Abstract:
A new segmented choke is provided. Designed to reduce thermal stresses created when the fluid temperature fluctuate, this invention is constructed of segmented ceramic members fit within a relatively thin-walled retainer, shrunk fit thereto, thereby allowing the retainer to be more compliant. Shorter, multiple segments used in this invention are also easier to manufacture, can be produced with tighter tolerances, provide easier access thereby reducing maintenance costs and allow for the inclusion of sensors in the individual ceramic segments. This invention also provides improvements in size, manufacturing cost, ease of use and operating efficiency over prior choke devices.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to devices for choking a fluid flow path. More specifically, this invention relates to ceramic choke designs that have multiple sections of ceramic with retaining mounts shrunk fit around them, which in turn are mounted into a housing.  
           [0003]    2. Description of Related Art  
           [0004]    A variety of choke devices have been used for some time in the control of fluid through a conduit. Typically, these prior devices consist of one large piece of ceramic, with a one piece housing that is shrunk to fit over the ceramic, thereby making a tight fit when cooled. The housing is typically composed of titanium. For general background material, the reader is directed to U.S. Pat. Nos. 4,774,914 and 5,246,074 each of which is hereby incorporated by references in its entirety for the material contained therein.  
         SUMMARY OF THE INVENTION  
         [0005]    It is desirable to provide a choke device for controlling the flow of fluid through a conduit. In particular, it is desirable to provide a choke design, which reduces thermal stresses. Moreover, it is desirable to provide a choke design that facilitates the use of sensors within the choke. It is also desirable to provide a choke design with improved manufacturability and maintenance.  
           [0006]    Therefore, it is the general object of this invention to provide a choke device that has a retainer and sleeve walls with smaller overall wall thickness, which reduces the thermal stresses created when the fluid temperature fluctuates.  
           [0007]    It is a further object of this invention to provide a choke device that uses a plurality of ceramic segments, each of which fits into a relatively thin walled retainer, thereby allowing the retainer to be more complaint.  
           [0008]    It is another object of this invention to provide a choke device that provides reduced stress variations associated with variances in choke clearances.  
           [0009]    Another object of this invention is to provide a choke device that uses a ductile retainer thereby providing the ability to withstand additional fluctuations in stress than is possible with brittle ceramic alone.  
           [0010]    A further object of this invention is to provide a choke device, which uses shorter segments that are easier to construct, and which can be produced with tighter tolerances.  
           [0011]    A still further object of this invention is to provide a choke device, which can more easily be assembled by shrink fitting with the retainers.  
           [0012]    Another object of this invention is to provide a choke device which has segmented members that can be replaced individually, allowing for reductions in maintenance costs.  
           [0013]    It is another object of this invention to provide a choke device that more accurately controls compressive stresses during construction of the choke.  
           [0014]    It is a further object of this invention to provide a choke device that accommodates the inclusion of sensors into individual segments of the choke, allowing for indicators of choke segment integrity without disassembly of the choke and taking it out of service.  
           [0015]    These and other objects of this invention are achieved by the device described herein and are readily apparent to those of ordinary skill in the art upon review of this disclosure and/or ordinary experimentation with the device described herein. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a section view of the preferred segmented choke of this invention.  
         [0017]    [0017]FIGS. 2 a  and  2   b  are detailed section and end views of the sleeve of the first segment of the preferred segmented choke of this invention.  
         [0018]    [0018]FIGS. 3 a  and  3   b  are detailed section and end views of the sleeve of the second segment of the preferred segmented choke of this invention.  
         [0019]    [0019]FIGS. 4 a  and  4   b  are detailed section and end views of the sleeve of the third segment of the preferred segmented choke of this invention.  
         [0020]    [0020]FIGS. 5 a  and  5   b  are detailed section and end views of the upper inner ring of the preferred choke of this invention.  
         [0021]    [0021]FIGS. 6 a  and  6   b  are detailed section and end views of the lower inner ring of the preferred choke of this invention.  
         [0022]    [0022]FIGS. 7 a  and  7   b  are detailed section and end views of the first housing section of the preferred choke of this invention.  
         [0023]    [0023]FIGS. 8 a  and  8   b  are detailed section and end views of the second housing section of the preferred choke of this invention.  
         [0024]    [0024]FIGS. 9 a  and  9   b  are detailed section and end views of upper flange ring of the preferred choke of this invention.  
         [0025]    [0025]FIGS. 10 a  and  10   b  are detailed section and end views of the lower flange ring of the preferred choke of this invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    Referring now to the figures and particularly to FIG. 1, which is a section view of the preferred embodiment  100  of the segmented choke of this invention. In this embodiment three ceramic sections  101 ,  102 ,  103  are provided within a retainer fixtures  104 ,  105 ,  106 . The first ceramic section  101 , containing a sleeve  200  and a first ceramic region  113 , is held in place by the first retainer  106 . The second ceramic section  102 , containing a sleeve  300  and a second ceramic region  114 , is held in place by the second retainer  105 . The third ceramic section  103 , containing a sleeve  400  and a third ceramic region  115 , is held in place by the third retainer  104 . Each ceramic section  101 ,  102 ,  103  is shrunk fit into its retainer fixture  104 ,  105 ,  106 . The retainer fixtures  104 ,  105 ,  106  are then mechanically mounted into a housing, which is composed of two parts an upper housing  111  and a lower housing  112 . The first  106  and second  105  retainer fixtures are held together by an upper mount  107 . The second  105  and third  104  retainer fixtures are held together by a lower mount  108 . The upper housing  111  and the lower housing  112  are held together by two flange rings  109 ,  110 .  
         [0027]    [0027]FIG. 2 a , a section view of the sleeve  200  of the first ceramic section  101  and associated retainer  106 , provides additional dimensional detail of the preferred embodiment of this invention. This sleeve  200  has a first end  202  and a second end  203 . In the preferred embodiment, the first end  202  has an inner diameter of 6.50 inches and an outer diameter of 6.750 inches. The second end  203  has an outer diameter of 7.250 inches. The length  205  of the side  204  of this preferred embodiment is 7.330 inches. FIG. 2 b  shows the end view of the sleeve  200  of the first ceramic section  101  and retainer  106 . The ceramic section  101  is adapted to permit the inclusion of a sensor for making a variety of flow rate, temperature, pressure and content measurements.  
         [0028]    [0028]FIG. 3 a , a section view of the sleeve  300  of the second ceramic section  102  and associated retainer  105 , provides additional dimensional detail of the preferred embodiment of this invention. This sleeve  300  has a first end  302  and a second end  303 . In the preferred embodiment, the first end  302  has an inner diameter of 6.50 inches and an outer diameter of 6.750 inches. The second end  303  has an outer diameter of 7.250 inches. The length  305  of the side  304  of this preferred embodiment is 7.330 inches. FIG. 3 b  shows the end view of the sleeve  300  of the second ceramic section  102  and retainer  105 . This ceramic section  102  is also adapted to permit the inclusion of a sensor for making a variety of flow rate, temperature, pressure and content measurements.  
         [0029]    [0029]FIG. 4 a , a section view of the sleeve  400  of the third ceramic section  103  and associated retainer  104 , provides additional dimensional detail of the preferred embodiment of this invention. This sleeve  400  has a first end  402  and a second end  403 . In the preferred embodiment, the first end  402  has an inner diameter of 8.80 inches and an outer diameter of 9.50 inches. The second end  403  has an outer diameter of 9.180 inches. FIG. 4 b  shows the end view of the sleeve  400  of the third ceramic section  103  and retainer  104 . This ceramic section  103  is also adapted to permit the inclusion of a sensor for making a variety of flow rate, temperature, pressure and content measurements.  
         [0030]    [0030]FIG. 5 a , a section view of the upper inner ring  107 , provides additional dimensional detail of the preferred embodiment of this invention. The preferred embodiment of this upper inner ring  107  has an outer diameter of 9.910 inches and an inner opening  502  diameter of 6.760 inches. The preferred ring  501  is composed of titanium. FIG. 5 b  shows the end view of the upper inner ring  107 .  
         [0031]    [0031]FIG. 6 a , a section view of the lower inner ring  108 , provides additional dimensional detail of the preferred embodiment of this invention. The preferred embodiment of this lower inner ring  108  has an outer diameter of 9.740 inches and an inner opening  602  of 6.760 inches. The preferred ring  601  is composed of titanium. FIG. 6 b  shows the end view of the lower inner ring  108 .  
         [0032]    [0032]FIG. 7 a , a section view of the first housing section  111 , provides additional dimensional detail of the preferred embodiment of this invention. This housing  111  has a first end  703  and a second end  704 . The preferred dimensions of this housing section  111  are shown in inches in this FIG. 7 a . A first gasket surface  701  and a second gasket surface  702  are provided. In its preferred embodiment the first housing section  111  is composed of titanium. FIG. 7 b  shows the end view of the first housing section  111 .  
         [0033]    [0033]FIG. 8 a , a section view of the second housing section  112 , provides additional dimensional detail of the preferred embodiment of this invention. This housing  112  has a first end  801  and a second end  802 . The preferred dimensions of this housing section  112  are shown in inches in this FIG. 8 a . In its preferred embodiment the first housing section  112  is composed of titanium. FIG. 8 b  shows the end view of the second housing section  112  and retainer  106 .  
         [0034]    [0034]FIG. 9 a , a section view of the upper flange ring  109 , provides additional dimensional detail of the preferred embodiment of this invention. This flange ring  109  has a first end  903  and a second end  904 . A ring  902  is provided with a plurality of openings  905   a - j , each of which is adapted to receive and accommodate bolt and nut fasteners. Alternative fasteners, such as rivets, screws and the like can be substituted without departing from the concept of this invention. The preferred material for the ring  109  is titanium. The preferred dimensions of this flange ring  109  are shown in inches in this FIG. 9 a . FIG. 9 b  shows the end view of the upper flange ring  109 .  
         [0035]    [0035]FIG. 10 a , a section view of the lower flange ring  110 , provides additional dimensional detail of the preferred embodiment of this invention. This flange ring  110  has a first end  1003  and a second end  1004 . The ring  1002  is provided with a plurality of openings  1005   a - j , each of which is adapted to receive and accommodate bolt and nut fasteners. Alternative fasteners, such as rivets, screws and the like can be substituted without departing from the concept of this invention. The preferred material for the ring  110  is titanium. The preferred dimensions of this flange ring  110  are shown in inches in this FIG. 10 a . FIG. 10 b  shows the end view of the lower flange ring  110 .  
         [0036]    It is to be understood that the above-described embodiment of the invention is merely illustrative of numerous and varied other embodiments, which may constitute applications of the principles of the invention. Such other embodiments may be readily devised by those skilled in the art without departing from the spirit or scope of this invention and it is our intent that they are deemed as within the scope of our invention.