Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
  • F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
  • F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
  • F16K17/0433—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded with vibration preventing means

Definitions

• the present invention refers to a fluid suction valve.
• the suction valve can be applied to a compressor.
• the elements usually present in a fluid suction valve are a body, a cover, an inlet duct, usually positioned in an axial direction, a seat, a shutter to close the seat through which the fluid passes and an outlet duct . With the shutter open the fluid therefore enters the valve inlet duct, crosses the seat and leaves via the valve outlet duct .
• valves existing include those used as suction valves in compressors.
• the cover is fixed to the compressor by means of coupling devices, and the fluid leaving the valve is sucked in by the compressor.
• valves are produced consisting of elements which, during the non-return phase, are subject to the pressure present inside the compressor, in the order of at least ten or fifteen atmospheres, which must therefore be suitably sized to withstand the pressure without jeopardising correct operation of the valve.
• the fluid is filtered by means of a filter.
• a drawback of the current valves is that given the arrangement of the elements subject to high levels of pressure, the latter must be suitably sized to withstand said stresses, consequently resulting in an increase in weight, overall dimensions and cost of the valve .
• a further drawback is that it is not possible to uniformly exploit the whole working surface of the filter without excessively increasing the overall dimensions of the suction valve-filter unit positioning the same above the inlet duct and therefore above the valve itself.
• a further drawback is that the hot oil for lubrication of the moving parts of the compressor can spatter into the valve, dirtying it, consequently reducing the valve area, and heating it, causing a temperature increase in the fluid sucked by the compressor with consequent reduction in ther odynamic efficiency of the same.
• compressors have been designed provided with a cast appendix which, protecting the valve from the splashes, reduces the amount of oil that enters the valve.
• the aim of the present invention is to produce a suction valve provided with internal parts subject to low pressures.
• a further aim is to produce a suction valve with low cost, reduced weight and overall dimensions, preferably vertical .
• a further aim is to ensure improved exploitation of the working area of the filter without having an excessively cumbersome valve.
• a further aim is to be able to divert the fluid sucked by a screw compressor, directing it tangentially to the screws to reduce the compressor pressure losses.
• a further aim is to prevent the oil present for example in a compressor from entering the valve, dirtying it and heating it, reducing the efficiency of the compressor.
• the suction valve according to the present invention comprises a body closed by a cover, an inlet duct and an outlet duct for the fluid obtained in the body and in the cover respectively, a seat to close the valve and a shutter designed to close said seat.
• figure 1 is a partially sectioned elevated lateral view of a first embodiment of a suction valve according to the present invention
• figure 2 is a partially sectioned elevated lateral view of a second embodiment of a suction valve according to the present invention
• figure 3 is a partially sectioned elevated view of a third embodiment of a suction valve according to the present invention connected to a compressor.
• a suction valve for a fluid comprising a body 30 fixed to a cover 10, a seat 13 and a shutter 50 designed to close said seat 13.
• the valve furthermore comprises an inlet duct 40 and an outlet duct 19 for a fluid obtained in the body 30 and in the cover 10 respectively.
• the shutter 50 is coupled to the body 30 and is able to run axially with respect to it to close the seat 13 of the valve by means of seal devices closing the outlet duct 19 and preventing reflux of fluid from a compressor 15.
• the cover 10 is attached by means of coupling devices to the body 30 and furthermore is fixed to the compressor 15 preferably interposing a base plate 18 fixed to the cover 10 which allows the valve to be fixed to different types of compressors.
• the cover 10 is a cylindrical ring having a first base surface 12 designed to connect the base plate 18, which is fixed in turn to a compressor 15, and a second base surface 11 attached by means of coupling devices to the body 30.
• the outlet duct 19 is defined by a circular aperture 16 obtained in the cover 10 in a central position, which crosses the first base surface 12 and the second base surface 11.
• Said aperture 16 is provided, starting from the first base surface 12 at the end of the valve, with a seat 13 with surface able to couple with the shutter 50 to close the valve.
• the shutter 50 comprises a stem 51 having an outer cylindrical surface 54 connected to a disc 53 by means of a portion 52 of smaller section.
• the disc 53 has a tapered or shaped outer surface in order to couple with a corresponding surface of the seat 13 and consequently close the valve.
• the disc 53 comprises a conical outer surface 55 and the seat 13 of the valve comprises in turn a corresponding conical surface 14 able to couple with said conical outer surface 55 to close the valve.
• the shutter comprises a disc 53', which comprises a ring-shaped outer surface 55' square to the valve axis.
• the seat 13 of the valve comprises in turn a corresponding ring- shaped surface 14' able to couple with said ring-shaped outer surface 55' to close the valve.
• the body 30 comprises a first tube 33 and a second tube 34 flanged larger than the first one, arranged coaxially the first one inside the second one and joined at one end by means of a circular crown-shaped plate 31.
• the second flanged tube 34 is provided with a flange 37 attached by means of coupling devices to the cover 10 and is furthermore provided with a plurality of radial apertures that define an inlet duct 40 of the valve.
• This allows the fluid entering the valve and permits passage of the fluid from the outside of the body 30 of the valve to the outlet duct 19 of the valve.
• the fluid is filtered via a filter 80 fitted on the body 30. In this way it is possible to improve exploitation of the working area of the filter 80 without having an excessively cumbersome valve.
• the outlet duct 19 and the body 30 are subject to atmospheric pressure only, since they are isolated from the compressor 15. Furthermore when the valve is open, during suction of the compressor 15, the pressure is not so great as to create structural problems for the valve. It is therefore possible to size the body 30 in order to minimise the thicknesses, and it is furthermore possible to have an inlet duct 40 of the radial valve defined by the radial aperture of the body 30, at the same time maintaining a sufficiently solid valve structure .
• the shutter 50 furthermore comprises a stem 51 which couples and is able to run axially with respect to the body 30 to open and close the valve.
• Said stem 51 is inserted and runs in the first tube 33 of the body 30.
• the portion 52 with smaller section of the shutter 50 crosses an aperture obtained at the end of the first tube 33, defining a housing 43 for an elastic element 71 designed to keep the aperture 16 of the cover 10 closed when the compressor 15 is at rest, exerting pressure on the shutter 50 and on the body 30.
• said housing 43 is connected to a pneumatic device by means of a duct 41 to close suction of the compressor 15 or in any case limit it so that it does not operate and consume energy unnecessarily when the requirement is partial or zero.
• gaskets are preferably fitted, housed in the cover 10, in the body 30 and in the shutter 50 respectively.
• a gasket 73 is fitted in the cover 10, protruding from the first base surface 11 and in contact with the corresponding base surface of the flange 37 of the body 30.
• the seal devices comprise the gasket 73. If necessary the seal devices comprise further gaskets positioned respectively on the ring-shaped surface 14', on the base surface 12 and on the outer surface 54 of the stem 51.
• the shutter 50 comprises a disc 53'' having the base surfaces slanting with respect to the valve axis by an angle a, and able to deflect the fluid sucked by the screw compressor 15 tangentially to the compressor screws, or in a radial direction, at the same time reducing the pressure losses due to the flow, and consequently increasing the efficiency of the compressor 15.
• the disc 53'' comprises a conical outer surface 55'' and the seat 13 of the valve comprises in turn a corresponding conical surface 14'' able to couple with said conical outer surface 55'' to close the valve.
• a suction valve for a fluid according to the present invention also permits a further increase in efficiency of the compressor 15 since the compressor 15 compresses the fluid at a lower temperature as the disc (53, 53', 53'') of the shutter 50 is shaped and arranged so as to prevent the hot lubricating oil present in the compressor 15 from crossing the outlet duct 19 of the valve and entering it since on the one hand it would dirty the valve reducing the valve area and, on the other, would heat the valve and consequently also the incoming fluid.
• the shutter 50 therefore also integrates the functions of any appendix that may be present in a compressor 15 used to prevent lubricating oil entering the suction valve .
• the shutter 50 can also be provided, as shown in figure 1, with at least one axial through hole 90 of reduced dimensions to stabilise the shutter 50, preventing vibrations during operation of the valve.
• Said at least one hole 90 connects the housing 43 with the outside of the valve causing a slight discharge of air which stabilises the shutter 50.
• several holes 90 can be present arranged symmetrically with respect to the longitudinal axis of the shutter.
• a further advantage is that since the body 30 of the valve is not subject to high pressures, it is possible to use less robust coupling devices between body 30 and cover 10.
• the reinforced polymeric material is preferably a reinforced technopolymer with good mechanical characteristics and good resistance to chemical agents.
• the technopolymer is chosen from a polyketone, a polysulphone, a polyphenylether and/or their mixtures.
• the reinforced technopolymer is a reinforced polyketone or derivatives of it .
• Production using a reinforced polymeric material also constitutes a further important aspect of the present invention.
• valve components can be made of moulded polymeric material, it is possible and expedient to provide inserts of different material in various critical points of the valve. Said inserts are generally made of metal .
• the use of inserts allows you to choose the material to be used not on the basis of the stress of the valve analysed globally, which inevitably leads to compromises between costs and benefits, with consequent reduced performance as regards both duration and resistance, but on the basis of the individual specific local requirements of the valve.
• valve is no longer studied as such in its entirety but is seen as a set of subsystems which can, with the present invention, be managed and studied in a completely separate and therefore much more efficient way.
• suction valve according to the present invention achieves the aims previously highlighted.
• the suction valve of the present invention thus conceived can be modified and varied in numerous ways, all falling within the same inventive concept. Furthermore in practice any materials, dimensions and components can be used, according to technical requirements .

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Compressor (AREA)

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Family Applications (1)

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Citations (7)

• 2004
  • 2004-03-30 IT ITMI20040624 patent/ITMI20040624A1/it unknown
• 2005
  • 2005-03-29 WO PCT/EP2005/003478 patent/WO2005095830A1/en active Application Filing

Patent Citations (7)

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