Year: 1896

page_text: Date of Application, 5th June, 1896
Complete Specification Left, 25th Feb., 1897-Accepted, 3rd Apr., 1897
1, CARL GUSTAF PATRIK DE LAVAL of 16 Handtverkaregatan, Stockholm,
Sweden, Doctor of Philosophy and Engineer, do hereby declare the nature of this
invention to be as follows:-
The present invention refers to an improvement in rotating boiler grates and has
for object to keep the grate as clean as possible and thus prevent the obstruction of
the passage of the air through same.
The improvement consists in a water cooled scraper which is placed near the
surface of the grate and projects in the fire. When provided in a water tube boiler
said scraper conveniently can consist of a tube connected with the water tube
system of the boiler, but this is not necessary.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.
1, CARL GUSTAF PATRIK DE LAVAL of 16 Handtverkaregatan, Stockholm,
Sweden, Doctor of Philosophy and 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 :-
The present invention refers to an improvement in rotary boiler grates, and has
for its object to keep the grates as clean as possible and thus to prevent the
obstruction of the passage of the air through same.
The improvement consists in a water cooled scraper which is placed near the
surface of the grate and projects into the fire space. When provided in a water
tube boiler said scraper can conveniently consist of a tube connected with the
water-tube system of the boiler, but this is not necessary.
In the accompanying drawing, which shows as an example a watertube boiler :
Figure 1 is a vertical section,
Figure 2 is a horizontal section,
Figure 3 shows the scraper and a part of the grate in elevation.
Referring to the drawing, a indicates the water-tube system. 6 is the rotary
grate which is basket shaped. In the grate bis situated a conical rotating block c
which is mounted on a central pivot d'. On the shaft e, which is rotated by any
suitable means, not shown in the drawing, is mounted the cog wheel e', meshing
with the toothed ring 6' at the upper part of the grate b. The antifriction rollers f
support said grate basket.
At the lower part of the grate there is a toothed ring 2 with which the cog-
wheel meshes. The latter is mounted on a suitably supported shaft a', which also

page_text: carries the cog wheel a' that meshes with the toothed ring as on the lower part of
the conical block c. Thus said block is rotated simultaneously with the grate
basket b. d indicates the scraper.
In the example shown in the drawing, said scraper consists of a tube and
constitutes a part of the boiler water-tube a which is bent down and projects into
the firespace near the inner surface of the grate basket b. Said tube may if desired
be flattened, as shown, but this is not necessary. The tube d may also be connected
with a water conduit for being cooled instead of being connected with the boiler
water tube as shown in dotted lines.
g is a lever for raising and lowering the block e as required.
h is an inner firebrick lining of the block c.
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. The combination with a rotary basket shaped boiler grate of a water tube,
projecting against the inner surface of the basket and adapted to act as a seraper,
substantially as and for the purpose set forth.
2. The combination with a rotary basket-shaped boiler grate, and a conical
rotating block, situated within said grate, of a watertube, projecting against the
inner surface of the basket and adapted to act as a scraper, substantially as and for
the purpose set forth.
Dated this Twenty-fifth day of February 1897
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.