Abstract:
A hydraulic fire door, especially a sliding door, which can be selectively opened or closed by an actuator. In order to ensure a particularly fire resistant fire door without the heat resistance of the basic structure thereof having to be particularly fire resistant, the actuator is arranged to supply aqueous liquid to the fire door in order to cool it using the aqueous liquid.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a hydraulic fire door, especially a sliding door, which can be selectively opened or closed, the fire door being provided with an actuator for moving the door from an opened position to a closed position. 
     Hydraulic fire doors are known. They are generally, i.e. not in the event of fire, used together with door openings, which are kept open. When fire occurs or when flue gases are created, the fire doors are closed in order to prevent the fire or flue gases from spreading. 
     If a fire door needs to be highly resistant in high temperatures, the door is correspondingly dimensioned and made of a material or materials that endure high temperatures. Therefore the fire door surfaces are typically made of steel. Steel fire doors do not allow to monitor the fire and/or flue gases through the door. The people possibly behind the closed steel doors cannot either be seen. Transparency would, however, help to evaluate how far the fire and flue gases have spread, and also to observe the people, which naturally is of advantage in the event of fire. The massive weight of steel makes the steel doors heavy. Where applied, for example on ships, the massive weight of the fire doors is a significant drawback. Known fire doors are provided with hydraulic pipe system and control systems that render the hydraulic fire doors fairly expensive. 
     The invention also relates to a fire protection system comprising a fire extinguishing system and a hydraulic fire door, more particularly to a sliding door, which can be selectively opened or closed, the fire door being provided with an actuator for moving the door from an opened position to a closed position. The fire protection system typically comprises several spray heads and fire doors. These fire doors are also associated with the problems described above. 
     The fire doors including hydraulic systems are notably constructed as systems separate from fire extinguishing systems, so that a piston cylinder unit in the fire doors comprising feeding pipes and a control system are placed apart in a pipe system and a control system of the fire protection system, consequently rendering the fire protection system very expensive. 
     BRIEF DESCRIPTION OF THE INVENTION 
     It is an object of the invention to provide a hydraulic fire door having an improved fire resistance and irrespective thereof the fire door can if desired be made of a material whose fire resistance is not particularly good. 
     This is achieved with a fire door of the invention characterized in that the actuator is arranged to supply liquid. For said purpose the present invention provides for a hydraulic fire door, especially a sliding door, which can be selectively opened or closed, the fire door being provided with an actuator for moving the door from an opened position to a closed position, wherein the actuator is arranged to supply aqueous liquid to the fire door in order to cool it using the aqueous liquid. The liquid to be employed in the actuator is used to close the door. A facing surface of the door is preferably cooled; the term facing surface referring in this context to any large door surface. The facing surface may be an outer surface or an inner surface. 
     The most significant advantages of the fire door of the invention are that the fire resistance thereof is very good without the heat resistance of the basic structure thereof, i.e. the frame or face surfaces of the door, having to be particularly good, in which case the fire door may, for example, be transparent and made of glass, and that an actuator, such as a piston cylinder unit, is utilized for improving the fire resistance thereof in order to cool the door, whereby the fire door and the apparatus cooling the door are formed of a compact unit. 
     The fire protection system of the invention is characterized in that the actuator is arranged to supply aqueous liquid to the fire door in order to cool it using the aqueous liquid. Present invention provides for a fire protection system comprising a fire extinguishing system and a hydraulic fire door, especially a sliding door, which can be selectively opened or closed, the fire door being provided with an actuator for moving the fire door from an opened position to a closed position, wherein the actuator is arranged to feed aqueous liquid to the fire door in order to cool it using the aqueous liquid. 
     Most preferably the actuator is connected with a line in the fire extinguishing system for supplying said liquid through an output starting from the actuator and a feeding channel to the upper part of the fire door and from there further to the facing surface of the fire door. Thus the large surfaces of the doors can from the beginning be evenly cooled, as the cooling is most efficient there where the temperature most likely is the highest in the event of fire. 
     The line is preferably the one leading to the spray heads of a fire extinguishing or fire fighting system, since the lines intended for the spray heads are then utilized as well as the pressures therein when closing and cooling the door, and the door hydraulics is not different from the fire extinguishing hydraulics. This allows great cost savings to be made. 
     The actuator is preferably a piston cylinder unit comprising a piston and a cylinder, since the structure of such a unit is simple. 
     The most significant advantage of the fire protection system according to the invention is that in addition to the fire extinguishing system it comprises a fire door, whose fire resistance is very good without the heat resistance of the basic structure thereof, i.e. the frame or facing surfaces of the door, having to be particularly good, in which case the fire door may, for example, be made of glass, or be transparent, and that the actuator is utilized for improving the fire resistance of the fire door (for cooling the door), the fire door and the apparatus cooling the door thus forming a compact unit. As the actuator is also connected to a line leading to the spray heads in the fire extinguishing system, great cost savings are made, since the lines in the fire protection system are greatly reduced as well as the need for control. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following the invention will be described in greater detail by means of the preferred embodiments with reference to the accompanying drawing, in which 
     FIG. 1 shows a first embodiment of a fire door in an opened position, 
     FIG. 2 shows a view along the cutting line II—II of FIG. 1, 
     FIG. 3 shows the fire door of FIG. 1 in a closed position, 
     FIG. 4 shows a second embodiment of the fire door in an opened position, 
     FIG. 5 shows a view along the cutting line V—V of FIG. 4, and 
     FIG. 6 shows the fire door of FIG. 4 in a closed position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a fire door of the invention made of glass, and in an opened position, or in a standard using position. Reference numeral  100  illustrates a door opening. In the event of fire and/or when an attempt is made to prevent the access of flue gases through the door opening  100 , said door opening is closed by means of the fire door. 
     The fire door is a sliding door. A piston cylinder unit  3  placed above the door enables the door to slide into the position shown in FIG. 3, in which the door covers the door opening. 
     The piston cylinder unit  3  is connected using a throttle valve  11  to a line  4  that leads to spray heads  10 . The throttle valve  11  is generally closed. 
     The throttle valve  11  comprises a thermal trigger means  12  and a solenoid  13 . The solenoid  13  is arranged to open the throttle valve  11  after obtaining a signal from the detector (not shown). The thermal trigger means may, for example, be a glass ampoule  12 , which is arranged to open the throttle valve  11  after having exploded at a high temperature. The throttle valve  11  may also, or alternatively, be used mechanically. 
     The piston cylinder unit  3  comprises a cylinder  2  and a piston  1  arranged therein. Reference numeral  18  indicates a free end of the piston and reference numeral  19  another end of the piston, to which a piston rod  20  is attached. An opening  21  in a cylinder end  62  surrounds the piston rod  20  so that a liquid tight wall of the opening surrounds the piston rod. The piston rod  20  comprises a through passage  22  that continues through a throttling  70  to the free end  18  of the piston. The passage  22  provides a start for channels  24  leading to a space  25  defined by the piston end  19 , the piston rod  20  and the end  62  at the cylinder  2  opening  21 . The channel passing through the piston, the throttling  70  and the channels  24  are dimensioned such that the pressure created on the channel  22  (the pressure is formed when the throttle valve  11  opens) causes a higher pressure to the space  25  than to a space  23  defined by the cylinder  2  and the free end  19  of the piston. The flow resistance on the channels  24  is lower than the flow resistance through the piston  1  owing to the throttling  70 . The structure may comprise only one channel instead of several channels. 
     The cylinder  2  includes an output  5  that leads to a feeding channel  6 . The feeding channel  6  travels downwards from the output, first formed as a pipe, along a passage  61  on the vertical edge of the door. At a central or middle part of the door the pipe  6  continues horizontally past an actuating means  9  intended to open the door and through an opening valve  8  of the door to the opposite edge of the door, where the feeding channel is formed of a relatively narrow vertical passage  60 . A door frame forms the passage  60 . The passage  60  is restricted at the bottom against a stop  80  and continues upwards to the corner of the door and from there horizontally as a passage moving along the upper edge of the door with several spray openings  7  at the bottom thereof arranged substantially at the entire width of the door. 
     The opening valve  8  is generally open. The opening valve  8  is closed only in such a case, when the closed door is to be opened, cf. FIG.  3 . The pipe  6  includes a check valve  90 . The opening valve  8  can be closed using a handle  9  in the opening valve  8 . The operation is mechanical and/or electric. 
     FIG. 2 shows that the door comprises two spaced glass surfaces  14   a  and  14   b , forming a so called double glazing, between which a space  15  is formed. 
     In the following the operation of the fire protection system in FIGS. 1 to  3  is explained. 
     When fire breaks out, the detector (not shown) that can be any detector reacting to fire, such as a smoke detector, provides a signal to the solenoid  13  of the throttle valve that opens the throttle valve  11 . Alternatively an ampoule  12  attached to the throttle valve  11  opens the throttle valve after having exploded owing to the heat; thus providing an alternate means for opening the throttle valve. The compressed water in the line  4  moves through the throttle valve  11  to the piston cylinder unit  3  so that a higher pressure is formed to the space  25  than to the space  23 . On account of the above the cylinder  2  moves in relation to the piston  1  and draws the door with it, as the door is fastened to the cylinder. When the cylinder  2  moves from the position shown in FIG. 1 to the right ending up in the position shown in FIG. 3, water flows to the space  23 . Water flows through the output  5  to the pipe  6  and through the opening valve  8  to the passage  60  that is filled from the bottom to the top. The passage  60  rapidly fills up as the volume thereof is fairly small, manifoldly smaller than the volume of the space  15  between the glass surfaces  14   a ,  14   b . The flowing water reaches the upper edge of the door and water starts to spray through the spray openings  7  onto the glass surfaces  14   a ,  14   b  cooling them evenly at least in the width direction of the door. The spray openings  7  are arranged to cool at first the upper part of the door, where the fire causes the highest heat stress to the door. A lower edge of the door comprises liquid outlet ports  16 . The flow through the liquid outlet ports  16  is smaller than the flow from the spray openings  7 . Therefore the space  15  is filled with water. The liquid outlet ports  16  provide the space  15  with an efficient, cooling water circulation. The liquid outlet ports  16  are naturally also intended to remove the water collected into the space  15  when the fire door is no longer subjected to an actual heat load. An overflow opening  17  is formed at the upper edge of the door that prevents an excess liquid pressure to be formed in the space  15 . The water heated in the fire can also be removed through the overflow opening  17  from the upper part of the space  15  where the fire heats the water the most. The water flows along the passage  61  through the overflow opening  17  to the outlet port in the lower part of the door, and new cold and cooling water is constantly sprayed into the space  15  from the spray openings  7 . 
     If the closed door in the position shown in FIG. 3 is to be opened, then a handle  9  is pulled and the opening valve  8  is shut and water can no longer flow inside the door and the door is opened. The door is opened since the pressure is normalized on both sides of the piston  1  of the piston cylinder unit  3 , i.e. in the spaces  23  and  25 . In the space  23 , the surface of the piston&#39;s free end  18  that the pressure affects is greater than the surface of the piston end  19  that in the space  25  points towards the piston rod. When the door is closed, liquid flows out from the space  25 . 
     FIGS. 4 to  6  illustrate another embodiment of the invention. The same reference numerals are used in FIGS. 4 to  6  as in FIGS. 1 to  3  for corresponding parts. 
     The embodiment in FIGS. 4 to  6  deviates from the one shown in FIGS. 1 to  3  in that the ampoule  120 ′ and solenoid  130 ′ are arranged close to the opening valve  8 ′. The throttle valve is merely a mechanical closing valve  11 ′ without an ampoule or a solenoid. The throttle valve  11 ′ is generally open and the spray heads  10 ′ are then typically sprinklers comprising ampoules reacting to heat. 
     The detector (not shown), which may be any detector reacting to fire, such as a smoke detector, provides through an electric wire  63 ′ the solenoid  130 ′ that opens the opening valve  8 ′ with a signal in the event of fire. Then, as the door is opened and is in the position shown in FIG. 4, the cylinder  2 ′ moves to the right and the door moves towards the position in FIG.  6 . Alternatively the ampoule  120 ′ connected to the opening valve  8 ′ opens the opening valve, after been broken in the heat created by the fire. It is further possible that the ampoule  120 ′ can also, or alternatively, be broken by heating using electric current. When the opening valve  8 ′ is opened, water flows into the space  23 ′ that is transferred via the output  5 ′ and the pipe  6 ′ through the opening valve to the passage  60 ′. When the passage  60 ′ is filled with water, which occurs rapidly, the water starts to spray into the space  15 ′ from the spray openings  7 ′ and to flow away through outlets  16 ′. 
     If the fire door is to be opened from the position shown in FIG. 6, the opening valve  8 ′ is closed, for example, by providing it with an electric impulse through the handle  9 ′, in which case a mechanical electric opening is concerned. Alternatively the electric impulse can be achieved without the handle  9  or another mechanical device using a detector. The door is opened when the opening valve  8 ′ is closed, and the liquid flows away from the space  25 ′. 
     The invention is described above by means of two examples and it is therefore pointed out that the details of the invention can be implemented in different ways deviating from the examples within the scope of the appended claims. Therefore, the door may for example include a single glass instead of double glazing  14   a ,  14   b ,  14   a ′,  14   b ′ or may include multi glazing. In a single glass door, the spray means  7 ,  7 ′ are arranged to spray to either of the two outer surfaces of the glass or to both outer surfaces. The door does not necessarily have to be a glass door, although this is to be recommended. Instead of a piston cylinder unit another hydraulic actuator can be used that allows the door to be opened and closed and vice versa. However, the piston cylinder unit is an easy way to implement the actuator. Instead of a sliding door the fire door may, at least in principle, be e.g. a hinged door, in which case the actuator, typically a piston cylinder unit, is pivoted to the door. However, a sliding door is in many respects a better solution as a fire door than a hinged door. It is possible to initiate the closing of the door and the spraying of the liquid into the door manually without having to start these functions by means of a detector or an ampoule.