Cyclone separator type mass analyzing system

Provided is a small-sized mass analysis system capable of analyzing an analysis target system being under atmospheric pressure. The mass analysis system (7) has a cyclone separator (1) including a hollow shaft motor (19) for rotationally driving a turbo blade (17). Combining a mass analysis device with the cyclone separator makes it possible to remove dust and introduce into the mass analysis device a gas present in a region where the pressure in the cyclone separator is sufficiently reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cyclone separator type mass analyzing system capable of removing dust from a gas containing the dust and performing a mass analysis of a gas in a vacuum system.

2. Description of the Related Art

In recent years, there has been a rising interest in the safety or the environment. For this reason, there is a demand for an apparatus capable of analyzing toxic substances suspended in an atmosphere in real time with high sensitivity.

As analysis apparatuses for a gas, a liquid, and a solid, a mass analyzing apparatus is known. In particular, a mass analyzing apparatus that has a vacuum system is known as mass analyzing apparatus for analyzing mass of a target gas. The mass analyzing apparatus can analyze the substances contained in the target gas. However, the mass analyzing apparatus needs to keep a high state of vacuum. For this reason, when the atmosphere is directly introduced into the mass analyzing apparatus, the analysis precision may be degraded and the inside of the vacuum device may be contaminated.

Japanese Patent Application Laid-Open (JP-A) No. 2008-224246 discloses a particle mass spectrometry. Further, JP-A No. H 07-55689 discloses a particle mass spectrometer. In the particle mass spectrometers disclosed in JP-A Nos. 2006-224246 and H 07-55689, an aerosol is introduced through an aerosol intake pipe, and a gas having plural types of particles suspended therein is classified according to each particle having a predetermined range of a ratio mass (mass of particle/charge), thereby obtaining a particle mass distribution.

SUMMARY OF THE INVENTION

However, even when such a particle mass spectrometer is used, the atmosphere may not be effectively analyzed. This is because the atmosphere contains much dust. For this reason, when the atmosphere is introduced into the particle mass spectrometer, the inside of the vacuum chamber is contaminated, and the analysis precision is degraded. Also, since a small hole (an orifice) used for differential exhaust is blocked, it is difficult to stably operate the mass analyzing apparatus. As a method which does not introduce dust into a vacuum, a method may be supposed in which a filter is installed at the front stage of a vacuum chamber. However, when a fine filter is used, not only dust but also a target gas for analysis may be absorbed and attached to the inside of the filter. For this reason, the mass analyzing apparatus equipped with the fine filter is not appropriate for the real-time analysis. Meanwhile, fine powders may not be removed in a rough filter.

In this case, a method may be supposed in which a low-vacuum chamber and a middle-vacuum chamber are connected in a tandem manner to the front side of an aerosol intake pipe of a particle mass spectrometer and a gas is introduced into a mass analyzing apparatus after a differential exhaust is performed and the vacuum degree thereof is gradually increased. However, in such a differential exhaust system, the apparatus is great in size.

Therefore, it is an object of the invention to provide a small mass analyzing system capable of analyzing an analysis subject system under the atmospheric pressure.

Basically, the invention is based on knowledge that a gas, from which dust is removed and of which a pressure is sufficiently reduced, may be introduced into a mass analyzing apparatus by combining a cyclone separator with a mass analyzing apparatus. In particular, the invention is based on knowledge that the atmosphere may be adjusted to a state in which the atmosphere may be directly introduced into the mass analyzing apparatus by using a swirl generating device13which is configured by the combination of a turbo blade17and a hollow motor19.

A first aspect of the invention relates to a mass analyzing system7that has: a cyclone separator1; an analyzing apparatus introduction port3that is attached to the cyclone separator1; and a mass analyzing apparatus5that is connected to the cyclone separator1through the analyzing apparatus introduction port3.

In addition, the cyclone separator1has a swirl generating container9, an intake port11that is attached to the swirl generating container9and is used to take a gas into the swirl generating container9, a swirl generating device13that swirls the gas taken into the swirl generating container9, and an exhaust port15that discharges a gas rotationally separated in the gas taken into the swirl generating container9. The mass analyzing apparatus5further has a vacuum system.

The swirl generating device13has a turbo blade17and a hollow motor19that rotationally drives the turbo blade17. The turbo blade17is provided so that the rotation center of the turbo blade17is coaxial with the center of the analyzing apparatus introduction port3. The pressure of the atmosphere may be adjusted to a state in which the atmosphere may be introduced directly into the mass analyzing apparatus5by usingthe swirl generating device13configured by the combination of the turbo blade17and the hollow motor19. That is, with such a configuration, the mass analyzing system of the invention may introduce a gas, from which dust is removed and of which a pressure is sufficiently reduced, into the mass analyzing apparatus5.

A second aspect of the invention relates to a method of analyzing a substance contained in a gas. The method comprises: rotationally separating a target gas contained in a gas by a cyclone separator1; introducing the rotationally separated target gas into amass analyzing apparatus5; and analyzing amass of a substance contained in the target gas introduced into the mass analyzing apparatus5.

The rotationally separating of the target gas comprises ionizing the target gas contained in the gas and accumulating the ionized target gas at the center portion of the cyclone separator1by swirling the target gas contained in the gas and disposing an ion source portion, which may be ionized under the atmospheric pressure through electrospray or discharge ionization, in the swirling gas.

In the introducing of the rotationally separated gas into the mass analyzing apparatus5, the target gas, which is in a low-pressure state due to the rotationally separating of the target gas and is ionized and accumulated at the center portion of the cyclone separator1, is introduced into the mass analyzing apparatus5.

The invention may introduce a gas, which is present in an area where dust is removed by the cyclone separator and the pressure inside the cyclone separator is sufficiently reduced, into the mass analyzing apparatus by combining the cyclone separator with the mass analyzing apparatus. Accordingly, an analysis subject system under the atmospheric pressure may be analyzed. Furthermore, since a pump for the differential exhaust is not needed, the mass analyzing apparatus may be decreased in size. For this reason, although the existing mass analyzing apparatus does not have portability, according to the aspects of the invention, an atmospheric mass analyzing apparatus which has portability may be provided.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1is a schematic diagram illustrating the configuration of a mass analyzing system of the invention. As illustrated inFIG. 1, the mass analyzing system of the invention has a cyclone separator1, an analyzing apparatus introduction port3, and a mass analyzing apparatus5. In the mass analyzing system of the invention, the cyclone separator1is connected to the mass analyzing apparatus5through the analyzing apparatus introduction port3which is attached to the cyclone separator1.

As illustrated inFIG. 1, the cyclone separator1has a swirl generating container9, an intake port11, a swirl generating device13, and an exhaust port15.

The swirl generating container9is a container which causes a gas to swirl therein. In a case where a liquid or a solid is charged in the swirl generating container9, the swirl generating container9may swirl the liquid or the solid. As the swirl generating container9, a swirl generating container which is used in the cyclone separator may be used. With regard to the detailed configuration of the swirl generating container9, as illustrated inFIG. 1, the swirl generating container has a trumpet-like inner wall of which the diameter becomes smaller as it moves downward. The swirl generating container9may be produced from the same material as that of a vacuum chamber. Furthermore, it is desirable to hermetically seal the swirl generating container9by a cover portion.

The intake port11is attached to the swirl generating container9, and is used to take a gas into the swirl generating container9. It is desirable to install the intake port11at the upper portion of the swirl generating container9. One intake port11may be attached to the swirl generating container9or two or more intake ports may be provided. In a case where a plurality of the intake ports11is attached to the swirl generating container9, it is desirable to provide the intake ports11at the positions symmetrical to each other with the swirl generating container9interposed therebetween. A filter may be appropriately installed at the intake portion of the intake port11. Since the intake port11has the filter, comparatively large trash may be removed. Accordingly, it is possible to prevent an accident in which large matters or living bodies (for example, insects) enter the swirl generating container9. The intake port11may be a pipe which has a circular cross-section. In this case, the diameter of the cross-section may be from 1 cm to 10 cm.

The swirl generating device13is a device which swirls the gas taken into the swirl generating container9. Furthermore, in a case where a liquid or a solid is charged in the swirl generating container9, the swirl generating container may swirl them. The swirl generating device13may include a turbo blade17and a hollow motor19which rotationally drives the turbo blade17. In addition, the turbo blade17is provided so that the rotation center of the turbo blade17is coaxial with that of the analyzing apparatus introduction port3. The turbo blade17has already known as disclosed in Japanese Patent No. 3637021.FIG. 2is a diagram illustrating an example of the turbo blade of the invention. As illustrated inFIG. 2, the turbo blade17of the invention has a disk-like rotation plate31and a plurality of vanes33which is installed on the rotation plate31. The plurality of vanes is provided so as to be symmetrical to each other with respect to the center of the rotation plate. In order to forma spiral air stream inside the swirl generating container9, it is desirable to arrange the plurality of vanes so that it is not arranged in a radial shape, but is bent in a predetermined direction. Further, as illustrated inFIG. 2, it is desirable that the plurality of vanes have a portion of which the height from the substrate becomes higher as it moves closer to the center of the rotation plate. Since the turbo blade17has such a shape, the spiral air stream may be effectively generated inside the swirl generating container9. It is desirable that the turbo blade17of the invention have a hole portion formed at the center of the substrate. In addition, it is desirable that the analyzing apparatus introduction port3be installed at the hole portion of the substrate with the hole portion. For example, the size of the hole portion of the substrate may be set such that the diameter is from 0.1 mm to 10 mm or from 0.4 mm to 2 mm. Further, the rotationally separated gas may be guided to a discharge port through the gap between the turbo blade17and the swirl generating container9. The hollow motor19is a motor which has a hollow penetration hole. In the mass analyzing system7of the invention, it is desirable to install the analyzing apparatus introduction port3inside the penetration hole. For example, the diameter of the penetration hole may be from 0.1 mm to 10 mm or from 0.4 mm to 2 mm. For example, the rotation speed of the hollow motor19may be 40,000 rpm or more.

The exhaust port15is a portion which discharges the rotationally separated gas in the gas which is taken into the swirl generating container9. Furthermore, in a case where a liquid or a solid is charged in the swirl generating container9, the exhaust port15is used to discharge the liquid or the solid. That is, the exhaust port serves as a discharge port.

The analyzing apparatus introduction port3is a portion which connects the cyclone separator1to the mass analyzing apparatus5. An example of the analyzing apparatus introduction port3has a gas pipe with an orifice. The analyzing apparatus introduction port3may be configured to introduce the gas inside the cyclone separator into the mass analyzing apparatus5through the hole provided at the center of the substrate of the turbo blade17and the penetration hole of the hollow motor19.

In addition, the mass analyzing apparatus5of the invention is a mass analyzing apparatus with a vacuum system. The invention relates to the mass analyzing apparatus which may be used as various types of mass analyzing apparatuses. Examples of the mass analyzing apparatus include a time-of-flight type, an ion-trap type, a quadrupole type, an FT-ICR type, a magnetic field type, and an ion mobility spectrometry (IMS) type. Among these examples, the time-of-flight type mass analyzing apparatus may be desirably used in the invention. The mass analyzing apparatus5with a vacuum system maintains the inside of the chamber at a high vacuum degree. For this reason, it is difficult to directly analyze the gas contained in the atmosphere. In the invention, the portion of the gas, from which dust is removed by using the cyclone separator1and of which the pressure is low at the swirling center, is introduced into the mass analyzing apparatus5. Accordingly, although a simple apparatus is provided, the apparatus may introduce the gas under the atmospheric pressure thereinto and analyze the elements of the gas.

As a desirable example of the mass analyzing apparatus, a mass analyzing apparatus is disclosed in Japanese Patent No. 4208674, JP-A No. 2005-79049, or JP-A No. 11-135060. The example of the mass analyzing apparatus is a “time-of-flight type mass spectrometer having an input orbit for ion implanting and an output orbit for ion extracting installed in a closed orbit formed by a plurality of sector electrical fields”. In general, the time-of-flight type mass spectrometer has a plurality of vacuum chambers and a plurality of pumps, and has a size of 1 m or more. Thus, generally, the time-of-flight type mass spectrometer is installed in a laboratory. The time-of-flight type mass spectrometer disclosed in Japanese Patent No. 4208674, JP-A No. 2005-79049, or JP-A No. 11-135060 may be decreased in size so that it may be carried. Thus, when the time-of-flight type mass spectrometer is combined with the mass analyzing system of the invention, a portable mass analyzing system may be obtained. Accordingly, there is no need to sample a gas and analyze the gas in the laboratory. Specifically, for example, when a user brings the mass analyzing system of the invention to the desired observation site, the local atmosphere may be analyzed in real time.

FIG. 3is a schematic diagram illustrating the mass analyzing system including an ionization portion and a guide wire. As illustrated inFIG. 3, the mass analyzing system7has an ionization portion21and a guide wire23. In addition, the ionization portion21is installed inside the swirl generating container9, and is used to ionize the gas which is taken into the swirl generating container9. The ionization portion21may be implemented as an available ionization portion if it may ionize the gas taken into the swirl generating container9. Examples of specific ionization method include atmospheric ionization, electrospray ionization, fast atom bombardment ionization, electron ionization, chemical ionization, electrolyte desorption ionization, and electrolyte ionization. In the invention, since it is an object to attract the charged target gas molecules to the guide wire23, atmospheric ionization or electrospray ionization may be desirably used as the ionization method.

The guide wire23is disposed so as to be coaxial with the analyzing apparatus introduction port3inside the swirl generating container9, and is used to attract a gas ionized by the ionization portion21. For this reason, it is desirable that the guide wire23have a charging property. Further, it is desirable that the mass analyzing system7have a voltage supply which is used to apply a potential to the guide wire23.

As another desirable type of the mass analyzing system7, an electrical discharge portion25is installed inside the swirl generating container9.

Next, the operational example of the mass analyzing system7of the invention will be described.FIG. 4is a conceptual diagram illustrating a shape in which the mass analyzing system of the invention is operated. The mass analyzing system7of the invention may be used for a method of analyzing a substance contained in a gas. In addition, the method comprises: rotationally separating a target gas contained in a gas by the cyclone separator1; introducing the rotationally separated target gas into the mass analyzing apparatus5; and analyzing the mass of the substance contained in the target gas which is introduced into the mass analyzing apparatus5.

The rotationally separating of the target gas contained in the gas using the cyclone separator1will be described. An example of the gas is an atmosphere. The gas in the specification may include not only a gas, but also a solid such as fine powder like the atmosphere. The turbo blade17rotates inside the swirl generating container9, so that a spiral air stream is generated as illustrated inFIG. 3. In addition, the gas is introduced from the intake port11into the swirl generating container9. Then, the introduced gas moves downward in a swirling manner. At this time, since heavy substance undergoes a strong centrifugal force, the heavy substance performs a large swirling motion. Meanwhile, since the light substance does not undergo a strong centrifugal force, the light substance performs a comparatively small swirling motion. In this way, the heavy substance is separated to the outside and the light substance is separated to the inside due to the centrifugal force. Accordingly, the gas is centrifugally separated by the specific weight thereof. The gas having a heavy specific weight is guided to the exhaust port15and is discharged to the outside. On the other hand, the swirling motion becomes violent as it moves downward. As a result, a pressure reduction area is formed at the lower center portion of the cyclone separator1. That is, the gas having a light specific weight is accumulated at the center portion of the cyclone separator1so that the pressure is reduced due to the rotationally separating. The pressure reduction area2is illustrated in the drawing. The pressure reduction area2is generated at the center portion of the mass analyzing system7of the invention by using the cyclone separator1. In particular, the portion of the pressure reduction area2near the mass analyzing apparatus becomes a low vacuum state.

Furthermore, the mass analyzing system7which has the ionization portion21and the guide wire23ionizes the gas contained inside the swirl generating container9. The charge which is opposite to the ionization charge is applied to the guide wire23. For example, when the gas is negatively ionized, the guide wire23is positively charged. Then, the ionized gas is attracted to the guide wire23and is accumulated near the center of the cyclone separator1.

In the introducing of the rotationally separated gas into the mass analyzing apparatus5, the gas of which the pressure is reduced and which is accumulated at the center portion of the cyclone separator1by the rotationally separating is introduced into the mass analyzing apparatus5. That is, since the center portions of the turbo blade17and the hollow motor19are hollow and are coaxial with the swirling center of the gas, the gas from which dust or the like is removed and of which the pressure is reduced may be introduced into the mass analyzing apparatus5.

Furthermore, the mass analyzing apparatus has been described so far in which the analyzing apparatus introduction port3and the mass analyzing apparatus5are installed at the downstream area where the gas taken from the intake port11swirls. However, the analyzing apparatus introduction port3may be installed near the intake port11. In this case, molecules (including excited molecules) or ions are emitted from the downstream area. In addition, the molecules or. ions emitted from the emitting portion of the downstream area cause an interaction with the gas which is taken from the intake port11and is rotationally separated. In addition, the gas which has been subjected to the interaction is taken from the analyzing apparatus introduction port3.

An example of the emitting portion has a direct analysis in real time (DART) ion source. Such a DART (registered trademark) ion source is disclosed in, for example, the specifications of Japanese Patent Application National Publication No. 2006-523367, US Patent No. 6949741, and JP-A No. 2007-256246. The entire content of such cited documents is incorporated herein by reference.

The DART method is atmospheric ionization which uses excited gas molecules (atoms) without charges. In this method, excited molecules produced by corona discharge or glow discharge are made to cause a reaction with a sample under the atmospheric pressure so that the sample is ionized, and the ionized sample is introduced into an ion introduction port (an orifice) of a mass spectrometer.

More than anything else, in the invention, the reduced pressure state is desirable instead of the atmospheric pressure state. That is, the preferred mass analyzing system of the invention has a pressure reducing mechanism which reduces the pressure inside the ion source or the swirl generating container9. An example of the pressure reducing mechanism has a pump. As a result of the pressure reduction, the pressure may be from 0.1 atm to 0.9 atm or from 0.2 atm to 0.5 atm. In the invention, since it is desirable to maintain the electrical discharge inside the swirl generating container9, it is desirable to conduct the reaction under the reduced pressure. In particular, when the reaction is conducted under the reduced pressure, the use of an expensive helium gas may be suppressed. Thus, a cheap gas, for example, a nitrogen gas may be used as a substituted gas.

Embodiment 1 relates to a mass analyzing system which analyzes elements contained in the atmosphere.FIGS. 5A to 5Care diagrams illustrating an example of the cyclone separator and the analyzing apparatus introduction port.FIG. 5Ais a front perspective view,FIG. 5Bis a bottom perspective view, andFIG. 5Cis an exploded diagram. As illustrated inFIGS. 5A to 5C, the cyclone separator1has the swirl generating container9, the intake port11, the swirl generating device13(the turbo blade17and the hollow motor19), and the exhaust port15(the dust exhaust port). As illustrated inFIG. 5C, the hollow motor19is fixed to the swirl generating container9by a connecting flange. The front end of the analyzing apparatus introduction port3near the swirl generating container9is tapered, so that an orifice is formed. Furthermore, the mass analyzing apparatus is omitted inFIGS. 5A to 5C. The cyclone separator1and the analyzing apparatus introduction port3illustrated inFIGS. 5A to 5Care connected to the mass analyzing apparatus and constitute the mass analyzing system7. In the drawings, the connecting flange35and the fixation screw37are provided.

Embodiment 2 relates to a mass analyzing system which has an ionization portion and a guide wire.FIG. 6is a schematic diagram illustrating the mass analyzing system which has the ionization portion and the guide wire. The guide wire is a wire which is formed of a conductive material. In this example, the ionization is conducted by atmospheric ionization so that the gas introduced into the swirl generating container9becomes, for example, a negative ion. In addition, an inner wall39of the swirl generating container9is formed as a high resistor. A voltage is applied to the inner wall and the guide wire23. Then, a potential difference occurs between the inner wail and the guide wire23. Accordingly, an electric field is generated inside the swirl generating container9. At this time, a voltage is applied so that the guide wire23is positively charged. Then, the ionized gas swirls while being attracted to the guide wire23. With such a configuration, dust or the like which is not easily ionized is not accumulated at the center portion. For this reason, dust or the like may be effectively centrifugally separated.

Embodiment 3 relates to a mass analyzing system which uses electrospray as an ionization method.FIG. 7is a schematic diagram illustrating the mass analyzing system which uses electrospray as an ionization method. In this system, a nitrogen gas is introduced from the intake port11into the swirl generating container9. Meanwhile, an analysis subject substance is made as a solution, and is sprayed by using the introduced nitrogen gas. Coulomb explosion is caused during the process of drying the liquid droplet, and ions are produced. The liquid droplet swirls due to the air stream inside the swirl generating container9. Then, the liquid droplet is actively dried. In addition, the large liquid droplet which does not change into an ion is centrifugally separated and is guided to the exhaust port15. When the liquid droplet is introduced into the mass analyzing apparatus5, the vacuum degree of the mass analyzing apparatus5may not be maintained and the inside of the mass analyzing apparatus is contaminated. In the mass analyzing system7of the embodiment, since only the liquid droplet changed into a gas and an ion may be introduced into the mass analyzing apparatus, the burden of the vacuum system may be reduced. Further, as described above, the ionized gas may be accumulated near the guide wire23and the selection efficiency may be improved by using the guide wire.

Embodiment 4 relates to a mass analyzing system which has an electrical discharge portion25inside the swirl generating container9.FIG. 8is a schematic diagram illustrating the mass analyzing system which has the electrical discharge portion inside the swirl generating container. As illustrated inFIG. 8, in the example of the system, a discharge probe is provided as the electrical discharge portion25. The inert gas is excited by causing an electrical discharge in the discharge probe. The excited inert gas is made to collide with the analysis subject substance. Then, charges are exchanged between the inert gas and the analysis subject substance. The mass of the produced ion is much smaller than that of dust. For this reason, the produced ion moves downward while swirling the vicinity of the center portion, and is guided from the center portion of the turbo blade17to the mass analyzing apparatus5through the orifice

Embodiment 5 relates to a mass analyzing system in which the analyzing apparatus introduction port3is positioned at the upstream area of the molecule stream instead of the downstream from the intake port11. With regard to the detailed configuration of the mass analyzing system, the above-described configuration may be appropriately employed.FIG. 9is a diagram illustrating the mass analyzing system of Embodiment5. The mass analyzing system further has an emitting portion27which is provided inside the swirl generating container9so as to emit molecules or ions from the swirl generating device13. Specifically, the mass analyzing system has the emitting portion27which passes the rotary shaft of the swirl generating device13. An example of the emitting portion27has an electrospray or a spray needle. In addition, ions or molecules (including excited molecules) are sprayed or emitted along the center axis of the hollow motor which constitutes the swirl generating device13. In this case, the analyzing apparatus introduction port3is provided at a position facing the emitting portion27.

The mass analyzing system of the invention may be effectively used in the field relating to an analytical instrument.

REFERENCE SIGNS LIST

3analyzing apparatus introduction port

7mass analyzing system

13swirl generating device