US2662478A - Diaphragm pump and compressor - Google Patents

Description

Dec. 15, 1953 Filed Jan. 12, 1951 F. E. SURRE DIAPHRAGM PUMP AND COMPRESSOR 2 Sheets-Sheet l WW KM M A TT'ORNCXS Dec. 15, 1953 F. E. SURRE DIAPHRAGM PUMP AND COMPRESSOR 2 Sheets-Sheet 2 Filed Jan. 12, 1951 JLM, 5M +0mw4,

l4 tin/Na) Patented Dec. 15, 1953 2,662,478 DIAPHRAGM PUMP AND COMPRESSOR Francois Eugene Surrc, Paris, France Application January 12, 1951, Serial No. 205,637

Claims priority, application France January 31, 1950 2 Claims.

This invention relates to compressors and pumps of the diaphragm type for the compression of gases and displacement of liquids, of the type wherein a diaphragm is oscillably mounted in a chamber of generally lot-conical form defined between two plates, the diaphragm being peripherally clamped between said plates, and one plate being provided with the suction and delivery valves for the gas or liquid to be compressed or pumped, while the other plate is formed with ports through which another and auxiliary liquid, generally oil or glycerine or sometimes water, may flow under the action of a pump-piston which in its reciprocations is adapted to suck and discharge said auxiliary liquid, which thus acts on the face of the diaphragm directed away from the gas or liquid to be pumped and imparts a reciprocatory motion or vibration to the diaphragm.

In a French Patent No. 864,365, filed March 26, 1940, issued January 13, 19%, a device was described for immediately and reliably detecting any puncture or crack occurring in the diaphragm of such a pump or compressor. Punctures or cracks may be produced by a hard particle of metal or the like which may have worked its way into the biconical chamber either in the section of the chamber adjacent the valve-carrying plate, or in the section adjacent the ported plate, finally to puncture the diaphragm. Then again, the metallic material forming the diaphra gm may become strained and crack after a prolonged operation of the or compressor.

To detect such punctures or cracks. it was proposed in the said French patent to construct the diaphragm in the form of a lamination of at least three adjacent thin diaphragm elements clamped at their periphery between the plates and movable as a single unit under the action of the auxiliary drive fluid, the central diaphragm element of the laminated assembly being formed with at least one radially-extending slot or groove of very narrow width extending as far as its pe riphery, so that, in the case of a puncture or of the fluid being pumped, or respectively of the drive fluid, depending on which of the outer diaphragm elements is damaged, will escape outwardly and may be caused to actuate a respectively corresponding indicating device of suitable type, thereby indicating damage to either of the outer diaphragms. In practice, diaphragmpumps or -compressors, provided with a leak detector of this type for indicating damage to a diaphragm, have been found to possess the following drawback. It may occur that the valvecarrying plate has received a shock or impact resulting in a slight distortion of the part of that plate which provides the seal around the periphery of the diaphragm assembly, or further slight variations may occur in the thickness of the dia phragm elements around their periphery. Such defects in the plate or in the diaphragm assembly may result in slight leakage of the fluid being pumped or compressed, of such minute degree as to be quite negligible from the standpoint of the loss incurred, but sufiicient, nevertheless, to result, after a sunicient time, in an actuation of the corresponding leak-detector, which will thus erroneously indicate damage to the corresponding diaphragm element.

It is the specific object of this invention to obviate this drawback, and thus more generally to provide a diaphragm-pump or -compressor equipped with leak-detecting means more reliable in operation than in prior constructions.

With this object in view, the present invention essentially consists of providing a circumferential peripheral groove in the inner face of the valve-carrying plate in the area thereof in which the diaphragm is clamped between the two plates, said groove communicating with the exterior through a duct formed through the said plate, so that any slight leak of the pumped fluid as may result from a defect in the plate or diaphragm, other than actual puncture or crack in the diaphragm, will be vented outwardly through such groove and duct, without erroneously actuating the related leak-detector A similar arrangement may be provided connection with the ported flange or plate, by sirni-- larly providing a circumferential peripheral groove in the face of the ported plate within the area thereof clamping the diaphragm against the opposite plate, and a duct formed radially in said ported plate to connect said groove with the exterior space, whereby any slight leakage of the operating fluid that may occur between the pcrted plate and the diaphragm, other than ac puncture or crack in the latter, will be VCDNd without erroneous actuation of the drive fluid leak detector.

The accompanying drawing illustrates by way of example one embodiment of the invention as applied to the pumped-fluid side of a diaphragmcompressor.

In the drawing:

Fig. 1 illustrates a. schematic view in vertical section of the compressor of the invention.

Fig. 2 is a detailed view, on an enlarged scale, of a portion of the compressor.

The compressor conventionally comprises a pair of plates a and b defining between them a biconical compression chamber 0. The plate member a. is provided with gas-intake and -delivery valves a1 and 41,2, respectively (Fig. 1), while the plate!) is formed with perforations or ports in through which an operating liquid such as oil or glycerine is alternatively discharged and sucked by a piston p acting in the pump body d. Mounted across the chamber is a composite diaphragm assembly consisting of three thin diaphragm elements e, er and e2 arranged one upon the other, clamped together attheir periphery between the plates at and b, and movable in vibratory reciprocation as a single unit under the action of the operating liquid within the compression chamber 0, 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 drive liquid. The two outer diaphragm elements er and e2 are solid or imperforate, whereas the central diaphragm element e is formed with radial grooves 63 on both sides thereof, extending from a point adjacent to its centre to the periphery of said diaphragm e. The three diaphragm elements e1, c2 and e extend with their periphery outwardly, beyond the area in which they are clamped between the plates a and 1), into an annular recess 1 formed partly in each of the plates a and b. The central diaphragm element 6 is extended further beyond this recess through a metallo-plastic seal ring 11 which seals this recess from the exterior. A duct g formed through the lower plate In in its peripheral area connects the lower side of the annular recess 1 through a pipe yr with a detector device 92. A duct it formed through the upper plate, a, connects the upper side of the annular recess 1 through a pipe in with another detector device 712. Each of said detector devices hz, 92 may, as shown in Fig. 1, comprise a container, filled with water, into which pipes hi and 91 open, respectively,

Should the upper diaphragm element e1 become punctured or cracked for any reason, part of the gas subjected to compression will flow out through the puncture or crack in the diaphragm element e1 and through the radial grooves 63 in.

the central element e, thence through the upper half of chamber 1 and out through the duct h to operate the related gas-leak detector hz connected to the duct It. If the lower diaphragm element e is the one'punctured or cracked, then part of the operating liquid will flow through such puncture or crack and the radial grooves es of central element e, and through the lower half of chamber f and out through duct 9, to actuate the related leak-detector g2 connected with the duct g. .In the former case one or more bubbles of gas, and in the latter case, one or more drops of oil or glycerine rises to the surface of the water in container 7L2, g2 respectively, to immediately indicate to the operator that the diaphragm should be replaced. The detector described herein is for the purpose of illustration, and may be replaced with another type of detector, visual, mechanical, acoustic, electrical, etc.

As stated above, however, slight defects may occur either in the valve-carrying upper plate a or in any of the diaphragm elements (e. g. distortion of the plate, or variations in the diaphragm thickness) and such defects may result in a very slight leakage of gas or fluid, especially at very high operating pressures without any perforation of the diaphragm assembly. While such leakage is generally so slight as to result in negligibly small losses of gas or fluid, it will suffice, nevertheless, to cause within a comparatively short time an erroneous operation of the sensitive leak-detector connectedwith the duct h, as if the upper diaphragm element e1 were punctured, whereas it is not.

To prevent this, a circumferential groove 2' is "formed in the inner face of the plate a within the area thereof clamping the diaphragm against the other plate, or at a slight inward spacing from the annular recess f. A duct is through the upper plate (1 leads outwardly from this groove i to the atmosphere. Thus, any leaking gas due to a defect in the sealing area of the upperdi'aphragm element and plate will be vented through groove 1' and duct k, without erroneously actuating the gas leak detector. If however gas leakage results from the fact that the upper diaphragm element e1 is actually punctured, then this gas will leak out through'the upper grooves: in the central elements; and out through recess 1 and duct h to actuate the gas-leak detector In, as described.

A similar arrangement may be provided in connection with the lower, operating-fluid, side of the assembly, including a circumferential groove 1 similar togroove i, in the inner face of the ported plate 1), within the area thereof in which it clamps the diaphragm against the opposite plate, and a duct m similar to duct'k formed through plate I) and leading outwardly from the said groove to the atmosphere. The arrangement would operate in a manner strictly analogous to that described in connection with the upper side of the apparatus.

It will be understood that the structural details illustrated and described are merely exemplary and'that many departures may be made therefrom within the scope of the claims.

What I claim is:

l. A fluid operating apparatus of the type comprising two plates defining a substantially biconical chamber, a composite metal diaphragm assembly stretched across said chamber and clamped at its periphery on the transverse plane of symmetry of said chamber in an annular sealing area thereof to divide said biconical chamber into two substantially conical half-chambers, means for the intake and discharge of a first fluid into and from one of said half-chambers and means for the intake and discharge of ;a second fluid into and from the other halfchamber, said diaphragm comprising a'lamination of at least three diaphragm elements including a central and two side elements, an annular recess provided radially outwardly of the clamping and sealing area of the diaphragm assembly between the two plates, sealing means arranged between the two plates radially outward-of said annular recess and through which said central diaphragm element extends, radial grooves provided in both faces of the central diaphragm element and extending into said annular recess, a duct extending from said annular recess through each of said plates, leak-detecting means connected with the outer end of each of said ducts, whereby any fluid passing through one perforation in a side diaphragm element from the respective half-chamber will be let out through said radial grooves and said annular recess and said duct to said respective leakdetecting means, in combination with an annular collecting groove provided radially in said clamping and sealing area in at least one of the plates opening into the respective half-chamber, connected With a duct to said annular goove and extending through said plate directly to the atmosphere, whereby any leak of said fluid due to a defect in said sealing area, without any perforation in the diaphragm by-passes said leakdetecting means and vents directly to the atmosphere.

2. A fluid operating comprising two plates defining a substantially biconical chamber, a composite metal diaphragm assembly stretched across said chamber and clamped at its periphery on the transverse plane of symmetry of said chamber in an annular sealing area thereof to divide said biconical chamber into two substantially conical half-chambers, means for the intake and discharge of a first fluid into and from one of said half-chambers and means for the intake and discharge of a second fluid into and from the other half-chamber, said diaphragm comprising a lamination of at least apparatus of the type sealing area of the diaphragm assembly between the two plates, sealing means arranged between tending into said annular recess, a duct extending from said annular recess through each of said plates, leak-detecting means connected With the outer end of each of said ducts, whereby any fluid passing through one perforation in a side diaphragm element from the respective halfchamber is led out through said radial grooves, said annular recess and said duct to said respective leak-detecting means, in combination with an annular collecting groove provided radially in said clamping and sealing area in each of the References Cited in the file of this patent FOREIGN PATENTS Country France Number Date Jan. 13, 1941

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