Abstract:
The invention relates to a drainage assembly of the type having an upward opening for the draining opening of a new or existing chemical reactor, particularly of the enameled type, characterized in that the outer outlet opening ( 6 ) for the drainage is provided in the lower portion thereof with a removable seat part in the form of a planar annual seal ( 11 ) having an upper portion with at least one recess ( 21 ) used as a seat for the under-face of the head ( 10 ) of the valve and as a full flow ramp. The invention is particularly intended for the manufacturers and users of chemical reactors, in particular of the enameled type.

Description:
[0001]    This application is a National Stage completion of PCT/FR2008/000225 filed Feb. 21, 2008, which claims priority from French patent application Ser. No. 07/01223 filed Feb. 21, 2007. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a drainage assembly having an upward opening sluice, more specifically, for enameled chemical reactors. 
         [0003]    In particular it comprises two planar surfaces which enclose and grip a flat seating of the valve head, providing sealing when closed and allowing complete discharge when open. The invention can be attached to the outlet of any reactor, either new or existing. 
       BACKGROUND OF THE INVENTION 
       [0004]    In the type of reactor this invention concerns, the head of the movable valve element on the drainage assemblies is housed in the evacuation space of the drainage orifice so as to free the outlet area when the movable element of the drainage assembly is in the upper open position. 
         [0005]    Conventionally, when in the closed position, this head rests on a seating made of chemically resistant synthetic material, for example, PTFE. 
         [0006]    Therefore, according to the prior art technique, this seating is formed in the upper portion of a sealing piece with a tubular body and a circular base forming a peripheral blocking and maintaining shoulder. The upper portion of this sealing piece serves as a seating for the movable element of the seal assembly and its lower shoulder portion acts as a sealing surface against the projecting portion of the drainage orifice pipe. The tubular portion is introduced into the evacuation pipe of the drainage orifice. It is adapted to the diameter of this evacuation pipe and its shoulder blocks and maintains it in place penetrating the pipe. 
         [0007]    On its other surface, this tubular seating and sealing piece is applied tightly against the upper flanged rim of the drainage assembly body. 
         [0008]    This prior art technique has several important disadvantages. 
         [0009]    The first disadvantage relates to retention of product which happens in the interstice located between the seating and the drainage pipe. This causes cross-contamination of products during two successive uses of the reactor. Actually, the adjustment between the seating and sealing element and the evacuation pipe is not perfect. Some product originating from the reaction in progress penetrates the small space that exists between this element and the interior lateral surface of the evacuation pipe of the outlet orifice. 
         [0010]    This small space is quasi-inaccessible, making it difficult or even impossible for cleaning and disinfection products to penetrate it, such that the remaining liquid constitutes a source of cross-contamination between the two products of two successive reactions; this is hardly desirable and even contraindicated, especially in the food and pharmaceutical industries. 
         [0011]    Moreover, the product trapped in this interstice may crystallize, causing serious difficulties when detaching the valve and consequently a high risk that the enamel coating will deteriorate. 
       SUMMARY OF THE INVENTION 
       [0012]    The goal of the present invention is to remedy these principal disadvantages. 
         [0013]    The first benefit of this invention is the complete absence of cross-contamination because of its smooth surfaces that lack interstices, and the absence of any contamination because of elimination of areas with limited access that are hidden when cleaning and disinfecting. 
         [0014]    Additionally, the drainage assembly of the invention can be attached to any type of currently used reactor, either new or existing, with an outlet that conforms to the general rules of standardization, independent of its particular shape, whether it be a tubular drainage outlet or one known as a thick flange outlet. 
         [0015]    It is only necessary to change the seating and the movable valve element in the lower mechanical assembly to obtain a drainage assembly with a full flow valve seating, thereby eliminating the retention area with its related problems and consequences, particularly those arising from product contamination and/or crystallization causing problems with disassembly and general risk of enamel deterioration. 
         [0016]    Obviously, the invention also makes it possible to attach this type of drainage assembly to new reactors. It is only necessary to provide a seal seating that is adapted to the shape of the corresponding valve head. 
         [0017]    In summary, the invention offers the cumulative advantages of full flow, absence of any dead zone, ease in cleaning and disassembly, and the ability to be used on all types of reactors, especially enameled reactors. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Other characteristics and advantages of the invention will become apparent from reading the following detailed description, taken in conjunction with the attached drawings, in which: 
           [0019]      FIG. 1  is a general view in longitudinal cross-section with the upper portion in two half-sections relating to two variations, the drawing showing in a single view two examples of drainage assemblies for a chemical reactor according to the present invention; 
           [0020]      FIGS. 2 and 3  are vertical cross-sections at the level of the movable element and the seating of the drainage assembly according to the invention in the case of a chemical reactor with conventional pipe; 
           [0021]      FIGS. 4 and 5  are vertical cross-sections at the level of the movable element and the drainage assembly seating according to the invention in the case of a chemical reactor with a thick flange; 
           [0022]      FIGS. 6 through 13  are schematic transverse cross-sections of variations of seating and sealing pieces with which the drainage assembly of the invention may be equipped. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    A chemical reactor, and more specifically an enamel type chemical reactor, comprises a bottom  1  with a drainage or emptying orifice  2  extending downward into a cylindrical drainage channel  3  ( FIG. 1 ) which is called, when it is long, a drainage pipe  4  ( FIGS. 2 and 3 ) and when it is shorter, a thick flange channel defined by the internal wall of a thick flange  5  ( FIGS. 4 and 5 ) and opening to the exterior through an exterior outlet orifice  6  defined by an annular return forming a frontal surface  7  that may be the surface of the drainage pipe or that of the thick flange  5 . 
         [0024]    For the sake of convenience, hereinafter the end portion of this pipe  4  or of this thick flange  5  will be called the outlet orifice structure. 
         [0025]    The exterior outlet orifice  6  is blocked by a movable valve  8  formed by a rod  9  and a head  10 . 
         [0026]    A removable seating and full flow piece  11  tightly contacts frontal surface  7  defining exterior outlet orifice  6  by pressing against it in either the pipe  4  variation or the thick flange  5  variation by being mechanically attached and then clamped, as will be seen below. 
         [0027]    Removable piece  11  is, in the embodiment shown, a flat annular seal that is preferably thick, used as a seal and seating for valve head  10  and for completely evacuating the product contained. It is made of chemically inert and resistant material, for example the material known by the acronym “PTFE.” 
         [0028]    A counter attaching piece  12 , for example, in the general form of an attachment flange, holds seating piece  11  sandwiched against frontal surface  7  on the annular outlet return to grip it using a mechanical attachment such as pins which immobilize and compress it in order to procure a seal against the exterior. 
         [0029]    Attaching flange  12  also allows the attachment of the mechanical body  13  of the drainage assembly. It forms a part of this mechanical body  13  in which the drainage assembly is housed. It encloses an outlet chamber  14  with a principal lateral outlet  15  and possibly lateral technical access  16 , as well as, at the bottom, a sealed guide  17  for valve rod  9  covered with caulking  18 . 
         [0030]    The valve extends downward into an actuating mechanism  20  which may have different mechanical forms.  FIG. 1  shows a manual mechanism actuating the valve between an upper position in which it is open and a lower position in which it is closed and tightly sealed in its seating. 
         [0031]    The invention is not limited to this type of mechanical assembly or actuating mechanism. In the case of existing chemical reactors, it allows a new drainage assembly to be added using a simple replacement procedure. 
         [0032]    Seating piece  11  has on the upper portion a hollow or recessed area that converges centrally and downward and serves as a sealing contact with valve head  10  and for full flow. 
         [0033]    This recessed area may have a simple or double ramp such as a conical ramp, for example with one narrow interior edge ramp used for sealing and one wider, full flow ramp concentric to and encircling the first ramp. These two ramps have different slopes, a medium slope for the interior edge ramp and a less steep slope for the other ramp. 
         [0034]    This example concerns a conical recess  21 , one portion of which cooperates with a corresponding conical contact surface  22  located on the base of valve head  10  and which rests on and seals the corresponding portion of conical receiving surface  21  of seating element  11  in the closed position. 
         [0035]    More specifically, conical recessed area  21  is a recessed area with dual concentric conical ramps formed from the center toward the exterior first by a conical shoulder  23  cooperating with corresponding conical contact surface  22  on valve head  10  to form a tight seal. Next, there is a conical ramp  24  sloped less steeply than shoulder  23 , allowing full product flow. This ramp begins at the periphery of shoulder  23  and extends, for example, to the area of, or up to, the interior peripheral edge of outlet orifice  6 . 
         [0036]    Obviously piece  11 , shaped in conical recessed area  21 , defines a circular central opening  25  allowing the evacuating product to pass through it. 
         [0037]    It should be noted here that conical recessed area  21  may very well consist of a simple ramp and that it is concentric with opening  25 . 
         [0038]    Piece  11  is essentially flat and thick and it does not have any central upwardly extending portion, as prior art devices do. 
         [0039]    It is possible to provide a protective rim, as will be seen in the variations that follow. 
         [0040]    To illustrate the numerous possible applications of the invention on different types of reactor outlets,  FIGS. 1 through 5  show the two principal types of outlet configurations for existing reactors, i.e., a reactor outlet with conventional pipe and reactor outlet with a thick flange  5 . 
         [0041]    In one case the channel  4  forming the drainage pipe is rather long, whereas in the other case it is considerably shorter because it concerns the thick flange variation  5 . 
         [0042]    According to one variation, head  10  of valve  8  is made taller so as to occupy as much space as possible inside the reactor drainage pipe. For this reason its upper extremity surface reaches in the closed position the level of reactor bottom  1 . 
         [0043]    A sensor, for example a temperature sensor  26 , is placed in valve head  10 , preferably near its upper extremity. It shows the temperature of the product contained at the level of reactor bottom  1 , and not just the temperature of the product in the inactive area just below and at the level of the drainage orifice. 
         [0044]      FIGS. 6 through 13  show different variations of seating piece  11 . 
         [0045]    All variations have the circular central opening such as opening  25  for the passage of product and complete product evacuation during drainage. 
         [0046]    There is a flat annular piece  11  that is semi-rigid in consistency and chemically resistant, having a reinforced periphery on each of its principal surfaces, for example, in the form of higher density upper and lower annular areas or areas formed of a less flexible material that is added on or co-extruded. The thickness of these areas varies depending upon the embodiment. They form integral seals and constitute contact surfaces with front surface  7  of the outlet flange of the reactor or of the peripheral return bordering the exterior outlet orifice  6  of the reactor and with counter attaching piece  12 . The mechanical strength conferred by the tight attachment of these two flanges squeezing the flat seal formed by the annular piece  11  ensures that this piece is immobilized and watertight. 
         [0047]    These contact surfaces may be made in the form of an exterior annular framework  27 , such as a metal framework. There may be two flat seals  28  and  29 , either integral or removable, situated in the periphery of the lower and upper surfaces of the seating piece. 
         [0048]    In each of the variations, formed in the upper surface there is the conical recessed area  21  with its conical shoulder  23  in the lower central portion serving as a seating to seal the valve. This central portion is surrounded by a conical ramp  24  with a smaller slope to allow complete flow. 
         [0049]    The interior configuration of this seating piece  11  varies. 
         [0050]    It may consist of a metal core  30  in the form of an annular disc of various shapes, or an annular piece  32  as shown, or a full space such as space  33  without any insert for the variations in  FIGS. 8 and 10 . 
         [0051]    Other differences exist between the variations. 
         [0052]    The lower surface may comprise a projecting interior rim  34  ( FIG. 7 ) or  35  ( FIG. 8 ) extending from a flange. 
         [0053]    Other variations ( FIGS. 11 and 12 ) have a non-projecting lower rim  36  but one which is defined by a groove such as groove  37 . 
         [0054]    The final variation shown in  FIG. 13  specifically concerns seatings with an expanded core. It comprises a fireproof peripheral metal rim or ring  38  extending upward into an upper shoulder-like rim  39  forming an enlargement. This fireproof rim  38  is designed to increase the time the seal on the drainage element remains effective, by preventing it from direct exposure to flame in the event of a fire. This metal rim is made in the shape of a peripheral metal band, for example, with an upper edge  39  and may exist on all the other variations. 
         [0055]    This flat seal may have an annular body  40  with a core  41 .