US2310265A - Pneumatic conveying apparatus - Google Patents

Description

Feb. 9, 1943. R. P. SWEENY 4 PNEUMATIC CONVEYING APPARATUS v Filed Sept. 18, 1939 m m A p & Q a w fi QM 5 .%N m 5 g N. vg 3 m Patented Feb. 9, 1943 UNITED STATES PATENT OFFICE PNEUMATIC CONVEYING APPARATUS Robert P. Sweeny, Atlanta, Ga.

Application september 18, 1939, Serial No. 295,514

Claims. (Cl. 302-25) v This invention relates to pneumatic conveying apparatus, particularly of the type used in connection with pneumatic cleaning apparatus in cotton mills.

The primary object of the invention is to provide apparatus for conveying dust and lint from 'a cleaning nozzle, which is used to strip lint or fibers from cards in a mill and to collect dust or bits of fibers, into a receiving chamber in which the lint and fibers are collected for reclamation. It is particularly an object to prevent knotting together of the fibers in transit from the nozzle to the receiving chamber.

I A further object is to provide pneumatic conveying apparatus in which none of the lint or other fibers will collect, thus to impair the efliciency of the conveyor.

It is also proposed to provide pneumatic conveying apparatus of particular cross-sectional conformation so as to provide the utmost in efiiciency in the utilization of compressed air as the conveying medium and, simultaneously, to dissipate the major portion of the force of the compressed air by the time the air reaches the conveyor, so as to avoid over-turbulation in the receiving chamber;

These and other objectives will be apparent from the following specification and drawing, in which:

Fig. 1 is a vertical cross section of the induction chamber, nozzle and expansion duct;

Fig. 2 is a cross section taken along line 2-2 of Fig. 1; and

Fig. 3 is an enlarged fragmentary plan view along the line 3-3 of Figure 1 looking in the direction of the arrows.

The constructionand function of the device may best be understood from Fig. 1 which shows the interior arrangement of the elements.

A shell of an induction chamber I4 is indicated by the numeral 52. The inner end of suction intake pipe l0 extends into the interior of a shell 52, where it forms a mouth 54. A flange I2 is provided on the outer end of suction intake pipe In for connection with a pipe (not shown) leading to a cleaning nozzle. Means for securing thesuction intake pipe In to the shell comprises the annular flange 56 which is held against the facing 58 of shell 52 by screws 60. As seen in the lower portion of Fig. 1, induction chamber I4 is provided with an input pipe [6 threaded, at l8, for connection with a pipe (not shown) which, in turn, is connected to a source of compressed air.

In order to prevent eddies from forming in the air flowing through the interior 62 of the induction chamber, a longitudinal rib 64, being shaped on streamlines, is provided on the interior wall of the chamber for dividing the upper portion of the interior into two halves. Fig. 3 shows rib 64 in plan view, looking from the under side in the direction of the arrows along the line 3-3.

Radial streamlined side ribs 65 and 65' extend inwardly from the inner wall of shell 52 for guiding andsupporting nozzle pipe l0 centrally in the chamber, and for guiding the incoming air towards nozzle 54.

Turbulence in the air stream is eliminated by providing the curved, concave end 66 on the inner end of pipe I0, which cooperates with the curved, convex inner face 68 of the shell 52.

At the outlet end I9 of the induction chamber,

the flanged end 12 of section 16 of the sectional expansion duct 20 is secured against flange 10 on shell 52 by means of screws 14. A complementary annular groove 13 and projection on the shell and section, respectively, assure a tight fitting engagement between the chamber and section, as well as a substantially continuous, smooth inner wall. A

The sectional expansion duct 20 is formed of three sections. 16, 88 and 96. Section 16 has a relatively small end adjacent the induction chamber for providing a restricted throat 18 from which the bore flares outwardly as shown at 88.

The flanged end 82 of section 16 is joined to a similarly flanged end 84 of the central section 88 by screws 86.

The central section 88 is substantially uniform in inner diameter throughout its length and, by means of the flanges 98, 92 and screws 94, is secured to the small end of section 96 which is substantially frusto-conical from end to end, and which spirals downwardly in the receiver, as shown in my co-pending application S. N. 329,840.

In operation, the induction chamber and expansion duct cooperate as an integral unit. As compressed fluid, air, is delivered through inlet I 6 into the interior 62 of the induction chamber, the velocity thereof is rapidly increased until it passes the restricted throat 18, thereby setting up a high vacuum at the interior of the mouth 54. The fluid then expands as it passes through the flaring section 88.

Exhaustive tests have proved that passage of air through section 88, which is of substantially uniform cross section throughout, 'produces a great pulling effect in the interior of the nozzle. The fluid is then passed through section 96, which is of gradually increasing cross section from end to end, wherein substantially uniform expansion occurs, from which it is delivered into the receiver.

In practice, a portion of the expansion duct is mounted in the receiving chamber of the cleaning apparatus and spirals downwardly from the top portion thereof.

It is apparent that there are no bumps or sudden interruptions in the path of the fluid which, in prior devices, have decreased the pulling power of the motive fluid. Of vital importance in this particular type of cleaning apparatus, eddies and turbulent currents, which would cause twisting and knotting of the lint, are eliminated.

The invention having been described in the foregoing specification, it is intended that it is not to be limited by the specific structure shown, but that the full scope of the invention be accorded the following claims.

I claim:

1. An induction chamber comprising a curved shell having a central chamber, an output opening through one side wall thereof, an intake opening through the side wall opposite said outlet opening, and an input opening through another side wall thereof, the interior of the wall of said shell from the input opening to said output opening being, in longitudinal cross-section, entirely concave-convex and of continuous, regular curvature, and a nozzle extending through said intake opening and across said central chamber substantially to said output opening, said nozzle comprising a pipe having the outer side thereof adjacent the outlet end curved inwardly from a, point substantially set back from said outlet end to said end, and a longitudinally extending rib, said rib being in plane which includes the longitudinal axis of said nozzle said rib depending inwardly from the wall of said shell, opposite said second input opening, the free edge of said rib being adjacent to said nozzle.

2. An induction chamber as claimed in claim 1, the inner wall of said shell opposite the inwardly curved side of said pipe being of such curvature as to provide a continuously decreasing space therebetween, the inner side of said pipe being straight sided and tapering towards the outlet end thereof.

3. Induction apparatus comprising an induction chamber, an elongated expansion duct at the output opening side of said induction chamber, said expansion duct having a throat portion in direct communication with said output opening, the smallest part of said throat portion being restricted with respect to said output opening and being of substantially uniform continuous cross section for a relatively short distance, a second portion of progressively increasing cross sectional area connecting with said throat portion, a third portion of uniform cross section connecting with said second portion, and a fourth portion of progressively increasing cross sectional area to the output end of said duct connecting with said third portion.

4. Induction apparatus comprising an induction chamber having an output opening, an expansion duct comprised of three separable pieces connected in series, the first of which is connected to said chamber in communication with said output opening, and having a throat portion the smallest part of which is restricted with respect to said output opening and being of substantially uniform continuous cross section for a relatively short distance, a second portion of the bore of which progressively increases in cross sectional area to the end thereof, the middle piece having a bore of substantially uniform cross section throughout and equal, in cross section, to the larger end of said first piece, the third piece having a bore progressively increasing in cross sectional area from the smaller end thereof.

5. Induction cleaning apparatus as defined in claim 1, and nozzle positioning and gas guiding means comprising at least one longitudinally extending rib, said rib extending inwardly from the wall of said shell and being positioned below said first-said rib.

ROBERT P. SWEENY.

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