JPH07272160A - Fire alarm equipment - Google Patents

Abstract

PURPOSE:To detect an incipient fire by providing an odor sensor for detecting burning odor generated at the time of fire in a plenum room so as to detect burning odor generated earlier than smoke due to fire when fire is broken out in the room. CONSTITUTION:Communication openings 13 in the shape of a slit which communicates with the inside of a ceiling 8 is provided in a recessed part P, the rack 14 for mounting the sensor of (n) type in front view is mounted on a reflection plate 12 above the communication openings 13, and the odor sensor S is mounted on the rear face of this rack 14. The odor sensor S is, for instance, formed from metallic semiconductor elements such as a stannic oxide film, is provided with elements detecting burning odor generated at fire, and sends a fire signal to a fire signal receiver at the time of detecting burning odor. This equipment uses the odor sensor S for detecting fire capable of detecting this burning odor so that fire is detected at a sufficiently early stage compared with a case of using the fire sensor of a smoke type even in the plenum chamber type room where fire is difficult to be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire alarm system suitable for a building having a plenum chamber for air conditioning in the ceiling.

[0002]

2. Description of the Related Art In recent years, in high-rise buildings, especially in so-called intelligent buildings, it has become common to provide large rooms with a small floor area and a large floor area.

In such a building, in order to effectively use a large floor area and to freely change the floor plan of the room, air conditioning in the room is often performed by a plenum chamber system. That is, the space above the ceiling is formed as a plenum chamber, and the ceiling is provided with an intake port and an air outlet, so that conditioned air is supplied into the room through this air outlet and the air in the room is taken in. The air is sucked from the mouth to the ceiling above the ceiling, and the sucked air is discharged to the outside through an exhaust duct arranged in the ceiling.

By the way, when a fire occurs in a room that is air-conditioned by the plenum chamber method, smoke from the fire is sucked into the back of the ceiling from the intake port near the fire point, so that the conventional ceiling surface is used. The smoke detector (fire detector) provided in the above has a problem that detection of a fire is delayed. Therefore, for example, Japanese Unexamined Patent Publication Nos. Sho 64-19498 and Sho 64-19499 disclose fire alarm equipment for detecting smoke in the plenum chamber.

[0005]

However, it is not possible to achieve early fire detection by simply detecting smoke during a fire in a room of the plenum chamber system where it is difficult to detect fire, as described above. To achieve this, sufficient devising is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and in a building in which a charging chamber is provided in the ceiling to perform intake and exhaust of the chamber, the charging chamber It is characterized in that an odor sensor for detecting a burning odor generated in the event of a fire is provided.

[0007]

[Function] When a fire occurs in a plenum chamber type room, the burning odor that occurs earlier than smoke is sucked into the ceiling from the intake port near the fire point, and the burning odor is detected by the odor sensor provided in the ceiling, Early fire detection can be achieved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a sensor mounting base according to a first embodiment of the present invention, FIG. 2 is a plan view of the sensor mounting base as seen from the underside of the ceiling, and FIG. 3 is a sensor mounting base from the inside of the room. The bottom view seen and FIG. 4 are views taken along the line AA of FIG. 2. The present embodiment will be described with reference to FIGS. A slit-shaped intake port 7 is provided in the ceiling 6, and a ceiling back 8 is divided into compartments by partitions such as beams supporting a slab (not shown), and an exhaust fan is exhausted from each compartment via an exhaust duct. Due to this, the exhaust of the room 9 is performed.
In addition, the ceiling 6 is provided with an outlet (not shown),
Air-conditioned air is supplied to the room 9 to form a general plenum chamber type air conditioner. Further, an illumination light fixture 10 is attached to the ceiling 6 by a fitting method.

A reflector 12 to which a fluorescent lamp 11 is attached is formed on the illuminating lamp fixture 10 as a recessed portion P which is recessed above the ceiling 6. The recessed portion P is provided with a slit-shaped communication port 13 that communicates with the ceiling back 8.
An n-type sensor mounting base 14 in front view is attached to the reflection plate 12 so as to be located above the communication port 13, and an odor sensor S is attached to the lower surface of the sensor mounting base 14.

The odor sensor S is formed of, for example, a metal semiconductor element such as a stannic oxide thin film, and has an element for detecting a burning odor generated in the event of a fire. It is configured to send a fire signal to the machine. When a fire occurs, it is known that a burning odor is generated due to the heating of the burning substance before the smoke is generated. By using the odor sensor S that can detect this burning odor, it is possible to detect the occurrence of the fire. Even in difficult-to-use Plenem chamber type rooms, it is possible to detect fires sufficiently early compared to the use of smoke type fire detectors.

The communication port 13 in the illustrated example is formed by forming a rectangular inspection port 15 provided on the reflection plate 12 into a slit shape by closing the central portion of the rectangular inspection port 15 with a plate 16 provided directly below the odor sensor S. Play a role as. It should be noted that the rail 16 provided on the reflection plate 12 causes the plate 16 to move to the reflection plate 1.
It is attached to 2 and is guided by this rail 17 to plate 1.
By shifting 6 from above the inspection port 15, the odor sensor S can be inspected from this inspection port 15.

In this way, the recessed portion P which is recessed above the ceiling 6 is formed, and in the recessed portion P, the room 9 and the ceiling back 8 are formed.
Since the communication port 13 for communicating with
Some of the burnt odor of the fire that has occurred in the above enters the ceiling 8 from the intake port 7 of the ceiling 6. The burnt odor flowing along the ceiling 6 collects in the recess P, reaches the lower side of the sensor mounting base 14 through the communication port 13, and is detected by the odor sensor S to the side opening of the sensor mounting base 14. You will exit from 18 to the attic 8.

In the first embodiment, the burnt odor of a fire rises toward the ceiling 6, flows along the lower surface of the ceiling 6, and is partly burnt in the recessed portion P which is recessed from the lower surface and located above. The burnt odor that has entered and is collected in the recess P is constantly discharged to the ceiling 8 through the communication port 13.
Therefore, the burning odor flowing on the lower surface of the ceiling 6 constantly enters the recess P. Next, a second embodiment of the present invention will be described. 5 is a plan view showing the room 21 and the ceiling 22 respectively, and FIG. 6 is a view taken along the line AA of FIG.

The ceiling space 22 is formed by the ceiling 23 of the room 21 and the slab 24, and is divided into left and right compartments R1 and R2 by a partition 25 for supporting the slab 24, for example.
It is divided into each.

A plurality of slit-like intake ports 26 are provided in the ceiling 23, and an exhaust fan 28 is provided at a discharge end portion 27c of a duct 27 which has openings 27a and 27b in the respective compartments R1 and R2. It is provided as a general plenum chamber type exhaust system.

A communication port 29 is provided in the partition 25, and both compartments R1 and R2 are ventilated by this communication port 29.

Fire detection is performed by an odor sensor S mounted near the communication port 29. The odor sensor S
Is the same as in the first embodiment, and although two are shown in the drawing, one may be provided.

When a fire occurs at the fire point F, the burning odor of the fire reaches the ceiling 23, and the compartment R1 from the intake port 26.
And R2, and from the compartment R2 near the fire point F to the compartment R1 through the communication port 29 of the partition 25, and into the duct 27 through the openings 27a and 27b to be exhausted to the outside. When the burning odor passes through the communication port 29, the burning odor is detected by the odor sensor S attached near the communication port 29. Therefore, regardless of the position of the fire point F,
The single odor sensor S installed near the communication port 29 of the partition 25 can always detect the burning odor at an early stage, and the accuracy of fire detection in the plenum chamber system can be improved.

The particles of smoke produced by a fire are considerably larger than those of a burning odor. Smoke-type fire detectors (photoelectric type) that are usually installed in buildings
Is known to depend on the size of the smoke particles, and the larger the particle size, the faster the smoke can be detected.

In a plenum chamber type building to which the present invention is applied, smoke particles tend to be finely separated when the smoke is sucked from the intake port and diffused into the filling chamber, which delays the detection of the smoke. It will be easier. On the other hand, the floating of odor (burnt smell) is a molecular state and is quite small from the beginning, and as described above, particles are not broken when being sucked and diffused. The detection ability is not adversely affected by the air flow. That is,
In a plenum chamber type building, the odor sensor can be said to be a more suitable fire detection means than a smoke detector.

[0021]

EFFECTS OF THE INVENTION The present invention provides a odor sensor for detecting a burning odor generated in a fire in a building in which a charging chamber is provided above the ceiling to perform intake and exhaust of the room. When a fire occurs in a room, it is possible to detect a burning odor that occurs earlier than smoke due to the fire, and therefore early fire detection can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a sensor mounting base of the present invention.

FIG. 2 is a plan view of the sensor mounting base of the present invention viewed from the back side of the ceiling.

FIG. 3 is a bottom view of the sensor mounting base of the present invention viewed from the inside of the room.

FIG. 4 is a view taken along the line AA of FIG.

FIG. 5 is a plan view showing a room 21 and a ceiling space 22 respectively.

6 is a view taken along the line AA of FIG.

[Explanation of symbols]

 S, odor sensors 6, 23, ceilings 7, 26, intake ports 8, 22, back ceiling 9, room 14, sensor mount 21, room (room)

Claims (1)

[Claims] 1. A building in which a replenishment chamber is provided on the ceiling above and below to inhale and exhaust air in the room, wherein the replenishment chamber is provided with a odor sensor for detecting a burning odor generated at the time of a fire. Fire alarm equipment.