The present invention relates to a closure for sprinklers and nozzles with heat activation for use in the field of fire-prevention and fire-fighting, and an intelligent controller for such closures.
Most fire protection systems, for example sprinkler systems in buildings, are automatically activated by heat-sensitive elements in the event of a fire. This ensures high reliability, as they react directly to the heat generated by the fire and are independent of any external alarm signal or human action. Common heat sensitive elements are, for example, fusible elements (see e.g. EP 1515780) or frangible glass bulbs (see e.g. U.S. Pat. No. 9,573,007). A major disadvantage of these devices is that they are only activated after the room air has been heated by the fire and the heat-sensitive element is subsequently heated by the heated room air. In the meantime, decisive minutes pass during which the fire can develop and spread. In addition, dangerous smoke formation can already take place in the start-up phase, before the fire really starts, which should be fought as quickly as possible with a water mist for example. There are methods that practically enable immediate fire detection, e.g. by means of smoke sensors. In EP 2038018, a closure for sprinklers and nozzles with heat activation is provided, whereby a smoke sensor or thermostat enables rapid fire detection. The nozzle is closed with a cover plate firmly connected to the nozzle body by means of a fusible element. In the event of fire, the room temperature and the temperature of the fusible elements increase until the fusible elements melt, the cover plate falls away and the nozzle is opened. Parallel to this, the fusible elements are arranged on heating elements which are controlled by the smoke sensor or the thermostat. If the sensors report a fire, the fusible elements can be actively fused with the heating elements and the nozzle can thus be opened long before the passive fusion of the fusible elements due to the heated room air. Such systems thus combine two parallel activation methods: early, active activation by controlled heating after fire detection by sensors and, if this fails, passive activation by the heat generated by the fire. Another advantage of the device according to EP 2038018 is the compact design of the closure which hardly protrudes from the nozzle body and is therefore quite easy to integrate in a ceiling or wall. In contrast, conventional sprinklers with frangible glass bulbs (see e.g. U.S. Pat. No. 9,573,007) always have a length of several centimetres.
In practice, however, it has been shown that the melting temperature of the fusible elements can change over the years. Responsible for this is the gradual deformation and change in the material structure of the fusible element due to creep caused by the constant tension it is under. For example, the fusible links in EP 2038018 carry both the force of the structural part under tension and the compressive force of the extinguishing agent under pressure. During creep, the temperature and its fluctuations in the monitored room also play an important role: for example, the deformation of the fusible elements is significantly accelerated at room temperatures of over 30° C. This can cause permanent deformation of the fusible elements over the years and change the melting temperature of the fusible element. After several years, the melting point can be higher than originally intended, so that the fusible element responds later, but it can also be lower, so that the fusible element responds earlier. Both cause damage that was originally intended to be avoided with the use of such devices. In contrast, breakable glass bulbs are reliable and stable heat-sensitive elements and besides, they are available on the market in various standard versions with different triggering temperatures.
The object of the present invention is to improve a closure for sprinklers and nozzles with heat activation according to EP 2038018 in such a way that the compact structure and the two parallel activation methods (active by controlled activation and passive by the heat generated by the fire) are retained, but the activation mechanism is improved in such a way that the reliability, stability and invariability of the activation temperature of the heat-sensitive element is guaranteed.
This object is achieved by a closure for sprinklers and nozzles with heat activation having the features of claim 1. Further features and embodiments are apparent from the dependent claims and their advantages are explained in the following description.
The drawings show:
The figures show possible embodiments which are explained in the following description.
The presented closure for sprinklers and nozzles with heat activation is suitable for use with water mist nozzles and/or with sprinklers. The nozzle consists of a nozzle body 1 which can be connected to an extinguishing agent supply 2 of a fire protection system and arranged on a ceiling 3 or wall 3 of a building (
The core of the invention is the method of fastening and the release mechanism of the cover 5, which is fastened to the nozzle body 1 in such a way that the heat-sensitive element does not have to carry the complete pressure forces of the compressed seal 4 and of the pressurised extinguishing agent of the extinguishing system in the waiting position, but only part of it. In this case, the heat-sensitive element can be put under less pressure or tension by means of an actuating element, e.g. a spring or a magnet, in order to release the closure. For closures with a fusible element, this reduces the gradual deformation and change in material structure of the fusible element due to creep. In general, it allows more freedom in positioning the heat-sensitive element in the closure, providing nozzles with a much more compact design. For example, in closures using frangible glass bulbs, the glass bulb can be oriented at a right angle to the axis of the exit channel 11 to provide a particularly compact nozzle.
According to the invention, it is envisaged to attach the cover 5 to the nozzle body 1 at least 2 points, for example diametrically opposite in the case of a round cover 5 (
It is important that the releasable arrangements 6 and the connection 7 are arranged in such a way that the detachment of the releasable arrangement 6 allows the mentioned movement of the cover 5 away from the nozzle body, until the complete detachment of the same.
Possible embodiments of the releasable arrangement 6 and of the connection 7 are explained in more detail in the following part with reference to
In an alternative embodiment of the closure, the releasable arrangement 6 comprises a latch 65 and a heat-sensitive element 52 which is arranged in the cover 5 behind the latch and holds the latch 65 in the closed position. A fusible element 61 or an explosive 63 may be used as the heat sensitive element. If a frangible glass bulb 64 is used as the heat-sensitive element, this may be arranged in the horizontal direction, i.e. at a right angle to the axis of the outlet channel 11, in order to save space and provide as compact an arrangement as possible. The glass bulb 64 can be integrated in the nozzle body 1 or, as shown for example in
In the embodiment according to
Another possible embodiment provides that the cover 5 is pre-assembled and integrated in a housing part 9, whereby this housing part 9 is designed in such a way that it can be easily attached to the nozzle body 1. For example, it is possible to provide the housing part 9 with an external thread which can be screwed into the corresponding counter-thread of the nozzle body 1 (
Preferably, a common heat-sensitive and frangible glass bulb for fire sprinklers available on the market can be chosen as the glass bulb 64. The glass bulb 64 ensures the passive activation of the closure: in the event of fire, the room air and the glass bulb 64 are heated until the glass bulb 64 bursts when a defined temperature is exceeded. For the active triggering of the closure, the glass bulb 64 is actively heated by means of a controlled electrical resistance or induction heating element. The electrical resistance or induction element may be a coil wound around the glass bulb 64, or a rectilinear path attached to its surface. In the preferred embodiment, the glass bulb is fully or partially coated with a resistive heating material. This ensures a larger contact area between the heating material and the glass bulb 64, thus promoting heat conduction from the heating element to the glass bulb. As soon as the glass bulb 64 no longer holds the latch 65 in the closed position, the actuating element 66 pulls it into the open position. From this moment on, the cover 5 is tilted away from the nozzle body 1 by the pressure of the extinguishing agent in the outlet channel 11.
The energy required to heat/trigger the fusible element 61, the explosive 63 and/or the glass bulb 64 originates either from an external energy source, e.g. via an electric line, or from a dedicated energy source, e.g. from an integrated battery. The heating of the heat sensitive element is controlled by an intelligent controller connected to one or more fire sensors 14, for example a smoke sensor or a thermostat. The intelligent controller is for example a microprocessor or a computer. In addition or instead, the intelligent controller may also receive an external fire alarm or instruction, for example from a central control station. The intelligent control offers the possibility that sensors first trigger an alarm and only after a defined time does the nozzle actually react with extinguishing agent. For example, a sensor triggers an alarm if toxic smoke endangers people without immediately putting the nozzle and the entire extinguishing system into operation and thus causing damage.
If some components (the energy source, the intelligent controller, the fire sensors 14 or the heat-sensitive element 52) are located in the cover 5 and others in the nozzle body 1, the nozzle must be provided with means for establishing electrical contact between the nozzle body 1 and the cover 5. In a possible embodiment of the invention, this electrical contact is established on the one hand by the releasable arrangement 6 and on the other hand by the connection 7. For this purpose, in the embodiment with glass bulb 64 in the cover 5, the second recess 13, the part of the edge of the cover 5 engaging therein, the first recess 12 and the latch 65 could comprise an electrically conductive material, consist of electrically conductive material or be coated with electrically conductive material.
Number | Date | Country | Kind |
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18188165.7 | Aug 2018 | EP | regional |
This is a divisional patent application which claims priority from non-provisional patent application Ser. No. 17/266,946, filed on Feb. 8, 2021.
Number | Date | Country | |
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Parent | 17266946 | Feb 2021 | US |
Child | 18581621 | US |