=56. Locating the Boiler Room.=—The ideal location for the boilers of
a factory or an industrial plant is in a separate building, which may
be denominated as the =power house=, and which may include as well, the
installation of the engines, dynamos, and other machinery necessary for
the generation of power and its transmission. More frequently, however,
the ground is not available for the erection of a separate building for
the power plant, and it becomes necessary to install the boilers and
engines in the factory itself. The location usually selected for these
vital features of the mill is the basement, and the arrangement of the
boilers and engines must be carefully considered in the designing of
this portion of the building.
=57.= In laying off the space to be occupied by the boilers, the
probable growth of the manufactory must be provided for by arranging
ample space for the installation of additional boilers.
It is best in arranging the boilers, to face them toward the available
coal supply, which is usually a coal bunker, vault, or bin, but in no
instance must the front of the boiler be nearer to a wall than the
length of the boiler tubes, unless special arrangements are made, for
this distance must be allowed in order to draw any defective or damaged
tubes and replace them with new ones. Also, by arranging the boilers
thus, the fireman has a minimum amount of carriage for the coal.
=58. Coal Storage.=—In designing the coal vaults, or coal storage,
their contents should be figured to allow for 1 or 2 weeks’ coal
supply, and as much more as is possible, to carry the plant over
periods of existing coal shortage due to strikes or interrupted traffic
from bad weather or other cause. In calculating the amount of space
required for coal storage, it is sufficient to multiply the number of
horsepower generated by the boilers by 4, which is the approximate
number of pounds of coal per hour for the generation of 1 horsepower.
This result, again multiplied by the number of hours for which the
boilers are run at their capacity, will give the quantity of coal
needed per day, in pounds. The weight per cubic foot of coal varies
from 80 pounds for soft coal to 90 pounds for hard coal, so that by
dividing the number of pounds by these quantities the cubic feet of
coal required per day is obtained. The bins may then be proportioned
for the number of days’ supply which the judgment of the designer may
assume as being necessary.
=59. Ash Disposal.=—Besides the consideration of the coal supply, some
disposition must be made of the ashes from the boilers. Frequently, a
bin is constructed of masonry, alongside of the coal supply, into which
the ashes are dumped by means of barrows. In large plants, this bin can
be emptied by means of an ash conveyor, or elevator, which will carry
the ashes to the level of the street or railroad track and thence into
a cart or car.
=60. Planning the Boiler Room.=—In locating the boilers in the boiler
room, which should be done in the plans of the building, for it is not
customary to cement the floor space covered by the boilers, and the
cost of the building is thus reduced, a passageway not under 3 feet,
and better 4 feet, should be left back of the boilers. This passageway
is required in order to have access to the clean-out doors and the
blow-off cocks. The ordinary horizontal return-tubular boiler, and
some water-tube boilers, can be constructed in a battery, with as many
boilers as may be desired in a row, especially when the passageway
is left back of the boilers. When setting other types of water-tube
boilers, space should be left between each battery of two, for in
these boilers, cast-iron doors are provided in the side walls for
blowing the soot from the tubes, and access must be had through the
side walls of the boiler for this purpose. It is therefore necessary in
laying out the boiler space for boilers of this character to provide
a passageway on one side of each boiler. In Fig. 29, a battery of
return-tubular boilers is indicated, showing the clean-out doors for
taking away the accumulation of soot and ashes that might be back of
the bridge wall, through a passageway at the rear of the boilers. Some
water-tube boilers are set in batteries of two, as the Babcock & Wilcox
water-tube, land-type boiler, which is provided with the necessary
clean-out doors, and doors for blowing the soot off the tubes in the
side wall.
[Illustration: _Front of Boilers_ FIG. 29]
It is therefore necessary in laying out the boiler room of a
manufacturing plant to consider carefully the character of the steam
generator and study its requirements, so that it may be successfully
operated and the proper spaces allotted.
[Illustration: FIG. 30]
=61. Doorway to Engine and Boiler Room.=—In the hasty design of
buildings, it is frequently found that the size of the doorways is not
sufficient to admit the boilers and machinery. This is a serious defect
in the planning of a manufacturing plant, as it requires either the
installation of the boilers and engines before the walls are entirely
built, or else the tearing out of brickwork and jambs in order to
accommodate them afterwards. An expedient for the enlargement of the
headroom of doorways and openings into the boiler and engine rooms that
are in the basement, is shown in Fig. 30. Here, if the lintel of the
doorway _a_ is kept below the floor level, where it would ordinarily
exist, the headroom of the doorway will be materially reduced, and
considerable difficulty will be encountered in taking any large piece
of machinery, or a boiler or steam drum, down the steps _b_. The
doorway is consequently increased in height by the introduction of the
bulkhead at _c_; while by this means the floor space above is slightly
reduced, yet use can frequently be found for the ledge or platform
frame at the top of the bulkhead, as at _d_.
=62. Floors Above Boilers.=—It is important in designing boiler rooms
in factories to have the floor construction over the top of the boiler
of incombustible material, and it is customary in the better class
of buildings to provide a section of fireproof floor over the top
of the boiler room. This floor construction may either be a brick
arch supported on steel beams, or hollow-tile construction, though
reinforced concrete is now finding favor in this purpose.
=63.= It is not altogether necessary that the boilers in a building
shall be placed in the basement, though as this is usually the least
valuable of the floor space it is the practice to so locate them. In
some electric-light stations, and in large factories, boilers have been
located on the first floor, and even in several instances on the fifth
and sixth floors. The exigencies that demand the latter installation,
however, must be great, for it can be readily seen that much power must
be expended in lifting the coal, etc. to the boiler room.