IMPROVEMENTS IN VENTILATING SHIPS, BUILDINGS, AND OTHER STRUCTURES, MINES, TUNNELS, AND THE LIKE, AND IN APPARATUS THEREFOR."
Year: 1881

page_text: LETTERS PATENT to James Campbell Baker, of Liverpool, in the County of
Lancaster, for an Invention of "IMPROVEMENTS IN VENTILATING SHIPS,
BUILDINGS, AND OTHER STRUCTURES, MINES, TUNNELS, AND THE LIKE, AND IN
APPARATUS THEREFOR."
PROVISIONAL SPECIFICATION left by the said James Campbell Baker at
the Office of the Commissioners of Patents on the 9th December 1881.
JOHN CAMPBELL BAKER, of Liverpool, in the County of Lancaster. "IMPROVE-
MENTS IN VENTILLATING SHIPS BUILDINGS AND OTHER STRUCTURES, MINES,
TUNNELS, AND THE LIKE AND IN APPARATUS THEREFOR."
In ventillating large areas or long avenues such as ships holds tunnels or mines-
if the air be all exhausted or introduced from one point there is a disagrecable
draft caused at that point while if taken from various points a separate pipe and
orifice is required from each point.
Now my Invention is designed to accomplish this object by means of one pipe
with numerous orifices. An ordinary pipe with numerous orifices would only
draw from one point namely the orifice nearest the exhauster, but I prevent this by
proportioning the area of orifices in a pipe to the diameter of that pipe and vary
the diameter or cross-section of the pipe throughout the length according to the
area of orifices to be supplied by air passing that point. Thus if the area of the
pipe were four circular inches with four or six circular inches of orifice, it would be
only two circular inches area at a point where it only supplied or drew from two
or three circular inches of orifice as the case may be. The orifices can be in the pipo
itself or in branch pipes.
In ventilating ships I bring a main pipe along one or both sides or the centro
below the deck and short branch pipes from this at intervals.
In tunnels or mines I in similar manner have main pipes and branch pipes but
every pipe is regulated as regards its sectional area by the area of orifices it has to
serve. I in some instances place plugs all along the main pipes so as if desirable to
draw off all the air at any given point instead of allowing it go to or draw from
the extremities. Sometimes too I join the various mains with branch pipes and
stop valves so that the ventilation can be applied to various parts of the ship mine
or other space at pleasure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Campbell Baker in the Great Seal Patent Office on the
9th June 1882.
JAMES CAMPBELL BAKER, of Liverpool, in the County of Lancaster. "IMPROVE-
MENTS IN VENTILATING SHIPS, BUILDINGS AND OTHER STRUCTURES, MINES,
TUNNELS, AND THE LIKE, AND IN APPARATUS THEREFOR."
In ventilating large areas or long avenues such as ships holds, large halls or
buildings, tunnels or mines- if the air be all exhausted or introduced from one point
there is a disagreeable draft caused at that point while if taken from or introduced
at various points a separate pipe and orifice leading to each of such points is
required.
Now my Invention is designed to accomplish the thorough ventilation of any
large enclosed space by means of one pipe or flue with numerous orifices either by
withdrawing the foul air or by forcing fresh air in but I prefer to exhaust the
vitiated air allowing the fresh air to find its way in through the ordinary openings
or special openings may be provided and if desired tho air heated as it enters by
passing over heated pipes or in any other convenient mannor.
An ordinary pipe or flue with numerous orifices would only draw from one point
namely the orifice nearest the exhauster, but I prevent this by proportioning the
total area of orifices in a pipe to the cross sectional area of that pipe and varying
the diameter or cross section of the pipe throughout its length according to the
area of orifices to be supplied by air passing that point. Thus if the area of the
pipe were four circular inches at a point where it supplied or drew from orifices of
à total area of four or three circular inches it would be only two circular inches in
area at a point where it supplied or drew from orifices of a total area of two to one
and a half circular inches and so on.
The orifices may be placed in the main pipe or flue or in branch pipes leading
therefrom to any convenient or required place in the area to be ventilated either to
prevent draught or replace the air at the spot where it is most vitiated. In the
Drawings I show my Invention as applied to a steam ship the foul or vitiated air
being exhausted by means of apparatus such as that described in the Specification
of Letters Patent No. 2175 of 1880 though any other apparatus for introducing or
withdrawing air may be used.
Fig. 1 is a longitudinal section of the after part of the ship.
Fig. 2 plan of same. Fig. 3 cross section on line x, y.
A is the exhauster, B the ventilating pipes. B' pipes leading to the fore part of
the ship. C branch pipes. D orifices for adinission of air into the pipe. The main
pipe B is carried along at either side of the ship just below the deck and short
branch pipes C are carried from this at intervals to the required place in the cabin
or hold for the purposes above described. Orifices D are located as required along
the main and branch pipes and are so proportioned that all pipes shall have a
larger area of orifices depending on it than a previously fixed ratio to the diameter
of the pipe at that point. Thus if the ratio be 1 to 1 a pipe of 6 inches diameter
has never more than 6 inches of orifices dependent on it. As the pipe B recedes
from the point of exhaustion A it diminishes in size to a capacity only equal or
proportionate to the amount of orifices beyond. Thus at the end nearest to A it is
of a diameter capable of conducting all the air admitted by the orifices throughout
its length whilst at the furthest end its capacity is only sufficient to conduct the
air admitted at D¹.
In buildings instead of laying pipes, I prefer to build flues though in tunnels or
mines the pipes may be more convenient, as also in buildings that are at present

page_text: erected but in each case I carry out the same principle (with or without branch
pipes or flues carried into separate rooms or particular places) of regulating the
sectional area of each flue or pipe at any given point to the total area of the
orifices it has to serve.
In some instances I place plugs or slide valves in various positions along the main
pipe or flue covering large orifices so that if required the greatest possible amount
of air may be withdrawn or supplied at that point instead of allowing it to be
drawn from or pass to the extremity. Sometimes too I place stop valves or cocks
at the points where the various branch pipes or sets of branch pipes are joined to
the main pipe or flue so that ventilation may be applied to the various parts of the
structure at pleasure.
This is particularly useful in the case of buildings such as halls, clubs, court
houses et cetera, where one room is more used than another or when one or more
rooms may be in use at a time. In practice it will be found best to make the
total area of orifice and of the pipe nearly equal to each other or strictly speaking
the area of pipes should equal the area of orifice measured by "vena contracta" not
actual areas.
Having now described my Invention and the best mode known to me of
carrying it into effect I wish it to be understood that I do not claim broadly the
use of pipes with apertures for, ventilating ships, buildings and other structures
but that what I believe to be new and desire to protect under the hereinbefore in
part recited Letters Patent is :-
1 The ventilating of enclosed spaces by means of a flue or pipe with numerous
orificies, whose capacity for conducting air is approximately proportionate at any
given point throughout its length to the area of the orifices it has to serve
substantially as described.
2 The manufacture or construction of ventilating pipes or flues with numerous
orifices of equal sizo whose diameter or cross section decreases as it receeds from
the point of exbaustion or compression in proportion to the area of orifices to be
supplied with air passing that point.
In witness whereof I the said James Campbell Baker have hereunto set my
hand and seal this Seventh day of June in the year of our Lord One
thousand eight hundred and eighty two.
5 Witness,
J. O. O'BRIEN,
Clerk to Messrs. W. P. Thompson & Co.
Patent Agents,
Liverpool & London.
JAMES C. BAKER. (L.S.)