Improvements in Tubular Heaters for Steam, or Fuel, or Hot Water, as a Medium to Heat Air.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Tubular Heaters for Steam, or Fuel, or Hot Water,
as a Medium to Heat Air.
WILLIAM TATTERSALL, 37, Glasslyn Road, Crouch End, London, N., Ventilating
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to heaters for increasing the temperature of air for
warming or drying purposes in which the air passes through the tubes and the
heating medium either steam hot water or the products of combustion from fuel
passes or circulates amongst the tubes.
My object is to increase the efficiency of such heating apparatus and to decrease
the liability to leakage of the heating medium-for the purpose of increasing the
efficiency I enclose the heater with an outer casing between which and the heater
a space is formed within which space I form spiral passages when the heaters
are circular in section and passages oblique to the direction of the tubes when
the heater is rectangular in section through these passages the air is forced or
exhausted so as to absorb heat from the outer shell of the heater within or at
the ends of the tubes. I also place spiral or rotary deflectors to give the air a
rotary motion inside the tubes and so cause it to be brought into closer contact
with the internal surfaces of the tubes and for a longer period than if the tubes
were free said spirals may project outside the tubes and have expanding ends.
To prevent leakage which is mainly due to unequal expansion and contraction
loosening the tubes in the end plates largely caused by the impact of cold air
against the heater at the end where it enters. I partly overcome this difficulty
by warming the air as already described before it impinges on the end of the
heater and in addition I protect the end of the heater by allowing the tubes to
project and filling in the spaces between the tubes with a nonconducting
material the tubes may be expanded to more securely hold it in position.
Dated this 13th day of February 1899.
COMPLETE SPECIFICATION.
Improvements in Tubular Heaters for Steam, or Fuel, or Hot Water,
as a Medium to Heat Air.
I, WILLIAM TATTERSALL, of 20, Grove Terrace, in the City of Bradford, Yorks,
Ventilating Engineer, and late of 37, Glasslyn Road, Crouch End, London, do
hereby declare the nature of this invention and in what manner the same is
077
Improvements in Tubular Heaters for Steam, or Fuel, or Hot Water,
as a Medium to Heat Air.
I, WILLIAM TATTERSALL, of 20, Grove Terrace, in the City of Bradford, Yorks,
Ventilating Engineer, and late of 37, Glasslyn Road, Crouch End, London, do
hereby declare the nature of this invention and in what manner the same is
077

page_text: to be performed, to be particularly described and ascertained in and by the
following statement:-
-
This invention relates to improvements in that class of air heaters in which
the air is passed through a number of tubes externally heated by steam or other
means, and the object of the improvements is to increase the efficiency of the
apparatus as well as reduce the liability to leakage of the heating medium.
To fully describe my invention reference is made to the accompanying sheet
of drawings forming a part of this specification, in which similar figures of
reference indicate corresponding parts in both of the views.
Figure 1, represents a diametrical section of a portion of a cylindrical heater
made in accordance with my improvements, but without its external casing.
Figure 2, is an end view of the same.
The cylinder 2, fed with steam or other heating medium is fitted with exter-
nally dished ends 3 in which the air tubes 4 are secured. The tubes 4 project
beyond the end 3 and the space between the ends of the tubes at the feed end
is filled in with any suitable bad-conductor-of-heat 5. The ends of the tubes
may be enlarged as shown at 4ª to help to retain the bad-conductor in position.
In use the cylinder is enclosed within a suitable casing and the air to be heated
is forced or drawn in by a fan preferably at the opposite end to that at which
it passes into the tubes 4 so that it passes along in contact with the periphery
of the heated cylinder and is therefore partly heated before it reaches the tubes 4.
This together with the non-conducting material 5 greatly prevents the ends of
the cylinder being cooled by the air and thus the ill effects of unequal expansion
and contraction are mainly avoided.
To keep the air intimately in contact with the periphery of the tubes they are
fitted with spirals 12 consequently a rotary motion is imparted to the air passing
through the tubes and centrifugal force tends to keep it against the walls.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. A tubular heater having tubes provided with internal spirals or helics,
substantially as herein shown and described and for the purpose specified.
2. A tubular air heater having the ends of the tubes projecting and the spaces
between the projecting ends filled in with a bad-conductor-of-heat, substantially
as herein shown and described and illustrated in the accompanying drawings.
Dated this 13th day of November 1899.
DRACUP & NOWELL,
Patent Agents, Bradford.