Gujarat Narmada Valley Fertilizers & Chemicals Interview Questions and Answers

Pumps: centrifugal, positive displacement, axial flow. Compressors: reciprocating, rotary, centrifugal.

• Centrifugal pumps use a rotating impeller to move fluid.

• Positive displacement pumps move fluid by trapping a fixed amount and forcing it through the discharge.

• Axial flow pumps use propellers to move fluid.

• Reciprocating compressors use pistons to compress gas.

• Rotary compressors use rotating screws or vanes to compress ...read more

Characteristic curve of a pump shows the relationship between flow rate and head developed by the pump.

• It is a graph plotted between flow rate and head developed by the pump.

• It helps in determining the efficiency of the pump.

• The curve is obtained by conducting experiments on the pump.

• It is used to select the appropriate pump for a given application.

Shutoff pressure is the maximum pressure a pump can generate when it is not pumping any fluid.

• Shutoff pressure is also known as deadhead pressure.

• It is the pressure at which the pump can no longer move any fluid.

• It is important to know the shutoff pressure to prevent damage to the pump and system.

• For example, if the shutoff pressure of a pump is 100 psi, the pump will stop generating flow when the pressure in the syste...read more

Types of columns and their selection criteria for engineering projects.

• Types of columns include steel, concrete, timber, and composite columns.

• Selection criteria depend on factors such as load capacity, material availability, and cost.

• For example, steel columns are often used in high-rise buildings due to their strength and durability.

• Concrete columns are preferred for their fire resistance and low maintenance.

• Timber c...read more

Design of column, heat exchanger, and centrifugal pump involves various factors such as fluid properties, operating conditions, and material selection.

• Column design involves determining the column diameter, height, and packing material based on the required separation efficiency and pressure drop.

• Heat exchanger design involves selecting the appropriate type of exchanger, determining the heat transfer area, and selectin...read more

Joule-Thomson coefficient is the change in temperature of a gas when it is allowed to expand or contract without any work being done.

• It is a measure of the rate of change of temperature with respect to pressure at constant enthalpy.

• It is used in cryogenic technology to determine the cooling effect of a gas when it expands through a valve or porous plug.

• The coefficient can be positive or negative depending on the gas an...read more

Refrigeration cycle is a thermodynamic process used in refrigerators and air conditioners to transfer heat from a low-temperature region to a high-temperature region.

• The cycle consists of four main components: compressor, condenser, expansion valve, and evaporator.

• The refrigerant is compressed by the compressor and then condensed in the condenser, releasing heat to the surroundings.

• The high-pressure liquid refrigerant ...read more