Magnetic clutch

Variable Flow Rate Conventional variable clearance volume and valve lifting devices are impracticable at high pressures and, should it be necessary to vary the flow rate, use has to be made of variable speed electric drives or magnetic clutches. Integral steam and gas engines have been used and Burckhardt (168) developed an hydrauhc drive to provide an integrated variable capacity machine, but its efficiency is less than that of a straight mechanical drive. 

Dual drive magnetic clutch Two or four cylinder open compressor Hydraulic motor... 

The electrical system provides power for the operation of the fan motor, the gear motor and magnetic clutches in the reversing drive, the timer motor, and the air solenoid valve. The manually initiated timer was adjustable for processing times up to 15 min. 

Smaller rotary positive displacement compressors are controlled with external bypass. Such equipment usually has a built-in relief valve that opens at a pressure short of damaging the equipment, but the external bypass still is necessary for smooth control. Large units may be equipped with turbine or gas engine drives which are speed adjustable. Variable speed gear boxes or belt drives are not satisfactory. Variable speed dc motors also are not useful as compressor drives. Magnetic clutches and hydraulic couplings are used. 

FIGURE 2.4 Schematic diagram of the arrangement based on measuring the wet bulb temperature (1) sample, (2) measuring chamber, (3) foil ballon, (4) dashpot, (5) air pump, (6) paddle wheel with magnetic clutch, (7) motor, (8) thermometer, (9) wet bulb thermometer, (10) thermostat. 

Magnetic Clutch... Thi.si clutch is essentially a horseshoe or bipolar electromagnet.. The pole, cores and-.yokes are made..of<.laminated S.A.E. 1010 steel, 1/16-in. laiiiinatio.ns insulated. with. bsked.-on bakelite varnish 0.002 in. thick, hThe energizing, coi ls haye 350.0 turns of No.- 25 Forinex-coated copper wire, w ound, on forms-of, Fosterite-. Vacuum Impregnate.. 

Safety rods from their holders by de-energizing the magnets in the magnetic clutches. This is a continuous process the magnet current is decreased, not interrupted. ... 

Solenoid 316 is one element in a holding circuit that also includes a magnetic clutch 320, a circuit breaker 321, a flow switch 322 and a manually operated circuit breaker 323, all connected in series by wiring 324. The circuit breaker 321 normally makes contact with con-... 

Safety rod magnetic clutch 260 is connected in parallel with control rod magnetic clutch 232. Thus, upon any failure of power in the mains or the opening of any of the switches 251, 252, or 250, all of the rods will be re-lieved of their counter weights and will fall into the pile by gravity. Stops may be provided on the rods, and any suitable braking action used to reduce the impact shock on the reactor. 

The motor 221 rotates a shaft 230 having on one end thereof a pulley 231 and on the other end thereof a control rod gear 234. The shaft 230 between the motor 231 and the gear 234 is split and an electromagnetic clutch 232 connects the two split portions of the shaft 230 when the magnetic clutch 232 is energized. The control rod gear 234 meshes with a rack I6 a on the control rod 168. 

In this circuit, the flow switch is connected to one side of power mains 225 by a conductor including a normally closed circuit breaker 333 adapted to be manually operated. The other side of the flow switch is connected to the magnetic clutch 232 and thence to the power main 225. As long as the proper amount of water is passing through the pipe 24, the flow switch 331 main-... 

The motor 256 is so designed as to slip electrically when the rack 251 is in contact with the stop 277 and the weight of the rack 251, line 250, and safety rod 176 are counterbalanced through the magnetic clutch 257 by weight 280 attached to the periphery of a pulley 281 mounted on the extension 282 of the sh 254 to reduce the load on the motor. 

Fig. 59. Different types of reactors used in the Merrifield peptide synthesis, (a) Agitation mode (c) External circulation (d) Drain line (i) Reagents inlet (m) Magnetic clutch (v) Vent line (x) gas stirring...

The devices are calibrated and can be constructed for flow stream capacities between 2 and 4800 m h [4]. They have good repeatability (0.015%) at high flow rates [4]. They can be used for temperatures up to 205°C and pressures up to 83 bar [4]. The temperature and pressure of the gas are captured and processed so that the volume is indicated in standard conditions of temperature and pressure (STP). The measured variable is deduced from the speed of the rotors, which is obtained through a magnetic clutch from the pressure chamber. 

The wiper is driven via a magnetic clutch and a frequency changer controls the revolutiort... 

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