MARINE BOILERS -- Boilers designed to fulfil special
demand from the merchant marine. An example of fire-tube boiler construction is
the
Scotch fire tube boiler that for a long time was a very
common marine steam boiler.
In diesel engine propelled vessels vertical steam boilers are used to save
space on the floor. One example of these boilers is the
Sunrod boiler. Marine boilers are nowadays mainly used for
heating purposes.
MAGNESIUM CARBONATE -- The magnesium carbonates are similar in
their properties to the corresponding calcium salts, with the exception that
the monocarbonate of magnesium is quite soluble, so that in order to, secure
the precipitation of the magnesia it is necessary to convert it to the hydrate,
which is relatively insoluble. The carbonate salts of lime and magnesia are
commonly referred to as "temporary hardness," because they are
precipitated to a considerable degree by merely heating the water, which drives
off carbon dioxide from the bicarbonate, forming the monocarbonate, which, in
the case of lime at least, is relatively insoluble.
MAGNESIUM SULPHATE -- Magnesium sulphate is highly soluble,
but when calcium salts are also present in the boiler, it reacts with them,
forming calcium sulphate, which is deposited as hard scale.
MAKEUP WATER -- Raw water that has been filtered and softened
and then introduced into the hotwell to compensate for water loss in the
system.
MANHOLE -- Opening in a drum that permits a person to crawl in
for inspection
MANHOLE RING -- A reinforced ring of metal fitted around the
manhole to provide local stiffness.
MANIFOLD -- A pipe or header for collection of a fluid from,
or the distribution of a fluid to a number of pipes or tubes.
MARINE DIESEL OIL -- Marine Diesel Oil is a middle distillate
fuel oil which can contain traces, often 10% or more, of residual fuel oil from
transportation contamination and/or heavy fuel oil blending. The MDO does not
require heated storage.
MDO -- Abbreviation for Marine
Diesel Oil
MICA -- A group of silicates which crystallize in the
monoclinic system; they have similar chemical compositions and highly perfect
basal cleavage. Mica is one of the best electrical insulators.
MICHELL BEARING -- A thrust or journal bearing in which
pivoted pads support the thrust collar or journal in such a way that they tilt
slightly under the wedging action of the lubricant induced between the surfaces
by their relative motion. The fluid lubrication conditions thus produced result
in a very low friction coefficient and power loss in the bearing.
MODULATING BURNER -- A burner which can vary output intensity
continuously from maximum fire down to a minimum point.
MOISTURE IN STEAM -- Particles of water carried in steam,
expressed as the percentage by weight.
MONOTUBE BOILER -- A boiler consisting of a
single tube. Feed water enters at one end and steam leaves at the other.
MOTIVE PRESSURE -- Line velocity pressure in steam piping.
MUD DRUM -- The bottom drum of a water tube boiler. A blow
down line is normally installed from this drum for draining.
MULTIPLE-EXPANSION ENGINE -- An steam engine in which the
expansion of the steam is divided into two or more stages, which are performed
successively in cylinders of increasing size.
Compound engine,
Triple expansion engine,
Quadruple expansion engine.
MULTI-STAGE BURNER -- A burner with more than two discrete
stages of output intensity.
|
