Boiler glossary I
IGNITION TEMPERATURE -- In the combustion of gases, the
temperature at which the heat loss due to conduction, radiation, etc., is more
than counterbalanced by the rate at which heat is developed by the combustion
IMPELLER -- The rotating member of a centrifugal pump or blower, which imparts kinetic energy to the fluid.
INCOMPLETE COMBUSTION -- The partial oxidation of the combustible constituents of a fuel.
INCRUSTATION -- Scale, a hard coating of deposits precipitated from solution at the boiler tube surface.
INDUCED DRAUGHT -- A forced draught system used for boiler furnaces, in which a fan is placed in the uptake induces an air-flow through the furnace.
INERT GASES -- Incombustible gases such as nitrogen. Also exhaust gases from a boilers controlled to contain maximum 5% oxygen is used as inert gas in cargo tanks onboard oil tankers.
INFRARED HEATER -- A system consisting of a hot surface that heats surrounding objects through infrared radiation.
INFRARED PHOTOMETER-- A meter measuring strength of infrared radiation, electromagnetic radiation with wavelengths greater than that of visible light and shorter than microwaves.
INHIBITOR -- A substance which selectively retards a chemical action. An example in boiler work is the use of an inhibitor, when using acid to remove scale, to prevent the acid from attacking the boiler metal.
INJECTOR -- A device utilizing a steam jet to entrain and deliver feed water into a boiler.
INTERMITTENT BLOWDOWN -- The blowing down of boiler water at intervals.
INTERNAL FEED PIPE -- (Dry pipe) A pipe running along the top of the steam space in which slots are cut in the top or sides for the purpose of admitting only dry steam to the line. One end of the pipe has a blank ending and the other end is connected to the steam outlet. Drainage holes are drilled along the bottom of the pipe.
INTERNAL MIX STEAM ATOMIZER-- The burner lance consists of two concentric tubes and the media supplies are arranged so that the steam is supplied down the centre tube and the fuel oil through the outer tube.
INTERNAL TREATMENT -- The treatment of boiler water by introducing chemicals directly into the boiler.
IRON -- Except in a few sections, this impurity in the boiler water is not troublesome.
ISENTROPIC -- Any process in which no change of entropy occurs. A theoretically ideal engine cycle that is adiabatic and frictionless.
ISOTHERMAL -- Occuring at constant temperature.