Archive for 2014

Specific energy consumption in furnaces

Specific energy consumption in furnaces

Specific energy consumption of furnaces


Specific energy consumption of furnaces is very useful for comparing with design values or best practical norms.

There are many factors affecting furnace specific energy consumption such as capacity utilization of furnaces, final heating temperature, use of inefficient burner, excess air ratio, improper insulation/refractories, high stack loss etc... Specific energy consumption test is the key for assessing current performance of furnaces and finding the scope for improvements and productivity.

Specific Energy Consumption

 = Amount of Energy consumed in Kcal/hr / Quantity of material processed, Ton/Hr

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Energy conservation in steam system.

Energy conservation in steam system.

Energy conservation in steam system.

  • Use back pressure steam turbines to produce lower steam pressures.
  • Install PHE based hot water system in place of direct steam injection system
  • Ensure that piping, valves, fittings and vessels are well insulated.
  • Use more-efficient steam de-super heating methods.
  • Optimize the de aerator vent rate.
  • Ensure process temperatures are correctly controlled.
  • Maintain lowest acceptable process steam pressures.
  • Reduce hot water wastage to drain.
  • Clean boiler heat transfer surfaces on regular intervals.
For more click on below link...

Energy saving in Fan & Blower

Energy saving in Fan & Blower

Energy saving in Fan & Blower


How to Recognize Fan & Blower Types


There are two primary types of fans: Centrifugal fans, and Axial fans.

Centrifugal fans use a rotating impeller to move air first radially outwards by centrifugal action, and then tangentially away from the blade tips. Incoming air moves parallel to the impeller hub and it turns radially outwards towards the perimeter of the impeller and blade tips.

As the air moves from the impeller hub to the blade tips, it gains kinetic energy. This kinetic energy is then converted to a static pressure increase as the air slows before entering the tangential discharge path.

Centrifugal fans are capable of generating relatively high pressures. They are frequently used in ‘‘dirty’’ airstreams (high moisture and particulate content), in material handling applications and in systems operated at higher temperatures.

Axial fans - as the name implies, these fans move the airstream along the axis or shaft of the fan.

Energy conservation opportunities

Energy conservation opportunities

Various capacity control method in Fan and Blower system

Various capacity control method in Fan and Blower system

Various capacity control method in Fan and Blower system


Different capacity control methods in fans and blowers are as follows:
Changing the blade angle is a method used with some vane-axial fans.

Restricting the air flow is accomplished with dampers or valves which close off the air flow at the inlet or outlet. Inlet vanes, which swirl the air entering the centrifugal fan or blower, are more efficient than dampers or butterfly valves.

Belt drives with various combinations of pulleys (sheaves) on the motor and the fan to vary the fan speed when driven by a single-speed motor.

Energy saving opportunities in Fan & Blower

Energy saving opportunities in Fan & Blower

Energy saving opportunities in Fan & Blower


Most important energy efficiency options.

Use energy-efficient motors for continuous or near continuous operation

Minimize fan inlet and outlet obstructions

Use variable speed drives for large variable fan loads

Clean screens, filters and fan blades regularly

Minimize fan speed

Use low slip or flat belts for power transmission

Check belt tension regularly

Eliminate variable pitch pulleys

Eliminate leaks in duct works

Minimizing system resistance and pressure drops by improving the duct system

Ensure proper alignment between drive and driven system

Use smooth, well-rounded air inlet cones for fan air intake

Avoid poor flow distribution at the fan inlet

Turn fans and blowers off when not needed

For more click on below link...

http://mechanical-engineerinterviewquestions.blogspot.in/2014/10/fan-blower-and-capacity-control-methods.html

Concept of Fan & Blower

Concept of Fan & Blower

Concept of Fan & Blower


How to Recognize Fan & Blower Types

There are two primary types of fans: Centrifugal fans, and Axial fans.

Centrifugal fans use a rotating impeller to move air first radially outwards by centrifugal action, and then tangentially away from the blade tips. Incoming air moves parallel to the impeller hub and it turns radially outwards towards the perimeter of the impeller and blade tips.

As the air moves from the impeller hub to the blade tips, it gains kinetic energy. This kinetic energy is then converted to a static pressure increase as the air slows before entering the tangential discharge path.

Centrifugal fans are capable of generating relatively high pressures. They are frequently used in ‘‘dirty’’ airstreams (high moisture and particulate content), in material handling applications and in systems operated at higher temperatures.

For more click on below link...

http://mechanical-engineerinterviewquestions.blogspot.in/2014/10/fan-blower-and-capacity-control-methods.html

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