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What does motor frame size ND160L represents? What is the frame size of induction motor?
If an existing motor is to be replaced with a new motor for the same driven system, the following things should be matched. The vertical distance between the ground and the center of the motor shaft. The distance between motor foot bolt holes lying parallel and perpendicular to the shaft axis must bRead more
If an existing motor is to be replaced with a new motor for the same driven system, the following things should be matched.
To ease the above process, International Electrotechnical Commission (IEC) standardized the motor frame size with a frame code.
For example, FRAME ND 160L is engraved in the motor nameplate, 160 represents the vertical distance between the ground and the center of the motor shaft, L represents “large”. L for large, S for short, and M for medium represents the extent of the distance between two bolt holes lying parallel to the axis of the motor shaft.
See lessWhat is the difference between shroud and back plate of an impeller?
Consider a closed impeller to which plates are welded on both sides of the impeller as shown in the following figure. These plates are called shrouds. The back shroud is also called as back plate.
Consider a closed impeller to which plates are welded on both sides of the impeller as shown in the following figure. These plates are called shrouds. The back shroud is also called as back plate.
See lessWhy Mean Sea Level Elevation is a necessary specification while purchasing a new centrifugal fan/blower?
The density of atmospheric air is a function of altitude. The relation between the density of air and altitude can be seen in the following figure. The total pressure developed by a centrifugal fan consists of static pressure and dynamic pressure. The dynamic pressure is directly proportional to theRead more
The density of atmospheric air is a function of altitude. The relation between the density of air and altitude can be seen in the following figure.
The total pressure developed by a centrifugal fan consists of static pressure and dynamic pressure. The dynamic pressure is directly proportional to the density of air media as shown in the following relation.
Hence if the density of air changes with the altitude, the total pressure generated by the centrifugal fan also changes.
See lessWhat are the usual air temperature and pressure settings used for testing the performance of a centrifugal fan?
In general, when a supplier performs a performance test on a centrifugal fan before engraving the nameplates, Normal Temperature and Pressure (NTP) is utilized as a standard condition. Because the density of air changes with altitude and temperature, the capacity, i.e., the mass flow rate of air (KgRead more
In general, when a supplier performs a performance test on a centrifugal fan before engraving the nameplates, Normal Temperature and Pressure (NTP) is utilized as a standard condition. Because the density of air changes with altitude and temperature, the capacity, i.e., the mass flow rate of air (Kg/s) through the fan changes.
NTP: Temperature is 20°C
Pressure is 1atm (101.325 Kpa)
See less9. Why does the increased intake air temperature increase the power consumption of a reciprocating compressor?
The temperature rise is inversely proportional to air density. i.e., the density of air reduces as the temperature rises. For a given amount of air, a decrease in density causes an increase in volume, implying that air takes up more space. Every compression stroke of a reciprocating compressor displRead more
The temperature rise is inversely proportional to air density. i.e., the density of air reduces as the temperature rises. For a given amount of air, a decrease in density causes an increase in volume, implying that air takes up more space. Every compression stroke of a reciprocating compressor displaces a fixed volume of air. Because of the decrease in density and a fixed volume of a cylinder, the compressor requires a greater number of strokes to reach the predetermined pressure level in the receiver tank. Thus, power consumption increases.
See lessWhat is the recommended temperature of lubricating oil used in a centrifugal pump?
The temperature of oil in the bearing chamber of centrifugal pump must be more than recommended pouring point and less than recommended flash point of a particular chosen oil grade.
The temperature of oil in the bearing chamber of centrifugal pump must be more than recommended pouring point and less than recommended flash point of a particular chosen oil grade.
See lessWhy there is a loss in dynamic pressure when air stream passes through nozzles, gates, orifices, coils…etc?
Dynamic pressure can be calculated by using the relation, Dynamic Pressure=( ρV^2)/2 It’s nothing but kinetic energy per unit volume of flow. Velocity profiles of air stream reorganize at locations like nozzles, orifices, gates, and coils. etc following the formation of vortices/eddies resulting inRead more
Dynamic pressure can be calculated by using the relation,
See lessDynamic Pressure=( ρV^2)/2
It’s nothing but kinetic energy per unit volume of flow. Velocity profiles of air stream reorganize at locations like nozzles, orifices, gates, and coils. etc following the formation of vortices/eddies resulting in the conversion of kinetic energy into heat. As a result, dynamic pressure is reduced.
Why the pressure relief valve installed at the discharge of every positive displacement type blower?
Positive displacement type blowers like roots and compressors like piston type, screw type. Etc are equipped with a relief valve at their discharges because the motor power is determined by the pressure developed. In case of any blockage in the pipelines that leads to motor burnout. Unlike in centriRead more
Positive displacement type blowers like roots and compressors like piston type, screw type. Etc are equipped with a relief valve at their discharges because the motor power is determined by the pressure developed. In case of any blockage in the pipelines that leads to motor burnout. Unlike in centrifugal fans where the power consumption is determined by the volume flow rate.
See lessWhat is static pressure of a centrifugal fan and its significance in ventilation?
The force exerted by the air stream per unit area of the duct wall is known as static pressure. The pressure is called static because it is independent of the velocity. Significance: System air resistance, often known as static pressure, is a measurement of the resistance to airflow. The static presRead more
The force exerted by the air stream per unit area of the duct wall is known as static pressure. The pressure is called static because it is independent of the velocity.
Significance:
System air resistance, often known as static pressure, is a measurement of the resistance to airflow. The static pressure of the air stream right before the filter is high if a filter in the air stream duct is blocked. One of the most important aspects in determining the filter replacement criteria is static pressure measurement.
See lessHow to calculate the mechanical efficiency of a centrifugal fan?
The mechanical efficiency of a device measures how well it converts input power into usable output. Similarly, the mechanical efficiency of a fan measures how well the impeller's kinetic energy (or the brake horsepower available at the impeller shaft) is transformed into the total energy of the airRead more
The mechanical efficiency of a device measures how well it converts input power into usable output. Similarly, the mechanical efficiency of a fan measures how well the impeller’s kinetic energy (or the brake horsepower available at the impeller shaft) is transformed into the total energy of the air stream (or the total pressure of the air stream).
Mech.Efficiency=(Total Pressure(Pa)×Volume Flow rate(m3/s))/(Brake Horse Power)
Since total pressure is involved, the mechanical efficiency of a fan is also known as total efficiency.
See less