Liquid purification or separation – With drip – overflow or content draining feature
Reexamination Certificate
2000-09-05
2001-04-24
Savage, Matthew O. (Department: 1723)
Liquid purification or separation
With drip, overflow or content draining feature
C210S442000, C210S453000, C210S455000, C210S457000
Reexamination Certificate
active
06221246
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a filter housing assembly including a closure plate specifically structured to independently hold successive filters in place without the need for the prior art nut and threaded standpipe that blocked access to successive filters. The closure plate is also structured to deflect leaks of pressurized hot fluid.
BACKGROUND OF THE INVENTION
Hot oils or heat transfer fluids are used for the indirect heating of processes by circulating the heated fluid between hot oil boilers and reactor vessels, tanks, molds, calenders, extruders, or heat exchangers. Such fluids are subjected to temperatures ranging from 300° F. (149° C.) to 750° (399° C.) for heating applications in the chemical, plastics, rubber, petrochemical, pharmaceutical, pulp and paper, textile, and food industries.
It is known to incorporate filters into such systems to remove contaminates from the fluid. See, for example, U.S. Pat. Nos. 5,484,523; 5,264,119; 5,022,986 and 4,272,368. None of the filter housings described therein disclose or suggest the structure of the closure plate as described herein.
U.S. Pat. No. 5,484,523 shows a centrally positioned sleeve projecting from the inside of the cover and externally threaded to engage an internally threaded top end of a filter. This arrangement undesirably requires the steps of threading successive filters to the sleeve on the cover and of unthreading the filters from the cover when replacing filters.
U.S. Pat. No. 5,264,119 shows a filter support to be mounted in a cylindrical cavity formed in the head plug of the filter. The filter support is glued into place to prevent leaks and displacement of the filter support during maintenance. The head plug may be attached to a bearing plate which is the closure for the top of the filter housing.
The filter assembly of U.S. Pat. No. 5,022,986 has a cap with a downwardly directed cylindrical rib projecting into the upper end of the filter and an ear extending downward adjacent the inside of the filter. The cap is secured to the housing and engages the entire top of the filter.
U.S. Pat. No. 4,272,368 discloses an end closure for a filter housing which is a cup-shaped member having a center tubular projection which serves as a support member for the filter element. The cup-shaped member is either attached to the housing or to another member in order to provide closure for the housing.
It is known to provide filter elements specifically tor the filtration of hot oils at temperatures up to 700° F. (371° C.) and pressures up to 150 psig (1034 kPa). These filter elements, as in the present invention, are installed in housings that comprise a top closure plate and a filter housing. The closure plate is a blind flange removably connected, as by bolts, to a top flange on the filter housing, with a gasket between the closure plate and the top flange.
The filter housing has two compartments: an upper dirty chamber and a lower clean chamber. An imperforate bottom plate separates the two chambers. Liquids enter the housing through the upper chamber and then pass through a filter element and drain into the lower chamber.
The filter element, as in the present invention, consists of filter media wound on a perforated core. In the prior art, the filter element is installed on a rigid, perforated standpipe with an exteriorly threaded upper end and a bolt and washer are used to secure the filter element to the standpipe and hold the filter element in place, with the bottom end of the standpipe being threaded and screwed into a threaded hole in the bottom plate.
FIG. 1
shows a filter housing assembly according to the prior art.
The filter elements must be periodically replaced during normal operation. Removal of a filter element requires removal of the closure plate, only after the filter has cooled and the pressure inside the housing has been relieved.
Several problems exist with the above-described conventional filter housing assembly. First, the cost of the bolt and of threading both ends of the standpipe is unnecessary. Second, the time and effort required to remove the bolt before removing a filter is unnecessary. Third, the closure plates of the prior art filter housings used for processing hot oils provide no protection from direct sprays of hot and pressurized liquid due to gasket failure, or improper sealing or misalignment during installation of the closure plate. Fourth, the filter element and the standpipe supporting the filter element lean under the very high pressures of liquid entering the upper chamber. This unnecessarily increases the difficulty of replacing a filter element.
SUMMARY OF THE INVENTION
The filter housing assembly of this invention includes a closure plate integrated with a spindle that is integrated with a top filter support to hold a filter element in place. A skirt encircles the closure plate to deflect leaks. The closure plate is a blind flange.
The spindle is integrated with the under side of the closure plate, as by welding, in position to slide into the top end of the tubular standpipe when the closure plate is operatively mounted on the top flange of the filter housing. The top filter support is integrated with the spindle, as by welding, in position to seat on the upper end of a filter and hold the filter in place when the closure plate is operatively installed.
The skirt is installed around the circumference of the closure plate in angularly spaced overlapping relation to the space created by a gasket between the closure plate and the top flange of the housing.
One object of this invention is to reduce the cost of the filter housing assembly. This is accomplished by integrating the closure plate with a spindle and top filter support and thereby eliminating the need for an expensive bolt and for threading the top end of the standpipe. The cost of the conventional threading on the bottom of the standpipe is also eliminated by integrating the bottom end of the standpipe with the bottom plate, as by welding.
Another object of the invention is to reduce the time necessary to replace filter elements within the filter housing. The invention allows access to the filter element by simply removing the closure plate rather than requiring the additional step of removing a bolt and washer before being able to remove a filter element.
Another object of the invention is to provide additional support for the filter element, which increases the pressure rating of the filter housing.
Still another object of the invention is to protect a person from a leak of pressurized hot liquid by providing a skirt that deflects the liquid and causes it to drip down the side of the filter housing.
REFERENCES:
patent: 2043781 (1936-06-01), Sorenson et al.
patent: 2392624 (1946-01-01), Tunis
patent: 2467061 (1949-04-01), Mason
patent: 2568181 (1951-09-01), Zimmerman et al.
patent: 4052317 (1977-10-01), Palnik
patent: 4588500 (1986-05-01), Sprenger et al.
patent: 5013434 (1991-05-01), Furrow
Hunt Clifton T.
Savage Matthew O.
LandOfFree
Filter housing assembly does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Filter housing assembly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Filter housing assembly will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2452045