IMPROVEMENTS IN FIRE-BARS, AND PARTS CONNECTED THEREWITH
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Isaac Shimwell McDougall at the
Office of the Commissioners of Patents on the 29th May 1878.
ISAAC SHIMWELL M°DOUGALL, of the Firm of McDougall, Brothers, of Manchester
and London, Manufacturing Chemists. "IMPROVEMENTS IN FIRE-BARS, AND PARTS
CONNECTED THEREWITH."
My Invention relates to fire-bars to be used in furnaces or fire-places, either as
stationary bars or as moving bars, and on to which the fuel is fed, either by hand
firing or by means of mechanical stokers, and it consists in constructing the fire-
bars in such a manner as to enable them to be partially filled with water, so that
the water and steam in the interior of the bars serves to maintain them in a cool
condition, whereby the wear of the bars and the adhesion thereto of clinker are
prevented, the steam generated in the interior of the bars being allowed to escape
by suitable outlets into the fire, thus obviating the necessity of circulation, and also
thereby assisting the consumption of fuel
Ordinary fire-bars are liable to wear from the great heat to which they are
exposed, and more so during the time when the clinker forming in the fire adheres
to the bars, and obstructs the spaces between the bars, preventing the free admission
of cold air necessary for the proper combustion of the fuel, and also for cooling the
metal of the bars.
With a view to overcome these difficulties various arrangements of hollow fire-
bars have been proposed, which however have been only partially successful. In
the case of hollow air bars, air being so imperfect a conductor of heat, the bars
become greatly heated, and in the case of hollow water bars, as hitherto used, the
intention has always been to pass the water into the bar at a considerable pressure,
and the complications arising from the attempts to ensure a free circulation of
water through the bars, and to enable them to withstand the internal pressure, have
caused difficulties which have not been completely overcome.
Now this Invention has for its object obtaining the advantages of water bars,
whilst obviating the difficulties referred to, and this object is effected in the following
manner-The hollow fire-bars are constructed of any desired length, and into their

page_text: lower portion water is admitted from a suitable water cistern or reservoir in such a
manner as allows the bars to be only partially filled with water.
In the higher portions of the fire-bars are formed suitable holes, slots, or perfora-
tions, through which the steam as it is generated by the heat of the fire-bars is
allowed to escape and pass freely into the fire. By this means the fire-bars will be
maintained comparatively cool, and the burning away and wear of the fire-bars
greatly diminished.
:
The clinker and dross will have very little tendency to adhere to the bars, or to
obstruct the air spaces, but will remain loose and free on the bars in such a condition
as to be easy of removal.
The steam is allowed to pass freely out of the bars as generated, and as it will
pass through the thickest and brightest part of the fire will cause the fuel to burn
more vigorously with a more complete combustion, and will also increase the draught
of the furnace and tend towards the prevention of smoke.
The Invention is also applicable to stationary metal bridge walls, which support
the ends of the fire-bars, the bridge walls being so constructed that water can be
allowed to fill the lower portion and holes, or slots being provided above the level
of the water to allow the steam to freely escape, as desired.