Patent Application
20130087494
The present disclosure relates to filtering fluids in a system having pressurized fluid flowing therethrough and particularly systems where the fluid is circulated in a closed system. Systems employing pressurized fluid such as hydraulic fluid or water may require filtering to remove foreign matter and debris which may accumulate in the system over time and in prolonged service. In providing filtering of such fluid systems, it has been found particularly convenient and economical to provide a pressure vessel with a removable filter element or filtering material employed in a basket which may be accessible for removal and replacement. The filtering element may have the form of a rigid porous container which may be filled with particulate filtering material or may comprise a filter bag or even a combination thereof or permanent removable straining elements such as perforated screen metal mesh or slotted wedge wire formed into a removable basket for providing the desired level of filtration. The pressure vessel is typically provided with a closure or lid which is releasable for enabling access to the interior of the vessel to permit removal and replacement of the filtering material or filter bag.
Where the filtering apparatus is employed for high volume flow or in systems where relatively high fluid pressure is employed, a significant pressure differential may occur across the filtering material or bag, upon containment of a significant amount of trapped material and clogging in the filter. This pressure differential may result in forces causing catastrophic structural failure of the basket resulting in fragments and debris entering the vessel outlet and the fluid system.
Where failure of the filter basket has been experienced, entry of loose metal fragments of the basket into the outlet of the vessel, and thus the fluid system, can result in significant damage to the fluid operating system and to the pumps employed for the fluid. Failures of this type can be particularly catastrophic in hydraulic fluid systems such as those employed for operating high volume flow cooling circuits in industrial plants, power generation applications and ships.
Thus, it has been desired to provide a way or means of protecting a fluid filtering apparatus from discharging metal fragments or other debris into the fluid system in the event of catastrophic structural failure within the filtering apparatus.
The present disclosure describes a fluid filtering apparatus having a pressure vessel defining a fluid chamber with an inlet and outlet communicating with the chamber. Fluid filtering material is disposed with a rigid porous container or basket which is disposed in the fluid pressure chamber. The basket may contain filtering material such as granular material or may be employed in conjunction with a filter bag. A porous barrier is provided in the outlet of the pressure vessel to contain and prevent entry into the outlet of fragments of the basket in the event of catastrophic structural failure of the basket. The barrier, in one version disclosed, comprises a metal mesh or plurality of spaced rods disposed in a grid and may be attached in the vessel outlet by suitable fasteners or weldment. In another disclosed version, the barrier has the form of a perforated plate and may have a ratio of open to closed area of about 2:1. The barrier is configured to provide the desired fluid flow yet is sufficiently robust to retain any loose fragments of the basket in the event of such failure.
Referring to
The lid 14 may be secured by fasteners such as swing bolts 13 pivotally attached via a pin 15 through apertures in attachment lugs 16 disposed about the open end of the vessel 10 and engaging a lug 23 on the lid 14. Additional lugs such as lug 19 may be provided on the open end of vessel 10 for pivotal mounting thereto of the lid by lug 21 provided on lid 14 and pivotal pin 17 if desired.
The pressure vessel has an outlet boss or standoff 18 formed on the side wall thereof with an attachment flange 20 provided thereabout for connection to a fluid pressure conduit (not shown). The flange 20 has a plurality of fastener apertures 22 formed therethrough and spaced circumferentially thereabout for enabling the attachment to the fluid pressure system. The boss 18 is provided with a passage or port 24 (see
Disposed circumferentially spaced from the boss 18 is an outlet boss 26 which has a circular attachment flange 28 provided thereon with circumferentially spaced apertures 30 provided on the flange for enabling attachment to a conduit (not shown) for supplying filtered pressurized fluid thereto. The boss 26 has provided therein an outlet passage or port 32 which communicates with the interior of the pressure chamber 12. The diameter of the interface between the vessel shell 10 and the boss 26 is larger than that of the outlet through the flange 28. The transition between the larger flow, inlet diameter and the smaller flow outlet diameter 32 is accomplished through a concentric or eccentric reducer 27.
Referring to
Referring to
The open end of the basket is sealed about its periphery through an aperture provided in a bulkhead or interior wall 46 provided in pressure chamber 12 which isolates the basket such that only the upper end thereof communicates with inlet passage 24; and thus, all fluid entering the inlet port 24 flows through the filtering material associated with the basket 44 before exiting to outlet port 32. If desired, the open end of the basket may have an outwardly extending flange 45 provided about the open end thereof for providing sealing about the aperture 47 in wall 46.
Referring to
It will be understood that in either version of the containment barrier 40 of
The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
