30+ National Organic Chemical Industries Interview Questions and Answers

Pump cavitation can be caused by low pressure or high temperature. It can be solved by increasing pressure or reducing temperature.

• Pump cavitation occurs when the pressure in the pump drops below the vapor pressure of the liquid being pumped.

• This can be caused by low pressure or high temperature.

• To solve the problem, you can increase the pressure or reduce the temperature.

• Other solutions include increasing the size of the pump or using a different type of pump.

• Distillation pl...read more

Flash point is the temperature at which a substance gives off enough vapor to ignite momentarily, while fire point is the temperature at which a substance will continue to burn after ignition.

• Flash point is the temperature at which a substance can ignite momentarily when exposed to an ignition source.

• Fire point is the temperature at which a substance will continue to burn after ignition.

• Flash point is typically lower than the fire point for a given substance.

• Flash point is us...read more

Unit operation refers to a single step in a process, while unit process involves a series of operations to achieve a specific goal.

• Unit operation is a single step in a process, such as mixing or filtration.

• Unit process involves a series of operations to achieve a specific goal, such as refining crude oil into gasoline.

• Unit operations are often combined to form a unit process.

• Unit processes are used in chemical engineering and manufacturing.

• Understanding the difference between...read more

Types of valves, mechanical seal, steam trap

• Types of valves: gate valve, globe valve, ball valve, butterfly valve

• Mechanical seal: used to prevent leakage in pumps and other rotating equipment

• Steam trap: used to remove condensate and non-condensable gases from steam systems

Heat exchangers are devices that transfer heat between two or more fluids.

• Types of heat exchangers include shell and tube, plate and frame, and finned tube.

• Shell and tube heat exchangers are the most common and consist of a shell with tubes inside.

• Plate and frame heat exchangers use plates to transfer heat between fluids.

• Finned tube heat exchangers have fins on the outside of the tubes to increase heat transfer.

• The choice of heat exchanger type depends on factors such as the ...read more

Pump curve shows the relationship between flow rate and head. Cavitation and priming are common issues in pump operation.

• Pump curve is a graph that shows the performance of a pump at different flow rates and heads.

• It helps in selecting the right pump for a specific application and also in troubleshooting pump problems.

• Cavitation occurs when the pressure in the pump drops below the vapor pressure of the liquid, causing bubbles to form and collapse, damaging the impeller and re...read more

The question is unclear and lacks context.

• Please provide more information about the reactor and the new shell.

• What is the reason for removing the old shell?

• What tools and equipment are required for the job?

• What safety precautions need to be taken?

• Are there any specific procedures or guidelines to follow?

• Consult with experts and refer to manuals before attempting the task.

Blowers can be classified into centrifugal, positive displacement, and regenerative types. PM stands for Preventive Maintenance.

• Centrifugal blowers use centrifugal force to increase air pressure

• Positive displacement blowers use a mechanical means to trap and transport air

• Regenerative blowers use a rotating impeller to create air flow

• PM is a maintenance strategy that involves regular inspections and repairs to prevent equipment failure

Types of steam include saturated steam and superheated steam. Continuous operations run without interruption, while batch operations are done in intervals. Types of heat exchanges include shell and tube, plate, and finned tube.

• Types of steam: saturated steam, superheated steam

• Continuous operations run without interruption

• Batch operations are done in intervals

• Types of heat exchanges: shell and tube, plate, finned tube

Steam ejector works based on pressure sensitivity.

• Steam ejector uses high-pressure steam to create a vacuum by entraining and compressing low-pressure gas or vapor.

• The pressure difference between the high-pressure steam and low-pressure gas or vapor causes the gas or vapor to be drawn into the ejector.

• The steam ejector is commonly used in refrigeration, distillation, and vacuum systems.

• The efficiency of the steam ejector depends on the pressure difference between the high-pre...read more

Handle hydrogen gas safely by following proper protocols and using appropriate equipment.

• Ensure proper ventilation in the area where hydrogen gas is being used or stored

• Use leak detection devices to monitor for any leaks

• Store hydrogen gas in well-ventilated areas away from ignition sources

• Use appropriate personal protective equipment such as gloves and goggles

• Train employees on the safe handling and storage of hydrogen gas

Empelr and no oil are not common terms in maintenance engineering. Please provide more context.

• Please provide more information or context for the terms empelr and no oil.

• Without context, it is difficult to provide a meaningful answer.

• It is possible that these terms are specific to a certain industry or company.

• Please clarify the question so that a proper answer can be given.

Reactors can be made of various materials depending on the application and requirements.

• Common materials include stainless steel, carbon steel, and titanium.

• Reactor linings can be made of glass, ceramic, or polymer materials.

• Materials must be chosen based on factors such as temperature, pressure, and chemical compatibility.

• Reactor materials must also be able to withstand corrosion and erosion over time.

• Materials used in nuclear reactors must be able to withstand high levels o...read more

To handle pressurized reactions, remain calm, assess the situation, communicate effectively, prioritize tasks, and seek help if needed.

• Remain calm and composed to think clearly and make rational decisions

• Assess the situation to understand the root cause of the pressure and potential risks

• Communicate effectively with team members and stakeholders to keep them informed

• Prioritize tasks based on urgency and importance to address the pressure effectively

• Seek help from colleagues o...read more

Centrifugal pump mechanism involves the conversion of mechanical energy into kinetic energy to increase the fluid's velocity and pressure.

• Centrifugal pump consists of an impeller that rotates to create centrifugal force.

• Fluid enters the pump through the center of the impeller and is flung outwards by centrifugal force.

• The fluid gains kinetic energy and pressure as it moves through the pump.

• The fluid is then discharged through the pump outlet at a higher velocity and pressure....read more

LEL (Lower Explosive Limit) and UEL (Upper Explosive Limit) are the concentration range of a gas in air that can result in an explosion if ignited.

• LEL of hydrogen is 4% in air

• UEL of hydrogen is 75% in air

• Concentrations below LEL are too lean to burn, while concentrations above UEL are too rich to burn

Reflux is the process of condensing and returning the vapors that rise from the distillation process back into the distillation flask.

• Reflux helps to improve the efficiency of the distillation process by preventing the loss of volatile components.

• It is achieved by using a condenser to cool the vapors and return them to the distillation flask.

• Reflux is commonly used in the production of high-purity chemicals and fuels.

• It can also be used to separate components with similar boi...read more

There are three types of vessels entry: Confined Space Entry, Hot Work Entry, and Cold Work Entry.

• Confined Space Entry involves entering a space that is enclosed and has limited access points.

• Hot Work Entry involves entering a space where welding, cutting, or other heat-producing activities are being performed.

• Cold Work Entry involves entering a space where maintenance or repair work is being done that does not involve heat-producing activities.

• Examples of confined spaces inc...read more

Mass transfer is the movement of substances from one place to another due to a concentration gradient.

• Mass transfer involves the transfer of mass or substances, such as molecules or ions, from one phase to another.

• It occurs due to a difference in concentration or partial pressure between the two phases.

• Examples of mass transfer include the diffusion of gases in air, the movement of solutes in a liquid, and the evaporation of a liquid into a gas.

• Mass transfer is important in v...read more

Heat duty can be found by calculating the amount of heat required to raise the temperature of a substance or system.

• Determine the mass of the substance or system

• Determine the specific heat capacity of the substance

• Determine the change in temperature

• Use the formula Q = mcΔT to calculate the heat duty

• Q = heat duty, m = mass, c = specific heat capacity, ΔT = change in temperature

Centrifugal pumps are devices that use centrifugal force to move fluids through a system.

• Centrifugal pumps are commonly used in industries such as oil and gas, water treatment, and chemical processing.

• They consist of an impeller that rotates to create centrifugal force, which pushes the fluid towards the pump outlet.

• The fluid enters the pump through the suction inlet and is accelerated by the impeller.

• The kinetic energy of the fluid is then converted into pressure energy as i...read more

Vaccum distillation is a process that separates liquids based on their boiling points under reduced pressure.

• Vaccum distillation is used to purify liquids with high boiling points or heat-sensitive compounds.

• It involves heating the liquid in a distillation flask under reduced pressure to lower its boiling point.

• The reduced pressure allows the liquid to vaporize at a lower temperature, preventing thermal degradation.

• The vapor is then condensed and collected as a purified liqui...read more

A venturi is a device used to measure the flow rate of a fluid by creating a pressure difference.

• A venturi consists of a narrow throat section and wider inlet and outlet sections.

• As fluid flows through the venturi, its velocity increases in the narrow throat, causing a decrease in pressure.

• The pressure difference is measured and used to calculate the flow rate of the fluid.

• Venturis are commonly used in industries such as HVAC, water treatment, and automotive.

• For example, a ve...read more

HE refers to Heat Exchangers and pumps are used to move fluids. Types of HE include shell and tube, plate and frame, and spiral. Types of pumps include centrifugal, positive displacement, and axial flow.

• Heat Exchangers: shell and tube, plate and frame, spiral

• Pumps: centrifugal, positive displacement, axial flow

A centrifugal pump works by converting mechanical energy from a motor into kinetic energy in a fluid through the rotation of an impeller.

• The pump's motor spins an impeller, creating a centrifugal force that pushes the fluid towards the outer edges of the pump casing.

• As the fluid moves through the pump, it gains kinetic energy and pressure, which allows it to be discharged through the pump outlet.

• Centrifugal pumps are commonly used in industries such as water treatment, HVAC s...read more

O&M operations refer to the maintenance and operation of facilities and equipment.

• O&M operations involve regular maintenance tasks to ensure smooth functioning of equipment and facilities

• This includes tasks such as inspections, repairs, and replacements

• Proper documentation of maintenance activities is essential for tracking and planning future operations

• Efficient O&M operations can help in reducing downtime and increasing the lifespan of equipment

Different types of pumps and heat exchangers are used in process engineering.

• Types of pumps include centrifugal, positive displacement, and axial flow pumps.

• Heat exchangers can be classified as shell and tube, plate and frame, or air-cooled.

• Pumps are used to transfer fluids in a process while heat exchangers are used to transfer heat between fluids.

• Selection of pumps and heat exchangers depends on the process requirements and fluid properties.

• Efficiency, pressure drop, and ma...read more