What is the difference between an industrial (pressure) boiler and a steam generator? Boilers create steam by boiling water in a pressure vessel by heating the water and creating creating molecules. As the water boils at its boiling point (the boiling temperature depends on the pressure generated) steam is obtained at the saturated pressure. This type of steam making represent older steam technology (because Tsaturated and Psaturated are linked for such a method to produce steam at a temperature different than the atmospheric pressure).
Steam generators on the other hand are modern devices with instant on-off features, steam velocity control features, independent back pressure control and significant high-temperature steam capability (without the need of pressure vessels or pressure unless required for the back pressure)
Traditional boilers yield saturated steam that can sometimes be mildly superheated. Thus boiler steam may be wet and contain water droplets. For example with a boiler one needs a high 10 Bar and even then the saturation temperature is only 180°C – even at 100 Bars the saturation temperature is only 311°C. Steam generators do not have to operate at high pressure for the high temperature- typically thus offer high-temperature dry-steam.
Steam Generators can operate at room pressure. Thus one can get high temperatures in the steam-gas without use of unwieldy pressures. High temperatures even up to 1300°C are obtained.
Industrial boilers have worked well but they are 19th and 20th century type technology machines with low efficiencies. They can reach 85% efficiency in many configurations (only at steady state which often takes long for boilers), but they still have significant drawbacks in temperature capability. For boilers, very often, as the pressure rating increases the efficiency falls. Steam generators, like the GHGA, MHGA, OAB or HGA type routinely offer over 95% efficiency even to 1000°C and beyond (a temperature unimaginable for boiler steam).
Temperature Limitations – Industrial boilers are temperature limited by pressure. To obtain higher temperatures, higher pressures are required. Not so for steam generators.
To operate at lower temperatures than rated, boilers typically sacrifice efficiency or safety. Not so for steam generators. As the pressure rating of a boiler increases, quite often its efficiency falls.
Combustion Process – Nearly all large scale industrial boilers utilize the combustion process. This leads to CO2 and NOX production as well as fossil fuel consumption. Combustion processes typically result in low efficiencies and high energy losses.
Safety – Pressure vessels can fail and explode (although this is rare as many boiler makers follow the best practices). Low water levels can result in boiler overheating and potentially the explode. Gas leaks pose an inhalation danger as well as an explosion risk.
Difficult to Use Boilers – Boiler operation is typically dependent on specific, trained individuals who are trained to read dials and follow numerous safety measures as per local code. Boilers are complicated.
Steam Generators use 21st century technology. No combustion or pressure vessels. The GHGA, MHGA, OAB and HGA patented technologies allow steam generators to operate with unparalleled efficiencies, saving you time, money and improving your process.
Steam Without the Wait
MHI has pioneered new steam technology for high quality steam.
BoilerFreeTM technology allows nearly instant steam production. Most MHI steam generators produce super-heated in under a minute from a cold start (it can take a boiler many hours or days). With a variety of outputs and configurations available, MHI has an energy efficient high-productivity solution for your steam application. Please contact MHI.