JP3073286B2 - Fire detection method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a fire, and more particularly to a method and an apparatus for detecting a fire capable of accurately detecting a specific substance generated at the time of an initial fire. Things.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting a fire, a method of monitoring heat and smoke in a monitoring area and discriminating a fire when a predetermined threshold value or a rising rate is reached is generally used. Also, if you are trying to find a fire in a computer room or a room with semiconductor manufacturing equipment, stretch the sampling pipe to collect the air inside the room, and use a particle counter or dust monitor to monitor the sampled air. A fire was detected based on the light reflection of the particles. However, the detection method based on the light reflection of the air particles as described above often causes misinformation due to dust. In recent years, it has been necessary to detect fires before they become important due to the combustion gas and smell generated by the initial fire, especially the smoldering fire (smoke is not observed at a temperature of about 200 ° C and only a burning smell is generated). For example, a method of detecting a fire based on a change in the resistance value of a semiconductor element due to these released gases is being studied.

[0003]

However, in the above method, it is difficult to selectively detect only the smell at the time of the initial fire. SUMMARY OF THE INVENTION It is an object of the present invention to solve the conventional problems as described above and to provide a fire detection method and apparatus capable of accurately detecting a fire, particularly a specific substance generated at the time of an initial fire.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors were able to solve the above-mentioned conventional problems. That is, the first aspect of the present invention is that the m / z value (mass number / charge number) detected by mass spectrometry of air sampled from the monitored area is 100 or more m / z of at least one substance generated by fire. It is intended to provide a fire detection method characterized in that it is determined that a fire occurs when a z value is included. A second aspect of the present invention is that the m / z value (mass number / charge number) of a substance generated by a fire is registered in one or more registration means in advance, and air sampled from the monitored area is subjected to mass spectrometry. Then, the m / z value of the substance detected by the mass spectrometry and the m / z
The present invention provides a fire detection method characterized by comparing values with at least one of the m / z values and determining that the fire has occurred when at least one of the m / z values matches. Further, a third aspect of the present invention is that
Mass spectrometry means for mass spectrometry of air sampled from the monitored area, registration means for registering one or more m / z values of substances generated by fire, and m / z detected by the mass spectrometry means Determining means for comparing a value with an m / z value registered in the registering means, and determining that a fire has occurred when at least one of the two m / z values coincides with each other. A fire detection device is provided.

Hereinafter, the present invention will be described in more detail. The present invention is to detect an initial fire, particularly a smoldering fire, with very high accuracy by measuring a specific substance generated at the time of an initial fire using a mass spectrometer.

In the present invention, means for detecting a specific substance generated in an initial fire can be generally performed using a mass spectrometer. Usually, a mass spectrometer has an ionization unit,
It is composed of a mass separation unit and an ion detection unit.

In the present invention, the air sampled from the monitored area is first ionized in the ionization section. The ionization performed in the ionization section can be performed by various methods. Among them, the so-called soft ionization method, which uses ⁶³ Ni, an atmospheric pressure ionization method in which a sample is ionized by β rays emitted from the liquid, a liquid ionization method, It is preferable to use an electrospray method or the like in which a sample is ejected from a thin tube to which a high electric field is applied, because a substance as described below can be analyzed with high accuracy. Subsequently, the ionized sample is preferably measured using a quadrupole mass spectrometer.

In the following, a case where an electrospray method is used as a soft ionization method will be described as an example. Specific substances generated in the initial fire include, for example, substances generated when cellulosic substances are burned. The present inventors have found that when cellulosic cotton, wood, cellulose powder, and paper are heated in the air at a low temperature of 300 to 400 ° C., a substance having an m / z value of 185 is commonly generated. Substances having an m / z value other than 185 have very low peak intensity in mass spectrometry, and were found to be the main component when the cellulosic material was heated at a low temperature.

Another example is a polymer such as a resin. It is known that when a polymer substance is subjected to mass spectrometry, ionized fragments such as monomers, dimers and the like constituting the polymer substance are detected.
When urethane resin, polypropylene and epoxy resin are baked at a low temperature, the m / z value is 98, 125, 245 for urethane, 348, 376, 390 for polypropylene, and 3 for epoxy resin.
It was found that there were specific peaks at positions of 360, 375, 391 at 00 ° C. heating and 202, 278, 388 at 350 ° C. heating. Each of the above m / z values is considered to be a cause of smell usually called burnt odor, and about 1
It is considered that those having a value of 00 or more have characteristics.

[0010] The m / z values of the above substances and / or other substances which are considered to be easily sunk by the initial fire (when sunk) are registered in the registration means and detected by the mass spectrometry means. M / z value registered in the registration means
When at least one of the values matches the z value, the determination unit determines that the fire has occurred. Note that the m / z value of each of the above substances is a value obtained when ionization is performed by an electrospray method, and when another ionization method is used, the m / z value naturally changes. In that case, the m / z value obtained by each ionization method may be registered in the registration unit.

FIG. 1 is a block diagram of a fire detecting device according to the present invention.
It was shown to. In FIG. 1, 1 is a microprocessor MP
U, 2 is a ROM in which a program for detecting a fire is stored, 3 is a ROM in which the names of combustible materials and data relating thereto are stored, 4 is an m / z value M corresponding to the names of the materials in the ROM 3 , A ROM for storing the number N thereof, 5 a working RAM, 6 an R for storing a substance name to be monitored.
AM and 7 are RAMs for storing the peak values selected from the mass spectrometer 11 by the data analysis unit 10, 8 is a display such as a display (an alarm unit such as a buzzer may be provided), and 9 is a numeric keypad. Operation unit such as
Is a data analyzer for processing the spectrum data from the mass spectrometer 11 and selecting only necessary peak values, 11 is a mass spectrometer having a sampling tube 17, and 12 is a signal transferring to a fire receiver or the like (not shown). Signal transmission / reception units 13, 14, 15, and 16 composed of serial-parallel converters and the like for reporting are interfaces.

FIG. 2 shows the contents stored in the ROM 3 and the ROM 4. Basically, the substance name is stored in the ROM 3, and the m / z value is stored in the ROM 4. For example, in the ROM 3, the number of substances A and their m / z values N
ROM 4 storing ₁ and m / z values M ₁₁ , M ₁₂ ,...
Is the leading address AD ₁ is stored in similarly, the head address AD ₂ the number of substance B and the molecular weight N ₂ and m / z value M _21, M _22, · · · are stored, substance C and the start address A
D ₃ , the substance D, the head address AD _{4, and the} like are stored.
The ROM 4 first stores the number N ₁ of m / z values at the position of the address AD ₁ and then stores the m / z values M ₁₁ , M ₁₂ ... At the position of the address AD _2. Number of values N ₂ and m / z
The stored value M _21, M ₂₂ · · ·, similarly with respect to materials of ROM 3, the number N and m / z value M of m / z values are continuously stored.

FIGS. 3 and 4 are block diagrams of the ROM 2
Shows a flowchart of a program to be incorporated in the program. First, it is assumed that the variable R has been reset to 0 in advance. When the substance stored in the ROM 3 is designated from the operation unit 9, YES is determined in step S1, the variable R is incremented, and the number R of the designated substance is set (S2). The substance stored in the ROM 3 is read from the operation unit 9 and the contents are stored in the RAM 6 (S
3). Steps S2 and S3 are repeated each time designation is performed. When the designation is completed, NO in step S1
Is read, and all the peak values detected by the mass spectrometer 11 are read from the data analysis unit 10 and stored in the RAM 7 (S4). Next, r is reset (S5), after r is incremented (S6), reads the start address AD ₁ and material A from the RAM 6 (S7), the first number N ₁ from the position of the address AD ₁ of ROM4 Read (S
8). Then n is reset (S9), after n was incremented (S10), reads the unique m / z value M ₁₁ in material A (S11), searches for peak value in the RAM7 there is a peak (S12). If there is a peak, YES is determined in step S13, and in step S14, if n does not match N, the process returns to S10 and another m /
Search Similar for z values M _12. On the other hand, if n = N, that is, a predetermined number of m / z values specific to the substance A are detected,
A fire is displayed on the display unit 8 (S15). And RAM6
The substance name is read in (S16), and the substance name is displayed on the display unit 8 (S17). Here, if r = R, the process returns to S1, and if r does not match R, the process returns to S6. On the other hand, in step S13, the m / z value specific to the substance A is stored in the RAM 7
If it is determined that the peak value is not within the range, step S
Proceed to 18 to perform the same for the next substance B. And
After searching all the specified substances, the peak value detected by the mass spectrometer 11 is read from the data analysis unit 10 again, and the m / z value is similarly searched.

[0014]

The present invention will be described below with reference to examples. Example 1 In order to set a specific m / z value for a given substance, a sample was prepared using a cellulosic material (cellulose powder, wood, cotton,
Filter paper) and plastic materials (urethane resin, polypropylene, epoxy resin), and these materials were calcined. Details of the test are shown below. The heating conditions were as follows: cellulose powder at 300 ° C, 350 ° C, 400 ° C, and wood at 35 ° C.
0 ° C, 400 ° C, cotton at 350 ° C, urethane resin at 350 ° C, polypropylene at 350 ° C, and epoxy resin at 300 ° C and 350 ° C. First, on a ceramic heater, a sample is placed in a 20-ml sample bottle so that all the substances generated by heating can be collected in the sample bottle. In this way, the substance emitted from the heated sample is removed. The sample was attached to the inner wall of the bottle. After heating for about 5 minutes, add methanol aqueous solution (1: 1) 3 to the sample bottle.
ml was added, the sample bottle was capped and shaken. There was no residue in the sample bottle. The sample solution thus prepared was collected with a syringe and analyzed by a mass spectrometer using an electrospray method (ES) as an ionization means. The mass spectrometer used and its conditions of use

A mass spectrometer, TSQ700 (supplied with ESI) manufactured by Finnigan Matt Co., Ltd., an applied voltage of ES, 4.7 KV in a positive mode, and sample loading were performed at about 3 μl / min.

The results are shown in FIGS. In each figure, the vertical axis indicates the peak intensity, and the horizontal axis indicates the m / z value. m /
There are many strong peaks at z values of 50 or less, which are due to the aqueous methanol solution and appear as the background. Therefore, all the peaks determined by the test take background into account.

Each sample shown in FIG. 5 is a cellulosic material, and a strong peak was obtained at m / z = 185 in common. It seems that this peak allows monitoring of all normal cellulosic materials. other than this,
Similar results were obtained for fibers (cotton), and for cellulose powder, 300 ° C, 350 ° C, and 400 ° C.
And the heating temperature was changed, but in all cases, m / z = 185
A strong peak was observed. This peak is considered to be due to the basic molecular weight M = 162 of the cellulose skeleton.

FIGS. 6 to 9 show synthetic resins other than cellulose. Therefore, a peak at m / z = 185 was not obtained, and characteristic peaks were obtained.
When the urethane resin was heated at 350 ° C. (FIG. 6), strong peaks specific to m / z values of 98, 125, and 245 were obtained.
Polypropylene consisting of simple monomer repeats (FIG. 7) resulted in a number of periodic peaks with m / z values of 348, 376, and 390.

FIGS. 8 and 9 show epoxy resins often used for adhesives and the like. For heating at 300 ° C., m
/ Z = 360, etc., a strong peak was obtained. However, heating at 350 ° C. promoted thermal decomposition, so that a low value of m / z (2
02, 278, 388). This indicates that the obtained peak changes depending on the state of the fire, and therefore it is better to set a plurality of sets of peaks when setting. In this experimental example, the measurement was performed for each of the above substances. However, other substances, for example, polystyrene and polyvinyl chloride can also be used, and it is estimated that styrene is around 104 and methyl methacrylate is 100 or the like.

From the above results, if the m / z value peculiar to each material is registered in the registration means, the substance generated by the initial fire can be detected. FIG. 10 shows a schematic configuration diagram of a fire detection device according to the present invention. This apparatus 11 employs a so-called electrospray method as an ionization method. Air from the monitored area is drawn by a pump 18 via a sampling tube 17. At the narrow part of the sampling tube 17, an aqueous methanol solution (1: 1) is discharged from the tip of the narrow tube 20 while being cooled by the surrounding cooling tube 19. If smell molecules exist in the air sampled here,
The pits 21 of the sampling pipe 17
Deposited on The aqueous methanol solution in which the odor molecules are dissolved is introduced into the mass spectrometer 11 and subjected to mass analysis by an electrospray method. The constriction of the sampling tube 17 and the cooling tube 19 are for facilitating aggregation of odor molecules. The method for collecting odor molecules according to the above configuration is necessary because an electrospray method is used. When an atmospheric pressure ionization method for ionizing odor molecules in a high-pressure electric field is used, the odor molecules are directly introduced into the mass spectrometer 11. May be.
In the atmospheric pressure ionization method, it is better to heat the sampling tube 17. By using the above apparatus, the m / z value specific to each material is registered in the registration means, and the m / z value of the substance generated by the initial fire and the plurality of m / z values to be registered are registered. It is accurate when they match, but when at least one matches, it is judged as a fire by the judging means.

[0021]

According to the present invention, there is provided a fire detecting method and apparatus capable of accurately detecting a specific substance generated particularly at the time of an initial fire, whereby a fire is detected during the initial fire and damage is prevented. The least difficult to stop.

[Brief description of the drawings]

FIG. 1 is a block diagram of a fire detection device according to the present invention.

FIG. 2 is a diagram showing contents stored in a ROM 12 and a ROM 13;

FIG. 3 is a ROM1 of a block diagram of a fire detection device of the present invention.
FIG. 2 is a diagram showing a flowchart of a program incorporated in the first embodiment.

FIG. 4 is a ROM 1 of a block diagram of a fire detection device of the present invention.
FIG. 2 is a diagram showing a flowchart of a program incorporated in the first embodiment.

FIG. 5 is a diagram showing a mass spectrum of a substance generated when a cellulosic material is smoked.

FIG. 6 is a diagram showing a mass spectrum of a substance generated when the urethane resin is baked.

FIG. 7 is a diagram showing a mass spectrum of a substance generated when sintering polypropylene.

FIG. 8 is a view showing a mass spectrum of a substance generated when an epoxy resin is calcined at 300 ° C.

FIG. 9 is a view showing a mass spectrum of a substance generated when an epoxy resin is sintered at 350 ° C.

FIG. 10 is a schematic configuration diagram of a fire detection device of the present invention.

FIG. 11 is an enlarged view of a main part of FIG. 10;

Continuation of the front page (56) References JP-A-5-89387 (JP, A) JP-A-5-89384 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08B 17 / 00-17/12

Claims (7)

(57) [Claims] 1. An m / z value (mass number / charge number) detected by mass analysis of air sampled from a monitored area.
But 100 of at least one substance caused by fire
A fire detection method, wherein a fire is determined when the m / z value is included. 2. An m / z value (mass number / charge number) of a substance generated by a fire is registered in one or more registration means in advance, and air sampled from a monitoring area is subjected to mass analysis. Comparing the m / z value of the substance detected by the mass spectrometry with the m / z value of the substance registered in the registration means,
A fire detection method, wherein a fire is determined when at least one of the two m / z values matches. 3. The method according to claim 1, wherein an m / z value (mass number / charge number) of the substance generated by the fire is 185. 4. An m / z value (quality ) of a substance generated by a fire.
Quantity / charge number) is 125 or 245 for urethane
Yes, 348, 376 or 390 for polypropylene
And 360, 375, 391, and 2 for epoxy resin.
02, 278 or 388, and 104 for styrene.
And 100 for methyl methacrylate.
3. The method according to 1 or 2. 5. Mass spectrometry means for mass spectrometry of air sampled from a monitoring area, and registration means for registering at least one m / z value (mass number / charge number) of a substance generated by a fire. Comparing the m / z value detected by the mass spectrometry means with the m / z value registered in the registration means, and judging a fire when at least one of the two m / z values coincides with each other. Means, and a fire detection device. 6. m / z value registered in the registration means (mass number / charge number), including m / z = 185, according to claim 5. 7. The m / z value (quality ) of a substance generated by a fire.
Quantity / charge number) is 125 or 245 for urethane
Yes, 348, 376 or 390 for polypropylene
And 360, 375, 391, and 2 for epoxy resin.
02, 278 or 388, and 104 for styrene.
, And the claims are methyl methacrylate is 1 00
5. The method according to 5.