Improvements in and Connected with Steam Generators, Fuel Economisers, and similar Apparatus, and in the Manufacture of Certain Parts thereof.
Year: 1888

page_text: Improvements in and Connected with Steam Generators, Fuel
Economisers, and similar Apparatus, and in the Manufacture
of Certain Parts thereof.
1 JOSEPH TWIBILL of Fall Ing Foundry, Wakefield in the county of Yorkshire,
Fuel Economiser Manufacturer, 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 relates to certain improvements in and connected with steam
generators fuel economisers and similar apparatus and in the manufacture of certain
parts thereof. Such apparatus and more especially fuel economisers are usually con-
structed of cast iron and consist of a slab, group or set of pipes having their ends fixed
into connecting pipes or boxes arranged at right angles thereto, as great an area as
Feed water is
possible being exposed externally to the action of heated gases.
delivered into one or other of the end boxes and circulates through the pipes absorbing
as much heat as possible before leaving the apparatus or being evaporated therein,
and precipitating certain impurities which may be removed from time to time; and
various types of mechanical scrapers are employed for keeping clean the outside of
the pipes.
The present improvements are applicable to tubular boilers, water heaters, fuel
economisers and such like apparatus in what form soever the pipes may be disposed,
and consist (1.) in the arrangement of the groups or sets of circulating pipes, and the
construction and disposition of the end connecting boxes in such a manner as to
increase the heating power, to direct and improve circulation and the deposition of
impurities and the removal of deposits. For these purposes I make all the circulating
pipes compound, preferably by placing a smaller and primary circulating pipe con-
centrically within each larger and secondary circulating pipes, an annular space of
suitable area intervening, and both primary and secondary circulating pipes being in
all cases open at both ends.
I construct one end connecting box with two separate chambers. Into one of these
the feed is delivered, and with that chamber all the primary pipes communicate, and
all the secondary pipes with the other; 1 construct the other end connecting box in
the same way but the two chambers are not separated completely, communications for
I circulation being provided. The improvements consist (2) in the application and
employment together of cast and drawn steel and in the method of construction there-
with whereby the apparatus is made stronger and more effective than heretofore, and
less liable to accidents and explosion.

page_text: The improvements comprise (3) an improved method of manufacturing hollow
castings such as conical or tapered pipes. (4) A special construction of scraping
device particularly applicable to taper pipes; and (5) an improved method of
preparing the feed supply prior to use.
In order that the invention may be fully understood I will describe it and its action
in reference to the accompanying drawings which represent its application to a fuel
economiser having the circulating pipes arranged vertically and the boxes at right
angles thereto, but I wish it to be understood that the improvements are applicable
to pipes and boxes grouped and arranged either vertically or horizontally or at any
angle, the essential features remaining unchanged.
Figure 1 is partly an elevation and partly a section of a fuel economiser, Figure 2
is a cross section on line y thereof, and figure 3 is a sectional plan of the lower box.
Figure 4 is a part elevation and part section of a different construction of economiser
with conical or taper pipes, showing also the improved scrapers: Figures 5 and 6 are
detail plans connected with scraping devices hereinafter explained. Similar leiters
refer to similar parts in all of the figures. Referring to the first head of my invention
ris. the arrangement and disposition of parts: A A are small open ended primary
circulating pipes placed concentrically within larger open ended secondary circulating
pipes B B which may be either tapered or parallel as illustrated. C and D are boxes
connecting the ends of these respective pipes. The boxes may be of any suitable form
in cross section but preferably as illustrated. In the box Ca central diaphragm e is
provided dividing the box longitudinally into two separate chambers c² of suitable
sectional area. The former chamber c receives the feed delivery and into it all the
primary pipes A open, and into the latter all the pipes B open. The other box D
also has a fixed or movable diaphragm & dividing it into two chambers d¹² com-
municating respectively with the pipes A and B as before but these chambers are
not completely separated as in the upper box C, circulating uptake apertures d³ ³
of suitable area being left. The open diaphragm d serves to support and hold the
ends of the primary pipes A A. In each box CD and in the diaphragm e circular
holes are formed lineable with and of the full external diameter of the pipes BB
when parallel; when taper the upper hole is of a diameter equal to the top of the
taper pipe. The holes are provided with covers f which may be fixed either
internally or externally after the fashion of ordinary man-or mud-hole covers for
boilers. 1 also provide holes of suitable shape and covers at the ends of the
boxes and D to get the diaphragms and covers in, and also for cleaning
purposes.
The primary pipes A A are passed concentrically into the secondary pipes B B and
extending to the diaphragms cd have their ends fixed thereinto by discs, collars,
ferrules a a or otherwise, care being taken to make the upper joints tight. I may
cast gills or flanges on the secondary pipes to increase the heating power (these are
not shown in the figures as their application will be readily understood).
The pipes B may be replaced or renewed by the introduction through holes f of
drawn steel pipes. To make the upper end tight an ordinary mandril or ferrule may
be used and the joint caulked if required through hole f.
By this above described construction much greater strength is given to the apparatus
the end boxes being doubly held or "cramped" together by two pipes instead of by
one only as heretofore, hence their is less liability of accidental drawing out of pipes,
or explosion. The action of the improved arrangement is as follows:-
The feed supply flows into chamber c¹ of box C and passes in a shower through
the primary pipes A inio chamber of box D, following more or less the direction
of the arrows it passes through the uptake apertures d³ d³ into chamber d² and
traversing the annular space intervening between .pipes A and B is projected into
chamber c of box C, whence it will circulate by delivery pipe G to the next group, or
to where required. By this arrangement during circulation the cold feed while in
chamber c will derive heat from the hotter water in chamber c and so on, there being
no dead water.
It will be obvious that the above described specific construction may be modified by.

page_text: arranging the pipes A and B not concentrically but in juxtaposition and fixed as
described, also by arranging the chambers c d in the form of pipes concentrically
within boxes or pipes C and D, the walls of chamber d' being perforated; or the feed
chamber might be arranged separately as a pipe or chamber above the chamber c²
in which case the primary pipes A A would pass through the caps or hollow bolts of
the covers. I prefer however the construction described as being the best within
my. knowledge.
Blow out apparatus of any ordinary type is or may be fixed to the boxes C and D
or where required for the removal of sludge and deposits the parts are readily accessible
for cleaning by the holes and the former being arranged opposite every compound
pipe, renewals and repairs can be easily effected if required, as well as cleaning.
Referring to the second head of my invention, viz. the method and materials to be.
used in the construction of apparatus: In the arrangement above described the
secondary pipes B, boxes C, D, diaphragms c, d may all be cast together in the usual
manner of iron or steel, but according to my improvements I find it a great advantage.
to apply and employ together cast and drawn steel, and this I do in the following
manner:
I use for the secondary pipes B drawn steel and I prefer to cast the boxes CD
in situ upon the ends of the said drawn steel pipes which are previously prepared and
heated to a proper temperature. I am thus enabled to make the whole apparatus
lighter, stronger, and with absolutely tight joints. I may however build the cast
steel boxes and drawn steel pipes together in the known manner, making the joints
by any suitable method.
The third head of my invention consists in the method I adopt in manufacturing
hollow castings, particularly conical or taper pipes for economisers and such like
apparatus.
The object of this part of my invention is to dispense with the time and skilled
labour necessitated by the present systems of casting. Hitherto pipes and hollow,
castings have usually been made in moulds arranged horizontally vertically or at an
angle, which have required to be dried by hot air or gas, and hence a considerable.
lapse of time is essential prior to the moulds being fit for use.
According to my improved method I manufacture hollow castings without moulding,
sand, or the labour of ramming up. For this purpose 1 use chambered or jacketed
moulding boxes or casings which are made internally to the exact shape and configu
ration of the exterior of the thing to be cast; concentrically within these jacketed
moulding boxes I place at a suitable distance (equal to the thickness of the proposed.
casting) the hollow core barrel, formed externally to the required shape.. These:
moulds do not contain rammed up sand but are coated with a composition of loam,
or black wash, which I find sufficient for the purpose of obtaining good smooth
castings of iron or steel. I superheat to a proper temperature by proper known.
methods both the jacketed moulding boxes and casings and the core barrel; the metal
is then run into the annular space intervening in the usual way, thus I am enabled to
procure a quick repitition of castings without unnecessary loss of time, and without.
the chilling and laborious and costly moulding in sand.
The fourth head of my invention comprises a special construction of scraping device:
For the external scraping of straight or parallel pipes any of the arrangements now in
yogue may be used. A difficulty has always arisen in efficiently scraping and cleaning.
taper pipes from top to bottom and many arrangements have been devised.
By my arrangement and construction I overcome this difficulty and for this purpose
I provide a ring or spectacle fork of cast iron or suitable material adapted to be
mechanically moved up and down the pipes and carrying five or more double scrapers,
that is, one end of each acts above, and the other end below the ring or spectacle:
The spectacle piece may be arranged to embrace two or more pipes as illustrated in
figures 5 at p, or it may be made as at p' figure 6, wherein either side of it embraces
the half circumference of two or more pipes, a single fork p² being provided for the
outside pipes of the sets.
All of the scrapers to each pipe, whether there be five or more above and below

page_text: :
each ring or spectacle piece, are segments of circles and overlap each other spirally as
illustrated in figures 4 and 5. The shank s¹ of each pair of scrapers has cast on it a
spherical or coned projection which is suitably centred in the carrying fork in a
corresponding bearing adapted to allow of sufficient movement of the shank and
scrapers ss, to admit of their self adjustment to clasp the taper pipe at both ends
completely at any part of its varying diameter. Sufficient space is left at the ends of
the pipes to allow the scrapers to pass right to the ends. Scrapers so constructed are
specially applicable to taper pipes and being adapted to roll in their bearings and
expand or collapse will automatically adapt themselves to the varying diameter of the
pipes, and also to readily reinove excrescences and pass over any structural irregularities
upon the surfaces thereof, and thoroughly clean them without leaving streaks of deposit
as is frequently the case.
The fifth head of my invention comprises an improvement relating to the preparation
of the feed supply, and consists in the provision in connection with the feed inlet E of
a receptacle e of any convenient form and dimensions for the storage of suitable puri-
fying media through which the feed is forced prior to arriving at the top of the feed
pipe delivering to the chamber c¹.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The arrangement and disposition of compound circulating pipes and the
construction of end connecting boxes for same substantially as hereinbefore described
and illustrated.
2. In steam generators fuel economisers and similar apparatus, circulating the
water from a feed chamber through primary circulating pipes, connecting chambers,
and secondary circulating pipes and chambers to delivery, the colder water during
circulation being always as far as practicable surrounded by or in juxtaposition to
hotter water substantially in the manner set forth.
3. In steam generators fuel economisers and similar apparatus the hereinbefore
described arrangement of compound concentric open ended circulating pipes A and B
in combination with end boxes therefor, one divided into two separate chambers and
both constructed, provided with fittings, and arranged substantially as and for the
purposes set forth and illustrated in the accompanying drawings.
4. In the construction of steam generators fuel economisers and the like, the appli-
cation and employment together of cast and drawn steel, the former for the pipe boxes
the latter for the pipes, cast or otherwise connected together as and for the purposes
set forth.
5. The hereinbefore described method of manufacturing hollow castings and conical
pipes for fuel economisers and similar apparatus in superheated casings and core barrels
formed to the required shapes, substantially in the manner described.
6. The construction of scraping devices for cleaning taper or conical pipes of fuel
economisers and similar apparatus with five or more double self-adjusting segmental
scrapers to each pipe spirally overlapping each other and operating as herein before
described and illustrated.
7. The provision in conjunction with steam generators fuel economisers and similar
apparatus of the kind specified, of a receptacle containing purifying media in
connection with the feed supply for the purposes set forth.
Dated this 17th day of Dray 1000.
J. C. CHAPMAN, Fel. Inst. P.A.,
70, Chancery Lane, London, W.C.,
Agent for Applicant.