JPH044204Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to an air pump that sucks and recirculates sampling air to the detection section of a particulate detection device that measures dust concentration and particle size distribution in a gas to be measured. The present invention relates to an air pump for a particulate detection device that can supply air to the detection section in a stable state on the discharge side.

BACKGROUND TECHNOLOGY As shown in FIG. 2, a particle detection device guides a gas to be measured containing dust particles in the direction of an arrow A to a detection unit 2 provided on the optical axis of a light emitting source 1 such as a laser oscillator. The light beam intersects with the light beam emitted from the light emitting source 1, and when the light beam hits floating particles in the gas to be measured, the scattered light is collected by a condenser lens 3, and detected by a photographic lens 4. This measures the dust concentration and particle size distribution in the gas to be measured. The air pump 5 sucks the gas to be measured into the detection section 2 and causes the sampling air that has passed through to flow back to the detection section 2 again.

As shown in FIG. 3, the air pump 5 conventionally includes a motor 6 as a power source, and a first suction/discharge section 7a and a second suction/discharge section of a diaphragm type, for example, for sucking and discharging sampling air. 7b, and the first and second suction/discharge portions 7
suction pipes 8a and 8b connected to the suction sides of the first and second suction and discharge portions 7a and 7b;
It has discharge piping 9a and 9b connected to the discharge side of
b were combined into one by a joint 11 to form a discharge port. In addition, in FIG. 3, symbols 12a and 12b
are the first and second suction and discharge portions 7a and 7b, respectively.
1 is a pump head, and reference numeral 13 is a mounting member.

Problems that the invention attempts to solve However, in such an air pump 5,
Since the discharge side air of the first and second suction and discharge portions 7a and 7b is directly led to the joint 11 which becomes the discharge port via the discharge piping 9a and 9b, respectively, the state fluctuation of the discharge side air will be prevented after that. This directly affected the condition of the piping system. In particular, when the suction and discharge parts 7a and 7b are of the diaphragm type, the sampling air is sent out by the reciprocating motion of the diaphragm in the suction and discharge parts 7a and 7b, which may cause pulsations in the air on the discharge side. The indications on the flowmeters 14a and 14b fluctuate, or
The sampling air flowing back to the detection section 2 also pulsated, making accurate measurements impossible. Furthermore, since the diaphragm reciprocates and compresses the sampling air and sends it out, the temperature of the discharge side air rises, and it is cooled and condensed in the piping route that flows back to the flowmeters 14a, 14b and the detection section 2. Something happened. In this case as well, the accuracy of measurement was affected. Furthermore, exhaust noise is generated on the discharge side due to wind noise caused by the reciprocating motion of the diaphragm, but simply connecting a piping system such as a tube to the joint 11 hardly achieves a noise reduction effect and is noisy. Therefore, the present invention aims to solve such problems.

Means for Solving the Problems The means of the present invention for solving the above problems has a suction/discharge section that is driven by a power source and sucks in air and discharges it. In the air pump of the particulate detection device, which sucks the gas to be measured into the detection section provided in the sensor and returns the air after passing through to the detection section, an air chamber of a predetermined volume is connected to the discharge side of the intake and discharge section. This is accomplished by an air pump of a particulate detection device characterized in that air is circulated from the discharge port of the air chamber to the detection section.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a perspective view showing an air pump of a particle detection device according to the present invention. This particulate detection device measures the dust concentration and particle size distribution in a gas to be measured containing dust particles, and as shown in FIG. 1, and a detector 2 installed on the optical axis of the light source 1, and a collector that collects scattered light generated when the light beam emitted from the light emitting source 1 hits suspended particles in the gas to be measured sucked into the detector 2. It has an optical lens 3, a photomultiplier 4 for detecting scattered light collected by the condensing lens 3, a signal processing circuit 15 for processing the detection signal, and an air pump 5'.

The air pump 5' sucks the gas to be measured into the detection section 2 and returns the sampling air after passing through to the detection section 2.
, the first suction discharge section 7a and the second suction discharge section 7b, the first suction pipe 8a and the second suction pipe 8b, the first discharge pipe 9a and the second discharge pipe 9b, and the suction It consists of a joint 10 as a port and an air chamber 16. The motor 6 serves as a power source for driving the first and second suction and discharge sections 7a and 7b. A first suction/discharge section 7a and a second suction/discharge section 7b are provided at both end portions of the motor 6. These suction and discharge parts 7a and 7b are for suctioning and discharging sampling air, and have a diaphragm inside that moves reciprocally by the drive of the motor 6, and the reciprocating movement of this diaphragm sucks the sampling air with negative pressure. At the same time, it is compressed and sent out. Pump heads 12a and 12b are provided at the upper ends of these suction and discharge parts 7a and 7b, respectively, and each pump head 12a and 12b has a suction side joint 17a and 17b and a discharge side joint 18, respectively.
a, 18b are provided. A first suction pipe 8a and a second suction pipe 8b are connected to the suction side joints 17a and 17b, respectively, and the other ends of these suction pipes 8a and 8b are joined together by a joint 10. Collectively, they are considered an inlet. In addition, the joints 18a and 18b on the discharge side are provided with a first discharge pipe 9a and a second discharge pipe 9b, respectively.
are connected. The reason why the two suction and discharge sections 7a and 7b are provided as described above is to increase the flow rate of the sampling air as much as possible.

Here, in the present invention, an air chamber 16 is connected to the other end sides of the first discharge pipe 9a and the second discharge pipe 9b. This air chamber 16 includes the first and second suction and discharge portions 7a,
It serves as a buffer that temporarily receives the air discharged from 7b, and is made of a material with excellent corrosion resistance and heat resistance, such as stainless steel, and is formed into, for example, a cylindrical shape having a predetermined volume as a buffer zone. In addition, a suction side joint 19a provided on the side surface of the air chamber 16,
The other ends of the first discharge pipe 9a and the second discharge pipe 9b are respectively connected to 19b, and a discharge port 20 is provided on one side end surface.

Next, the operation of the air pump 5' configured as described above will be explained. First, when the motor 6 is driven, the diaphragms in the first and second suction and discharge parts 7a and 7b reciprocate, and the negative pressure causes sampling air to be sucked in from the joint 10 as a suction port as shown by arrow B. The water flows into the first and second suction pipes 8a and 8b as shown by the broken line arrows. Next, each pump head 12a, 1
2b, the first and second discharge pipes 9a, 9 are compressed by the reciprocating movement of the diaphragm.
b, and is discharged into the air chamber 16 through the respective joints 19a and 19b, as indicated by the broken line arrow. Here, the air chamber 16
has a predetermined volume as a buffer zone with respect to the discharge amount of the first and second suction and discharge portions 7a and 7b, so that the pulsation of the sampling air is suppressed by temporarily flowing into the inside of this air chamber 16. is removed, the temperature is lowered, and a sound silencing effect is also obtained. In this state, the sampling air is discharged from the outlet 2 of the air chamber 16.
0 as indicated by arrow C, and is returned to the detection unit 2 shown in FIG.

Effects of the invention As explained above, the invention has the suction and discharge part 7.
An air chamber 16 having a predetermined volume is connected to the discharge side of the air chambers a and 7b, and this air chamber 1
Since the sampling air is circulated from the discharge port 20 of No. 6 to the detection section 2, the buffering action of the air chamber 16 causes the sampling air
Even if there is a change in the state of the discharge air from a, 7b, the pulsation of the discharge air can be eliminated and the temperature can be lowered and stabilized. Therefore, sampling air can be circulated to the detection section 2 in a stable state. From this, it is possible to make the measurement in the particulate detection device accurate and to improve its accuracy. Furthermore, the buffering effect of the air chamber 16 provides a noise reduction effect, reducing exhaust noise and allowing quiet operation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an air pump of a particle detection device according to the present invention, FIG. 2 is a block diagram schematically showing the particle detection device, and FIG. 3 is a perspective view showing a conventional air pump. 1... Light emitting source, 2... Detection unit, 5'... Air pump, 6... Motor (power source), 7a, 7b...
Suction and discharge part, 8a, 8b...Suction piping, 9a, 9
b...Discharge piping, 10...Joint, 16...Air chamber, 20...Air chamber discharge port.

Claims (1)

[Scope of utility model registration request] It has an intake/discharge section driven by a power source that sucks in air and discharges it, and sucks the gas to be measured into a detection section provided on the optical axis of the light beam from the light source, and detects the air after passing through it. The air pump of the particulate detection device is characterized in that an air chamber of a predetermined volume is connected to the discharge side of the suction/discharge section, and air is circulated from the discharge port of the air chamber to the detection section. Air pump for particulate detection equipment.