Process Engineering Equipment Handbook Episode 3 Part 2 ppt

Power Transmission P-165 FIG. P-139 Generic hydrodynamic coupling types and dimensions in mm. (Source: J. M. Voith GmbH.) P-166 Power Transmission Geared variable-speed couplings for low-speed machines Design and function. A reduction gear is located after the coupling for applications in the drives of low-speed machines. The coupling and the gear are contained in a common housing the lower part of which is designed as an oil tank. By the optional installation of a hydrodynamic retarder with favorable braking characteristics, a high retardation of large masses of the connected driven machine is achieved. Speed control is carried out by changing the oil-fill of the coupling through the scoop tube that reaches into the working chamber of the coupling. The transmitted power and the speed can be controlled steplessly. (See Fig. P-140.) Oil supply. Working and lube oil are both supplied by the integrated oil tank, however, from separate circuits. The oil supply for the motor and the driven machine may also originate from this source. Performance diagram. This serves to identify the appropriate coupling types and sizes in relation to the input power and the required output speed. Coupling types. Controlling low-speed machines such as coal mills, induced draught fans, and crude oil pumps demands different coupling designs. Depending on the application and for optimum adaptation to existing space conditions, the gear stage is either designed as helical or bevel gear. Genetic coupling types are as follows (see Fig. P-141): 1. A helical step-down gear is arranged behind the variable-speed turbocoupling. This type is suitable for applications in coal mills, crushers, low-speed pumps, and fans (Type R A). 2. Geared variable-speed coupling for low-speed driven machines with high moment of inertia, e.g., coal mills. This type features a bevel gear stage behind the turbocoupling (Type R B). Torque Conversion* A torque converter can be used where torque and speed have to be transmitted or controlled between a driving and a driven machine in a simple and economical way. A torque converter is “open” to both sides. It absorbs torque from the driving machine and transmits it according to requirement to the driven machine. This process is governed by the “natural” characteristics of the converter, or can be controlled at will by varying the pitch of the guide blades (adjustable converter). In both cases, the converter can be incorporated in a process control system. In this prospectus, the attempt is made with examples to concisely yet clearly describe the hydrodynamic torque converter, its characteristics, and its application possibilities. The most important areas of application are listed in Fig. P-142. Note symbols in Fig. P-143. When is it expedient to use a simple torque converter and when an adjustable one? This varies from case to case. The most important criteria in this decision are the characteristics of the prime mover and the load curve governed by the job to be handled. What is regulated, what is controlled? See Figs. P-144 through P-146. * Source: J.M. Voith GmbH, Germany. Power Transmission P-167 FIG. P-140 Geared variable-speed coupling for low-speed machines. (Source: J. M. Voith GmbH.) P-168 Power Transmission FIG. P-141 Generic model of geared variable-speed couplings for low-speed machines. (Source: J. M. Voith GmbH.) FIG. P-142 Torque conversion applications. (Source: J. M. Voith GmbH.) FIG. P-143 Symbols for a torque converter and an adjustable torque converter. (Source: J. M. Voith GmbH.) P-169 How the torque converter works The pump impeller of the converter, a centrifugal pump, converts the torque M P absorbed from the motor into kinetic energy in a fluid mass. See Fig P-147. In the turbine wheel the fluid mass is decelerated producing the turbine torque M T . The guide wheel (reaction member) absorbs the differential torque M R between input and output torque that results in the multiplication of torque. The ratio and curve of torque multiplication M T /M P is conditioned by the form of the converter blades. FIG. P-144 Using a motor of constant speed and a torque converter without adjustment mechanism, jobs such as startups can be undertaken smoothly and steplessly along the “natural” characteristic curve of the converter. This is a starting process. The operating range is centered around peak efficiency. (Source: J. M. Voith GmbH.) FIG. P-145 Using a variable-speed motor and a nonadjustable torque converter, a method of regulation is obtained that permits any desired curve to be operated corresponding to the input/output speed ratio. This case illustrates how the efficiency peak remains practically the same. (Source: J. M. Voith GmbH.) FIG. P-146 Using a constant-speed motor and an adjustable torque converter, any operating point can be run within the characteristic range of the turbine, e.g., a constant torque can be held under fluctuating load or specific speeds in alternating succession. At first glance, an adjustable torque converter works uneconomically in specific ranges, because the efficiency decreases with progressively closed guide blades. This is deceptive. If one projects the operating points from the turbine characteristic range onto the efficiency curves, the result is a good overall efficiency. (Source: J. M. Voith GmbH.) 144 145 146 P-170 Power Transmission Power Transmission P-171 For this reason, every converter design has its own characteristic family of curves. The integral gear pump produces the necessary operating pressure and dissipates heat generated by directing the oil stream to the cooling unit. Application case 1: Gas turbine starting The gas turbine is loaded by its compressor and the mass of the generator. It cannot be started without assistance. As a starting motor either an electric motor can be 1 2 3 4 1 4 2 3 FIG. P-147 Torque converter components. (Source: J. M. Voith GmbH.) P-172 Power Transmission used, providing that sufficient power can be taken from the mains, or alternatively a diesel engine. See Fig. P-148. Possible solutions. The torque converters shown in Figs. P-149 through P-152 can be employed wherever large masses have to be accelerated rapidly and smoothly, wherever high breakaway torque has to be overcome, and wherever speeds have to be automatically adapted to loads. A torque converter, however, is not only an efficient but also an economical solution to a drive problem: low prime costs, low space requirements, and practically wear-free operation are facts which speak for this. Torque converters for gas turbine starting sets are particularly adaptable. They can be supplied with a filling and draining facility of with a guide blade adjustment mechanism; in all cases, the blading can be matched to the torque loads to be handled. Previously supplied torque converters include those with ratings up to 4000 kW at speeds of 3600 1/min (60 Hz) and 3000 1/min (50 Hz). The operating fluid for the torque converter is taken from the lube oil system of the gas turbine. The oil tank simultaneously serves as a heat accumulator. Application case 2: Variable-speed engine and fluctuating loads (Figs. P-153 through P-159) Several diesel engines drive the drilling rods, lifting gear, and mud pumps through a chain compound under constantly fluctuating load. During drilling, speeds must be steplessly varied and shock loads absorbed. At the same time, the mud pumps press flushing and ballast material into the drill-hole at different rates and pressures to flush out the drill cuttings. The lifting gear works with high acceleration and retardation when the, often, several thousand meters long drilling rods need to be dismantled quickly. The automotive governed diesel engines, with their available speed and torque capacity, are incapable of fulfilling these tasks satisfactorily. Possible solutions. Both types of converters are also suitable for other similarly loaded machines, e.g., heavy earth-moving machines, light shunting locomotives, FIG. P-148 Schematic of a torque converter in a drivetrain. (Source: J. M. Voith GmbH.) Power Transmission P-173 scrapers, loader plants, bucket dredgers, cranes, and winches. The converter protects the plant from overload and overdrive, matches itself steplessly and automatically to arising resistance, and dampens shock and vibration between driving and driven machines. The use of a torque converter substantially increases the length of life reliability of a plant. FIG. P-149 Torque converter with constant filling. The gas turbine is brought out of standstill at a high breakaway torque and is accelerated under increasing compression resistance to firing speed. After this, hot combustion gases in the turbine support the compressor so that with increasing speed the torque requirement decreases up to the self-sustaining speed of the turbine. When this speed has been reached, the starting equipment is disengaged by means of an SSS- clutch. The gas turbine oil tank serves as an accumulator for heat generated in the torque converter. (Source: J. M. Voith GmbH.) FIG. P-150 Torque converter with filling and draining control. With the torque converter drained, the starting motor is accelerated up to rated speed. After this, the converter is filled and the gas turbine started as under Fig. P-149. To disengage the starting equipment, the torque converter is simply drained. A freewheeling device is dispensed with. (Source: J. M. Voith GmbH.) FIG. P-151 Torque converter with filling and draining control and guide blade adjustment (C1). A torque converter equipped in this way fulfills the functions described under Figs. P-149 and P-150. Additionally, the gas turbine can be held constant at any required speed. A similar influence on speed is obtained by varying the circulating oil flow, e.g., by accurately dosed ventilation of the oil circuit (C2). (Source: J. M. Voith GmbH.) 151 [...]... 700 620 560 450 400 35 0 32 5 27 5 25 0 22 5 21 5 20 0 185 175 165 155 150 140 125 30 35 40 45 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 20 0 22 0 40 45 52 58 65 75 90 100 110 125 140 150 160 170 180 20 0 21 0 22 5 24 0 25 0 27 0 98 104 109 116 122 133 148 157 168 1 83 20 1 20 9 21 8 22 8 23 8 24 6 25 6 27 4 28 6 29 6 31 4 82 87 94 1 02 109 117 130 146 158 180 176 20 5 21 4 22 5 23 5 26 0 25 6 25 6 30 2 30 2 30 2 40 45 52 60... 20 5 21 4 22 5 23 5 26 0 25 6 25 6 30 2 30 2 30 2 40 45 52 60 65 73 82 98 110 120 121 145 156 165 175 195 191 191 23 6 23 6 23 6 4 4 5 7 8 8 8 8 8 12 12 12 12 13 13 15 15 15 15 15 15 1.9 2. 1 2. 5 2. 8 3. 4 4.0 5.7 6.6 7.6 12 13 16 17 20 22 27 28 32 43 45 49 0.0 02 0.0 03 0.0 03 0.004 0.006 0.009 0.015 0. 020 0. 028 0.0 52 0.0 73 0.095 0.110 0.150 0.180 0 .26 0 0 .29 0 0 .37 0 0.540 0.610 0.760 MA, release torque—adjustment range;... GmbH.) TABLE P -21 Safeset® ST Series with Sleeve Bearing Size ST MA (kNm) nmax (rpm) d1 (mm) d2 (mm) d7 (mm) L1 (mm) L2 (mm) L3 (mm) G (kg) J (kgm2) 30 35 40 45 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 20 0 22 0 0 .3 0.6 0.4–0.9 0.6–1 .3 0.8–1.7 1.1 2. 2 1.8 3. 6 3. 0–6.0 3. 9–7.8 5.0–10.0 7.5–15.0 10.0 20 .0 13. 0 25 .0 17.0 33 .0 20 .0–40.0 23 . 0–46.0 36 .0–71.0 39 .0–78.0 49.0–98.0 63. 0– 126 .0 70.0–140.0... Power Transmission P-1 83 FIG P-171 Performance characteristics (see Fig P-170b) (Source: J M Voith GmbH.) FIG P-1 72 Vorecon multistage variable-speed drive type RWS 10-9 E2 driving the boiler feed pumps at Kajaani power station, Finland Input speed ne = 1490 rpm; power requirement Pa = 1 430 kW; output speed na = 6000 rpm (Source: J M Voith GmbH.) FIG P-1 73 Vorecon type RWE 5 F3 driving a compressor...P-174 Power Transmission FIG P-1 52 Torque converter models available (A) Type E (L) 10z FG Power rating = 1416 kW at 29 50 1/min (gas turbine GTMS 9001 E, 50 Hz) Effective operating range 80 percent Peak efficiency 34 percent Optional: filling and draining facility or guide blade adjustment (B) Type E 8.5 wG (F) Power rating = 560 kW at 21 0 1/min (gas turbine TG 20 /B2, 50 Hz) Special feature: 4-fold... solid shelf and primary coupling flange (Source: J M Voith GmbH.) FIG P -20 0 Turbocoupling with brake flange (Source: J M Voith GmbH.) FIG P -20 1 Turbocoupling with twin circuit “type DT.” (Source: J M Voith GmbH.) P-195 P-196 Power Transmission FIG P -20 2 Pulley type coupling without bearing cover type TRI (Source: J M Voith GmbH.) FIG P -2 03 Turbocoupling with overhung pulley installation—type TR (Source:... clutch is incorporated in front of the torque converter P-178 Power Transmission 160 1 62 161 1 63 FIG P-160 Schematic of a torque converter in a process pump train (Source: J M Voith GmbH.) FIGS P-161, P-1 62 Characteristics of torque converter used in reciprocating machinery trains (Source: J M Voith GmbH.) FIG P-1 63 Torque converter schematic (see also Fig P-164) (Source: J M Voith GmbH.) Power Transmission... Transmission P-191 FIG P-1 92 Safeset ST series (Source: J M Voith GmbH.) FIG P-1 93 Safeset SR-PF 800 for a wind tunnel drive with a release torque of 7000 kNm (Source: J M Voith GmbH.) In this design the torque is not transmitted over the welded Safeset-ring but directly from a flange shaft to a flange sleeve (See Figs P-1 93 and P-194.) Shear tubes The couplings are equipped with 1– 12 shear tubes of a suitable... release torque—adjustment range; nmax, maximum permissible rpm; G, mass (weight); J, inertia moment Power Transmission 181 1 82 1 83 184 185 P-189 186 FIG P-181 Remove the used shear tube (Source: J M Voith GmbH.) FIG P-1 82 Insert a new shear tube (Source: J M Voith GmbH.) FIG P-1 83 Remove the protection plug from the oil charge port (Source: J M Voith GmbH.) FIG P-184 Connect the pump Loosen the shear... Safeset® coupling can be returned to operation after a minimum of delay by replacing the tube and reapplying the pressure Since the release process does not cause any wear, no maintenance is required apart from a regular oil change Permitted temperature range is -20 to +60°C Temperatures exceeding this range are possible with special measurements Operating procedure after overload Follow Figs P-181 through . As a starting motor either an electric motor can be 1 2 3 4 1 4 2 3 FIG. P-147 Torque converter components. (Source: J. M. Voith GmbH.) P-1 72 Power Transmission used, providing that sufficient power. condensate pumps FIG. P-1 73 Vorecon type RWE 5 F3 driving a compressor in a Swedish refinery. Input speed n e = 29 80 rpm; power requirement P a = 1 530 kW; output speed n a = 15, 030 rpm. (Source: J facility or guide blade adjustment. (B) Type E 8.5 wG (F). Power rating = 560 kW at 21 0 1/min (gas turbine TG 20 /B2, 50 Hz). Special feature: 4-fold torque multiplication. Optional: filling and draining