Improvements in Methods for Inducing Circulation of Water in Steam Generators and in Apparatus therefor.
Year: 1890

page_text: Date of Application, 2nd Oct., 1890
Complete Specification Left, 17th June, 1891-Accepted, 18th July, 1:91
PROVISIONAL SPECIFICATION.
Improvements in Methods for Inducing Circulation of Water in
Steam Generators and in Apparatus therefor.
I, BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool in the
County of Lancaster Civil Engineer do hereby declare the nature of this invention
to be as follows:-
This invention is intended to promote circulation, prevent the deposition of lime
or other calcareous substances on the furnace flue plates reduce corrosive action
and maintain the furnace flue plates at a more equable temperature from end
to end.
In the application of my invention to marine practise or for steam generators
of the marine type, I utilise the arrangement shewn in Figs. 1 & 2 which consists
of a series of circulating rings or pipes or tubes F placed inside the inner surface of
the furnace flues A, each series of pipes being connected to the interior of boiler
one connection to the water in the lower part G of boiler and another to upper or
steam space H of boiler, so that the steam and water issue in jets or cascades I on
to and over the water in the boiler.
I may use a steam and water separator inside boiler consisting of a perforated
plate Jon which the steam and water as they issue from pipes are deflected.
I provide cleaning plugs at each of the junctions K of a special form so that any
deposit can be easily cleaned out.
Cantomhor 1800
B. H. THWAITE.
COMPLETE SPECIFICATION.
Improvements in Methods for Inducing Circulation of Water in
Steam Generators and in Apparatus therefor.
I BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool in the
County of Lancaster Civil Engineer do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention is intended to promote circulation; prevent the deposition of
lime or other calcareous substances on the furnace flue plates, reduce corrosive
action and maintain the furnace flue plates at a more equable temperature from end
to end.
In the application of my invention to marine practise or for steam generators of
the marine type; I utilize the arrangement shown in Figs. 1 and 2, which consists
in a series of circulating rings of pipes or tubes F, placed inside the inner surface
of the furnace flues A, each series of pipes being connected to the interior of
boiler; one connection to the water in the lower part G of boiler and another to
upper or steam space H of boiler, so that the steam and water issue in jets or
cascades I, on to, and over, the water in the boiler.
I may use a steam and water separator inside boiler, consisting of a perforated
plate J on which the steam and water as they issue from pipes are deflected. I

page_text: provide cleaning plugs at each of the junctions K, of a special form so that any
deposit may be easily cleaned out.
The following is a synopsis of advantages that accrue from the use of my said
invention.
-
Prevents incrustation. Removing old incrustation and preventing new.
No yearly outlay for anti-incrustants.
No loss of heat by bad conduction due to incrustants.
No stoppage of boiler to enable the dangerous chipping practice necessary to
remove hard incrustation.
.
No raising of the temperature of the crown plate of flue to a dangerous and often
collapsable degree-due to the incrustation, and want of circulation.
No reduction of the best heating surface efficiency of the boiler by incrustation
and imperfect circulation.
Less inequality of heating of flue, usually due to incrustation and inadequate
circulation.
No straining of front plates and weeping of joints due to the great expansion of
crown plate because of the fierce heat of the direct fire on plates covered with
incrustation because of bad circulation.
No impulse of and unequal expansion of flue owing to the constantly changing
condition of the water-due to irregular and imperfect flow or circulation of the
water, causing cracks and otherwise destroying the integrity of the flanges and
joints of the flues.
Reduces tendency to internal corrosion by preventing incrustation and by the
enormous influence of water in rapid circulation, it removes the locale and incipient
causes of corrosive activity.
Prevents priming.
By the cascade feature of the Thwaite circulator the steam separates from the
water, owing to its lighter specific gravity, the steam filling the steam space and
the water falling; hence the cause of priming, ergo-the ascensional expulsion of
the water bubbles through the water is prevented. "This feature is a great advantage
as a safety characteristic.
Prevents discolouration of the water gauge glass owing to the fact that the dirty
scum from the water; and floating on its surface is driven by the active circulation
of the water round the furnace part of the flue to the back end of the boiler, this
action preserves the water gauge glasses from the discolouring influence.
Combines in a striking and practically perfect degree, the rapid circulating
characteristics of the water tube boiler, with the intrinsic merits of large storage
capacity of the Lancashire, Cornish and return tube marine boilers.
.
Converts the present type of Lancashire Cornish and marine boilers into instru-
ments of high efficiency and raises them to the level of perfection of the engines.
The invention adds advantages of increased efficiency greater power, more
comfort (due to increased safety) in working, increased durability, less expense of
control, to boilers of the internal flue and shell class.
Having now particularly ascertained and described the nature of my said inven-
tion and in what manner the same may be performed I declare that what I
claim is included in the following
The arrangement of coiled tubes fixed inside the furnace flues of a boiler by
which the water is led from the lower to the upper part of boiler substantially as
described and shown by Figures 1 and 2 of drawings.
Dated this 16th day of June 1891
B. H. THWAITE.