This application claims priority of Taiwanese Application No. 102207777, filed on Apr. 26, 2013.
1. Field of the Invention
The invention relates to a sampling device, particularly to a sampling device adapted for sampling dissolvable airborne components.
2. Description of the Related Art
Airborne Molecular Contamination (AMC) is not only potentially harmful to human bodies, but also impacts negatively on yield rates in fine precision industries such as in semiconductor manufacturing. Due to miniaturization of semiconductor devices, the controlling of AMC is becoming ever more critical.
Currently, AMC detection involves sampling airborne components by having the same dissolved in liquid and analyzing the ion density of the liquid having airborne components dissolved therein using ion chromatography. For easier sampling, Taiwanese Patent No. M378380 discloses a conventional sampling device which uses a dialysis membrane to separate a gas channel from a liquid channel to prevent oily organic gas from attaching to a liquid channel wall that defines the liquid channel, which would otherwise hinder airborne components in the gas channel from being dissolved in liquid in the liquid channel. However, since airborne components have to penetrate the dialysis membrane to reach the liquid, some may be attached to the membrane without ever reaching the liquid, hence affecting the test result.
Another conventional technique utilizes a porous glass coated with TiO2 nanoparticles to form a super-hydrophilic surface. This conventional technique uses relatively expensive materials and has relatively great manufacturing complexity.
Therefore, the object of the present invention is to provide a sampling device adapted for sampling airborne components and capable of eliminating the aforesaid drawbacks of the prior art.
According to the present invention, there is provided a sampling device adapted for sampling airborne components and including a gas guiding unit and a liquid guiding unit.
The gas guiding unit includes a first plate that has a top surface formed with a gas outlet, a bottom surface formed with a gas inlet, and a first abutment surface interconnecting the top and bottom surfaces, and formed with upper and lower guiding grooves. The upper and lower guiding grooves are proximate respectively to the top and bottom surfaces, and communicate fluidly and respectively the gas outlet and the gas inlet.
The liquid guiding unit includes a second plate that has a second abutment surface and a side surface. The second abutment surface abuts against the first abutment surface and is formed with a passage groove that is defined by a groove-defining surface. The passage groove has a top groove portion, a bottom groove portion and an intermediate groove portion that interconnects the top and bottom groove portions, and that has a depth smaller than those of the top and bottom groove portions. The passage groove communicates fluidly the upper and lower guiding grooves of the gas guiding unit, and a side surface formed with a liquid inlet that is in fluid communication with the top groove portion, and a liquid outlet that is in fluid communication with the bottom groove portion.
The liquid guiding unit further includes a liquid-retaining mechanism that includes a liquid-retaining net clinging to the groove-defining surface of the liquid guiding unit so that liquid introduced into the top groove portion via the liquid inlet forms a liquid membrane on the liquid-retaining net through capillary action.
Gas introduced into the lower guiding groove via the gas inlet flows into the upper guiding groove through the passage groove with airborne components contained therein dissolving in the liquid membrane. The liquid containing the dissolved airborne components flows into the bottom groove portion and exits the sampling device via the liquid outlet.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
With reference to
With reference to
The liquid guiding unit 20 further includes a stop plate 4 connected watertightly to the second plate 2 and cooperating with the second plate 2 to define the bottom groove portion 24. In this embodiment, the liquid inlet and outlet 231, 241 are formed in the same side surface 25, but the liquid inlet and outlet 231, 241 may be disposed on opposite sides should it be required in practice.
The liquid-retaining mechanism 3 is disposed on the second plate 2 and includes an anchor plate 31 and a liquid-retaining net 32. The anchor plate 31 is mounted to the second plate 2 by two screwing bolts 33, and is disposed adjacent to the top groove portion 23 for holding the liquid-retaining net 32 to cling on the groove-defining surface 221. Liquid introduced into the top groove portion 23 via the liquid inlet 231 forms a liquid membrane on the liquid-retaining net 32 through capillary action. Gas introduced into the lower guiding groove 15 via the gas inlet 17 flows into the upper guiding groove 16 through the passage groove 22 with airborne components contained therein dissolving in the liquid membrane. The liquid containing the dissolved airborne components flows into the bottom groove portion 24, is guided by the inclined bottom section 242 of the groove-defining surface 221 to exit the sampling device 100 via the liquid outlet 241, and then may be extracted by the liquid pump as a sample for subsequent use in ion chromatography. The liquid-retaining net 32 preferably has 100 to 400 meshes per square inch and may adopt commercially available mesh used in household screen windows and doors.
The operation of the sampling device 100 according to the preferred embodiment of the present invention is described in detail as follows.
Liquid used for sampling the airborne components is introduced into the top groove portion 23 via the liquid inlet 231, flows down to the liquid-retaining net 32, spreads over the liquid-retaining net 32 to form a liquid membrane through capillary action, slowly flows down to the bottom of the liquid-retaining net 32 and then the bottom groove portion 24, and eventually exits the passage groove 22 via the liquid outlet 241.
Gas containing airborne components is introduced into the lower guiding groove 15 via the gas inlet 17 and guided by the inclined groove surface 152 into the passage groove 22. The gas is in contact with the liquid membrane as the gas flows upwards along the liquid membrane and the airborne components in the air are dissolved in the liquid membrane. After passing the passage groove 22, the gas continues flowing upwards to the upper guiding groove 14 via the inclined groove surface 142 and eventually exits the gas outlet 16.
As described previously, the liquid would flow downwardly along the liquid-retaining net 32, having the airborne components dissolved therein along the way, and is collected at the bottom groove portion 24 and extracted from the liquid outlet 241 for testing for Airborne Molecular Contamination (AMC).
The liquid membrane formed on the liquid-retaining net 32 increases a contacting surface between the liquid and the gas, and the gas is exposed directly to the liquid to effectively increase the airborne component absorption efficiency of the liquid. Comparing to the conventional sampling device, the liquid-retaining net 32 of the present invention provides the same absorption surface with a reduced amount of liquid, thereby saving on the usage of the liquid. In addition, the liquid retaining net 32 is easily accessible, and can be mounted to the second plate 2 with ease, thereby simplifying the manufacturing process and reducing cost.
The sampling device 100 of the present invention can be adapted for use with testing instruments to function together as a sampling and testing system.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Number | Date | Country | Kind |
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102207777 | Apr 2013 | TW | national |