Improvements in Sand Blast Apparatus.
Year: 1897

page_text: Date of Application, 22nd May, 1897
Complete Specification Left, 15th Feb., 1898-Accepted, 2nd Apr., 1898
[Communicated from abroad by BENJAMIN CHEW TILGHMAN, Junior, of 1126, South
Eleventh Street, Philadelphia, Pa., United States of America, Engineer.]
Improvements in Sand Blast Apparatus.
I, JEREMIAH EUGENE MATHEWSON, of Tilghman's Patent Sand Blast Company,
Limited, of Broadheath, near Manchester, in the County of Lancaster, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to apparatus to be used in connection with the sand-blast,
and having for its object to collect and remove the dust, sand, etc., resulting from
the operation of the sand-blast, and the separation, for re-use, of such sand as is
of proper weight and size for this purpose; and the invention is particularly
designed for such work as cleaning castings, and other metal surfaces, though
its usefulness is by no means limited to such employment.
The apparatus consists of a room or chamber which should be substantially
air-tight, but provided with one or more regulatable openings. This chamber has
a grating, or grated platform, upon which the article to be treated with the sand-
blast is to be placed, and below the grating is a hopper adapted to receive the
sand and dirt resulting from the operation of the sand-blast, and a conduit leading
from the bottom of the hopper to a pneumatic elevating apparatus.
Dust and air collecting pipes are situated in the hopper, and connected directly
or indirectly with some air sucking apparatus. It is through these pipes that
the air is drawn from the hopper.
The pneumatic elevator consists of a vessel divided into two chambers, an up-
take pipe leading from the lower part. Slots or perforations are formed through
the partition, and below them an annular disc is situated in the chamber to form
sand valves.
When in operation, a blast of air enters the lower chamber, and this air blast
will sweep the sand into the opening in the up-take pipe, and upward through
said up-take pipe, the upper end of which enters a sand-separating device.
A pipe leads from the top of this separator to a centrifugal separator having a
hopper-shaped bottom, the pipe opening first into an enlarged, preferably cone-
shaped conduit, situated in the shell of the latter separator, and having in its
upper part a screw-like deflector, by which the air coming from the pipe is given
a rapid rotary movement. The lower part of the conduit is formed with a number
of vertical openings leading from it into the shell of the separator, and through
which the heavier particles carried by the air are forced out to the space within the
shell. The air itself, carrying, of course, a certain amount of dust, passes down-
ward through a pipe into a water tank, into which the pipe, preferably increasing
in diameter, passes below the water level in the tank, so that the air is forced to
bubble up through the water, and is thereby washed.
The air space of the water tank is connected through a suitable conduit to a
suction blower.
To prevent the entry of large particles of sand into the dust nines these nines

page_text: are formed with openings leading through their walls at the bottom, and provided
with deflecting plates, so that only such thin stuff as would be carried upward in
the hopper can enter the dust pipes with the air currents.
An air compressor connects with a reservoir for compressed air, and said reservoir
connects with the air space of a sand-blast apparatus of any convenient con-
struction.
This sand-blast apparatus is so placed that a pipe or pipes leading from the
separator will conduct the sand into the apparatus.
The operation of the device, as a whole, will be readily followed. The suction
apparatus has the double function of elevating the sand coming from the hopper,
and of maintaining an energetic and sufficient suction in the hopper, to insure that
all dust will be drawn down through the grating, and as this latter function is
apt to require greater energy than is required for the elevation of the sand, it
is preferred to use two dust pipes, one connecting with the elevator, and the other
connecting with the air sucking apparatus without communication with the elevator,
dampers permitting the nice regulation of the amount of air passing to the elevator,
and depended upon for the transportation of the sand. It is obviously possible to
provide for the elevation of the sand coming from the hopper by an air current
entirely distinct from that drawn from the hopper, though it is just as obvious
that it is decidedly advantageous to use at least a portion of the air drawn from
the hopper for the elevation of the sand, also drawn from the hopper. The air and
sand, elevated by means of the pneumatic elevator, and passing then to the first
separator, the heavier and re-usable portions of the sand are there separated from
the air, and lighter and unusable particles of sand and dust. These lighter
particles pass from this first separator to the centrifugal separator, where a large
portion of the finer sand is tossed or separated from the air, and the air, carrying
only the very fine dust, is then passed down into the water tank, where it is
thoroughly washed, and from which the air issues practically clean.
Dated this 22nd dow of Mar 1907
NEWTON & SON,
Agents for the Applicant.
Improvements in Sand Blast Apparatus.
I, JEREMIAH EUGENE MATHEWSON, of Tilghman's Patent Sand Blast Company,
Limited, of Broadheath, near Manchester, in the County of Lancaster, 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:―
This invention relates to apparatus to be used in connection with the sand-blast,
and having for its object to collect and remove the dust, sand, etc., resulting from
the operation of the sand-blast, and the separation, for re-use, of such sand as is
of proper weight and size for this purpose; and the invention is particularly
designed for such work as cleaning castings, though its usefulness is by no means
limited to such employment.
In the accompanying drawings,
Fig. 1 is a side elevation, partly in section, illustrating the apparatus as a whole,
and in the form in which it is preferred to use it.
Fig. 2 is a cross sectional view taken as on the section line 1-1 of Fig. 1,
and
Fio 3 a vertical section taken as on the contion li
יחד.
+

page_text: The apparatus consists of a room or chamber A, in which is situated the sand-
blasting apparatus, and in which the article to be sand-blasted is introduced.
This chamber should be substantially air tight, but provided with one or more
regulatable openings, such as are indicated at C, whereby any desired amount of
draught can be admitted to the chamber. B is a grating or grated platform upon
which the article to be treated with the sand-blast is to be placed, and below the
grating B is situated a hopper D, adapted to receive the sand and dirt resulting
from the operation of the sand-blast upon the article under treatment. G is a
conduit leading from the bottom of the hopper D through which the sand is
permitted to run, a damper g regulating its freedom of motion. E and F are
dust and air collecting pipes situated in the hopper, and connected directly or
indirectly with some air sucking apparatus. It is through these pipes, which, for
certain purposes, may be consolidated into a single pipe, that the air is drawn
from the hopper, and through the grating, from the chamber A, a constant and
energetic downdraught being thus secured through the grating, and; obviously,
through the chamber A also.
H and I are parts of a pneumatic elevator. H is a vessel divided into two
chambers H and H by means of a partition H³, the uptake pipe I leading through
the chamber H', and through the partition H³, into the chamber H. Slots or
perforations are also formed through the partition H³, and below them an
annular disc H2 is situated in the chamber H, said disc being of such size as to
leave an annular opening around its outer edge, as well as the circular opening
in its centre, which should register substantially with the lower end of the up-
take pipe I. The pipe G leading from the bottom of the hopper D leads into
the chamber H', and, as it is preferred to construct it, a dust collecting pipe, as F,
situated in the hopper D, connects, as by conduit F3, with the chamber H+ of
the pneumatic elevator, f³ indicating a damper in pipe F³. It will be seen that the
sand, etc., passing through pipe G into the chamber H¹, will issue through the
opening into the chamber H, but the sand will run out of the opening onto
the annular plate H2, and in case the apparatus is not in operation, will soon form
little conical heaps upon the plate H2, which will seal the opening h¹, and prevent
the chamber H from filling up with sand. When in operation, a blast of air
enters the chamber H, preferably through the pipe F³, and this air blast passing
through the centre opening h³ in the plate H³, as well as through the annular
space indicated at ha around the outer edges of the disc H2, will sweep the sand
into the opening in the up-take pipe I, and upward through said up-take pipe,
the upper end of which, I, enters a sand separating device, preferably a settling
chamber, such as is indicated at J. This settling chamber is virtually a con-
siderable enlargement of the up-take pipe, in which the velocity of the air and sand
is checked, so that the heavier particles will fall by gravity into the hopper shaped
bottom J of the separator. It is advantageous to construct this device, as shown,
with a baffle plate Ja situate between the top of the pipe I and the out-take pipe K
leading from the separator, as, by means of this baffle plate, the separator not
only ensures the checking of the velocity of the air current, but also necessitates
a change in its direction, which of course will facilitate the separation of the
heavier particles of sand, and not only so, but avoids the sand-blast-like action
which would take place, if the sand was permitted, on issuing from the pipe I,
to strike freely on the top of the separator. J³ indicates a spout leading from the
lower part of the hopper bottom of the separator J, by which the sand can be with-
drawn from time to time, indicating a valve in this pipe. K is a pipe leading
from the top of the separator J, as shown, to a centrifugal separator L, having a
hopper-shaped bottom L', the pipe K opening first into an enlarged, preferably
cone shaped, conduit L³, situated in the shell of the separator L, and having in
its upper part a screw-like deflector L³, by which the air coming from the pipe L
is given a rapid rotary movement. The lower part of the conduit L2 is formed
with a number of vertical openings L' leading from it into the shell of the separator,
and through which the heavier particles carried by the air are forced out to the

page_text: space within the shell; the air itself, carrying of course a certain amount of dust
passes downward through the pipe M into the water tank N, which is a closed
chamber partially filled with water, to a level indicated at N¹, and the pipe M,
preferably increasing in diameter as indicated at M¹, passes through below the
water level in the tank, so that the air is forced to bubble up through the water,
and is thereby washed. A grating, as indicated at M³, may be used to insure the
breaking up of the air as it issues from the pipe extension M¹. The dust pipe E
connects, through a pipe E³ having a damper e³, with the enlarged portion_M'
of the pipe M, and the air space of the water tank N is connected through a
conduit leading from an opening N³ to a suction blower, as indicated at P.
To prevent the entry of large particles of sand into the dust pipes E or F, these
pipes are formed with openings E and F¹, leading through their walls at the
bottom, and provided with deflecting plates E, E, F, F, best shown in Fig. 3,
so that only such thin stuff as would be carried upward in the hopper can enter
the dust pipes with the air currents.
Q indicates an air compresser, connecting through pipe R with a reservoir for
compressed air, as indicated at S, said reservoir connecting by a pipe T with the
air space U of a sand blast apparatus U, t indicating a valve for regulating the
admission of air to the sand-blast apparatus, and T indicating a pressure gauge.
The sand-blast apparatus U is situated in the air chamber U₁, a sand chamber U2
connecting by a vertical passage U³, having a regulating valve u³, with a horizontal
air passage U, opening freely into the air chamber U₁, the sand and air passing
from U through flexible pipes V to the nozzles V¹. As shown, the sand-blast
apparatus is provided with hoppers U5 and U6, U7 being a valve by which the
opening in the hopper Us can be closed, this valve being attached to the valve
rod Us having the handle U. U10 is the sand valve of the hopper U6, and is
attached to a sliding valve stem U₁, having the handle U12 U13 indicating a
spider resting on the hopper Ue, and adapted to engage the handle U¹, and prevent
the valve U from opening beyond a determined distance. This same function
is performed for the valve U by the head or handle U13 upon which the head
or handle U rests, when the valve U is open. This sand-blast apparatus is so
placed that the pipe or pipes J3, leading from the separator J, will conduct the
sand into the upper hopper U6, from which, by opening the valve U10, it will
pass into the hopper U³, from which, in turn, by opening the valve U7, it will pass
into the sand chamber U².
The operation of the device as a whole will be readily followed. The suction
apparatus has the double function of elevating the sand coming from the hopper D,
and of maintaining an energetic and sufficient suction in the hopper D to insure
that all dust will be drawn down through the grating, and as this latter function
is apt to require greater energy than is required for the elevation of the sand, it
is preferred to use the two dust pipes E and F, one connecting with the elevator,
and the other connecting with the air sucking apparatus, without communication
with the elevator, the dampers e³ and f³ permitting the nice regulation of the
amount of air passing to the elevator and depended upon for the transportation
of the sand. It is obviously possible to provide for the elevation of the sand
coming from the hopper D by an air current entirely distinct from that drawn
from the hopper, though it is just as obvious that it is decidedly advantageous
to use at least a portion of the air drawn from the hopper for the elevation of the
sand also drawn from the hopper, the air and sand elevated by means of the
pneumatic elevator H and I passing then to the separator J; the heavier and
re-usable portions of the sand are there separated from the air and lighter and
unusable particles of sand and dust, which pass from the separator J to the
centrifugal separator L, where a large portion of the fine sand is separated from
the air, and the air carrying only the very fine dust is then passed down into the
water tank N, where it is thoroughly washed, and from which the air issues
practically clean.

page_text: Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to me
from abroad, I declare that what I claim is:-
1. In an apparatus for sand-blasting, the combination of a grating, as B,
adapted to support the article to be treated, a hopper for sand below said grating,
one or more dust pipes, as E, F, opening into said hopper and connected to an air
sucking apparatus, a conduit, as G, leading from the bottom of the hopper, a
pneumatic sand elevator, as H, I, arranged to receive sand from conduit G, and a
sand separator, as J, arranged to remove the sand and air from the elevator, and
separate the heavy from the light particles.
2. In an apparatus for sand-blasting, the combination of a grating, as B, adapted
to support the article to be treated, a hopper for sand below said grating, a dust
pipe, as F, opening into the hopper, a conduit G leading from the bottom of the
hopper, a pneumatic sand elevator, H, I, having a sand chamber H', into which
conduit G leads, and an air chamber H, connected, as by pipe F³, with dust
pipe F, a sand separator J arranged to receive the sand and air from the elevator,
and an air suction apparatus arranged to draw air from the separator, and through
it from the hopper and elevator.
3. In an apparatus for sand-blasting, the combination of a grating, as B, adapted
to support the article to be treated, a hopper for sand below said grating, a dust
pipe, as F, opening into the hopper, a conduit G leading from the bottom of the
hopper, a pneumatic sand elevator H, I, having a sand chamber H¹, into which
conduit G leads, and an air chamber H connected, as by pipe F³, with dust pipe F,
a sand separator J arranged to receive the sand and air from the elevator, and a
water tank N, a conduit as, K, M, leading from the separator to said tank, and
below the water level thereof, and an air suction apparatus connected with said
tank above its water level.
4. In an apparatus for sand-blasting the combination of a grating as B, adapted
to support the article to be treated, a hopper for sand below said grating, a dust
pipe opening into the hopper, a conduit G leading from the bottom of the
hopper, a pneumatic sand elevator H, I, having a sand chamber H', into which
conduit G leads, and an air chamber H* connected, as by pipe F3, with dust pipe F,
a sand separator J arranged to receive the sand and air from the elevator, a water
tank N, a conduit, as K, M, leading from the separator to said tank, and below
the water level thereof, a dust pipe, as E, opening, like pipe F, into the hopper D,
a conduit as E³ connecting dust pipe E with conduit M, dampers, as f³ and e³,
situated in pipes F3 and E³, and an air suction apparatus connected with tank N
above the water level.
5. In an apparatus for sand-blasting, the combination of a grating, as B, adapted
to support the article to be treated, a hopper for sand below said grating, a dust
pipe, as F, opening into the hopper, a conduit G leading from the bottom of the
hopper, a pneumatic sand elevator H, I, having a sand chamber H₁ into which
conduit G leads, and an air chamber H connected, as by pipe F³, with dust
pipe F, a settling chamber J arranged to receive the sand and air from the
elevator, a conduit K leading from the settling chamber, a centrifugal separator L
arranged to separate sand coming from conduit K, a water tank N, a conduit M
leading from separator L below the water level of tank N, and an air suction
apparatus connected with the air space of the tank.
6. The sand-blasting apparatus combined, arranged, and operating as herein
shown and described.