US3176623A

US3176623A - Protective system for a diaphragm pump

Info

Publication number: US3176623A
Application number: US211538A
Authority: US
Inventors: Hugh K Howerton; Allen E Bladen
Original assignee: American Instrument Co Inc
Current assignee: American Instrument Co Inc; Superpressure Inc
Priority date: 1962-07-20
Filing date: 1962-07-20
Publication date: 1965-04-06
Anticipated expiration: 1982-04-06

Description

April 6, 1965 H. K. HOWERTON ETAL 3,176,623

PROTECTIVE SYSTEM FOR A DIAPHRAGM PUMP Filed July 20, 1962 m T m u m a B m m 5 0 a T W 6 MM F WZ% 3 u w v1 0 3 W AX J 3 H5 N 4 MN m M 2 .U H mm M w 7 if 1% F w/ A F'IEZ 0.: our

United States Patent 3,176,623 PRGTEQTWE SYJEEM FGR A DEAPHRAGRE PUMP Hugh l5. Howerton, Silver Spring, and Allen E. Eladeu,

This invention relates to compressors and pumps of the diaphragm type, and more particularly to a warning and protective system for a pump or compressor of the type employing an oscillating diaphragm driven by an operating fluid as the means for compressing or pumping a gas.

A main object of the invention is to provide a novel and improved warning and protective system for use with a diaphragm pump, the system being arranged to detect leakage of operating fluid associated with the pump and to provide a positive warning of such leakage as well as to deenergize the pump and cut of? the of gas thereto, whereby to prevent the contamination of gas undergoing compression.

A further object of the invention is to provide an improved protective system for a diaphragm pump which is automatically operated to stop the pump and cut off the supply of gas thereto when any leakage of operating fluid occurs therein, whereby to prevent contamination of gas undergoing compression, the system involving relatively simple parts, being highly sensitive, and providing a quantitative visual indication of the presence and amount of such leakage as well as an automatic alarm when there is leakage.

A still further object of the invention is to provide an improved automatic operating fluid leakage detecting and alarm system, as well as an automatic supply valve controlling system for a diaphragm pump, said system involving relatively inexpensive components, being reliable in operation, and greatly amplifying the usefulness of such pumps.

Further objects and advantages of the invention will become apparent from the following description and claims and from the accompanying drawings, wherein:

FIGURE 1 is a diagram showing the schematic piping and electrical connections of an improved diaphragm pump protective system constructed inaccordance with the present invention.

FIGURE 2 is a perspective view of the leak detector employed in the system of FIGURE 1.

FIGURE 3 is a diagram showing a plan view of the optical arrangement employed in the leak detector of the protective system of FIGURE 1.

Referring to the drawings, 11 generally designates a diaphragm pump of generally conventional construction, said pump comprising a pair of

plates

12 and 13 defining between them a biconical compression chamber 14. The plate member 12 is provided'with suitable gas intake and delivery valves (not shown) provided in ports communicating with the gas supply and delivery conduits shown respectively at 15 and 16, while the plate 13 is formed with perforations or ports 17 through which an operating fluid, such as oil or water, is alternately discharged and sucked, by a piston, not shown, acting in the pump body 18. Mounted across the chamber 14 is a composite diaanaszs Patented Apr. 6, 1965 a housing 32 having the inlet conduit 33. and the outlet conduit 34 opposite inlet conduit 33, as shown, thehousing being generally rectangular, for example. The inlet conduit 33 may be connected to the central portion. of one side wall 2%) of the housing and the outlet conduit 34 may be connected to the opposite side wall 21 thereof at a point ofiset forwardly relative to the inlet conduit 33, as shown in FIGURE 3.

A suitable source of exciting radiation, such as an ultraviolet or visible light source 36, is mounted to emit radiation into the housing through an admission tube 37 connected to the intermediate portion of the front wall 38 of the housing substantially perpendicular to the path of gas flowing through the housing. Tube 37 is provided with a window 43 transparent to the radiation from source as and with an optical filter 23 to pass only a'desired wavelength or narrow Wavelength range of the radiation 7 from said source.

phragm assembly 19 consisting of several thin diaphragm elements arranged one upon the other, clamped together at their periphery between the

plates

12 and 13, and movable in vibratory reciprocation as a single unit under the action of the operating fluid within the compression cham ber 14, thus causing correlated suction and discharge of the gas on the face of the diaphragm assembly opposite from that subjected to the action of the driving fluid.

Designated at 27 is a detector device, which comprises Mounted obliquely in the housing 32 in a position to receive radiation from the source 36 and also to receive the gas flow from the inlet conduit 33 is a plate member 24 which is coated with non-reflective material, for example, lustreless black lacquer such as Lustreless Black Lacquer No. E27, manufactured by Lenmars Lacquers, Inc, Baltimore, Maryland. The plate member 24- may be mounted at approximately an angle of 45 to the axis of tube 37 and to the axis of conduit 33, in the path of the incoming gas from conduit 33, as shown in FIGURE-3.

A detector tube 4% is connected to the corner portion of housing 21 between the front wall 38 and side wall 253, said tube extending in a direction normal to the plate member 2.4, namely, at an angle of 45 to thewalls 38 and 29. A photosensitive device 43, such as a photocell or a photomultiplier tube, is mounted to receive radiation excited in material collected on plate member 24 as a result of impinging direct radiation thereon from the source 36. I

As shown in FIGURE 1, the gas inlet and

outlet conduits

33 and 34 are connected to spaced points along the pump outlet conduit 1d so as to circulate a sample of the gas discharged from the pump through the leak detector 27.

A suitable fluorescent tracer material may be provided in the operating fluid, such as Fluorescein or 4 -Methylumbelliferone, or it is possible to utilizethe natural luminescence of commercial oils. Such fluorescent indicating material, if used, maybe dispersed in a medium which is soluble in the operating fluid, so thatin theevent of leakage of said operating fluid into the detecting housing 32, the indicating material, depositing on the plate member 24, will fluoresce when excited bya radiation from source 36, andsuch fluorescence will activate the photosensitive device 43 and generate an electrical signal. The

output of device 43 is amplified in a suitable amplifier 44 and is applied to an indicating meter 45 of the relay type.

The meter 45 is provided with a conductive indicating arm 46 which is engageable with a stationary contact 47 at a signal valve corresponding to the appearance of leakage, or to a maximum limit of leakage,.whichever is desirable. I 7

As shown diagrammatically in FIGURE 3, the housing 32 is provided with the suitable low-fluorescence windows transparent to ultraviolet light, shown at 48 and 419, such as silica windows, for transmitting the radiation from the source 36 to the interior of the housing and from the fluorescing indicating material to the. photosensitive device 4-3. a c

An optical cut-oil filter 26 is provided in tube 40 to prevent the exciting radiation from source 36 from reaching the photo-sensitive device 43 but permitting luminescence of hydrocarbons depositing on plate member 24 to source 51. A wire 53 is connected to the stationary contact 47. One terminal of the alarm device 50 is connected to wire 53 and the other terminal thereof is connected to a wire'54,"which is connected in turn to the remaining terminal of source 51.

Wires 53 and 54 are connected to the winding of a relay 55 having a firstarmature 56 which normally engages a 1 contact 57. A solenoid valve 58 is provided in the gas supply" conduit 15. The winding of valve 58 is connected to a pair of

current supply wires

59 and 60 through armature 56 and contact 57. Valve 58 is open when energized and closed when deenergized. Therefore, when 61 and contact 62, asshown, so'that said motor becomes deenergized responsive to the energization of relay 55.

The alarm device 50 becomes energized simultaneously with the energization of relay 55, providing the warning signal indicating that there is leakage of the operating fluid.

If desired, valve 58 and its control circuit may be omitted, but the basic operation of the indicator will remain unchanged.

The meter 45 provides a continuous indication showing the amount of leakage so that it is possible to ascertain at all times whether or not the pump is in a safe condition and to detect the failure or deterioration of the dia- "Phragm element 21.

If desired, the meter scale may be eliminated and the device may be used simply to cut off the pump or to provide an alarm at a predetermined leakage point.

In a typical detection device according to the present invention, the excitation radiation from source 36 monochromated by and passing through the filter 23 had a wavelength of 3280 Angstrom units; the emission radiation (from the leakage material deposited on plate member 24) passing through the filter 26 had a wavelength of 4100 Angstrom units; the filter 26 was designed to block all radiation .having a wavelength below 3500 Angstrom units;

While a specific embodiment of an improved protective system for a diaphragm pump or compressor has been disclosed in the foregoing description, it will be understood that variousmodifications within the spirit of the invention may occur to those skilled in the art. fore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended tion exposed to fluid from said pumping space, whereby to collect particles ofthe fluorescent material thereon in the There- (,1, event of leakage of the driving fluid into said pumping space, a source of exciting radiation, means to irradiate said face from said source, and photo-sensitive means mounted to receive fluorescent radiation from the particles of fluorescent material collecting on said face.

2. In combination, a fluid operated device of the type 7 comprising a chamber, a flexible diaphragm mounted in said chamber and defining a driving fluid space on one side thereof and a pumping space on the other sidethereof, a driving fluid containing fluorescent material in said driving fluid space, a sampling chamber communicatively connected to said pumping space, a collection plate mounted obliquely in said sampling chamber and having a substantially non-reflective face oriented so as to be exposedto fluid from said pumpingspace, whereby to collect particles of the fluorescent material thereon in the event of leakage of the driving fluid into said pumping space, a source of exciting radiation, means to irradiate said face from said source, and photo-sensitive means mounted to receive fluorescent radiation from the particles of fluorescent material collecting on said face.

3. In combination, a fluid operated device of the type comprising a chamber, a flexible diaphragm mounted in said chamber and defining a driving fluid space on one side thereof and a pumping space on the other side thereof, a driving fluid containing fluorescent material in said driving fluid space, a sampling chamber, means to pass fluid from said pumping space through said sampling chamber, a colleetionmember mounted in said sampling chamber and having a substantially non-reflective collection surface oriented obliquely in said chamber so as to be exposed to fluid passing through said sampling chamber, a source of exciting radiation, means to irradiate said collection surface from said source, and photo-sensitive means mounted to receive fluorescent radiation from particles of fluorescent material deposited on said collection surface.

4. In a leak detector, a housing, a gas inlet conduit connected to one end of the housing, a gas outlet conduit connected to the opposite end of the housing at a location offset from the gas inlet conduit, whereby to pass gas through said housing, a collectionmember in said housing having a substantially non-reflective surface oriented obliquely so as to be exposed to the gas passing through said housing, whereby to collect particles of fluorescent material carried by the gas, a source of exciting radiation, means to irradiate said surface from said source, and photo-sensitive means mounted directly opposite. said surface to receive fluorescent radiation from particles of fluorescent material deposited on said surface.

5. The structure of claim 4, and wherein said collection member comprises a plate obliquely arranged relative to the direction of gas flow through saidhousing.

6. The structure of claim 5, and wherein said irradiation means is located so as to direct radiation onto said plate at an acute angle thereto and said photo-sensitive means is located to receive fluorescent radiation travelling in a direction substantially perpendicular to said plate.

7. The structure of claim 4, and first filter means interposed between said source and said surface limiting the exciting radiation to a first predetermined wavelength range, and second filter means interposed between said surface and said photo-sensitive means limiting the fluorescent radiation reaching said photo-sensitive means to V a second predetermined wavelength range.

driving fluid space, and fluid inlet and discharge conduit means connected to said pumping space, a leak detection chamber, conduit means connecting opposite ends of said leak detection chamber to spaced portions of said discharge conduit means, a collection member mounted in said leak detection chamber and having an oblique substantially non-reflective face oriented in a position to receive leakage driving fluid flowing through said leak detection chamber, a source of exciting radiation mounted to irradiate said face, and photo-sensitive means mounted directly opposite said face to receive fluorescent radiation from particles of fluorescent material collecting on said face.

10. The structure of claim 9, and valve means in said means responsive to the reception of fluorescent radiation by said photo-sensitive means.

References Cited by the Examiner UNITED STATES PATENTS 2,263,108 11/41 Stuart 25071 2,593,313 4/52 Kamm 73-17 2,666,148 1/54 Arvintz 250218 2,741,544 4/56 Chaikin 250-71 2,943,635 7/60 Greer 10344 3,061,723 10/62 Kapff 250-71 LAURENCE V. EFNER,'Primary Examiner.

fluid inlet conduit means, and means to close said valve 15 ISAAC LISANN, Examiner.

Claims

1. IN COMBINATION, A FLUID OPERATED DEVICE OF THE TYPE COMPRISING A CHAMBER, A FLEXIBLE DIAPHRAGM MOUNTED IN SAID CHAMBER AND DEFINING A DRIVING FLUID SPACE ON ONE SIDE THEREOF AND A PUMPING SPACE ON THE OTHER SIDE THEREOF, A DRIVING FLUID CONTAINING FLUORESCENT MATERIAL IN SAID DRIVING FLUID SPACE, A SAMPLING CHAMBER COMMUNICATIVELY CONNECTED TO SAID PUMPING SPACE, A COLLECTION PLATE MOUNTED OBLIQUELY IN SAID SAMPLING CHAMBER AND HAVING A SUBSTANTIALLY NON-RELFECTIVE FACE LOCATED IN A POSITION EXPOSED TO FLUID FROM SAID PUMPING SPACE, WHEREBY TO COLLECT PARTICLES OF THE FLUORESCENT MATERIAL THEREON IN THE EVENT OF LEAKAGE OF THE DRIVING FLUID INTO SAID PUMPING SPACE, A SOURCE OF EXCITING RADIATION, MEANS TO IRRADIATE SAID FACE FROM SAID SOURCE, AND PHOTO-SENSITIVE MEANS