CONSTRUCTING FURNACES POR MARINE AND OTHER BOILERS AS WELL AS FOR OTHER FURNACES, TOGETHER WITH THE APPARATUS EMPLOYED THEREIN FOR THE PURPOSE OF HEATING THE AIR PREVIOUS TO ENTERING THE FURNACE OR FURNACES, & FOR CONSUMING THE SMOKE, AND THE SAVING OF FUEL
Year: 1855

page_text: by one.
PROVISIONAL SPECIFICATION left by George Napier at the Office of
the Commissioners of Patents, with his Petition, on the 15th August
1855.
. I, GEORGE NAPIER, of Renfrew Street, Glasgow, in the County of Lanark,
and of Adelphi, London, in the County of Middlesex, Engineer, do hereby
declare the nature of the said Invention for "CONSTRUCTING FURNACES POR
MARINE AND OTHER BOILERS AS WELL AS FOR OTHER FURNACES, TOGETHER WITH THE
APPARATUS EMPLOYED THEREIN FOR THE PURPOSE OF HEATING THE AIR PREVIOUS TO
ENTERING THE FURNACE OR FURNACES, & FOR CONSUMING THE SMOKE, AND THE
SAVING OF FUEL," to be as follows:-
My Invention consists of two or more furnaces, with two or more flues to each
furnace, one of which flues being for the purpose of conveying the air from the
front of the boiler, or building, or other more convenient part to a retort or
receiver, comprising two or more separate chambers or copartments, according
to the number of furnaces in use, which I propose to place in such a situation
& so constructed, that the air being made to pass through it becomes heated
to a high temperature, and then, conveyed from behind or otherwise by means
I
of an under flue into the ash-pit (which is closed), passes up between the
furnace bars and through the fire, and then proceeds through the other or
ordinary flue or flues towards the chimney or funnel, enveloping the retort in

page_text: its passage by means of an outer case, for the purpose of receiving and using
the spent heat on its passage to the chimney stalk or funnel.
In the other or ordinary flue or flues of the furnace, which adjoin the air
flue, is placed at some convenient spot a damper or valve, so constructed as to
open and shut a passage or communication between the said air flue and the
ordinary flue or flues, before mentioned, during the process of firing; this
damper or valve being intended to be opened simultaneously with the furnace
door when required for the purpose of coaling, while a damper or valve
placed at the mouth or other convenient part of the air flue becomes at same
time partly or wholly shut, thereby causing the whole smoke and gasses from
the newly-fired furnace (first having passed through the ordinary flue or flues)
to enter the air flue, then through the retort, and from thence, by means
of an under flue, into the ash-pit or ash-pits (which is or are closed) of the
other furnace or furnaces, passes up between the furnace bars, and through
the fire, and then proceeds through the ordinary flue or flues towards the
chimney or funnel, enveloping the retort, and pursuing the same course as the
heated air before mentioned, which last air damper or valve is also made to
shut simultaneously with the opening of the flue valve by means of a balance
pulley or other contrivance connecting the one with the other.
The same
process is followed and acted upon alternately in coaling the other furnace or
furnaces by similar valves and apparatus made applicable to each. The valve
of communication between the flues before mentioned is intended to continue
open so long as there remains any smoke unconsumed.
In addition to the usual double furnace doors, I propose to have a perfo-
rated damper or outer door, between which & the said doors there is to be
a narrow space, to allow a current of air to descend through an opening in the
dead plate or in front of it to the ash-pit, in furtherance of the object above
described, as well as serving as a protection to the stokers from the radiation of
heat outwards. The ash-pit is to be completely closed in front by a door, to
be opened only when necessary to remove the ashes. The said retort and outer
case may be made of iron, brick, or other material.