Application of Superheat to Firetube Package Boilers
A moderate size chemical or food processing plant will use about 1500 BHP of steam generating
capacity, typically at 100 psi pressure with a temperature of about 338°F. With the retrofit of a practical
superheater to an existing boiler, steam with a temperature of 650ºF can be produced and sent to the plant.
Higher steam temperature will allow for exponentially increased heat transfer rates in production
machinery. Production rate increase will vary by equipment and process but should at least be in the 10%
to 30% range.

Arguably the most effective and profitable application of superheated steam from a package boiler is the
ability to generate and sell significant electricity with minimal investment and very fast payback rates. A
1500 BHP package firetube boiler designed to operate at 350 psi can be equipped with a superheater
making 750°F steam. Steam at this pressure and temperature can then be sent through a one megawatt
turbine and will exhaust steam at 100 psi and 570ºF. With no other alterations to the plant, except the
installation of a high pressure superheater equipped package boiler and a steam turbine, one megawatt of
electricity can be generated in addition to moderate superheat supplied to the plant as process steam.
The value of one megawatt-year of electricity at 10¢/kWhr is $876,000.00. Currently, typical electricity
rates in the US vary for 10¢ to 20¢ per kilowatt-Hour. Cost for such an installation would be about
$3M.