US1644121A - Screen - Google Patents

Description

1644121 Oct. 4, 19274 A. E. GREENE 7 SCREEN -Filed Sept. 22, 1926 llllllllllllllllllllll I IN VENTOA Patented Get. 4,1927. UNITED. STATES AMBROSE E. GREENE, BERKELEY, CALIFORNIA.

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Application filed September 22, 1926. Serial No. 136,907.

My invention has for its'object .a screen particularly adapted to cover and protect the suction inlet of a centrlfugal pump or the like.

It is characterized by being fo rmed. of a l skeleton structure on which is spirally wound a half round wire with the flat face of thev wire exposed to the inflowing fluid. It is' provided with an end member remote from the suction inlet end of the screen and preferably having perforations in said end member somewhat larger than the spaces between the spiral windings and which, when the screen is positioned axially Vertical auto'-' matically clears or discharges vdbris or foreign matter which passes through the interstices of the screen and admlts of the ready discharge downward through said larger openings.

Referring to the accompanying drawing and specifications my invention will be made clear.

In the drawing, Fig. l is a fragmentary side iew of the screen, a portion of the wire wound thereon and artly broken to show the interior construction.

Fig. 2 is a cross section through'the end portion of Fig. 1 with the wire removed and is adapted to externally engage the suction inlet of any conventional centrifugal pump not shown but well known.

Fig. 3 is an .end view looking into the screen frame from its outlet end with the spiral windings removed.

Fig. 4 is similar to Fig. 3 except that it is from the opposite end.

Fig. 5 is similar to Fig. 2 except that it is externally threaded to engage internal threads of a suction inlet.

Fig. 6 is a fragment of one of'the frame ribs of Fig. 2, with the spiral windings thereon shown in section.

.Fig. 7 is ashowing of the screen set with its axis vertical on the end of a conventional suction p' e. v

Througlibut the figures similar numerals Q refer to identical parts.

A connecting member is shown by' the numeral 1 which in Fig. 1 is adaptetd to externally engage the suction inlet of a pump or a pipe end and form the main supportv for a plurality of rib members four of which are indicated at 2, :3, 4 and 5.

An end plate 6 perforated with large openings as 7 engages the opposite. end of the ribs 2, 3, 4, 5. I

4, 5, and its other en The member .1, end plate 6, and ribs 2, 3,

4, and 5 are preferably welded together to form a skeleton frame and the ribs are preferably notched on their outer edges as shown at 8 to receive a spirally wound wire 9 One end of this wire is weldedat 10 to the member 1' and the: wire is then wound continuously and spirally over the ribs 2, 3,

finally welded to the plate 6..

i p This spiral or helical windingv formsv in effect the screen surface andbetween the windings the spaces as 11, provide, openings for the entry of fluidwhich passing through the member 1, enters the pipe or suction inlet aforesaid, the windings straining out or rejecting dbris and foreign matter.

The wire which I employ is of half round cross section and the notches 8 are made half round and the round portion of the wire fitted therein so that, to the fluid approaching "the screen the flat surfacesof the wire are first presented.

The narrowest part of the opening between the wires at any point is therefore first presented to the inflowingfluid which approaches in the direction of the arrow 12 (see Fig. 6) and this space is indicated by the dimension line 13.

Any twigs or dbris which find their way a through the space 13 immediately after entering are prevented from wedging between the wires because of the clearance provided by the receding surfaces of the halfround shape, the clearance space increasing rapidly from 13 to that indicated by theidimension line 14 when any material has passed half way through the space between any two adjacent wrappings.

The screen therefore automatically clears itself and the wedging or blocking of any dbris in-the interstices is prevented.

N 0 material enters the screen larger than the dimension line 13, and anything just equal to the'dimension 13 passes freely without wedging.

When the screen is positioned with its axis vertical with the member 1 engaged to the lower end of a suction pipe and the plate 6 vertically thereb'elow it will be noted that the velocity of fluid moving within the screen towards the member 1 will be a minimum at the center of the screen and therefore any large material entering through the opening 13, such as stones or the like which might be transported by the high entering velocity will, on arriving at the point of minimum velocity within the screen, be acted on by gravity and fall through the opening 7 of the plate 6, the said openings being purposely made larger than the interstices between the wire wrappings. The plate 6 may be made of ring form with the rib welded about the periphery of the ring and with a large openlng if preferred. The remoteness of the plate or rlng 6 from the member 1, occasions such a substantially lower velocity of flow through the opening 7 that foreign material will not enter therethrough and foreign matter entering between the wires discharges downward due to the lower velocities at the screen axis.

It is well known that the transporting power of a stream is substantially proportional to the fifth ower of the velocity, and as the velocity tl irough the interstices of the screen adjacent the member 1 is greatest and through those portions of screen remote from said member is the least, that such foreign material as may be transported by the velocity of entry will as it approaches the screen axis have its velocity retarded and therefore will fall and pass out through the opening 7, in t-heplate 6 in the direction of the arrow 15 as previously described.

I claim:

'1. A strainer skeleton comprising sin-end 'member having means on one side to engage a pump suction or the like and ribs extending from the other side of said member and converging, a spacing and connecting element at the other end of said ribs, said ribs having their outer edges notched helically to receive a screen wire, Iascreen wire helically wound in said notches and said element having an opening greater than the space between any two adjacent notches.

2. A strainer comprising a circular collar, a plurality of ribs in spaced relation and fixed about the periphery of said collar and extendingtoward the apex as elements of the surface ofa truncated cone,.notches in said ribs adapted to receive a wire heliof the surface of a truncated cone, notches in said ribs adapted to receive a wire helically wound thereon and an end member fixing the said last named ends of said ribs an opening in said end member greater than the space between any two notches and a half round wire wound helically about the ribs and in the notches from the collar to the end member and forming a screen surface.

1 4. A strainer comprisin a threaded collar at one end and a perforated end plate at the other. end, a frame work of ribs fixed to the collar and the plate and holding them in spaced relation, a plurality of spirally aligned notches in said ribs and wire wound in said notches about said ribs.

5. A strainer as set forth in claim 4 wherein said ribs converge toward said perforated plate and wherein the said wlre has a half round cross section with the rounded portion lying in said notches.

6. A strainer comprising a .circular col-, lar, a plurality of ribs, each of said ribs having one end fixed about the periphery of said collar and converging towards their opposite ends forming in effect elements of the surface of a-truncated cone, a perforated end member to which said converging ends arefixed, said ribs having notches in helical alignment adapted to receive a Wire helically wound therein.

7. A strainer as set forth in claim 6 wherein a wire is wound in said notches and has a half round cross section with the flat portions thereof lying in the surface of a truncated cone.

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