Deaerator - ADG | ADCA

ADCA ADG – Atmospheric Semi-Deaerator for Boiler Feedwater

The ADCA ADG is an atmospheric semi-deaerator designed for preheating boiler feedwater and reducing dissolved oxygen and CO₂ content. The assembly consists of a deaeration head, horizontal storage vessel, and vent line. Under correct operation, residual O₂ is typically below 1.6 mg/l. Final oxygen removal is achieved with a chemical oxygen scavenger when required by boiler water chemistry.

Operating Principle

Hot condensate return is introduced at the bottom of the vessel via a sparger pipe. Softened make-up water enters the deaerator head and is heated by a counter-current flash steam cascade. Released gases are vented, while semi-deaerated water collects in the storage vessel, where additional steam injection can be applied if necessary.

Technical Specifications

• Type: ADG deaerator head
• Maximum allowable pressure: 0.5 bar
• Maximum allowable temperature: 120°C
• Minimum operating temperature: -10°C
• Design code: AD-Merkblatt
• Connections: flanges EN 1092-1 or ASME, sockets ISO / NPT
• Construction: carbon steel with internal stainless steel components
• Optional: full stainless steel construction

Sizes and Selection

Selection table links models ADG150, ADG200, ADG250, ADG300, ADG400 to maximum steam production 5,000 to 50,000 kg/h. Sizing requires make-up water flow/temperature, condensate flow/temperature, heating steam pressure, required vessel capacity, and maximum deaerated water flow.

System Configuration

Typical configuration may include direct steam injector, recirculation pump, magnetic level indicator with switches, temperature sensor, vacuum breaker, humidity separator, level control valve, and pneumatic on/off steam valve. Options include vent condenser or flash steam recovery from TDS/blowdown.

Installation and Maintenance

The ADG head is installed vertically, with the storage vessel mounted horizontally. Pipework must be independently supported to avoid thermal expansion loads. After commissioning, all connections should be checked for leakage within 24 hours.