JP2699076B2 - Fluid atmosphere smoke sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smoke sensor for use in a fluid atmosphere, and more particularly to a smoke sensor for use in a fluid atmosphere which is attached to an air conditioner or various types of cooling and heating equipment. . [Prior Art] Conventionally, various types of smoke sensors have been provided. Such a conventional smoke sensor is usually fixed to an upper part of a wall or the like, and uses a voltage drop generated in a bridge circuit when the smoke enters the smoke sensor to take advantage of the smoke. The presence or absence was detected. Further, among such conventional smoke sensors, a specific configuration of an ionization type smoke sensor is as shown in FIG.
And a sensor chamber 20 which is open to the outside by an inlet and an outlet, and both chambers 1
An intermediate electrode 30 is disposed on each of the sensor chambers 20 and 20.
The presence or absence of smoke is determined based on the voltage difference between the two electrodes 30 when smoke enters the flow path between the entrance and the exit in the interior. [Problems to be Solved by the Invention] Since such a conventional smoke sensor has the above-described structure, when smoke is filled in the sensor chamber, the smoke causes a voltage drop. It was sufficiently possible to detect the presence or absence of smoke based on the voltage drop. However, in such a conventional smoke sensor, the smoke sensor itself is placed in a fluid atmosphere, for example, in a place where the wind is blowing, regardless of whether it is natural wind or artificial wind. Sometimes, even if smoke enters the flow path of the sensor chamber, the flowing wind will cause a voltage drop different from the expected voltage drop, so that it is possible to correctly grasp the presence or absence of smoke. It was difficult. This is because, for example, as shown in FIG. 7, as the wind speed increases, the output voltage drops, so that even in the measurement of the smoke density as shown in FIG. The result was different. Therefore, if such a conventional smoke sensor is used, for example, even if the same amount of voltage drop is shown, it cannot be distinguished whether the voltage drop is due to smoke or wind. Even if a voltage drop due to the presence of a certain smoke is detected, the actual smoke density at that time cannot be grasped. For example, in the characteristic diagram shown in FIG.
% / Foot, the wind speed is from 0.1m / s to 0.5
Since the drop voltage changes from about 0.7v to 0.5v as the speed changes to m / s, it is impossible to detect the smoke density correctly only by the change amount of the drop voltage. Therefore, the present invention, by making the shape of the intermediate electrode a specific shape, regardless of the flow rate of the fluid flowing through the flow path in the sensor chamber, when the same drop voltage is shown,
It is intended to provide a smoke sensor having almost the same smoke density. [Means for Solving the Problems] In order to solve the problems described above, the present invention provides a reference chamber closed from an external atmosphere and a sensor chamber open to the outside, and flows through the sensor chamber. In a smoke sensor for use in a fluid atmosphere, which detects the smoke concentration in the fluid by the potential difference between an intermediate electrode provided in the reference chamber and the sensor chamber, a fluid having a velocity of 0.5 m / s or less flows through the flow path of the sensor chamber. An inlet and an outlet are provided, and the intermediate electrode on the outlet side is disposed at a height of 0.4 to 0.7 of the height of the flow path from the inlet to the outlet.
Erected up to the height of [Examples] Hereinafter, examples of the present invention will be described. Various experimental processes leading to the present invention will be sequentially described, and finally, how effective the present invention is will be described. First, the inventor of the present invention expected that the amount of voltage drop would be substantially equal to that of the conventional ionization type smoke sensor as shown in FIG. As shown in the above, an experiment was conducted by manufacturing a sensor chamber 20 with a net at the entrance and a sensor chamber with a net at the exit. As a result, as shown in FIG. 7, for example, a curve gradually descends even when a net is attached to the entrance, and even when a net is attached to the exit, as shown in FIG. The curve gradually decreased, and it was confirmed that the initial purpose of obtaining a predetermined amount of voltage drop corresponding to the smoke density could not be achieved regardless of the wind speed. Further, the inventor of the present invention has made the length of the intermediate electrode 30 extremely long as shown in FIG.
Although it was considered to provide an intermediate electrode 30 that almost coincides with the flow path, thereby eliminating the influence of the fluid, as shown in FIG. 4, the output voltage still drops according to the wind speed. Had become. Then, the present inventor then formed a part of the intermediate electrode 30 on the outlet side by standing in the sensor chamber 20 as shown in FIG. , And the same experiment was conducted while changing from H = 0 to H = 9. The specific measurement value at that time is It became. FIG. 2 shows the result, and as is clear from this figure, the displacement voltage with respect to the still wind increases when the height becomes higher than about H = 0.55, and the height becomes higher. It was found that the displacement voltage at the time of still wind decreased when the value was less than that. Therefore, in order to obtain a practical output voltage in which the influence of the wind speed can be almost ignored, it was found that this height was in the range of H = 4.0 to H = 7.0 with respect to the height 10 of the flow path. . In other words, it was confirmed that in this range, even in a fluid at a constant speed, for example, an air conditioner or an air conditioner or a variety of air-conditioning equipment provided with a wind passage portion can sufficiently withstand use. Then, as shown in FIG. 3, the inventor tried to form only the intermediate electrode 30 on the outlet side by curving upward, and found that the height was about half of the height of the sensor chamber 20. In this case, as shown in FIG. 4, it was possible to obtain an output voltage in which the influence of the wind speed could be almost ignored. However, at this time, if the direction of the wind was reversed, the effect of the wind speed could not be ignored, as shown in FIG. Still further, as shown in FIG.
Was extended to the exit side, and an extension electrode 30 was provided along with the extension, and the extension electrode 30 was formed by curving upward toward the exit direction. As shown in FIG. 4, it was confirmed that, even when the height was set to about half of the height, a similar output voltage could be obtained with this sensor regardless of the wind speed. Therefore, according to various experiments by the inventor, in the smoke sensor, when the outlet side intermediate electrode 30 is formed to be erected to a height of 0.4 to 0.7 of the height of the flow path of the sensor tubing, the Regardless of whether the standing type is vertical or curved, in the range of the experiment, there is almost no change in output when the wind speed is up to about 0.5 m / s, and therefore the descent corresponding to the presence or absence of smoke It was confirmed that the voltage did not spread to such an extent that a detection error substantially occurred. Therefore, by using the smoke sensor according to the present invention, for example, it is usually used as an air conditioner or various types of air conditioning equipment, and by incorporating the smoke sensor according to the present invention therein, the smoke concentration can be reduced even in a fluid atmosphere. It can be measured. It should be noted that, even when the air conditioner or various air conditioning equipment is not used and the air conditioner or various air conditioning equipment is used, it can be used as a normal smoke sensor. [Effects of the Invention] As described above, the present invention forms the outlet side intermediate electrode up to the height of 0.4 to 0.7 of the height of the flow path of the sensor tubing, thereby forming the inside of the sensor chamber. The present invention provides a smoke sensor having substantially the same smoke density when the same drop voltage is shown at 0.5 m / s or less of the flowing fluid, regardless of the flow velocity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 5 are drawings for explaining the present invention, FIG. 1 is a schematic diagram of a smoke sensor for use in a fluid atmosphere according to the present invention, and FIG. FIG. 3 is a schematic diagram showing another embodiment of the smoke sensor for fluid atmosphere according to the present invention, FIG. 4 is a characteristic diagram of the smoke sensor for fluid atmosphere, and FIG. FIG. 6 is a schematic view showing still another embodiment of a smoke sensor for use in a fluid atmosphere according to the present invention, and FIGS. 6 to 10 are drawings for explaining a conventional smoke sensor and experimental results up to the completion of the present invention. FIG. 6 is a schematic diagram showing a conventional smoke sensor, FIGS. 7 and 8 are characteristic diagrams,
FIG. 9 and FIG. 10 are schematic diagrams for explaining the experimental results up to the completion of the present invention. 10 Reference chamber 20 Sensor chamber 30 Electrodes

Claims (1)

(57) [Claims] A reference chamber closed from the external atmosphere and a sensor chamber open to the outside are provided, and the smoke density in the fluid flowing through the sensor chamber is reduced.
In a smoke sensor for use in a fluid atmosphere, which is detected by the potential difference between an intermediate electrode provided in a reference chamber and a sensor chamber, an inlet and an outlet are provided for flowing a fluid having a velocity of 0.5 m / s or less in a flow path of the sensor chamber, and an outlet is provided. A smoke sensor for use in a fluid atmosphere, wherein the intermediate electrode on the side is formed so as to stand up to a height of 0.4 to 0.7 of the height of the flow path from the entrance to the exit.