 15'