IMPROVE.. MENTS IN APPARATUS FOR CREATING OR INCREASING AIR DRAUGHTS IN FLUES OR. OTHER CHANNELS FOR VENTILATION, & OTHER PURPOSES
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Edward Hewett at the Office of
the Commissioners of Patents, with his Petition, on the 6th Juno,
1861.
I, EDWARD HEWETT, of St. Leonard's-on-Sea, in the County of Sussex;
Brewer, do hereby declare the nature of the said Invention for "IMPROVE..
MENTS IN APPARATUS FOR CREATING OR INCREASING AIR DRAUGHTS IN FLUES OR.
OTHER CHANNELS FOR VENTILATION, & OTHER PURPOSES," to be as follows:-
My Invention of improvements in apparatus for promoting or increasing
draughts for ventilation and other purposes, consists in the application of
screw blades or vanes in suitable channels, which, by their rotation, propel the
air through such channels. In the case of house chimuics, I place the screw
blades, by preference, at or near the top of the chimney, and impart motion to.
them by means of a rotating cowl or top actuated by the wind. This rotatory:
top may be mounted on the same axis as the screw blades, & fitted in centrali
bearings, in which it is free to rotate, which it does in the manner of a
horizontal windmill, when there is sufficient wind to drive it, and in whatever
direction it may blow. Instead of a rotating top, such as described, it may.
be a small windmill with vertical sails mounted on the chimney top; or it may,
be on the top of the house, & motion communicated therefrom to the axis of
screw. The power from the same mill may also, be applied to the axis of the
screw blades of several chimnies fitted therewith. The screw blades may be.
simply one turn of the Archimedian screw, or several short sections thereof;.
or they may be flat blades set at an angle; they are in either case rotated so as

page_text: to create an upward current to throw the air out at the top, thereby exhausting
the lower part, & producing a thorough draught in the chimney, which
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effectually prevents down draught or return of the smoke to the room.
draughts or smokey chimnies occur only when the wind drives the smoke down,
in which case there would be always sufficient power to drive the apparatus,
therefore, the descent of the wind in the chimney would be prevented. This
apparatus for increasing the draught in chimnies to carry off the smoke or
increase the draught through the fire may be applied in the flues or chimnies
of steam engines & other furnaces, & motion imparted to them by the engine
or other power. For the ventilation of mines, I simply apply this screw in
the upcast shaft, or in a channel in communication therewith, and cause it to
rotate by any suitable power; its motion creates a current of air, which
continues its straight course through the screw blades and channel in which
they are placed. The screw blades may also be applied to force the air into
the mine; or it may be a chamber for the purposes of ventilation, instead of
effecting it by exhaustion, as above described. In any case I apply one or
more screws, or sections of screws, or it may be blades set at an angle, which
have the effect of drawing the air through such channel in the direct line of
the axis of such screws or blades applied-for-ventilation- & other purposes.
These blades do not diminish the area of the flue or channel, or necessitate
any tortuous course for the air, or even a departure from the direct line of the
channel.