MXPA97001915A - Valve dosing that has the detection for the failure of the se - Google Patents

Abstract

A piston-type metering valve is exposed to provide a hermetically sealed chamber behind the diaphragm that separates the aseptic portion of the valve from the mechanical portion of the valve. An external vacuum source is connected to an opening in the chamber whereby a constant negative pressure is maintained inside the chamber. Any fracture in the diaphragm will be detected by a pressure detector located within the sealed chamber. In one embodiment, the visual inspection for the presence of the liquid product in the sealed chamber can be reached through a window in the housing of the metering valve located adjacent to the diaphragm and the chamber seals

Description

VALVE DOSING THAT HAS THE DETECTION FOR THE FAILURE OF THE SEAL FIELD OF THE INVENTION The present invention relates in general to automated filling machines for liquid containers and their concerns, more specifically, to a metering valve that includes the elements that allow the electrical and visual detection of a defective seal in the environment of the sterile valve.

BACKGROUND OF THE INVENTION A variety of dosing devices for liquid or semi-viscous products are known for their use in automated filling machines. These valves serve to allow a predetermined quantity of the product to flow from a reservoir supplying the product into a container.

A valve that is commonly used in automated filling machines REF: 24124 is a piston valve. A piston valve typically includes an elongate cylindrical housing, with an outlet at the lower end of the housing. An entry on the side of the housing, above the outlet, allows the product to flow into the housing. n Valve seat defines the separation between the inlet and the outlet. A plug is placed against the outlet side of the valve seat. The obturator is attached to a rod that runs coaxially with the obturator housing or impeller of the pneumatic rod attached to the upper part of the housing. When the rod is forced down the rod impeller, the plug is disengaged from the valve seat allowing the product to flow from the inlet to the outlet. This downward position is held until the desired amount of the product has flowed through the valve. Then the impeller of the rod flies the rod upwards forcing the obturator against the valve seat. This prevents the product from spilling through the outlet until a new container is in place for filling The shelf life of liquid products such as milk or juice is directly related to the amount of contaminants that are allowed to come into contact with the product before being sealed in the sterile environment of a container. The greater the amount of contaminants, the shorter the shelf life. Therefore, it is desirable to maintain an aseptic sealed environment for the products when they pass through the valve. It is also desirable to maintain a seal between the liquid product and the rest of the mechanical portions of the valve to prevent dirt from the valve or corrosion of its parts.

The manufacturers of piston-type metering valves have attempted to solve the aforementioned problems by attaching a flexible diaphragm around the rod to the inner wall of the housing above the inlet whereby the mechanical portion of the valve, which includes the impeller, is sealed. of the pneumatic rod, of the effective seal as long as the diaphragm remains intact but, because the diaphragm is continuously stretched by the movement of the rod and the pressure of the product, the material of the diaphragm tends to be fatigued. This creates the additional problem of detecting a fracture in the diaphragm seal. In current, the only way to achieve such detection is by stopping the filling machine and disarming the valve. The dead time of the machine and the work of a machine technician is added to the cost of the final product.

BRIEF DESCRIPTION OF THE INVENTION A metering valve is exposed to overcome many of the problems of the prior art by rocking a sealed chamber in a sealed manner behind the diaphragm that separates the aseptic portion of the valve from the mechanical portion of the valve. An external vacuum source is connected to an opening in the chamber whereby a constant negative pressure is maintained inside the chamber. Any contact or pressure detector located inside the sealed chamber. In one embodiment, visual inspection for the presence of the product in the sealed chamber can be achieved through a window in the housing of the dosing valve located adjacent to the diaphragm and the sealed chamber.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a metering valve.

FIG. 2 is a perspective sectional view of the metering valve of the F I G. 1.

FIG. 3 is a perspective view of the glass jacket of FIG. 1.

FIG. 4 is a side view of the glass jacket of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES FIG. .1 illustrates a piston-type metering valve 20 that includes the elements that allow electrical and visual detection of a defective seal. The valve housing is formed of a lower body of the valve 22 and an upper body of the valve 24. The lower body of the valve 22 has a cylindrical interior (not shown) in L-shape. In communication with the interior of the lower body of the valve 22 is an inlet 26 which enters through a side wall 28 of the lower body of the valve. The inlet 26 can be connected to the product tank (not shown in FIG 1). Also in communication with the interior of the lower body of the valve 22 is a circular outlet 30 at one end of the lower body of the valve 22. A seat of the circular valve (not shown in FIG. 1) is formed on the inner surface of the side wall 28 of the lower body of the valve 22 between the inlet 26 and the outlet 30.

At the other end of the lower body of the valve 22 is a connecting cylinder 32 for connecting the lower body of the valve 22 to the upper body of the valve 24. A pair of observation ports 34 (only one shown) are cut out of the side wall of the connecting cylinder 32 and projecting nose 36 is formed around the end of the connecting cylinder 32. A cylindrical transparent sleeve 38 made of, for example, hardened glass is concentrically fitted within the connecting cylinder 32. A ring or nut 39 it is placed in a channel (not shown in FIG.1) at the end of the transparent sleeve 39.

The upper body of the valve 24 has a connecting flange 40 at one end which is complementary to the connecting cylinder 32 of the lower body of the valve 22. A flange 42 is formed around the connecting flange 40. This connecting flange 40 substantially has the same outer diameter as the transparent sleeve 38 so that it can slide inside the connecting cylinder 32 to engage sealing the o-ring 39 and the transparent sleeve 38. The upper body of the valve 24 is connected to the lower body of the valve by a clamp 44 which engages the flanges 36 and 42.

A mound block 46 is formed at the other end of the upper body of the valve 24 to which a pneumatic rod impeller 48 is mounted. An inner surface (not shown in FIG. 1) is formed through the interior of the upper body of the valve 24 which is in axial alignment with the impeller of the rod 48 and the valve seat (not shown in FIG 1) of the lower body of the valve 22. Opening and closing of the valve 20 it is effected by the clutch and disengagement of the plug cover 50 and the plug ring 52 with the outlet side of the valve seat (not shown in FIG 1). The cover of the plug 50 is connected by a rod of the valve 54 to a rod 56 which is in turn connected to be driven by the driver of the rod 48. The ring of the plug 52 is engaged between the cover of the plug 50 and a flange 57 of the stem of the valve 54. A piston 58 is connected to the stem of the valve 54 for movement with the valve stem 54 and the rod 56. The piston 58 made of, for example, stainless steel is secured in Slip shape Aole by a bushing 59 made of, for example, plastic within the inner surface in the upper body of the valve 24 allowing the piston 58 and the rod 56 to slide in axial f -rma on the inner surface. A sealing ring 60 slidably engaging the piston 58 is also mounted within the inner surface. A screw 62 enters through the side wall of the upper body of the valve 24 and slidably engages a channel 6 4 in the piston 58 thereby limiting the axial movement of the rod 56 and preventing rotation thereof.

A flexible circular diaphragm 66 engages on its inner edge between an upper flange 68 of the valve stem 54 and the piston 58. The diaphragm 6 6 is also secured on its outer edge by the displacement between the transparent sleeve 38 and a groove formed on the inside of the side wall 28 near the inlet 26. The diaphragm 66, for example, is made of an FDA-approved silicon elastomer having a nomex polyimide fabric with a number of 62 X 58 cords. ropes / pu 1 gada (157.5 X 147.3 ropes / cm) having a tension force of 145 X 135 1 Ibras / pu 1 gada (167.06 X 155.52 kilograms / cm).

FIG. 2 shows a perspective sectional view of the metering valve 20 illustrating the orientation of its parts when assembled. The interior of the valve body 22 and the upper body of the valve 24 are shown to show the seat of the valve 70 and the groove 72 for the engagement of the outer edge of the diaphragm 66. The lower cavity defined within the bodies of the upper and lower valve 22 and 24 is divided by the diaphragm 66. The diaphragm 66 seals the path of the aseptic product (indicated by arrow 74) of a chamber 76 surrounding the piston 58. The chamber 76 is sealed in a sealed manner and defined by the diaphragm 66 at its lower end, by the sealing ring 60 at its upper end, and by the transparent jacket 38 and by the inner wall 78 and the inner surface 80 of the upper body of the valve 24 An interior surface 82 on the interior wall 78 running parallel to the interior surface 80 is in fluid communication with the chamber 76. A vacuum line 84 is connected to the interior surface 82 through a ueco 85 in the upper body of the valve 24. This vacuum line 84 is connected to a vacuum source (not shown) which maintains a negative pressure of, for example, 80% of the atmospheric pressure within the chamber 76. An adapter 86 holds a contact or contact detector. pressure 88 inside another cavity 89 through the upper body of the valve 24 to the inner surface 82. This detector 88 is electrically connected to a monitoring circuit that detects any elevation in pressure inside the chamber 76 or, if a contact detector is used, the presence of liquid spilled in the chamber 76 by the low pressure. Such an increase in pressure or in the pressure of the liquid will be indicative of a fracture in the diaphragm 66. Alternatively, a contact detector can be used in 88 and / or an external pressure detector can be used outside the dosing valve .

As can be seen, the downward axial movement (indicated by the arrow 90) of the rod 56, the piston 58 and the valve stem 54 will cause the seal ring 52 to disengage from the seat of the valve 70. The diaphragm 66 it is flexible allowing it to move with the stem of the valve 54 and the piston 58. The closing of the valve by an upward force of the impeller of the rod 48 is desirably accelerated due to the negative pressure inside the chamber 76 behind the diaphragm 66 creates an additional force up on the diaphragm 66.

The chamber 76 and the diaphragm 66 can also be visually inspected through the transparent sleeve 38. The presence of the product in the chamber 76 will visually indicate a fracture in the diaphragm 66. FIGS. 3 and 4 illustrate the transparent sleeve 38 in greater detail. As can be seen, in FIG. 4, the end of the transparent sleeve 38 slidably engaging the diaphragm 66 has a concentric inner flange 100 which extends under the external projection 102. The end of the transparent sleeve 38 slidably engages the connecting flange 40. of the upper body of the valve 24 has a concentric channel 104 creating an inner projection 106 and an outer projection 108. The o-ring 49 (shown in FIGS 1 and 2) is located partially in this channel 104.

Although the present invention has been described with reference to a specific embodiment, those skilled in the art will recognize that changes can be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects referred to therein.

Having described the invention as above, property is claimed as contained in the following

Claims (1)

1. CLAIMS A metering valve characterized in that it comprises: a) a housing having an inlet and an outlet defining a path through which the product enters and leaves the housing; b) a valve disposed within the housing between the inlet and the outlet; c) a mechanical impeller connected to the valve adapted to open and close the valve; d) a seal inside the housing that separates the product path from the mechanical impeller; and e) detection means for the detection of a seal fracture. A metering valve according to claim 1, characterized in that the detection means comprises a window in the housing adjacent to the mechanical impeller and to the seal. A dosing valve according to claim 1, characterized in that the detection means comprise: a) an additional seal that creates a sealed chamber within the housing between the seal and the additional seal; b) a vacuum source in communication with the sealed chamber for maintaining a negative pressure inside the chamber; Y a pressure detector in communication with the sealed chamber. A dosing valve characterized in that it comprises a) an elongate cylindrical housing having an outlet at a first end and an entrance through a side wall defining a path for passing the product through the housing and an interior surface at a second end; b) a valve seat disposed between the outlet and the inlet; c) an obturator adapted to engage the valve seat with which the inlet of the outlet is sealed; d) a rod attached to the obturator and extending therefrom through the inner surface at the second end of the housing; a rod driver attached to the second end of the housing for moving the rod between a first position in which the obturator engages the valve seat and a second position in which the obturator disengages the valve seat; f) a diaphragm mounted around the second end of the housing; Y g) detection means to detect a fracture in the diaphragm. A dosing valve according to claim 4, characterized in that the detection means comprise a window in the housing adjacent to the diaphragm. A metering valve according to claim 4, characterized in that the detection means comprise: a seal adjacent the second end of the housing creating a sealed chamber within the housing between the diaphragm and the seal; a vacuum source in communication with the sealed chamber for the maintenance of a negative pressure inside the chamber; Y c) a pressure detector in communication with the sealed chamber.