Motor Pumps

Most rotating equipment includes electric motors or steam dryers that generate noise at a constant frequency. Air cooler fans are a source of noise that can be reduced by lowering the fan speed and increasing the number of blades. Pump motor noise can be reduced by including a shroud or fan cover that is accurately lined. Centrifugal compressor noise reduction can be achieved by blade design and the use of compressor pulsation noise reduction, silencers, and vibration isolation. 

Equipment includes all prefabricated machines, apphances, or systems such as tanks, heat exchangers, pumps, motors, switchgear, and boilers. 

Shelf area, m Floor s ace, m Weight average, kg Pump capacity, mVs Pump motor, kW Condenser area, m Price/m (1995) ... 

Flowever, motor manufacturers may adopt more flexible designs with more reserve capacity and better speed-torque characteristics to suit the requirements of a particular sector. These are particularly for installations where the distribution system may have wider voltage fluctuations or the load itself may have varying load demands. It is possible that the same motor may have to drive more than one type of loads at different times. An agricultural pump motor may be one such application where it may also have to drive a thrasher or a winnower at different times. A motor with higher flexibility would be more desirable for such applications. 

Textile motors Crane motors Determining the size of motor Sugar centrifuge motors Motors for deep-well pumps Motors for agricultural application Surface-cooled motors Torque motors or actuator motors Vibration and noise level Service factors Motors for hazardous locations Specification of motors for Zone 0 locations Specification of motors for Zone I locations Motors for Zone 2 locations Motors for mines, collieries and quarries Intrinsically safe circuits, type Ex. f Testing and certifying authorities Additional requirements for ciritical installations Motors for thermal power station auxiliaries Selection of a special-purpose motor... 

Wliere N = the speed of the pump/motor in revolutions per minute Q = the square root of the flow in gallons per minute at the Best Efficiency Point BEP. For double suction pumps, use A BEP Flow. NPSHr = the net positive suction head required by the pump at the BFiP. 

The base should be sufficiently strong to withstand the machinery weight and minimize vibrations. Five times the mass is the rule. If the pump, motor, and base plate weighs 1,000 lbs, the foundation should weigh at least 5,000 lbs. 

Failure is considered both on a local basis i.e., loss of utihty supply to one item of equipment (e.g., electric power to a pump motor) and on a general basis i.e., loss of supply to all consuming equipment in a process unit (e.g., cooling water to all coolers and condensers). For the purpose of these pressure rehef design considerations, a process unit is defined as one which meets all the following criteria ... 

A MDP-IA HVAC A Rx cooler 3A No heat removal Pump motor burnout in 3-10 corttinuous service hours Shift walk around No wamine for faults AC and SWS suppirt AVsIemv of I1VA( monitored but not HX... 

The fault tree (Figure 7.4-1) has "Pre.ssure Tank Rupture" as the top event (gate G1). This may result from random failure of the tank under load (BEl), OR the gate G2, "Tank ruptures due to overpressure" which is made of BE6 "Relief valve fails to open" AND G3, "Pump motor operates too long." This is made of BE2, "Timer contacts fail to open," AND G4, "Negative feedback loop inactive" which is composed of BE3, "Pressure gauge stuck," OR BE4, "Operator fails to open switch," OR "BE5, "Switch fails to open,"... 

Sensors TS 1-2-4 regulate the batteries for heating and cooling in a se quence to achieve the required temperatures (Fig. 9.56). Regulating valves for heat recovery are controlled by a frequency converter RCl for the pump motor. When a greater output is required from the heating battery, the pump motor speed increases before the valve MV2 opens. If the extract temperature is lower than the outdoor temperature, the speed of the pump motor increases before valve MVl opens. To avoid ice formation at low outdoor temperatures, the sensor TS7 operates on a lower limit, depending on the demands of the battery in the exhaust. 

Taxonomy No. 3.3.7.2.1.1 Equipment Description ROTA flNG EQUIPMENT- PUMPS MOTOR DRIVEN-PRESSURE-CENTRIFUGAl ... 

Primarily focuses on pumps, motor-operated 121, valves, and breakers... 

Premature disk failure Operator error Pump motor failure Reaction inliibitor system failure Coolant system failure Outlet piping obstruction Motor alann failure Pressure sensor failure... 

If the maximum flow-rate required is 20,000 kg/h, calculate the pump motor rating (power) needed. Take the pump efficiency as 70 per cent and allow for a pressure drop of 0.5 bar across the control valve and a loss of 10 velocity heads across the orifice. 

Flow Q Hgt. Material Head Pump Motor Power Ave. ... 

System total heads should be estimated as accurately as possible. Safety factors should never be added to these estimated total head values. This is illustrated by Figure 4.8. Suppose that OAi is the correct curve and that the centrifugal pump is required to operate at point A. Let a safety factor be added to the total head values to give a system curve OA2. On the basis of curve OA2, the manufacturer will supply a pump to operate at point A2. However, since the true system curve is OA, the pump will operate at point Ai. Not only is the capacity higher than that specified, but the pump motor may be overloaded. 

Vacuum pumps on all furnaces should have run monitors installed and interlocked to ensure that the pump itself (not just the pump motor) is operating. 

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