UnoCareer Interview Questions and Answers

Surging and choking are two common operating conditions in centrifugal compressors.

• Surging occurs when the flow rate through the compressor is reduced to the point where the compressor cannot maintain a stable flow and pressure. This leads to a pulsating flow and can cause damage to the compressor.

• Choking happens when the flow rate through the compressor is increased to the point where the compressor cannot handle the volume of gas being fed into it. This results in a decreas...read more

Deaerator is placed at higher elevation to create a pressure difference for efficient removal of dissolved gases from feedwater.

• Higher elevation creates a pressure difference which aids in the removal of dissolved gases from feedwater

• This helps in preventing corrosion in the boiler system

• It also improves the efficiency of the boiler by reducing the amount of oxygen in the feedwater

Stroke length of a reciprocating compressor is the distance the piston travels from top dead center to bottom dead center.

• Stroke length is an important parameter in determining the displacement volume of the compressor.

• It is typically measured in inches or millimeters.

• For example, a reciprocating compressor with a stroke length of 4 inches will have a piston that travels 4 inches up and down within the cylinder.

• Stroke length affects the compression ratio and efficiency of the...read more

Various types of pumps with characteristics curves

• Centrifugal pumps: high flow rates, low pressure, used in HVAC systems

• Reciprocating pumps: high pressure, low flow rates, used in hydraulic systems

• Diaphragm pumps: positive displacement, used for metering and dosing applications

• Gear pumps: used for lubrication systems, constant flow rate

• Axial flow pumps: high flow rates, low head, used in irrigation systems

The range of a cooling tower typically varies based on the size and capacity of the unit.

• The range of a cooling tower can vary from small residential units to large industrial units.

• Smaller cooling towers may have a range of a few tons of cooling capacity, while larger industrial cooling towers can have a range of hundreds or even thousands of tons.

• The range of a cooling tower is typically measured in terms of cooling capacity, which is the amount of heat that can be removed ...read more

Cooling towers are heat rejection devices that use water to transfer heat from a system into the atmosphere.

• Cooling towers work on the principle of evaporation to remove heat from the water being circulated through the tower.

• The hot water is pumped to the top of the tower and distributed over the fill or packing, where it is exposed to air.

• As the water flows over the fill, some of it evaporates, which removes heat from the remaining water.

• The cooled water is then collected at...read more

LP dosing refers to the process of injecting a low pressure chemical solution into a system or process.

• LP dosing is commonly used in water treatment plants to add chemicals such as chlorine or coagulants to the water supply.

• It is also used in industrial processes to introduce additives or inhibitors into pipelines or equipment.

• LP dosing systems typically consist of a pump, piping, and injection point where the chemical is introduced into the system.

• The dosing rate is carefull...read more