Solutions


Installations

Many batch processes require short-duration, high-flow rate steam daily or weekly. A steam accumulator accommodates these peaks by storing excess steam.

Steam accumulator main purposes could be defined:

  1. Leveling quantity, pressure and temperature between steam generation and consumption
  2. Balance between waste steam supply and consumption
  3. Availability for instant steam demand

Every steam system is different, although each time installation must be analyzed on a case-by-case basis.


Benefits


Generally steam accumulator installations improve plant performance, reduced fuel costs and minimized greenhouse gas emissions. This effective and easy way to meet targets reduce carbon footprint in state or private company policies.


  • Minimize boiler short cycling losses; combustion efficiency increased 5%
  • Enable downsizing boiler capacity; capital cost reductions
  • Boiler load factor maximized; emissions reduced
  • Eliminate boiler carry-over; longer service life
  • Additional peak load capacity is minimized or eliminated; fuel savings and capital cost reductions
  • Immediate response to sudden load change; enable biomass boiler operation
  • Steam pressure stability; more production and better quality
  • Eliminate atmospheric venting; fuel and water savings
  • Minimize dumping to condenser; fuel savings
  • Old oversized boilers’ lifetime could extended; capital cost reductions
  • Usual project payback time is short as two or three years and financing investment should not be difficult.

The 3rd Generation

The 1st Sliding pressure steam accumulator was patented by McMahon in 1873. Steam accumulators were reinvented 100 years later in Scandinavian pulp&paper industry. “Steam Age” application is still valid modern industry; boilers holdup volumes are getting smaller, oil price keeps rising, biomass boiler have long response and emission reduction are topic. The 3rd Generation steam accumulator was introduced 1996 in Kirkniemi, Finland. New design features are:

  1. H-type steam rake and vertical mixing pipes (turn-down ratio 30:1, good steam distribution and smooth operation)
  2. Internal ”dry pan” demister (high volumetric efficiency and dry steam)
  3. Stress calculation with fatigue analysis required (modern design codes, extended NDT, mean pressure difference and number of cycles per lifetime)
  4. Optimized wall thickness and material strength (thermal sleeve, loose supports, welding details, PWHT and boiler water quality)
  5. Advanced controls (”active” or ”passive” accumulator, one display screen, fully automated description, single master pressure transmitter, smart level control )