Abstract:
A hygienic insert connector assembly that prevents biological contamination within food, beverage and biopharma processes includes an insert to pass through an opening into a fluid chamber, a support assembly, a seal disposed around the insert to seal the opening into the fluid chamber, and a seal compression mechanism. When the seal is axially compressed, the seal radially expands and contacts both the wall of the opening into the fluid chamber and the insert to collectively form a fluid tight seal. This eliminates the potential for product entrapment with the associated biological contamination risk, and allows efficient in-place cleaning and sterilization. The connector assembly can be installed in any orientation and functions such that positive pressure inside the fluid chamber enhances the sealing mechanism. The simple design enables the insert to be easily removed, examined, and re-inserted in conformance with international sanitary design standards.

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of, and claims priority from, co-pending U.S. application Ser. No. 11/538,117. The &#39;117 application, which is entitled “Method and Apparatus for Simplified Hygienic Access to a Fluid Chamber,” was filed on Oct. 3, 2006, and is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to devices for permitting simplified and hygienic access to the interior of fluid chambers. 
     BACKGROUND 
     Operations involving the handling and processing of fluids entail fluids being contained in various types of fluid chambers. As used herein, the term fluid refers to any process material that is of a sufficiently flowable nature and may include, but is not limited to, a liquid, a gas, a gas/liquid mixture, a liquid/solid mixture or a gas/solid mixture. These fluid chambers may take the form of pipes, conduits, tubes, or open channels for transporting fluids under the influence of gravity or of pumping systems, or they may take the form of vessels, tanks, or vats for carrying out various chemical or other processes. Monitoring process variables within a fluid chamber is a key component of overall process assessment and control, and such assessment and control may require injection and/or extraction of materials to or from the chamber. While access ports for measurement and control may be designed within a fluid chamber initially, such is not always the case. The introduction of continuous processing methods often requires the need to monitor process and product conditions in-line using various types of sensors. 
     There are numerous challenges to designing access devices for fluid chambers, particularly for industries processing food, drinks, pharmaceuticals, and bio-products, for example. Industry standards require the design to conform to specific criteria in order to be approved for sanitary applications. Such, access devices should be designed to maintain hygienic conditions in the area where the access device penetrates the fluid chamber. Maintenance of hygienic conditions is promoted by not having crevices or voids where process products may collect and stagnate creating biological risks. 
     In addition to the hygienic risk from product entrapment in voids during normal processing, such voids can also entrap products during draining procedures, and form pockets or voids that collect gases during filling and startup procedures. This is particularly true for highly viscous fluids that do not easily drain by gravity and require substantial pressure to create steady flow through the process. 
     Accordingly, the access device should be robust and designed such that both the device and a seal that is used to seal the device to the fluid chamber can be securely held in place without the pressure within the chamber compromising the integrity of the connection. Additionally, the design of a hygienic process connection has to be simple and capable of being easily disassembled for inspection and cleaning purposes. 
     There are known devices that are designed for gaining access to fluid chambers used for processing/conveying fluids under hygienic requirements.  FIGS. 1 and 2 , for example, illustrate a conventional method for inserting a sensor into a hygienic processing pipeline. Such devices are provided with an elastomeric seal  104  for forming a sealed relationship between the access device  101  and the edge of an opening  103  in the fluid chamber  102 . The design of these connection assemblies is generally that, when installed, the seal  104  lies between the wall of the chamber  102  and the access device  101  to be inserted in the chamber. When the access device  101  is installed, a clamping ring  105  compresses the seal  104  axially between the surface of the chamber  103  and the access device  101 . 
     The geometry of the access device in the vicinity of the chamber opening where the seal is located can introduce localized zones of fluid stagnation  106  within the chamber. These zones can have a negative hygienic impact on the fluid contained within the chamber since they cannot be effectively cleaned in situ by routine Clean-In-Place (CIP) procedures. This often results in the need to dismantle the support structure and access device in order to carry out manual cleaning procedures on the dismantled components at frequent intervals. These procedures are both labor intensive and time consuming. 
     Another disadvantage of this kind of access device installation geometry is the restriction it places on the choice of installation location within the process. For example, the non-vertical orientation of the access device  101  can result in incomplete fluid drainage on shutdown procedures, and create voids or pockets that can trap gases during filling and startup procedures. Both can result in product contamination and waste. Further, restricting the angular orientation of the access device  101  in an attempt to reduce the fluid drainage problems invariably worsens the gas entrapment problem. 
     A further problem encountered by the known forms of access device  101  is that an increase in the fluid pressure within the chamber will have a tendency to move the access device  101  away from the seal  104  and the chamber opening  103  resulting in a reduction in the compression of the seal  104 . This produces an increased hygienic risk from fluid ingress into the seal  104  contact areas, as well as leakage of the product out of the chamber. 
     SUMMARY 
     The present invention is a device, referred to as a connector assembly, which permits easy access to a fluid chamber and forms a substantially fluid tight seal between the device and the fluid chamber. In contrast to the method employed in conventional devices, whereby the seal is established outside the fluid chamber, the method employed by the present invention establishes the seal within the interior of the fluid chamber. The resultant advantages of this approach will become apparent from the following detailed description and drawings. 
     The device includes an insert that projects through a simple opening in the chamber. A seal is disposed around the insert and between spaced-apart compression members. At least one of the compression members is movable with respect to the other for compressing the seal. The seal extends beyond the opening such that a portion of the seal is disposed within the fluid chamber. When the device is installed, the insert and seal are positioned such that the seal lies in the opening of the chamber. Axial compression of the seal causes the seal to radially expand and form a fluid tight seal between the seal and the wall of the opening into the chamber, and between the seal and the body of the insert. 
     The present invention also provides a method of gaining access to a fluid chamber through a simple opening in the chamber. This method includes providing access to the fluid chamber by projecting an insert through the opening in the fluid chamber. A seal extends around the insert and is positioned such that the seal projects axially through the opening into the fluid chamber. The method includes creating a fluid-tight seal between the insert and the wall of the opening by axially compressing the seal. This causes the seal to be forced radially against the wall of the opening, and compresses the end and bore of the seal against the insert. 
     Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-section view showing a state-of-the-art hygienic process connection assembly with the sealing mechanism and stagnant zone. 
         FIG. 2  is a longitudinal section view showing a state-of-the-art hygienic process connection assembly with the sealing mechanism and stagnant zone. 
         FIG. 3  is a perspective view of the connector assembly installed on a pipe. 
         FIG. 4  is a sectional view of the connector assembly showing the seal thereof in an uncompressed state. 
         FIG. 5  is a sectional view of the connector assembly showing the seal thereof in a compressed state. 
         FIG. 6  is a sectional view of an alternate embodiment of the connector assembly showing the seal thereof in an uncompressed state. 
         FIG. 7  is a sectional view of an alternate embodiment of the connector assembly showing the seal thereof in a compressed state. 
         FIG. 8  is a sectional view of another embodiment of the connector assembly. 
         FIG. 9  is a sectional view of yet another embodiment of the connector assembly. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     With reference to the drawings, the present invention is a connector assembly, indicated generally by the numeral  10  that provides access to a fluid chamber  20  having a chamber wall  22 . As discussed herein, the connector assembly  10  is described in the context of being used in a hygienic application. However, this is for illustrative purposes only. Those of ordinary skill in the art will readily appreciate that the present invention may also by employed in conjunction with non-hygienic applications. 
       FIGS. 3-5  illustrate a first embodiment of the connector assembly  10 . The connector assembly  10  comprises an insert  40  adapted to pass through an opening  24  into the fluid chamber  20 , a support assembly  30  to support the insert  40 , a seal  50  disposed around an outer surface  45  of the insert  40  to seal the opening  24  into the fluid chamber  20 , and a compression mechanism to compress the seal  50 . When the seal  50  is axially compressed, the seal  50  radially expands and contacts the wall  26  of the opening  24  into the fluid chamber  20  as well as compressing the end of the seal  50  against the insert flange  44  and the seal bore against the insert body  45  to form a hygienic and fluid tight seal. The connector assembly  10  is designed so that positive pressure inside the fluid chamber  20  enhances the seal that is formed. Additionally, the connector assembly  10  is designed to minimize biological contamination risks and the transfer of thermal or electrical energy from the wall  22  to the insert  40 . 
     The support assembly  30  comprises a support member  31 , one or more U-bolts  36 , and mounting nuts  38 . Support member  31  has an opening  32  through which the insert  40  can be assembled via the proximal end of the insert. Mounting holes to accept the ends of U-bolts  36  are disposed on opposite sides of the opening  32 . Support member  31  is positioned adjacent to fluid chamber  20  such that throughway opening  32  aligns with opening  24  in the chamber. The surface of the support member  31  facing the fluid chamber  20  may be contoured or machined so that it conforms to the shape of the fluid chamber  20  and provides a surface-to-surface contact. The support member  31  is secured to the fluid chamber  20  with the U-bolt  36  and pair of mounting nuts  38 . If desired, more than one U-bolt  36  or other form of clamping device can be used. 
     The insert  40  may comprise a measurement probe, thermowell, or sleeve, or similar structure that extends into the fluid chamber  20 . Insert  40  has a generally cylindrical body  42  with a flange  44  at the distal end. A portion of the outer surface  45  includes threads  46 . Wrench flats  47  on the body  42  facilitate gripping the insert and preventing it from turning during installation or removal as hereinafter described. The proximal end of the insert  40  may have external threads  49  to provide a means of making a measuring signal connection or other conduit (not shown). For illustrative purposes, the complementary compression surfaces of the flange  44  and the end of the seal  50  are shown as plain surfaces. However, those skilled in the art will appreciate that other surface profiles and bonding methods could be used. 
     Disposed on insert  40  is a compressible seal  50 . Seal  50  has a generally annular shape with a central opening sized such that the seal  50  fits snugly around the insert  40 . As seen in the drawings, when the connector assembly  10  is secured to the chamber  20 , the insert  40  is positioned such that the seal  50  is disposed within the opening  24  in the fluid chamber  20  and such that a portion of the seal  50  extends into the interior  23  of the fluid chamber  20 . When axially compressed as described below, the seal  50  radially expands to form a fluid-tight seal with the wall  26  of the opening  24 , as well as with the insert flange  44  and the seal bore against the insert body  45 . A portion of the seal  50  contacts the wall  26  of the opening. The portion of the seal  50  extending into the fluid chamber  20  expands beyond the wall  26 . The diameter of the portion of the compressed seal  50  extending into the fluid chamber  20  is greater than the diameter of the opening  24 . The profile of the opening  24  and seal  50  are shown as circular in shape, although other geometries are possible. 
     The compression mechanism for compressing the seal  50  comprises first and second compression members disposed on opposite ends of seal  50  and an actuator  80  to squeeze the seal  50  between the compression members. At least one of these compression members is movable for engaging and compressing the seal  50 . In the embodiment illustrated in  FIGS. 3-5 , the flange  44  on the insert  40  functions as the first compression member. A shoulder  34  within the opening  32  of the support member  31  functions as the second compression member. The actuator  80  comprises a threaded nut  80  that engages with the external threaded portion  46  of the insert  40 . A bushing  70  may be inserted between the actuator  80  and the support member  31  to provide electrical and/or thermal isolation for the insert  40  when made from non-conductive material. The actuator  80  is rotated in a direction such that the bushing  70  is driven into contact with the support member  31 . Further rotation of actuator  80  retracts insert  40  and compresses seal  50  between the flange  44  and the shoulder  34  in the support member  31 . The threaded portion  46  ends at a point along insert  40  in order to pre-compress the seal  50  by a pre-determined amount. 
     The geometry of the flange  44  produces compressive forces that are generally perpendicular to the end surface of the seal  50 . The elastomeric properties of the seal  50  cause it to expand radially when compressed axially. The radial expansion of the seal  50  occurs in a manner substantially perpendicular to the wall  26  of the opening  24 , thereby creating a uniform seal between the insert  40  and the wall  26  of the opening  24 . The compression of the seal  50  by the insert  40  also forms a fluid-tight and hygienic seal between the flange  44  and the end surface of the seal  50 . 
     Because the fluid-tight and hygienic seal is formed between the seal  50  and the wall  26  of the opening  24 , the effectiveness of the seal is independent of the surface curvature of the chamber  20 . This permits the device to be inserted into small diameter chambers whose radius is smaller than the diameter of the opening  24 . 
     The support member  31  is designed such that, once attached, the second compression member is immovably fixed to the fluid chamber  20 . This ensures that the compression forces on seal  50  are maintained under varying pressure conditions within the chamber  20 . At the same time, since opening  32  in support member  31  is smaller than the diameter of the flange  44  on insert  40 , insert  40  is prevented from being ejected from the chamber  20  as a result of excess pressure within the chamber  20 . 
     When installed, the connector assembly  10  provides a hygienic connection into the fluid chamber  20  without voids, pockets or crevices that enables the connection assembly  10  and fluid chamber  20  to be collectively installed at any angular orientation without any risk of gas entrapment during filling and product hold-up after drainage. 
       FIGS. 6-7  illustrate a second embodiment that is similar in most respects to the first embodiment. For clarity, the reference numbers used to denote components of the second embodiment are the same as the first embodiment where the components are similar. Detailed descriptions of components previously described are omitted. For brevity, the second embodiment is described below by highlighting the differences from the first embodiment. 
     An object of the second embodiment is to allow the insert  40  to be installed and removed without dismantling the support member  31  from the chamber. The insert  40  in this embodiment comprises a sleeve with an axial opening  43  providing access to the interior of the fluid chamber  20 . The throughway opening  32  in the support member  31  is enlarged enough to allow passage of the insert  40 . The support member  31  in this embodiment comprises a mounting block that is integrally formed with the fluid chamber  20 , or is permanently affixed to the fluid chamber  20 , such as by welding. Those skilled in the art will appreciate that a removable support member  31 , as shown in  FIGS. 3 and 4 , could also be used. 
     In the second embodiment, the bushing  70  is designed to engage the seal  50 , and function as the second compression member. Bushing  70  includes threads which engage mating threads in the support member  31 . The bushing  70  is tightened to prevent the bushing  70  from moving axially relative to the support member  31 . Seal  50  is thus positioned directly between flange  44  and bushing  70 . The bushing  70  can also provide electrical and/or thermal isolation for the insert  40  when made from a non-conductive material. 
     The second embodiment functions in substantially the same manner as the first embodiment. The actuator  80  comprises a nut that is tightened to compress the seal  50  as shown in  FIG. 5 . When the seal  50  is axially compressed, it expands radially into contact with the inside wall  26  of the opening  24  into the fluid chamber  20 , and compresses the end of the seal  50  against the insert flange  44  and the seal bore against the insert body  45 . The threaded portion  46  limits the travel of the actuator in order to pre-compress the seal  50  by a predetermined amount. 
     When installed, the connector assembly  10  provides a hygienic connection into the fluid chamber  20  without voids, pockets or crevices. This enables the connection assembly  10  and the fluid chamber  20  to be collectively installed at any angular orientation without any risk of gas entrapment during filling and product hold-up after drainage. To remove insert  40 , actuator  80  is rotated to release the pressure on the seal  50 . Due to the natural resiliency of the material, the seal  50  will contract so that the insert  40  and seal  50  can be withdrawn easily from the fluid chamber  20  by removing the bushing  70 . The insert  40  can be repeatedly inserted, compressed and subsequently withdrawn multiple times without detriment to the seal performance. 
     Various materials may be used to manufacture the connector assembly  10  of the present invention. In some applications it may be desirable to isolate components of the connector assembly  10  from thermal and/or electrical conditions in the wall  22 . For example, seal  50  may include material having a low thermal conductivity to minimize the thermal energy transmitted through the seal. Similarly, selecting a material for seal  50  having high electrical resistance will inhibit the transmission of electrical energy. In a similar fashion, insert  40 , bushing  70 , actuator  80  and/or support member  31  may be partially or completely formed from thermal or electrical isolating material to prevent transfer of thermal or electrical energy from the wall  22  through the support member  31  to the insert  40 , or from the portion of the insert that is outside the fluid chamber  20  to the sensing end of the insert  40  that extends beyond the sensor flange  44  into the fluid chamber  20 . 
     In use, the connector assembly  10  is inserted into the opening  24  in the fluid chamber  20  and the actuator  80  is tightened by rotating the actuator  80 . Rotation of the actuator  80  causes the insert  40  to move axially such that the seal  50  is compressed between the first and second compression members. The seal  50  radially expands when it is axially compressed. This radial expansion of the seal  50  creates a generally fluid-tight seal between the wall  26  of opening  24  and outer surface  45  of the insert  40 . It also compresses the end of the seal  50  against the insert flange  44  and the seal bore against the insert body  45 . 
     As illustrated the fluid-tight seal provided effectively isolates fluid contained in the fluid chamber  20  from contact with exterior surfaces of the chamber. Moreover, no voids or crevices are created within the chamber that would give rise to stagnant fluid zones. The absence of voids and crevices makes it possible to undertake clean-in-place (CIP) practices to ensure hygienic operating conditions. In addition, if the pressure within the chamber increases, the increased pressure will further compress the seal  50 , which enhances the fluid-tight seal. 
       FIG. 8  is a sectional view illustrating another embodiment of the connector assembly  10 . In this embodiment, the connector assembly  10  also includes a thermally conducting collar  90  and a thermally isolating barrier  92 . The collar  90  transmits thermal energy between the fluid chamber  20  and the adjacent section of the insert  40 , thereby reducing the temperature gradient between the insert flange  44  lying within the fluid chamber  20  and the part of insert  40  in contact with collar  90 . The collar  90  may be disposed, for example, around the body of insert  40  between the end of the seal  50  and the base of the bushing  70 . The isolating barrier  92  may be constructed from a low thermally conductive material and may be integrated into the insert  40 . The thermally conducting collar  90  and the isolating barrier  92  can function independently or collectively to restrict the flow of thermal energy between the insert flange  44  lying within the fluid chamber  20 , and the remainder of the body of insert  40 . 
       FIG. 9  is a sectional view illustrating another embodiment of the connector assembly  10 . In this embodiment, the connector assembly also includes a seal thermal expansion relief member  94 . The relief member  94  may be constructed from an elastic material and may be disposed between the actuator  80  and the bushing  70 . The relief member  94  enables the seal  50  to axially expand and contract as a result of temperature variations within the fluid chamber  20  without adversely affecting the integrity of the sealing mechanism. 
     The connector assembly  10  of the present invention provides a device that permits access to the interior of a fluid chamber  20 . The fluid chamber  20  may assume various forms, such as a pipe or vessel, and typically contains fluid being transported and/or undergoing some type of process. The fluid chamber  20  may be a closed system that totally isolates the fluid from the external environment, or the fluid chamber  20  could be an open vat or channel for directing the flow of a fluid. Installation into an “open” fluid chamber operating at near atmospheric pressure could also be achieved without the necessity for the support member  31  to be secured to the wall of the chamber. 
     In order to measure certain conditions within the fluid chamber  20 , the connector assembly  10  permits access through the wall of a fluid chamber  20 . For example, the insert  40  may comprise a measurement probe for monitoring conditions inside the fluid chamber, or a thermowell such that a sensor can be inserted into and removed from the chamber  20  while maintaining the processing conditions and hygienic integrity. In some cases, control and assessment of the processes being carried out within the fluid chamber  20  may require bleeding or siphoning material from the fluid chamber  20 , or injecting material into the fluid chamber  20 . In such cases, the insert  40  may comprise a sleeve with a fluid passage to allow material to be introduced into or removed from the fluid chamber  20 . The present invention can also be used to make a fluid connection between the fluid chamber  20  and a fluid conduit. 
     The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. For example, although the connector assembly  10  may be used to connect an insert into a fluid chamber  20  without compromising hygienic integrity, it may also be used in less critical, non-hygienic applications. In such cases, the present invention would form a radial, fluid-tight seal against the wall of the opening in the fluid chamber by axially compressing a seal within the fluid chamber interior. Accordingly, the present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.