improvements in apparatus for supermeating steam
Year: 1897

page_text: Date of Application, 1st Feb., 1897
Complete Specification Left, 30th Nov., 1897-Accepted, 1st Mar., 1898
WE, SAMUEL CHATWOOD, of 76, Newgate Street, in the City of London, Bankers'
Engineer, and SAMUEL RAWSTHRONE CHATWOOD, of the Lancashire Safe and Lock
Works; Bolton, in the County of Lancaster, Manager, do hereby declare, the nature
of this invention to be as follows:-
This invention applies where steam is superheated by passing it through heated
pipes.
The invention consists in obtaining the necessary velocity and agitation of the
steam by placing spirals in the tubes: for example the tube would have placed
within it a steel bar of + or Y or flat section twisted into a spiral which would nearly
fit the tube. The steam would thus be caused to traverse a very much longer path
than the length of the tube. Other sections could be employed but the + section
is likely in practice to be the most advantageous.
"
The advantages gained are that the steam is made to travel at a high velocity so
as to take up the heat from the pipe while the " way through the superheater is
not restricted; also that great lengths of pipe are not necessary.
It is possible to gain some of the advantages of the above arrangement by putting
vanes here and there in the pipes to give a spin to the steam passing them or
obstructions which would cause the steam to be agitated and brought into contact
with the pipes. Also by putting in an inner bar or pipe thereby reducing the
capacity of the pipe while maintaining the area of its outer and inner surfaces.
Dated this 30th day of January 1897.
SAMUEL CHATWOOD.
SAM. R. CHATWOOD.
improvements in apparatus for supermeating steam,
We, SAMUEL CHATWOOD, of 76, Newgate Street, in the City of London, Banker's
Engineer, and SAMUEL RAWSTHRONE CHATWOOD, of the Lancashire Safe and Lock
Works, Bolton, in the County of Lancaster, Manager, 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 applies where steam is superheated by passing it through heated

page_text: steam by placing spirals in the tubes; for example the tube would bave placed within
it a steel bar of + or Y or flat section twisted into a spiral which would nearly fit
the tube. The steam would thus be caused to traverse a very much longer path than
the length of the tube. Other sections could be employed but the + section is
likely in practice to be the most advantageous.
The advantages gained are that the steam is made to travel at a high velocity so
as to take up the heat from the pipe while the "way" through the superheater is
not unduly restricted; also that great lengths of pipe are not necessary.
The annexed drawing shows pipes or tubes suitable for the practice of our inven-
tion, and having variously formed spiral bars within them.
Figure 1 is a longitudinal section and Figure 3 a transverse section of a pipe con-
taining a flat and comparatively narrow spiral bar, which occupies comparatively.
little space within the pipe but which yet is very efficient in imparting rotary motion
to the steam in passing through and thereby ensuring rapid motion of the steam
which is in immediato contact with the wall of the pipe.
Figure 3 is a longitudinal section, and Figure 4, is a transverse section showing
another form in which the spiral bar is wider and extends diametrically from side to
side in the pipe.
'
Figures 6 and 6 show other forms. In all the object is the saine, principally to
impart rotary motion to the steam and thereby ensure high velocity and to prolong
the travel of the steam passing in immediate proximity to the heated walls of the
pipe.
It is possible to gain some of the advantages of the above arrangement by putting
vanes here and there in the pipes to give a spin to the steam passing then or
obstructions which would cause the steam to be agitated and brought into contact
with the pipes before mentioned. Thus the spiral bar need not be continuous, but
short lengths of such bars may be placed at intervals within the tube forming vanes
to impart rotary movement to the steain. Or vanes mounted on a rod centrally
placed within the pipe may be employed-such an arrangement is shewn by the
Figures 7 and 8. Also some advantage may be gained by putting in an inner bar
or pipe into the superheating pipe thereby reducing the capacity of the pipe while
maintaining the area of its outer and inner surfaces. Such arrangements are
illustrated by the Figures 9 to 12. Or obstructions, preferably conical may be
provided within the externally heated pipe as seen in Figures 13 and 14.
When we employ an inner bar within the super-heating pipe, the principal object
is to narrow the channel through which the steain must pass, and thereby to bring it
into closer proximity to the heated walls. It is preferred to employ a cylindrical bar
and to cause it to occupy a central position within the pipe by suitably supporting
it at intervals.
Having now particularly described and ascertained the nature of our said
invention and in what manner the saine is to be performed, we declare that what we
claim is :-
1. Super-heating apparatus comprising pipes which are heated externally and
have steam passed through them for the purpose of super-heating; such pipes con-
taining spirally twisted bars which in the passage of the steam through the pipes
imparts to it a rotary motion substantially as described..
2. Super-heating apparatus comprising pipes which are heated externally and have
steam passed through them for the purpose of super-heating: such pipes containing
obstructions which in the passage of the steam through the pipes mix and agitate
the steam substantially as described.
3. Super-heating apparatus comprising pipes which are heated externally, and have
steam passed through them for the purpose of superheating such pipes containing
inclined vanes at short distances apart so arranged as to impart to the steam a
rotary motion substantially as described.
4. Super-heating apparatus comprising pipes which are heated externally and have
steam passed through them for the purpose of superheating; such pipes containing

page_text: bars occupying the spaces at and near the centre of the pipes and compelling the
steam to pass by the narrow passage left for it between the wall of the pipe and the
bar, substantially as described.