JPH0126016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sample collection device for dust particle size distribution. This allows the time-dependent changes in elemental composition by diameter to be determined.

Conventionally, a so-called cascade impactor is most commonly known as a dust particle size distribution measuring instrument. As shown in Figure 1, a large number of cannulae are connected in sequence by tightening them with thumbscrews, and a cavanie is installed, which has a sample gas inlet in the upper end of the cannula and a suction inlet in the lower end of the cannula. A shallow container-shaped dust collector is attached to the spout of the nozzle hoop connected and fixed to each mantle, and the inner diameter of each nozzle spout and the distance between the spout and the dust collector are adjusted downward. The structure is such that the closer they are to each other, the smaller they are formed and arranged facing each other.

In this device, the suction port C is connected to a vacuum pump, and the sample gas that enters the inlet port B is sequentially ejected from the nozzle and sprayed onto the top surface of each dust collector, and then the thumbscrews are loosened and each Each tube is disassembled and the dust accumulated on the top surface of each dust collector is weighed and the particle size distribution is measured.
In order to obtain a collected sample every unit time with this device, it is necessary to repeatedly disassemble and assemble the entire device each time, which is inconvenient from a practical standpoint.

In contrast, the present invention is configured such that several dust collectors corresponding to each nozzle are formed into a set of assemblies so that dust collection is continuously performed every unit time. , an embodiment of the present invention will be described with reference to the drawings, as shown in FIG. 2A,
A cylinder chamber 4 divided into several stages by upper and lower partitions 3 is formed by sequentially stacking shallow container-shaped envelopes 2 on the upper surface of the control box 1, and further divides the inside of the cylinder chamber 4 vertically into each stage. A through hole is provided in the hole, and a funnel-shaped nozzle 5 is attached to each hole, and a vertical shaft 6 is skewered between the upper and lower partitions 3, and several rotating disks 7 are inserted into each of the holes. A part of the periphery is inserted into a slit provided in the vertical partition 8, and the nozzle 5 is installed by inserting it downward.The vertical shaft 6 is rotated continuously or intermittently at a low speed via a drive device provided in the control box 1. I'm starting to do that.

The rotating disk 7... may be circular as shown in FIG. 2B and can be used for either continuous or intermittent rotation, or it may be a large number of small disks 7' on the edge frame as shown in FIG. 2C. . . , and the small disks rotate intermittently at intervals of one interval.

Further, the nozzle 5 may have a funnel-shaped bottom portion 5' formed either as a single hole as shown in FIG. 2D or as a honeycomb-shaped multi-hole portion as shown in FIG. 2E.

In FIG. 2A, the required sample gas to be measured is supplied to each sample gas inlet 10 arranged on the outer peripheral surface of the sealing cover 9 provided at the upper end of the cylinder chamber,
After successively passing through the nozzles 5..., the dust is sucked into the filter holder 11 at the lower end connected to the vacuum pump of the control box, and the contained dust is transferred to the rotating disk 7... located below each nozzle 5... The dust is deposited on the top surface of each dust collector, and after rotating the rotating disk 7 continuously or intermittently as described above to form a dust accumulation layer on the top surface of the rotating disk 7 at regular intervals, By sequentially removing the mantles 2 and extracting the rotating disks 7 from the vertical shaft 6, the time-based particle size distribution of each deposited dust can be measured.

FIG. 3 shows a modification of the device shown in FIG. 2, in which each part is designated by the same reference numerals as in FIG. Figure 3A
The rotating disks 7... each have a main gear 12 fitted and fixed therein to the vertical shaft 6, and a main gear 12.
It is formed as a disc-shaped gear case housing several secondary gears 13 surrounding the rotating disc 7, which is connected to the shaft of the secondary gears 13, and has several small discs 7' on its upper surface. is installed. In this case, the nozzle 5 is provided with a large number of holes so that dust can be collected uniformly on the disk by rotation of the small disk 7'. The center lines of these small circular plates 7' are located directly below the center of the nozzles 5, so that the jets from the nozzles 5 are directed over the entire upper surface of the small circular plates 7'.

As is clear from FIGS. 3B and 3C, inside the rotating disk 7, there is a main gear 1 which is fitted onto the vertical shaft 6 and rotated.
Several auxiliary gears 13 are engaged and accommodated surrounding the main gear 2, and furthermore, a regulating pawl 14 is attached which is pressed to one side by a spring and limits the rotation of the main gear and the auxiliary gear to one direction. Therefore, when the vertical shaft 6 is rotated in the counterclockwise direction as shown in FIG. 3B, the auxiliary gears 13 that engage with the large gear 12 also rotate, and the small discs 7'... rotates individually, but the rotating disk 7 itself does not rotate. Furthermore, when the vertical shaft 6 is rotated in the clockwise direction shown in the figure, the rotating disk 7 itself rotates due to the engagement of the regulating pawl 14 as shown in FIG. '...does not rotate.

With this structure, in the apparatus shown in FIG. 3, the sample gas supplied through the sample gas inlet 10 sequentially passes through the nozzle 5 and rotates the rotating disk 7' below the nozzle. By setting the operation panel of the control box in advance, when the dust collides with the
When rotated in the direction shown in Figure B and the small disk 7'... is rotated once, the center of the nozzle 5... coincides with the center of the small disk 7' below it, so the nozzle 5...
...Dust is uniformly accumulated on the small disks 7' of each lower stage over a predetermined period of time, for example, one hour per rotation. Next, the rotary disks 7 are rotated in the opposite direction, that is, in the direction shown in FIG. By repeating this,
Time-specific dust is obtained for each small disk 7'...
It is advantageous for long-term continuous measurement.

As explained above, in the present invention, the dust collector in the conventional device has a single fixed surface, but is formed on a rotating plate so that the dust can be collected divided into multiple surfaces. Therefore, the particle size distribution of dust can be further subdivided by time, and the dust can be collected uniformly on the collection surface for chemical analysis, which is extremely efficient.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional front view of a conventional device, FIG. 2A is a cross-sectional front view of the device of the present invention, FIGS. 2B and C are plan views showing an example of the rotating disk in FIG. 2A, and FIG. Figures 2D and E are respectively partially sectional front views showing an example of the nozzle, Figure 3A is a sectional front view showing another example of Figure 2A, and Figures 3B and C are respectively Figure 3A. FIG. 2 is a plan view showing the inside of a rotating disk in FIG. 1... Control box, 2... Mantle, 3... Upper and lower partition,
4... Cylinder chamber, 5... Nozzle, 6... Vertical axis, 7...
Rotating disk, 7'...Small disk, 10...Sample gas inlet, 11...Filter holder, 12...Main gear, 13...Secondary gear, 14...Regulation claw.

Claims (1)

[Claims] 1 Consists of a housing that can be separated into individual parts, with the interior divided into several upper and lower stages, and a sample gas inlet at the top end,
Inside a cylindrical chamber with a sample gas suction port at the bottom, several rotating disks are inserted through the vertical axis connected to the control mechanism, and a portion of each disk is inserted into several upper and lower stages defined in each of the above-mentioned stages. A sampling device for dust particle size distribution for a sample gas, which is arranged so as to face below a nozzle, and the upper surface of these rotating disks is formed as a dust collection surface.