Fluid handling – With cleaner – lubrication added to fluid or liquid sealing... – Cleaning or steam sterilizing
Reexamination Certificate
2000-06-30
2001-11-13
Walton, George L. (Department: 3753)
Fluid handling
With cleaner, lubrication added to fluid or liquid sealing...
Cleaning or steam sterilizing
C134S102100, C134S16600C, C134S171000, C137S015040
Reexamination Certificate
active
06314987
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to aseptic valves and, more particularly, to an aseptic product discharge valve and related methods of preventing contamination of a fluid food product processing system by microorganisms.
BACKGROUND OF THE INVENTION
Many fluid food products are aseptically processed to prevent the undesirable effects of microorganism. Aseptic processing can significantly extend the shelf life of most foodstuffs and often involves the continuous sterilization of a fluid food product circulated within a closed process system. In a typical aseptic process, a fluid food product is thermally pasteurized by heating to an elevated temperature for a duration sufficient to reduce the viability of microorganism to acceptable levels. Following pasteurization, the fluid food product is typically transported through a cooling media before packaging into a sterile container. One example of such a system is shown and described in U.S. Pat. No. 5,802,96, which is assigned to the assignee of the present invention. In most processing and packaging operations, the cooling side of the system is much more prone to contamination by microorganism. One potential point of contamination is the occasional requirement to draw off a quantity of sterile product or other media from the sterile atmosphere of an aseptic cooling system to an unsterile atmosphere, such as an open tank or gutter. Over time, microorganisms can migrate up the discharge line and contaminate the system.
Conventional valves produce a fluid tight seal between a movable valve member and a complementary valve seat so as to discontinue or restrict flow. Absent suitable precautions, microorganisms resident in the discharge line downstream of the discharge valve can readily traverse the fluid-tight seal, invade the sterile piping system, and compromise the sterility of the closed process system.
Various manners of dealing with contamination issues in food processing systems have been utilized in the past. One typical system is a double block and bleed valve system which involves using two spaced apart valves in the discharge line with steam injection between the two valves. The valves are sequentially opened and timed with the introduction of stream to maintain sterility at the outlet. Unfortunately, this type of system is rather complicated and still may not maintain optimum sterility at the discharge location.
It would there fore be desirable to provide a product discharge valve, especially useful in the fluid food product industry, which combines simplicity of design with effective sterilization of the discharge location.
SUMMARY OF THE INVENTION
The present invention provides an aseptic product discharge valve that injects steam adjacent the interface between a valve member and an associated valve seat. The aseptic product discharge valve includes a tubular structure having a longitudinal passageway with an outlet for discharging the flow of the fluid food product. The valve further includes a chamber that is positioned radially outward of the longitudinal passageway and a steam conduit for supplying steam to the chamber. In one embodiment, the chamber is an annular chamber having an annular opening into the longitudinal passageway. The valve member may be moved by an actuating assembly configured to move the valve member between a closed position to prevent the flow of fluid food product through the outlet and at least one open position to allow the flow of fluid food product through the outlet. The actuating assembly may be a linear actuator coupled with the valve member by a valve stem.
The aseptic product discharge valve further includes a hollow valve stem having a cavity for receiving steam and a number of radial ports that perforate the hollow member. Steam at super-atmospheric pressure is delivered from a steam conduit attached for fluid communication with the valve stem that supplies steam to fill the cavity. The radial steam ports allow steam to bathe the full circumference of the downstream surface of the valve member. The steam injected from the opening in the annular chamber bathes the valve seat and the upstream surface of the valve member. The multiple steam injection locations form a barrier to the migration of microorganisms either along the inner surface of the discharge conduit or the outer surface of the valve stem, past the interface between the valve member and the valve seat.
Additional features, advantages and objectives of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 646103 (1900-03-01), Faber
patent: 646104 (1900-03-01), Faber
patent: 721453 (1903-02-01), Lunken
patent: 870487 (1907-11-01), Bertram
patent: 1358968 (1920-11-01), Mattern et al.
patent: 1780525 (1930-11-01), Jacobsen
patent: 1831457 (1931-11-01), Larsen
patent: 1954217 (1934-04-01), Morrow
patent: 2254472 (1941-09-01), Dahl
patent: 2378607 (1945-06-01), Watts
patent: 2682277 (1954-06-01), Marshall et al.
patent: 2698120 (1954-12-01), Fairchild
patent: 3633607 (1972-01-01), Werra
patent: 3643679 (1972-02-01), Hansson
patent: 3998589 (1976-12-01), Rechtsteiner et al.
patent: 4037784 (1977-07-01), Sabarly
patent: 4144901 (1979-03-01), Stevenson
patent: 4160002 (1979-07-01), Janovtchik
patent: 4325401 (1982-04-01), Ukai et al.
patent: 4614661 (1986-09-01), White et al.
patent: 4913185 (1990-04-01), Mattei
patent: 5058619 (1991-10-01), Zheng
patent: 5152500 (1992-10-01), Hoobyar et al.
patent: 5193571 (1993-03-01), Levati
patent: 5311899 (1994-05-01), Isayama et al.
patent: 5395569 (1995-03-01), Badertscher et al.
patent: 5439024 (1995-08-01), Zimmerly
patent: 5746239 (1998-05-01), Ondrus
patent: 5863587 (1999-01-01), Badertscher et al.
patent: 5881574 (1999-03-01), Petrich
patent: 5927318 (1999-07-01), Ishibashi et al.
FMC Corporation
Walton George L.
Wood Herron & Evans L.L.P.
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