Year: 1887

page_text: Date of Application, 3rd May, 1887
Complete Left, 3rd Feb., 1888
Complete Accepted, 23rd Mar., 1888
I, JOHN GRIFFTHS, of Millwell Lane, Higher Bebington, in the County of Chester,
Engineer, do hereby declare the nature of my said Invention, to be as follows :—
This Invention has more particularly for its object certain improvements in steam
generators whereby the heat of the fuel used may be more effectively transmitted to
the water and rendered available for steam making, and the tubes may be readily
cleaned without destroying the draught as usually takes place under ordinary conditions
of working steam generators of steam ships; also to obtain complete combustion of
the fuel used.
A marine steam generator provided with improvements according to this Invention
consists as follows:
The furnaces are constructed in the usual manner, of cylindrical form and the fuel
is burned in the ordinary way. From the furnaces the products of combustion are
led upward to second flues of cylindrical form, and brought back to the front end of
the steam generator; they are then returned and led to the uptake through nests of
tubes. Combustion chambers, or boxes are provided to convey the gases from the
furnace to the flues and from the flues to the nests of tubes. The latter combustion
chambers may be provided with doors in the front of the generator, or access may be
had to them through short tubes connecting the front plate and the back of the
combustion chambers together. When the short tubes are employed they are provided
with stoppers and by removing the stoppers one by one the tubes of the generator
may be swept and cleaned, without destroying the draught of the generator. Or this
same result may be obtained by constructing the door with openings and the stoppers
and removing them one by one when sweeping the tubes. The smoke box and
D
11

page_text: uptake are placed at the back of the generator and the smoke box is provided with
doors at the bottom of it so that it can be cleared of all dirt and soot that may be
swept, or pass into it.
In the front of each furnace 1 provide a tube, or tubes-which may be controlled
by suitable valves-which form a communication between the furnaces and the second
combustion chambers. These tubes admit air and flame into the combustion chamber
above and in this way ignite and support combustion of any unburned gases that pass
into such combustion chambers.
By the above construction of steam generator the gases of combustion have to
travel a much greater distance than they would do in the ordinary type of marine
steam generator and thus a greater amount of their available heat is utilized, also a
greater amount of heating surface is provided than that of the ordinary type of steam
generator of equal proportions. Further the tubes can be swept and cleaned without
destroying the steam producing power of the generator whilst under steam.
Dated this Second day of May 1887.

page_text: I, JOHN GRIFFITHS, of Millwell Lane, Higher Bebington, in the County of Chester,
Engineer, do hereby declare the nature of my said 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 has more particularly for its object certain improvements in steam
generators whereby the heat of the fuel used may be more effectively transmitted to
the water and rendered available for steam making, and the tubes may be readily
cleaned without destroying the draught, as usually takes place under ordinary
conditions of working steam generators of steam ships, also to obtain complete
combustion of the fuel used.
A marine steam generator provided with improvements according to this Invention
consists as follows: :-
The furnaces are constructed in the usual manner, of cylindrical form and the fuel
is burned in the ordinary way. From the furnaces the products of combustion are
led upward to second flues of cylindrical form and brought back to the front end of
the steam generator; they are then returned and led to the uptake through nests of
tubes. Combustion chambers, or boxes are provided to convey the gases from the
furnace to the flues and from the flues to the nest of tubes. The latter combustion
chambers may be provided with doors in the front of the generator, or access may
be had to them through short tubes connecting the front plate and the back of the
combustion chambers together. When the short tubes are employed, they are
provided with stoppers and by removing the stoppers one by one the tubes of the
generator may be swept and cleaned without destroying the draught of the generator.
Or this same result may be obtained by constructing the door with openings and the
stoppers and removing them one by one when sweeping the tubes. The smoke box
and uptake are placed at the back of the generator and the smoke box is provided
with doors at the bottom of it so that it can be cleaned of all dirt and soot that may
be swept, or pass into it.
In the front of each furnace I provide a tube, or tubes-which may be controlled
by suitable valves-which form a communication between the furnaces and the
second combustion chambers. These tubes admit air into the combustion chamber
above and in this way ignite and support combustion of any of the gases that pass
into such combustion chambers. Or these tubes may be placed at the ends of
the flues.
By the above construction of steam generator the gases of combustion have to
travel a much greater distance than they would do in the ordinary type of marino.
steam generator and thus a greater amount of their available heat is utilized, al

page_text: greater amount of heating surface is provided than that of the ordinary type of steam
generator of equal proportions. Further the tubes can be swept and cleaned without
destroying the steam producing power of the generator whilst under steam.
The Drawings hereto annexed illustrate examples of steam generators applicable
chiefly for navigable vessels, constructed according to my Invention. They show a
two and a three furnace steam generator. The various views are marked with
figures and letters of reference corresponding with those used in the following
explanation. Like letters and figures are used to denote like parts wherever they
occur in the Drawings.
Recording to this invention.
Figure 2 is an end view partly in section of same.
Figure 3 is a sectional elevation of a.three furnace steam generator according to
this Invention..
Figure 4 is an end view of same in section.
With reference in the first instance to the first two figures of the Drawings,
A designates the furnaces of the generator; B are the second flues; C the passages;
or combustion chambers communicating between the furnaces A and flues B.
G designates the nests of tubes and D are the combustion chambers communicating
between the flues B and the tubes G. H is the smoke box provided with drop
doors h¹ for cleaning purposes. I are the tubes through which access is had to the
chambers D and tubes G for cleaning purposes. are stoppers, one of which is
provided to each of the tubes I. In Figures 3 and 4 a modified construction of this
portion of the boiler is shown. It consists in forming the front of the chambers D
as a door and providing such door with apertures and stoppers . By this con-
struction cach tube can be cleaned separately and at the same time greater facilities
for renewing, or stopping tubes are afforded.
In Figures 3 and 4 a three furnace generator is shown. Communication between
the furnaces A. and the flues B in this case is obtained by circular passages C in lieu
of combustion chambers. In other respects this example is constructed substantially
in the same manner as that set forth with reference to Figures 1 and 2. .
In the example shown in Figures 3 and 4 tubes K are provided to serve as a stay
for the rear end of the flues B and to serve as a secondary air supply to the gases
issuing from the furnaces. This supply may be regulated by a suitable valve, or
damper placed on the pipes. The tubes may be provided in connection with all forms
of steam generators according to this invention.
It will be seen by the above examples that this steam generator is of cylindrical
form and externally similar to the ordinary "round" boiler and it may have one,
two, or more furnaces according to size and amount of heating surface required.
Each furnace A leads into a combustion chamber, or passage C and a circular flue B
is connected to this chamber, or passage. This constitutes the "return flue." The
flue B is connected and opens into a second combustion chamber D having either a
water space between it and the front of the boiler, or door only. The chamber D
communicates with the back of the boiler, or smoke box H by the ordinary boiler
tubes G of such number and diameter as required.
One of the chief features in the steam generator herein described is the provision
made for cleaning the tubes G separately while under steam. This is effected by
removing the stoppers of the short tubes I, or of the apertures in the door and
then cleaning each tube separately and afterwards closing the aperture by replacing
in it the stopper. The tubes, or apertures as the case may be, are kept air tight by
the stoppers, slides or equivalent means.
It will be seen that the flame and hot gases pass first through the furnaces info
combustion chambers, or passages C, then through the "return flues" B into com-
bustion chambers D; thence through the tubes G into the "smoke box H and thence

page_text: to the funnel, or funnels. The distance thus travelled is about double that of the
ordinary type of steam generator of this type illustrated and consequently a far
larger proportion of the available heat is absorbed and used before reaching the
funnels.
About thirty per cent more heating surface is afforded by the herein described
steam generator and this more efficient than the ordinary cylindrical boiler of equal
external dimensions.
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:
First. In multitubular steam generators, apertures having stoppers (such as i
or their equivalent) by which access can be had to the tubes of the generator
substantiaHy as and for the purposes set forth.
Second. In steam generators of the type herein described the combination of
furnaces A chamber, or passages C, flues B, chambers D and tubes G, substantially
as set forth.
Third. The steam generator consisting essentially of the furnaces A A, chambers C (),
flues B B, chambers D; tubes I and G, and smoke box H, constructed and arranged
as set forth with reference to Figures 1 and 2 of the Drawings.
Fourth. The steam generator consisting essentially of the furnaces A A A,
passages CCC, flues B B B, chambers D D D, tubes G and smoke box H, con-
structed and arranged as set forth with reference to Figures 3 and 4 of the
Drawings.