Patent Publication Number: US-2009236555-A1

Title: Gate valve

Description:
BACKGROUND OF INVENTION 
     The invention relates to a gate valve according to the preamble of claim  1 . 
     Gate valves, which especially comprise a laminar gate element, have many times problems with sealing. The pressure of medium possibly prevailing in the flow path causes in the closed position of the valve bending of the gate element and weakening of sealing, which leads for the parts of certain mediums guided in the flow path, inter alia, to the dirtying of the guide and/or sealing surfaces of the valve body. This possibly impedes the movement of the gate element between the open position and the closed position. Furthermore, dirt can in some embodiments cause problems with hygiene. One has tried to solve these problems with different sea) and/or valve structures. However, these have usually been complex and thus led to arrangements expensive of their costs. Specification EP0260962, for instance, describes a gate valve provided with a turnable gate element which includes above-mentioned disadvantages. Also several gate valve arrangements are known in which the valve body is cast and the gate mechanism and the gate element are complex. They are awkward and complicated of their processibility, whereby manufacturing costs are high. 
     An object of this invention is to achieve a totally new arrangement for a gate valve with which the disadvantages of known solutions are avoided. Another object of the invention is to achieve a valve structure the processibility of which is good and which is also easy from the viewpoint of assembly. A further object of the invention is to achieve an adequately good arrangement for the part of sealing. 
     BRIEF DESCRIPTION OF INVENTION 
     It is mainly characteristic of a gate valve according to the invention that the gate element comprises a gate part and an actuating body along with which the gate part is arranged to move in a space between the walls of the body. 
     Furthermore, the gate valve according to the invention is characterised by what is stated in claims  2 - 25 . 
     The arrangement according to the invention has numerous significant advantages. The gate valve according to the invention is excellent of its processibility. By arranging for the gate part a separate part moving in relation to the actuating body which part seals against the edges of the flow path, an extremely advantageous and reliable arrangement for a valve is achieved. By using a valve body and a gate element of laminar structure, it has been possible to achieve an easily modifiable structure for different use requirements. By arranging cleaning means into connection with the valve, it is possible to prevent the accumulation of material being conveyed in the flow path into the space between the body walls and, simultaneously, it is possible to prevent malfunctions caused by dirtying. By arranging the channel space required for cleaning on the edge of the valve body, an extremely advantageous structure operationally and in respect of its manufacturing technique is achieved. By using a profile as the edge part which comprises support surfaces for the walls of the gate valve body, an advantageous construction also from the viewpoint of the assembly of the valve is achieved. By arranging for the gate parts two parts moving in relation to each other which parts seal against the edges of the flow path, an extremely advantageous and reliable arrangement for a valve is achieved. By arranging an elastic element between the gate parts, an advantageous and easy arrangement from the viewpoint of the assembly of the valve is achieved. By using a spring element, such as a diaphragm spring element, as the elastic element, elastic characteristics can be effectively affected. The elastic element can be replaced according to the requirements of the target of application. By arranging an opening for pressure medium in the second gate part, it is possible to further affect the elastic element by means of the medium. Then, the sealing of the gate element can be further improved. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       Next, the invention will be described in detail by means of an example with reference to the accompanying drawing in which 
         FIG. 1  shows a valve according to the invention in a flow path open position, 
         FIG. 2  shows a valve according to the invention in a flow path closed position, 
         FIG. 3  shows a valve according to the invention as a cross-section along line III-III of  FIG. 4 , 
         FIG. 3A  shows a detail A of  FIG. 3  enlarged, 
         FIG. 4  shows a valve according to the invention, 
         FIG. 5  shows a valve according to the invention partially cut, 
         FIG. 6  shows a detail of a second embodiment of the valve according to the invention as cut in a gate element closed position, 
         FIG. 7  shows a further embodiment of the gate valve according to the invention partially cut, 
         FIG. 8  shows the valve of  FIG. 7  from the direction of the actuator, 
         FIG. 9   a  shows the edge part of an embodiment of the valve according to the invention as bent from the side, 
         FIG. 9   b  shows the edge part of an embodiment of the valve according to the invention as bent from the end, 
         FIG. 9   c  shows the edge part of an embodiment of the valve according to the invention before bending from the side, 
         FIG. 10  shows a cross-section of the edge part of an embodiment of the valve according to the invention, 
         FIG. 11  shows a second embodiment of the valve according to the invention, 
         FIG. 12  shows a second embodiment of the valve according to the invention in a flow path closed position cut along line XII-XII of  FIG. 14 , in a different scale, 
         FIG. 13  shows a detail A of  FIG. 12  enlarged, 
         FIG. 14  shows a second embodiment of the valve according to the invention, 
         FIG. 15  shows a second embodiment of the valve according to the invention from inside the valve body in a gate element open position, 
         FIG. 16  shows a second embodiment of the valve according to the invention from inside the valve body in a situation between the gate element open position and closed position, and 
         FIG. 17  is a cross-section of the edge part of a body according to an embodiment of the gate valve in accordance with the second embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
       FIGS. 1 and 2  show a first embodiment of a valve according to the invention as a perspective figure. A gate element of the valve is shown with dashed lines in the figure in an open position and in  FIG. 2  in a closed position. 
     The figures show an embodiment of the valve according to the invention, especially a gate valve which comprises a body  1 , a gate element  2  which is movable in the body in the cross direction in relation to a flow path  3  between at least two positions, a first position in which the flow path  3  is open and a second position in which the flow path is closed. Typically, the valve also comprises means  4  for moving the gate element  2  between at least two said positions. The gate element  2  comprises two gate parts  5 ,  6 , between which gate parts  5 ,  6 , a force effect can be provided which prevails in gate parts  5 ,  6  in the opposite directions substantially in the direction of the flow path  3  pressing the gate parts  5 ,  6  towards the edges i.e. the edge area of the flow path at least in the position of the gate element in which the flow path is closed. In the figures, the flow path  3  passes via channel parts  15 ,  16  arranged in the valve body through the valve body  1 . In the embodiment of the figure, the gate element  2  is arranged to move by means of an actuator  4  between an upper position in which the flow path is open and a lower position in which the flow path is closed. The gate element  2  is arranged to move in a space  11  between body walls  9 ,  10 . The surfaces of the walls  9 ,  10  facing each other typically operate as the guide surfaces of the gate element. Onto the wall of the flow channel is formed a gap from which the gate element moves and closes the flow channel. The gate parts  5 ,  6  of the gate element  2  extend outside the edges of the flow opening of the flow channel  3 . Typically, in connection with a conventional circular flow opening of the cross-section of the flow path, the diameter of the gate part  5 ,  6  is thus larger than the diameter of the flow opening of the flow path  3  in the intersection of the gate element  2  and the flow path  3 . 
     Between the gate parts  5 ,  6 , there is at least one elastic element  7 . In the case of the figures, the elastic element  7  is an annular element. It can also be of different shape. Depending on the target of application, there can be several elements. 
     Alternatively, the valve can comprise means for providing a force effect between the gate parts  5 ,  6  by means of pressure medium. It is e.g. possible to consider that between the gate parts there is a chamber space  22  which is fillable with pressure medium.  FIG. 6  shows an example of such an embodiment which will be described below in detail. 
     Correspondingly, it can be considered that between the gate parts there is an elastic cushion which is filled with pressure medium at least when the gate element closes the flow path  3 . 
     The gate element  2  comprises an actuating body  8  along with which the gate parts  5 ,  6  are arranged movable. In the embodiment of  FIGS. 1-5 , the actuating body is a laminar part in which is formed a space  18  for the gate parts  5 ,  6 . In the embodiment of the figures, the space  18  is an opening formed in the actuating body in which the gate parts are arrangeable. Then, the edges of the opening  18  operate as the support surfaces of the gate parts  5 ,  6  when moving the gate element. 
     According to an embodiment, the gate part  5 ,  6  is formed at least partially of elastic material. Then, the gate parts  5 ,  6  are able to bend a little in the opposite directions i.e. typically to bulge from their middle part in the direction of the flow channel, when they are in the closed position of the flow path. In  FIG. 3A , the bending of the gate parts is clearly visible. 
     The gate part  5 ,  6  is according to an advantageous embodiment a laminar part. In the embodiments of  FIGS. 1-5 , the gate parts are circular plate parts. Naturally, any other shape is possible in accordance with the target of application. 
     In the embodiment of the figures, the valve body  1  comprises the first wall part  9  and the second wall part  10  and the space  11  remaining between them for the gate element  2 . The gate element is moved in the space  11  in the embodiment of the figure by means of the actuator  4  which is a cylinder-piston combination. The actuator is in the embodiment of the figures fastened to shoulders formed in the body by fastening means. A piston rod operates as a valve stem  21  which is joined with joining means  19 ,  20  to the gate element  2 . The gate element comprises the actuating body  8  in the figure. 
     The gate part  5 ,  6  is arranged in the space  18  formed in the actuating part  8  freely movable along the actuating part  8  between the guide surfaces of the body part. 
     According to an advantageous embodiment, the elastic element  7  is of rubber, plastic or equivalent elastic material. The gate part is typically of stiffer material than the elastic element. 
     According to a second embodiment, the elastic element  7  is a spring element, such as a diaphragm spring element. 
     In an embodiment according to the embodiment of  FIG. 6 , one of the gate parts comprises an opening  23  into a space  22  between the gate parts. Then, from the medium channel  3 , pressure prevailing on the side of pressure is able to pass into the space  22  between the gate parts. Between the gate parts, there is the elastic element  7 . The prevailing pressure aims at pressing on one hand the gate part and especially the elastic element  7  which is pressed more tightly against the walls  9 ,  10  of the gate parts  5 ,  6 . Based on the differences of pressure areas, a desired pressing force is provided in the elastic element  7 . Between the gate parts  5 ,  6 , there is an edge part  24  which is in the edge area of the gate parts or in its vicinity. A module comprising the edge parts and the elastic element of the gate parts is arranged in the opening  18  of the actuating body moving along the actuating body. 
     According to an embodiment, the actuating body  8  is a laminar part in which the opening  18  has been arranged in which opening the gate part  5 ,  6  and the elastic element  7  between them are arranged to fit. The opening  18  has been formed e.g. by die cutting or cutting, such as by laser cutting. Then, an arrangement fulfilling dimensional tolerances accurate enough is achieved. Correspondingly, the wall parts  9 ,  10  of the body can be of plate material and cut e.g. by laser cutting. 
     The surface on the side of the flow channel  3  of the first gate part  5  and the surface on the side of the flow channel  3  of the second gate part  6  extend in the closed position of the valve to a greater distance in relation to each other in the direction of the flow channel than in the open position of the valve. Then, the gate element of the valve as if bulges in the opposite direction in the flow opening sealing the opening more effectively. By using the force effect between the gate parts, leakings from the flow channel  3  in between the gate element  2  and the wall of the body  1  can be prevented more effectively. 
     According to an advantageous embodiment, the valve can further comprise means  14 ,  26 ,  27 ,  28  for cleaning at least the space  11  between the walls  9 ,  10  of the body part of the part. 
     Typically, the valve can comprise means  14 ,  26 ,  27 ,  28  for cleaning at least the space  11  between the walls  9 ,  10  of the body part of the part by spraying medium. 
     According to  FIG. 5 , medium can be conveyed from a medium source  26  with a pump device  27  along a channel  28  into a channel  13  of a pipe  12  and from there via openings  14  into the space  11 . The openings  14  are typically arranged in the vicinity of the channel  3  in  FIG. 5  especially in the area of the space  11  where the gate element  2  has to extend in the closed position. 
     The body  1  comprises the edge part  12  into which is arranged the channel space  13  in which there is at least one opening  14 , advantageously several openings, which opens to the space  11  between the first wall part  9  and the second wall part  10  for conveying medium into the space in question. According to an embodiment of the invention, the body  1  is formed by joining the wall parts  9 ,  10  from their edge part  12  e.g. by welding. A channel part  15  is joined to the first wall part  9  by welding. Correspondingly, a channel part  16  is joined to the second wall part  10  by welding. In the wall parts, there naturally is the flow opening  3 . Between the wall parts remains the space  11  for the gate element  2 . The laminar-structured valve of the embodiment is considerably advantageous and easy to manufacture especially in smallish production runs e.g. to casting-structured valve arrangements. 
     In the embodiment according to  FIGS. 7-10 , the edge part  12  is formed of a profile in which there are a channel part  12 ′ and a support part  12 ″. The channel part  12 ′ comprises the channel space  13 . The support part  12 ″ is advantageously thinner in the cross direction than the channel part  12 ′. The support part  12 ″ of the edge part forms as bent a support surface for the body walls  9 ,  10  of the gate valve. 
     The support part  12 ″ of the edge part comprises notches  29 , whereby the edge part  12  is bent to be curved in the area comprising the notches  29 .  FIGS. 9   a  and  9   b  show the edge part  12 , formed of a profile according to the embodiment, as bent.  FIG. 9   c  shows the edge part  12  formed of a profile as straight, before bending. 
     The walls  9 ,  10  are arranged by fastening elements  31 ,  32  to the support part  12 ″ of the edge part. Then, the support part  12 ″ remains between the walls  9 ,  10 . In the support part  12 ″ and corresponding points on the walls  9 ,  10  are formed openings  30  through which the screw part of a screw element  31  operating as the fastening element extends and, from the opposite side, by means of a counter element, such as a nut element  32 , the walls  9 ,  10  are sealed against the support part  12 ″. The thickness of the support part  12 ″ is advantageously somewhat greater than the thickness of the gate element. 
     In the embodiment according to the figures, the channel part  12 ′ is arranged outside the outer edge of the walls  9 ,  10 . 
       FIG. 10  shows a cross-section of the edge part  12 . It shows the channel part  12 ′ comprising the channel  13  and the support part  12 ″ thinner than the former. In addition, the opening  14  extending from the channel space  14  through the support part  12 ″ is drawn in the figure. The opening  14  extends from the channel space  13  through the support part  12 ″ of the edge part  12 . The edge part  12  is formed as a profile part, whereby the channel part  12 ′ and the support part  12 ″ are of the same piece. 
     The embodiment of the gate valve according to  FIGS. 7-10  is an extremely advantageous alternative for the welded structure. Then, inter alia, welding is avoided, whereby the assembly of the valve is very easy. 
       FIG. 11  shows a second embodiment of a valve according to the invention as a perspective figure. 
       FIGS. 11-17  show a second embodiment of the valve according to the invention, especially a gate valve, which comprises a body  101 , a gate element  102  which is movable in the body in the cross direction in relation to a flow path  103  between at least two positions, a first position in which the flow path  103  is open and a second position in which the flow path is closed. Typically, the valve also comprises means  104  for moving the gate element  102  between at least two said positions. The gate element  102  comprises a gate part  105  and an actuating body  108  along with which the gate part is arranged movable. In the figures, the flow path  103  passes via channel parts  115 ,  116  arranged in the valve body through the valve body  101 . In the embodiment of the figure, the gate element  102  is arranged to move by means of an actuator  104  between the first position in which the flow path is open and the second position in which the flow path is closed. The gate element  102  is arranged to move in a space  111  between body walls  109 ,  110  and an edge part  112 . The surfaces of the walls  109 ,  110  facing each other typically operate as the guide surfaces of the gate element  102 . In the body, there is a gap at the point of the flow channel from which gap the gate element moves and closes/opens the flow channel. The gate part  105  of the gate element  102  extends outside the edges of the flow opening of the flow channel  103  in the closed position. Typically, the cross-section of the flow path is circular according to a typical embodiment. The diameter of the gate part  105  is thus typically larger than the diameter of the flow opening of the flow path  103  at the intersection of the gate element  102  and the flow path  103 . 
     The gate element  102  comprises an actuating body  108  along with which the gate part  105  is arranged movable. In the embodiment of  FIGS. 15 and 16 , the actuating body  108  is a laminar part in which is formed a space  118  for the gate part  105 . In the embodiment of the figures, the space  118  is an opening formed in the actuating body in which the gate part  105  is arrangeable. Then, the edges of the opening  118  of the actuating body operate as the support surfaces of the gate part  105  when moving the gate element. In the embodiment of  FIGS. 15 and 16 , the actuating body  108  is a laminar part in which is formed, e.g. by cutting, such as by laser cutting or die cutting or by some other suitable way, an opening in which the gate part  105  is arrangeable. In the embodiment of the figures, the actuating body is of the shape of a drop. 
     According to an embodiment, the gate part  105  is formed of plate material. The gate part  105  has been formed according to an embodiment somewhat smaller than the opening  118  of the actuating body, whereby it is able to somewhat move in the space limited by the opening and the walls  109  and  110  of the actuating body. Typically, the gate part is able to move in the direction of the flow channel  103 , at least when it is in the closed position of the flow path. In  FIG. 13 , it is clearly visible that the gate part has pressed against one wall  110  of the body in the edge area of the flow path. Then in the flow channel  103 , from the effect of the pressure difference between pressures prevailing on different sides of the gate element  102  of the valve is achieved the pressing of the gate part  105  against at least one of the walls  109 ,  110  and simultaneously the sealing of the gate point. According to an embodiment, the gate part  105  is manufactured of plate material. A suitable type of material is e.g. plastic material. Also other suitable materials are applicable. 
     The gate part  105  is according to an advantageous embodiment a laminar part. In the embodiments of the figures, the gate part is a circular plate part. Naturally, any other shape is possible in accordance with the target of application. 
     In the embodiment of the figures, the valve body  101  comprises the first wall part  109  and the second wall part  110  and the space  111  remaining between them for the gate element  102 . The gate element is moved in the space  111  in the embodiment of the figure by means of an actuator  104 . The actuator is in the embodiment of the figures fastened to the body by fastening means. In the embodiment of the figure, the gate element  102  is moved by turning i.e. rotating it around a rotation axis R. A drive shaft  122  of the actuator  104  is fastened to the gate element by coupling means  123 . The drive shaft  122  is rotated from the position of  FIG. 15  i.e. open position towards the position in which the gate element  102  closes the flow path  103 .  FIG. 16  shows a situation in which the gate element  102  is moving towards the closed position. The closed position is shown e.g. in  FIG. 12 . 
     The gate part  105  is arranged in the space  118  formed in the actuating part  108  freely movable along the actuating part  108  between the guide surfaces of the body part. According to an embodiment, the thickness of the gate part  105  substantially corresponds the thickness of the actuating part  108 . It can also be somewhat thinner than it. 
     According to an embodiment, the actuating body  108  is a laminar part in which is formed the opening  118  in which the gate part  105  is arranged to fit. The opening  118  has been formed e.g. by die cutting or cutting, such as by laser cutting. Then, an arrangement fulfilling dimensional tolerances accurate enough is achieved. Correspondingly, the wall parts  109 ,  110  of the body can be of plate material and cut e.g. by laser cutting. 
     According to an advantageous embodiment, the valve can further comprise means  114 ,  126 ,  127 ,  128  for cleaning at least the space  11  between the walls  109 ,  110  of the body part of the part. Typically, the valve can comprise means  114 ,  126 ,  127 ,  128  for cleaning at least the space  111  between the walls  109 ,  110  of the body part of the part by spraying medium. 
     According to  FIG. 16 , medium, especially cleaning medium, can be conveyed from a medium source  126  with a pump device  127  along a channel  128  into the channel  113  inside the edge  112  of the body part and from that channel  113  via the openings  114  leading to the space  111  into the space  111 . The openings  114  are typically arranged in the vicinity of the channel  103  in the figure especially in the area of the space  111  where the gate element  102  has to extend in the closed position. There can be openings arranged also elsewhere for the length of the edge  112  of the body part. 
     The body  101  thus comprises the edge part  112  into which is arranged the channel space  113  in which there is at least one opening  114 , advantageously several openings, which opens to the space  111  between the first wall part  109  and the second wall part  110  for conveying medium into the space in question. 
     In the embodiment according to the figures, the edge part  112  is formed of a profile in which there are a channel part  112 ′ and a support part  112 ″. The channel part  112 ′ comprises the channel space  113 . The support part  112 ″ is advantageously thinner in the cross direction than the channel part  112 ′. The support part  112 ″ of the edge part forms as bent a support surface for the body walls  109 ,  110  of the gate valve. 
     The support part  112 ″ of the edge part comprises notches  129 , whereby the edge part  112  can be bent to be curved in the area comprising the notches  129 . 
     The walls  109 ,  110  are arranged by fastening elements  131 ,  132  to the support part  112 ″ of the edge part. Then, the support part  112 ″ remains between the walls  109 ,  110 . Into the support part  112 ″ and at corresponding points on the walls  109 ,  110  are formed openings  130  through which the screw part of a screw element  131  operating as the fastening element extends and, from the opposite side, by means of a counter element, such as a nut element  132 , the walls  109 ,  110  are sealed against the support part  112 ″. The thickness of the support part  112 ″ is advantageously somewhat greater than the thickness of the gate element. 
     In the embodiment according to the figures, the channel part  112 ′ is arranged outside the outer edge of the walls  109 ,  110 . 
       FIG. 17  further shows a cross-section of the edge part  112 . It shows the channel part  112 ′ comprising the channel  113  and the support part  112 ″ thinner than the former. In addition, the opening  114  extending from the channel space  114  through the support part  112 ″ is drawn in the figure. The opening  114  extends from the channel space  113  through the support part  112 ″ of the edge part  112 . The edge part  112  is formed according to an embodiment as a profile part, whereby the channel part  112 ′ and the support part  112 ″ are of the same piece. 
     The embodiment of the gate valve according to the figures is an extremely advantageous alternative for the welded structure. Then, inter alia, welding is avoided, whereby the assembly of the valve is very easy. 
     The laminar-structured valve of the embodiment is considerably advantageous and easy to manufacture especially in smallish production runs to e.g. casting-structured valve arrangements. 
     It is obvious to those skilled in the art that the invention is not limited to the embodiments described above, but it may be varied within the scope of the enclosed claims. When necessary, the features possibly described in this specification together with other features may also be used separately from each other.