Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B11/00—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation
  • F04B11/0008—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators
  • F04B11/0016—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators with a fluid spring

Definitions

• This invention relates to a method of and means for absorbing pressure shocks and in particular, but not exclusively, it relates to the controlling of water hammer normally caused when a shock is applied to water in a system where a sudden variation in pressure occurs, such as when a tap is suddenly closed.
• the object of the present invention is to provide a simple and effective device, and method of manufacture, which, when arranged to prevent water hammer, can be connected to a line to prevent such water hammer occurring.
• the device according to this invention comprises a housing which can be connected into a pressure line and which is capable of withstanding the pressures developed but into this housing are fitted gas-containing pads which have the water pressure applied to them so that during normal flow the pads remain in a static condition but in the case of a sudden rise, such as occurs during water hammer, the pads are compressed to absorb the pressure shock to thereby relieve the water hammer reaction.
• the method of absorbing pressure shocks comprises forming a series of pads each comprising flexible membranes marginally joined together and containing a gas, stacking the said pads one on another with the membranes in contact, confining the stack of pads in housing means, such as a cage, and applying to the pads the pressure shocks to compress the pads to absorb at least part of the pressure shocks.
• the pads are preferably preloaded in the housing means.
• the device for absorbing pressure shocks comprises a series of pads each comprising flexible membranes marginally joined together and containing a gas, the pads being stacked one on another with the membranes in contact, and held in housing means so that pressure can be applied to the pads to compress the pads to absorb at least part of the pressure shocks.
• the pads can be preloaded by compressing them in the housing means, or in a fluid pervious cage mounted in the housing means.
• FIG. 1 is a part sectional side elevation of a pad which forms the basis of the invention.
• FIG. 2 is a longitudinal section of a two-part cage with the parts separated and showing a series of pads ready for assembly into the cage.
• FIG. 3 is a view of the device of FIG. 2 showing the two parts of the cage assembled to compress the pads within it.
• FIG. 4 is a view showing such a cage located in a housing which is adapted to be connected to a pressure line for absorbing pressure shocks in the line.
• FIG. 5 is a view similar to FIG. 4 but instead of using the cage, the housing itself supports the pads and includes a screen to protect the pads within the housing.
• FIG. 6 is a view of a device similar to that shown in FIG. 4 but showing a large capacity unit having a series of cages located in the housing.
• FIG. 7 shows another form of the device in which the series of cages is placed into a housing surrounding a flow-through tube which is apertured as shown in fragmentary section to allow fluid to flow into the space containing the cages.
• FIG. 8 is a view showing how the device can be used as a compression member to be placed between two components which are to be separated by a flexible cushion, the device differing from that of FIG. 3 in that pressure can simply be applied endwise.
• FIG. 9 shows a device similar to that of FIG. 8 but arranged so that the cage can have tension applied to the two opposite sides' thereof to compress the pads.
• each pad 1 is formed by placing together two flexible membranes 2 and 3 and forming a marginal seal at 4 to form a sealed pad which contains in it a compressible fluid.
• the pads 1 can be formed of circular sheets of a suitable material which will remain gas-tight. This can be achieved for instance, by having an
• each pad 1 is of disc like structure with both its sides of convex form.
• the gas can be nitrogen.
• the polythene or similar materials can be heat welded together at 4 around or near the periphery to ensure the required strength, and to prevent leakage a rim 6, as indicated by dotted lines in FIG. 1, can be positioned around the periphery of the device which can be crimped or otherwise forced down onto the materials which are to be held together in the leak-proof fashion, and this rim 6 can contain a sealant or gasket means, if such is required.
• pads 1 are placed one on another in the manner shown in FIG. 2 and are then compressed in a cage 8 consisting of a pair of interengaging cage members 9 and 10 which when pushed together have interengaging ends 11 and 12 which move past each other as shown in FIG. 3 so that they interlock to hold the two cage members 9 and 10 of the cage together against outward movement.
• the enlarged perspective view of the interengaging ends 11 and 12 show the taper which allows the ends 11 and 12 to move past each other and then interlock.
• the action of confining the pads 1 in the cage 8 results in a precompression of the pads and this precompression can be selected to suit the particular conditions and pressures to which the device is to be subjected and in connection with which it is to form shock absorbing means.
• the cage 8 containing the pads 1 is held in a housing 20 having a removable end closure 21 and supplied with a fluid inlet 22 which allows fluid to flow into the housing 20 to extend around the cage 8 and thus to apply pressure to the pads 1, the pads 1 of course being further compressible beyond the initial loading which exists when the pads are forced together within the cage so that when for instance pressure in a water main to which the device is connected suddenly rises to produce a shock wave, the compression of the pads 1 absorbes this shock and prevents the water hammer action which would otherwise cccur.
• the housing 20 contains the pads 1 without being held in a cage, but to protecc the edges of the pads, partic ⁇ ularly at the inlet 22, a mesh 24 surrounds the perimeter of the assembled pads 1 and lies against the inner wall of the housing 20, the end closure 21 in this case serving to compress the pads 1 when the end closure 21 is assembled on the housing 20.
• FIG. 6 which is generally adapted for industrial use, a larger housing 25 is used again with a fluid inlet 26 and in this case a series of cages 8 are positioned within this housing.
• the housing 28 surrounds a pipe 29 to form a cavity around the pipe 29 in which cavity a considerable number of cages 8 are placed and in this case the pipe 29, within the area bound by the housing 28, has a series of apertures 30 through it so that liquid
• OMH_ flowing through the pipe 29 has access to the chamber formed by the housing 28 to again act to prevent water hammer when such a device is applied to a water pipe.
• the device of FIG. 8 is similar to the device of FIG. 3 but in this case the one interengaging cage member 32 is connected to the other inter ⁇ connecting cage member 33 by having hook-shaped ends 34 of extending projections 35 interengage with hook-shaped ends 36 on the extending circular projection 37, shown enlarged in the circle, of the other cage member 33 so that pressure exerted on the pads 1 can be increased by moving the two cage members 32 and 33 towards each other and this movement again has the required ability to absorb shocks which is the basis of this invention.
• the pressure is in this case is applied to the ends 40 in the direction of the arrow 41.
• the one inter- connecting cage member 42 has extending projections

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Pipe Accessories (AREA)
• Buffer Packaging (AREA)

Applications Claiming Priority (4)

Publications (2)

Family

ID=25642570

Family Applications (1)

Country Status (4)

Families Citing this family (4)

Citations (2)

Family Cites Families (8)

• 1983
  • 1983-08-04 EP EP19830902423 patent/EP0115501A4/de not_active Withdrawn
  • 1983-08-04 JP JP50260583A patent/JPS59501375A/ja active Pending
  • 1983-08-04 WO PCT/AU1983/000102 patent/WO1984000797A1/en not_active Application Discontinuation
  • 1983-08-08 CA CA000434075A patent/CA1202544A/en not_active Expired

Patent Citations (2)

Non-Patent Citations (3)

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