Here is a list of terms to help better understand your particular needs in a process steam boiler. These definitions are applicable to Industrial Steam Boilers and Steam Generators; Fired Steam Generators and Unfired Steam Generators; Saturated Steam and Unsaturated Steam.
Boiler Horsepower (BHP): BHP is a term used to indicate the heat output of an industrial steam boiler (industrial steam generator). Technically, BHP is 33,475 BTU/hr (or 8,430 kcal/hr) which is derived from the amount of energy needed to produce 34.5 pounds of steam/hour at a pressure of 0 psig and temperature of 212°F, with feedwater at 0 psig and 212°F.
Calorie (C): The amount of heat required to raise the temperature of one gram of water one degree Celsius at a pressure of one atmosphere.
Dry steam generation: Clayton steam generators produce steam that is 99.5% dry (only 0.5% water content). Most boilers can only produce 98% dry steam (2% water).
Enthalpy (H or h): Thermodynamically, enthalpy is the sum of the internal energy of a body and the product of its volume, multiplied by its pressure. The definition for boiler calculations, enthalpy is the amount of heat in a fluid and is usually expressed as BTU/lb or kcal/gram. Enthalpy is considered to be 0 at 32°F (0°C) in these cases.
From and at 212°F: A term used to qualify the amount of steam produced by a steam boiler (steam generator). (See Steaming Rate.) The qualification indicates that the amount of steam produced is at a pressure of 0 psig and 212°F and feedwater at 0 psig and 212°F.
Gross Steaming Rate: The amount of steam produced by a boiler at the outlet of the boiler flange. This includes the amount of steam produced to heat the water in the feedwater receiver (deaerator or hotwell).
Heat of Vaporization: For steam boiler calculation purposes, this is the amount of heat required to convert water at saturated conditions to vapor (steam) at the same saturated conditions. Same as Latent Heat.
Heat Recovery Steam Generator (HRSG): These steam generators are comprised of four major components. These components are an economizer, an evaporator, a superheater and a water preheater.
Latent Heat: See “Heat of Vaporization,” (above).
Net Steaming Rate: The amount of steam produced, by a boiler, after blowdown and after steam is used for heating the water in the feedwater receiver (deaerator or hotwell).
On-demand Water Tube Boiler: Boilers produce steam on demand to meet processing needs. They start up quickly and respond on demand to meet steam load requirements.
PLC Control System: A programmable logic controller (PLC) or programmable controller is an industrial digital computer which has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, or robotic devices, or any activity that requires high reliability control and ease of programming and process fault diagnosis.
Saturated Liquid: Liquid that is at a saturated pressure and temperature.
Saturated Steam: Steam (vapor) that is at a saturated pressure and temperature.
Saturated Vapor: Vapor that is at a saturated pressure and temperature.
Saturated Water: See “Saturated Liquid,” (above).
Saturation Pressure: The pressure at which saturation takes place at a given temperature.
Saturation Temperature Sensible Heat: The heat (enthalpy) in a liquid, usually expressed as BTU/lb or Cal/g.
Specific Heat: The amount of heat (enthalpy) required to raise the temperature of one unit of mass one degree. Usually expressed as BTU/lb/F or Cal/kg/C.
Steam Boiler Heat Exchanger: A heat exchanger transfers heat from one fluid to another. (see Clayton Steam Boiler Heat Exchanger.
Steaming Rate: The rate at which a boiler produces steam, usually expressed in lbs/hr or kg/hr. (See Steaming Rate.)
Sub-cooled Liquid: A liquid that is at a temperature or pressure below the saturation temperature and pressure.
Superheat: The extra heat imparted to a vapor (steam) in heating it from a dry saturated condition. Also the corresponding rise in temperature.
Thermal Enhanced Oil Recovery (TEOR): TEORs produce steam which is injected into the reservoir and heats heavy oil resulting in reduced viscosity
For more information and definitions about steam boiler systems, contact your local Clayton representative.