IMPROVEMENTS IN APPARATUS OR MEANS FOR VENTILATING SHIPS OR VESSELS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents on the 29th September 1881. A commu-
nication from abroad by Colin Archer, of Laurvig, in the Kingdom of
Norway.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN APPARATUS OR MEANS FOR VENTILATING SHIPS
OR VESSELS." A communication from abroad by Colin Archer, of Laurvig, in the
Kingdom of Norway.
This Invention relates to improved means or apparatus for ventilating the
interior of ships or vessels as hereinafter described. By means of this Invention
the rolling motion of the ship is utilized for the purpose of establishing a forced
circulation of air in such a manner that noxious or combustible gases are effectually
drawn off or removed from any required part of the vessel. The circulation of air
is accelerated in bad weather whilst the sea water is effectually excluded, and
owing to its great simplicity the apparatus is not liable to get out of order, and
repairs may be effected with facility when needled.
In carrying out this Invention an inverted syphon is employed, formed by a pipe
or tube of suitable size and material, such as lead, for example, placed in any
convenient position across the ship's hold so as to form approximately an arc of a
circle.
Each extremity of this pipe is connected with an air pipe of smaller size, fitted
with an inlet valve admitting air from the hold into the pipes, but preventing its
return, and a corresponding outlet valve which allows the air to escape from the
pipes into the atmosphere. The air pipes are carried from each side of the hold up
through the decks at a point suitably protected from the sea, such as inside a
deck-house, for example, and terminate in the open air. Sufficient water is
introduced into the large or syphon pipe to prevent any passage of air between its
two extremities.
During the rolling of the ship this water will be set in motion from side to side,
so as to alternately exhaust and compress the air at the opposite ends of the
inverted syphon pipe and thereby cause air to be expelled through the outlet
valves communicating with the atmosphere and be drawn in through the inlet
Povice 911

page_text: valves communicating with the hold. A hose or flexible tube may be connected
with the inlet valves and carried to any part of the ship from which it may be
desired to remove vitiated air. In order to supply the place of the air thus
pumped out of the hold, small pipes may be fitted through the decks at convenient
points, say, at the ends of the vessel. The improved ventilating apparatus being
placed near the middle of the ship a constant circulation of air will then be
established from the ends of the vessel towards the centre, where the vitiated air
is drawn off by the ventilators, as herein before described.
The quantity of air removed from the hold by one of theso ventilators is
directly in proportion to the amplitude and period of the ship's rolling, the
radius of the curve of the inverted syphon pipe, and the diameter of that part of
the piping which is alternately filled and vacated by the water.
That portion of the piping which contains air only may be ordinary galvanized
iron pipes of suitable diameter corresponding to the size of the apparatus.
A simple and effective valvo, which may be employed in the apparatus
hereinbefore described, is constructed with a round cup of hard wood or metal
having a hole in the bottom into which one of the air pipes of the ventilating
apparatus may be screwed and also provided with a lid fitted air tight, and
presenting an orifice for the reception of another of the said air pipes.
A hollow ball, smooth and round, of india rubber or other elastic material and
contained within the cup forms the valve proper.
This ball allows air to enter the cup from below, a slight pressure being sufficient
to raise it from its seat, but a tendency to escape downwards is effectually
prevented by the ball closing the hereinbefore described opening in the bottom of
the cup. The under side of the lid is provided with grooves in order to allow the
air to escape upwards when the ball is raised by pressure of air from below.