Steam accumulator

A steam accumulator is an insulated cylindrical tank holding superheated water and steam under pressure. Steam from the boiler enters through a perforated pipe near the bottom; part of it condenses and heats the water, and the rest fills the space above the water level. Fully charged, it is about three-quarters full of water, with temperature and pressure raised. When steam demand exceeds boiler capacity, the accumulator takes over: as steam is drawn off, pressure falls slightly and some of the hot water flashes into steam. Most of the energy sits in the water at saturation temperature rather than in the steam space, so the more water the tank holds, the better it absorbs load swings.

The accumulator evens out peak loads on the boiler and prevents the surging, water carry-over and impurity entrainment that sudden pressure drops cause, so the plant runs without pressure swings in busy and quiet periods alike. Sizing starts from peak and average steam demand, peak duration and boiler capacity to find the steam deficit; an efficiency factor of 90 % is applied, the volume is derived from operating pressure and temperature, and a 20 % safety margin is added. Typical uses include power plants, textile finishing, canning, aerated concrete and EPS production, rubber autoclaves, sterilisation and heat storage in solar energy systems.

The tank is delivered on a single skid and only needs connecting to power, feedwater and steam users. A demister at the outlet holds back moisture for very dry steam, and a vacuum breaker protects the tank from the negative pressure that forms as it cools while out of service. Shell and end plates are P355GH to EN 10028-2, nozzle tubes P235GH or P265GH, with 100 mm of high-density insulation. The PLC supervises overpressure protection, staged water level safeguards, steam temperature and emergency shutdown, with data via Modbus, Modbus TCP/IP or Profinet. On request, a version certified to ATEX for Ex zone 1 is built.