Services for Deaerator Tanks

1. Deaerator Tank Design and Sizing

2. ASME Pressure Vessel Design

3. Piping Design for Deaerator Systems

4. P&ID Development for Deaerator Integration

5. Steam Distribution System Design

6. Deaerator Tank Material Selection

7. Condensate and Blowdown System Design

8. Level Control and Flow Monitoring

9. Vapor Removal System Design

10. Safety Valve and Relief System Design

11. Pressure Control and Monitoring Systems

12. Corrosion Protection and Material Coating

13. Thermal Stress and Expansion Analysis

14. Deaerator Tank Insulation Design

15. Reboiler and Heat Exchanger Design

16. Deaerator Integration with Boiler Systems

17. Instrumentation and Automation Design

18. Custom Fabrication and Assembly

19. Commissioning and Startup Support

20. Operational Optimization and Troubleshooting

Deaerator Tank Engineering Guide

What is a Deaerator Tank?

A deaerator tank is a crucial component in steam generation and boiler systems used primarily to remove dissolved gases, particularly oxygen and carbon dioxide, from feedwater. These gases, if allowed to remain in the system, can lead to severe corrosion of the boiler and other equipment, reducing efficiency and lifespan.

The deaerator works by utilizing heat and pressure to strip dissolved gases from the water. The tank typically consists of a heated vessel where steam is used to raise the temperature of the incoming feedwater, allowing the dissolved gases to escape and be vented out.

Applications of Deaerator Tanks

 Applications for deaerator tanks across various industries:

1. Power Generation Plants – To remove oxygen and prevent corrosion in boilers.

2. Steam Boilers – Used in various industries to supply clean and deoxygenated feedwater to the boiler.

3. Chemical Plants – Deaeration of water used in processes where oxygen could negatively affect reactions.

4. Oil Refineries – Protects boilers from corrosion caused by dissolved gases in feedwater.

5. Pulp and Paper Industry – Deaerators are used to ensure the quality of water used in steam generation.

6. Pharmaceutical Manufacturing – Prevents contamination in critical steam systems where water purity is essential.

7. Food and Beverage Industry – In high-temperature sterilization and pasteurization systems, deaerated water is required.

8. Distillation Systems – Deaerators help maintain the purity of steam in distillation and separation processes.

9. Marine Applications – On ships for steam generation and water purification systems.

10. Textile Industry – Used in boilers to provide deoxygenated water for dyeing and finishing processes.

11. HVAC Systems – Ensures the quality of steam used for heating and cooling systems.

12. Heat Exchanger Systems – Prevents scaling and corrosion in heat exchangers.

13. District Heating Systems – Ensures the integrity of hot water loops used in heating buildings.

14. Steel Manufacturing – Deaerators remove oxygen from water used in cooling systems for steel production.

15. Power Plant Auxiliary Systems – Ensures high-quality feedwater for turbines and cooling towers.

16. Chemical Reaction Control – Used in processes where oxygen presence can alter chemical reactions.

17. Closed-loop Cooling Systems – Prevents corrosion in closed-loop systems that use water for cooling.

18. Refining Process Water – Ensures the removal of gases from water used in refinery processes.

19. Boiler Feedwater Treatment – Prevents scaling and corrosion by removing dissolved gases from feedwater.

20. Geothermal Power Plants – Ensures that steam and water systems are free from corrosive gases.

Process Design for Deaerator Tanks

The design of a deaerator tank must ensure efficient removal of dissolved gases without causing excess energy loss or creating excessive pressure within the system. The design process involves several factors including water quality, steam conditions, and operational requirements.

Key Process Design Considerations:

1. Steam and Feedwater Flow Rate: Accurate sizing based on the required feedwater and steam flow rates.

2. Deaeration Efficiency: Proper temperature, pressure, and steam-to-feedwater ratio to optimize gas removal.

3. Water Temperature and Pressure: Adequate heat input to achieve the desired deaeration while avoiding excessive pressure.

4. Gas Removal Capacity: The tank should be capable of removing all dissolved gases, particularly oxygen, to prevent corrosion.

5. Design of Venting Systems: The deaerated gases must be vented safely from the system.

6. Water Outlet and Inlet Design: Ensuring uniform distribution of steam and water inside the tank for effective deaeration.

7. Safety Systems: Pressure relief valves, temperature sensors, and emergency shutdown systems to ensure safe operation.

8. Draining and Blowdown: Efficient systems to drain out any residual water or condensate from the deaerator.

9. Material Compatibility: The materials used must be resistant to corrosion, especially when deaerating feedwater with high levels of oxygen.

10. Pressure Control: Maintaining appropriate pressure inside the deaerator to prevent damage to equipment and ensure effective deaeration.

Mechanical Design for Deaerator Tanks

The mechanical design of a deaerator tank involves ensuring that the tank can handle the high-pressure and high-temperature conditions typical in boiler systems. It is also critical to ensure the tank’s longevity by using corrosion-resistant materials and creating reliable support structures.

Key Mechanical Design Considerations:

Design Aspect

Description

Material Selection

Stainless steel or carbon steel with corrosion-resistant coatings are commonly used for deaerator tanks.

Pressure Vessel Design

Designed to handle high pressures, typically using ASME standards for pressure vessels.

Vessel Shape & Size

Usually vertical, cylindrical shapes with sufficient capacity to store deaerated water and handle large volumes.

Vent and Drain Systems

Deaerators require a vent system for removing air and gases and a drain to remove any unwanted liquid.

Nozzle Placement

Properly located nozzles for inlet steam, outlet water, and vents to prevent flow restrictions and turbulence.

Level Control and Safety

Continuous level control to ensure proper water and steam interface. Includes pressure relief valves for safety.

Steam Distribution System

A steam header with evenly distributed steam to the tank, ensuring efficient deaeration.

Heat Transfer Efficiency

Proper design to facilitate effective heat exchange between the steam and feedwater.

Tank Supports

Structural support to hold the tank in place, designed for vibration resistance and thermal expansion.

Corrosion Allowance

Sufficient material thickness to account for long-term exposure to water, steam, and oxygen removal processes.

Instrumentation for Deaerator Tanks

Proper instrumentation ensures that the deaerator operates efficiently and safely by monitoring and controlling essential variables such as pressure, temperature, and water levels.

Key Instrumentation for Deaerator Tanks:

1. Pressure Transmitters: To monitor the pressure inside the deaerator and ensure safe operation.

2. Temperature Sensors: To maintain optimal temperatures for steam and feedwater during the deaeration process.

3. Level Indicators: To measure the water level and control the flow of feedwater and steam.

4. Flow Meters: To monitor the flow of both feedwater and steam entering the deaerator.

5. Dissolved Oxygen Analyzers: To verify the efficiency of the deaeration process by measuring the remaining oxygen levels.

6. Safety Valves: Automatically release pressure if it exceeds safe limits.

7. Condensate Temperature Sensors: To ensure that the condensate exiting the deaerator is at the proper temperature for further use.

8. Vibration Sensors: To detect any abnormal vibrations caused by steam flow or structural issues.

9. Control Valves: To regulate the flow of steam, water, and gases in the deaerator.

10. Emergency Shutdown Systems: For automatically halting operations if safety parameters are exceeded.

 

Related Components for Deaerator Tanks

• Piping Systems: For feeding and returning water and steam to the deaerator.

• Heat Exchangers: To manage heat transfer between steam and feedwater.

• Pressure Relief Valves: To ensure the deaerator does not exceed its pressure limits.

• Blowdown Tanks: For handling water that needs to be drained from the deaerator during operation.

• Instrumentation: Including level and flow sensors to manage the operation of the tank.

Conclusion

A deaerator tank is essential in protecting steam generation and boiler systems from corrosion caused by dissolved gases in the feedwater. Proper process design, mechanical design, and instrumentation are key to ensuring efficient operation and long-term reliability.

At Sandhya Design Consultancy, we specialize in providing customized solutions for deaerator tanks, ensuring your systems are optimized for performance, safety, and longevity.