Deaerator - TDG | ADCA

ADCA TDG – Thermal Deaerator for Boiler Feedwater

The ADCA TDG is a disc-type thermal deaerator designed for boiler feedwater treatment. The unit heats returned condensate and softened make-up water to remove dissolved oxygen and CO₂ prior to boiler entry. Technical documentation specifies oxygen reduction capability to below 0.02 mg/l, with final adjustment via chemical oxygen scavengers where required.

Operating Principle

Feedwater enters the deaeration dome and is heated by direct steam contact in a counter-current cascade arrangement. Liberated gases are vented, while deaerated water is collected in a horizontal storage vessel. Steam blanketing is maintained in the tank to minimize reabsorption of gases.

Construction and Connections

• Deaeration dome: vertical installation
• Storage vessel: horizontal cylindrical design
• Material: carbon steel with internal stainless steel components
• Optional: full stainless steel construction
• Connections: flanges EN 1092-1 or ASME, threaded ISO / NPT
• Design code: AD-Merkblatt

Operating Limits

• Maximum allowable pressure: 0.5 bar
• Maximum allowable temperature: 120°C
• Minimum operating temperature: -10°C
• Turndown ratio: 100:1

Sizes and Sizing Criteria

Models range from TDG-10 to TDG-200, with maximum flow rates from 1 to 20 m³/h for heating water from 10°C to 105°C. Selection requires make-up water flow/temperature, condensate flow/temperature, heating steam pressure, required tank capacity, and maximum deaerated water demand.

System Configurations

TDG units can be integrated with steam pressure reducing stations, tank temperature control, steam injection systems, level control, level indicators, safety valves, vacuum breakers, chemical dosing, and vent condensers for heat recovery from vented steam.

Applications

Used in industrial boiler houses where O₂/CO₂ corrosion, boiler thermal stress, and feedwater stability affect operation. In systems with low condensate return or high make-up rates, additional steam injection to the dome may be required.