IMPROVEMENTS IN THE SAND BLAST PROCESS
Year: 1884

page_text: I JEREMIAH EUGENE MATHEWSON 265, Upperthorpe, Sheffield in the County
of York Engineer do hereby declare the nature of my said invention for
IMPROVEMENTS IN THE SAND BLAST PROCESS to be as follows:-
My invention relates to improvements in the sand blast process as described in
the Specification of A. V. Newton, N° 2147.
It is found that the most powerful and economical agent to give the velocity to
the sand is a jet of steam, but in addition to the inconveniance of its heating the
article operated upon, and the consequent liability to breakage if the article is made
of glass, steam also condenses, and the moisture so formed damages the patterns
made of paper and other tender materials; causing also the damp sand to adhere,
and clog the finer parts of the design.
Now my invention is to avoid these drawbacks to the use of steam, and it
consists, briefly, in the employment of a current of air, made to act upon the jet of
steam and sand, in such a manner that while the jet of steam gives the velocity to
the sand, the current of air moving in a different direction carries away the steam
before it reaches the article operated upon, thus leaving it comparatively cool
and dry.
This result may be conveniently effected by causing a jet of steam to propel a
stream of sand through the axis of a close cylinder or chamber having an opening
in the side opposite the jet, large enough or thereabouts for the passage of the cone
of flying sand.
An exhaust pipe is connected with the Cylinder or chamber from which a current
of air is drawn, preferably by the action of a steam jet; the supply of air being
compelled to enter at the opening above mentioned through which the sand is
fying. It thus meets and drives back the steam, carrying it away through the
exhaust pipe, but leaving the sand to continue its course.
ROBT F. DRURY,
Agent for the Applicant.

page_text: I JEREMIAH EUGENE MATHEWSON 265 Upperthorpe, Sheffield, in the County of
York Engineer do hereby declare the nature of my invention for IMPROVEMENTS
IN THE SAND BLAST PROCESS and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement, that
is to say:-
My invention relates to improvements in what is now well known as the sand
blast proce-s, and which is described in the Specification N° 2147, 1870.
In practice it is found that the most powerful and economical agent for imparting
the requisite velocity to the sand, or other granular substance used in this process,
is a jet of steam; but in addition to the great inconvenience of its heating the
article under operation, and the consequent liability to breakage if the article is of
glass; steam also condenses, and the moisture so formed upon the articl, damages
the "patterns" when made of paper, or other material affected by heat or moisture,
and also causes the sand to adhere and thus to fill up or clog the finer parts or lines
of the design or stencil.
My invention is to overcome or avoid these drawbacks to the use of steam, and
it consists (briefly) in the employment of a current of air, made to act upon the jet
of steam and sand, in such a manner as to carry off the steam before it reaches the
articles under operation, but not to interfere materially with the velocity of the
sand; the article is thus kept cool and dry.
This operation may be conveniently effected, by causing a jet of steam to propel
a stream of sand through a close chamber provided with an opening in the side
opposite the jet to allow the passage of the cone of flying sand.
An exhaust pipe is connected with the chamber through which a current of air
is drawn, preferably by the action of a steam jet.
And in order that my invention may be clearly understood, I annex a sheet of
drawings of an apparatus made according to my invention.
Fig. 1, is an elevation (partly in section) of a sand blast apparatus.
Fig. 2, is an enlarged view of the nozzle, used in this apparatus.
A is a Chamber, preferably of sheet iron, about twenty four inches in height and
eighteen inches in diameter; B is the sand vessel, for the supply of sand; C is
the nozzle of the sand blast pipe, which passes through the bottom plate D, of
the chamber A, communicating with the conical pipe M, and supported by the
bracket E. The nozzle is in connection with the steam pipe F, and the flexible
sand supply pipe G.
His an exhaust pipe, of about four inches diameter, with its open top end
preferably reaching nearly to the top of the chamber; and the coned end I, being
provided with a steam jet J, of about one eighth of an inch diameter.
K, K, are steam taps for controlling the amount of steam passing through the
nozzles C and J.-L is the sand valve, through which the sand passes from B to
the pipe G. M is a conical pipe placed over the nozzle C, its wider end reaching to
within a few inches of the orifice N, through which the sand passes into the second
chamber O, and strikes the underside of the article P. The conical pipe M, may be
dispensed with, without altering the main results, but I have found it advantageous
in practice.

page_text: The arrows inside the Chamber A indicate the course of the air which is drawn
through the orifice N, by the operation of the steam jet J, it will thus be seen that
a current of cool air is drawn into the chamber A, through the same hole through
which the sand is flying; it thus neets the steam mixed with the sand, and carries
it away through the pipe H, leaving the dried and cooled sand to continue its
course.
The same effect may be produced if a current of air is forced into the chamber O
by means of any suitable blowing apparatus, so that it would pass through the
orifice N, and carry away the steam down the pipe H; no steam jet J, being
required. Also by an induced or forced current of air moving across or at right
angles, or nearly so, with the cone of flying sand; but the plan herein first described,
and illustrated, I find the most convenient and effective.
The application of the "sand blast" to cut and otherwise operate upon various
substances is well known, and the nozzle C, and sand-valve L, are in use for other
sand blast purposes, therefore I wish it to be understood that I do not claim them,
neither do I bind myself to the precise details, or form of apparatus, as theso may
be varied to suit the shape or nature of the articles to be operated upon.
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
1st In the "sand blast" process, the use of an artificially produced current of air
acting upon a jet of steam, propelling sand or other granular substance, for the
purpose herein before specified.
2nd In a sand blast apparatus, the use of a cone shaped pipe (M) placed over the
jet nozzle (C), also the use of an exhaust or induction pipe, in combination with
a steam jet, H, I, J, for the purpose specified and substantially as described and
illustrated.
3rd The combination of the various parts constituting the apparatus as herein-
before described and illustrated.
Dated the 23rd day of January 1885.