Differential pressure apparatus for detecting accumulation of particulates in a filter

• US 5,718,822 A
• Filed: 09/27/1995
• Issued: 02/17/1998
• Est. Priority Date: 09/27/1995
• Status: Expired due to Term

• Current Assignee: The Metraflex Company
• Original Assignee: The Metraflex Company
• Inventors: Richter, James R.
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US08/534,724
• Time in Patent Office: 874 Days
• Field of Search: 210/90, 210/329, 210/448, 210/446, 210/447, 73/716, 73/717, 73/722, 73/723, 73/728, 200/83 A, 55/274, 55/DIG. 34, 95/25
• US Class Current: 210/90
• CPC Class Codes: B01D 35/02 Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks, B01D35/05 takes precedence; water pipe system filters E03B3/18, E03B7/07; dirt catchers in sewers E03F; filters or strainers for pipe-lines in general B08B, E03F; object or dirt catching devices in sinks or the like E03C1/26; suction strainers or filters for pumps F04B53/005, F04D29/70
• CPC Class Codes: B01D 35/143 Filter condition indicators

Abstract

An apparatus and a method are provided for detecting accumulation of particulates in a fluid stream. A differential pressure switch is incorporated in the apparatus for detecting changes in pressure in the fluid stream passing through a strainer having a filter wherein the particulates accumulate at the filter. A body is insertable into a wall of the strainer wherein the body is in communication with the fluid stream. A pressure responsive device is responsive to changes in pressure in the fluid stream due to accumulation of the particulates. A signal producing device is activated to produce a signal upon detection of a predetermined pressure differential in the fluid.

Claims

1. An apparatus for detecting accumulation of particulates in a fluid stream, said apparatus comprising:

a strainer housing having an interior through which said fluid stream passes between an inlet and an outlet, and a threaded opening in communication with said interior;

a filter situated intermediate said inlet and said outlet capable of collecting said particulates in said fluid stream; and

a differential pressure switch capable of detecting a pressure difference between an upstream side of said filter and a downstream side of said filter and producing a signal upon detection of a predetermined pressure differential, said pressure switch comprising;

a body insertable into said threaded opening of said strainer housing wherein said body has an interior with a first port in communication with said fluid stream upstream of said filter and a second port in communication with said fluid stream downstream of said filter;

a diaphragm positioned in said body between said two ports to flex with changing pressure;

a pair of normally separated electrical contacts and means associated with said diaphragm to cause engaging of said contacts upon sufficient flexure of said diaphragm; and

signal producing means activated upon closure of said contacts to produce a signal.

2. The apparatus of claim 1 further comprising:

output means receiving the signal from the differential pressure switch and producing an output signal.

3. The apparatus of claim 2 wherein the output signal is visible.

4. The apparatus of claim 1 wherein the strainer housing is a Y-type.

5. The apparatus of claim 1 wherein the strainer housing is a basket-type.

6. The differential pressure switch of claim 1 further comprising:

a magnet carried on said diaphragm;

a first contact in the interior of said body; and

a second contact in the interior of the body attractable towards the first contact upon a predetermined movement of the magnet towards the second contact.

7. The apparatus according to claim 1, wherein said first port comprises an open end of said body and said diaphragm is positioned to cover said open end.

8. The apparatus according to claim 1, wherein said means associated with said diaphragm comprises a push rod in contact with said diaphragm wherein said push rod is arranged to move with said diaphragm when said diaphragm flexes.

9. The apparatus according to claim 8, wherein said push rod carries a first of said electrical contacts, while a second of said contacts is stationarily mounted within said body.

10. The apparatus according to claim 1, wherein said second contact includes a magnetically attractable connector which is normally biased away from said first contact, but which is attracted towards and into contact with said first contact when said magnet is moved towards said connector.

11. An apparatus for detecting accumulation of particulates in a fluid stream, said apparatus comprising:

a strainer housing having an interior through which said fluid stream passes between an inlet and an outlet and a threaded opening in communication with said interior;

a filter situated intermediate said inlet and said outlet capable of collecting said particulates in said fluid stream; and

a differential pressure switch capable of detecting a pressure difference between an upstream side of said filter and a downstream side of said filter and producing a signal upon detection of a predetermined pressure differential, said pressure switch comprising;

a body insertable into said threaded opening of said strainer housing wherein said body has an interior with a first port forming an open end of said body in communication with said fluid stream upstream of said filter and a second port in communication with said fluid stream downstream of said filter;

a diaphragm positioned to cover said open end of said body between said two ports to flex with changing pressure;

a pair of normally separated electrical contacts and a push rod in contact with said diaphragm wherein said push rod carries a first of said contacts and is arranged to move with said diaphragm when said diaphragm flexes to cause said first contact to engage a second of said contacts which is stationarily mounted in said body upon sufficient flexure of said diaphragm; and

signal producing means activated upon closure of said contacts to produce a signal.

12. The apparatus according to claim 11, wherein said signal is visible.

13. The apparatus according to claim 11, wherein said signal is audible.

14. The apparatus according to claim 11, wherein said strainer housing is a Y-type.

15. The apparatus according to claim 11, wherein said strainer housing is a basket-type.

16. An apparatus for detecting accumulation of particulates in a fluid stream, said apparatus comprising:

a strainer housing having an interior through which said fluid stream passes between an inlet and an outlet and a threaded opening in communication with said interior;

a filter situated intermediate said inlet and said outlet capable of collecting said particulates in said fluid stream; and

a differential pressure switch capable of detecting a pressure difference between an upstream side of said filter and a downstream side of said filter and producing a signal upon detection of a predetermined pressure differential, said pressure switch comprising;

a body insertable into said threaded opening of said strainer housing wherein said body has an interior with a first port forming an open end of said body in communication with said fluid stream upstream of said filter and a second port in communication with said fluid stream downstream of said filter;

a diaphragm positioned to cover said open end of said body between said two ports to flex with changing pressure;

a pair of normally separated electrical contacts and a magnet in contact with said diaphragm wherein said magnet is arranged to move with said diaphragm when said diaphragm flexes and wherein one of said electrical contacts includes a magnetically attractable connector which is normally biased away from the other of said contacts, but which is attracted towards and into contact with said other of said contacts when said magnet is moved towards said connector upon sufficient flexure of said diaphragm; and

signal producing means activated upon closure of said contacts to produce signal.

17. The apparatus according to claim 16, wherein said output signal visible.

18. The apparatus according to claim 16, wherein said output signal is audible.

19. The apparatus according to claim 16, wherein said strainer housing is a Y-type.

20. The apparatus according to claim 16, wherein said strainer housing is a basket-type.