JP3126648U - Odor identification device - Google Patents

Abstract

[PROBLEMS] To improve the complexity of preparatory work and cleaning work such as filling and storage of a cleaning gas in cleaning of a sample suction port with a cleaning bag, and a reduction in cleaning effect caused by the flow of a sample through a pipe in the apparatus. An odor identification device is provided.
After the measurement of the sample is completed, the sample container is removed from the suction port, and nitrogen gas from the nitrogen cylinder is removed from the valve V3-filter F1-valve V21-valve V22-hexagonal valve 3-valve V1-suction port 2. The flow is made to flow backward toward the suction port 2 through the route and discharged from the suction port 2, and the suction port 2 and the piping in the vicinity of the suction port 2 are forcibly cleaned without using a cleaning bag. Manual cleaning work is eliminated.
[Selection] Figure 1

Description

  The present invention relates to an odor identification device used in the field of research and development related to odors such as foods and fragrances, the quality control field related to odors such as the production of foods and chemical products, and the field of odor environment management.

  The odor identification device (hereinafter abbreviated as “device” in principle) introduces a sample into the device by suction using a built-in pump, etc., or injection by an injector, etc., and leads the odor sensor to identify the sample using the sensor's response output. (For example, refer to Patent Document 1). When a sample is measured, the sample adheres to the sample connection port (hereinafter referred to as the suction port) of the device and the flow path of the sample, and its history remains. Therefore, when measuring another sample, first clean the suction port. After the gas-filled bag is connected and the inlet and piping are cleaned, another sample is measured. Hereinafter, the operation of the conventional apparatus will be described with reference to FIG.

  FIG. 3 shows an example of the configuration of the apparatus. The sample container 1 is connected to the inlet 2 of the apparatus. The six-way valve 3 and the valves V1 to V4 switch the path of the fluid flowing through the apparatus. The collection tube 4 contains a carbon-based adsorbent, for example, and adsorbs odor components. The collection tube 4 is heated to an appropriate temperature by a heater (not shown) for heating. The pump 5 sucks the sample and causes the sample to flow through a necessary path in the apparatus and discharge it from the first exhaust port. The nitrogen cylinder 6 is filled with dry nitrogen gas. The dry nitrogen gas is used as a carrier gas when the sample is introduced into the flow cell 8.

  The flow cell 8 incorporates a plurality of odor sensors having different characteristics using a metal oxide semiconductor as a sensitive film, and detects various odors. This sensor uses the change in conductivity of the sensor due to the oxidation-reduction reaction between the oxygen molecules adsorbed on the sensitive film and the molecules of the odor components. Need to be replenished. For this reason, oxygen-containing air is supplied as needed from the air cylinder 7 filled with compressed air. Some odor sensors do not require supply of oxygen, for example, sensors using conductive polymers. When such sensors are used, the air cylinder 7 and the air mixing path can be omitted. it can.

  The filters F1 to F3 using molecular sieves or activated carbon are mixed in the gas flowing in via the valve V3 or the valve V4, for example, when there are impurities that are mistaken as odor components, etc. Impurities are removed. Although other elements such as a pressure reducing valve, a pressure gauge, a flow meter, and a flow rate adjusting valve are used in the apparatus as necessary, they are not shown because they are not directly related to the present invention.

  The main procedure of measurement is shown below. First, collection of odor components in a sample will be described. In this step, the opening direction of each valve and the six-way valve 3 is such that the sample in the sample container 1 passes through the path of the suction port 2-valve V1-hexagonal valve 3-collection pipe 4-valve V2-pump 5. Select. The sample passes through the above path by the suction force of the pump 5 and is discharged to the first exhaust port. In this step, the odor component is adsorbed and accumulated in the collection tube 4 at an arbitrary temperature, for example, 40 ° C.

  The six-way valve 3 has six connection ports to the outside, and has a structure in which two types of positions, a first position and a second position, are sequentially selected by rotation. If the six connection ports are a, b, c, d, e, and f in the clockwise direction, for example, the first position is open between ab, cd, and ef (shown by solid lines in FIG. 3). Thus, the circuit between bc, de, and fa is closed (indicated by a dotted line in FIG. 3). In the second position, the open circuit and the closed circuit are reversed from the first position. FIG. 3 shows the first position, that is, a state where ab, cd, and ef are open. The first position is the position when collecting odor components.

  After the collection of the odor component is completed, the selection direction of the valve V1 is switched, the direction of the suction port 2 is closed, and the path from the filter F1 direction to the six-way valve 3 is opened. The valve V2 is switched in the direction of the flow path A, and the nitrogen gas from the nitrogen cylinder 6 is supplied from the valve V3-filter F1-valve V1-hexagonal valve 3-collecting pipe 4-valve V2-flow path A-first exhaust port. The residual sample, residual moisture, etc. in this route are removed. At this time, the odor component in the sample adsorbed by the collecting tube 4 at an arbitrary temperature, for example, 40 ° C. is continuously adsorbed by the collecting tube 4 and only the residual moisture in the collecting tube 4 is removed. . During the measurement period, the six-way valve 3, the flow cell 8, and the path from the six-way valve 3 to the flow cell 8 are usually kept at a temperature slightly higher than room temperature, for example, 75 ° C. by a heater (not shown). It prevents changes in the characteristics of the odor sensor due to fluctuations, and prevents high boiling point compounds in the sample from adhering to the inner wall of the path.

  Next, the position of the six-way valve 3 is switched, and the nitrogen gas from the nitrogen cylinder 6 is switched to the route of the valve V3-filter F2-the six-way valve 3-the collection pipe 4-the six-way valve 3-the flow cell 8-the second exhaust port. While flowing, the heating of the collection tube 4 is started at a rising rate of 10 ° C./second, for example. By this heating, the odor components in the collection tube 4 are sequentially desorbed, conveyed to the nitrogen gas, pass through the flow cell 8, and detected as various odor components by a plurality of odor sensors built in the flow cell 8.

  As described above, the nitrogen gas is used as a carrier gas that carries the odor component to the flow cell 8. In accordance with the above switching, an appropriate amount of air from the air cylinder 7 is mixed with nitrogen gas through the path of the valve V4-filter F3-flow cell 8, and oxygen is supplied to the odor sensor in the flow cell 8. In this step, the flow direction of the carrier gas in the collection tube 4 is opposite to the flow of the sample when collecting the sample or the flow of nitrogen gas when removing the residual sample and residual moisture.

  After completion of the measurement, the sample container 1 is removed from the suction port 2, a bag (not shown) filled with clean gas is connected to the suction port 2, the pump 5 is operated, and the suction port 2 and the piping in the apparatus are washed. Prepare for the next sample measurement.

JP 2002-22692 A

  The structure of the conventional odor discriminating apparatus is as described above, and the suction port 2 and the piping in the apparatus, which are performed before measuring another sample, are cleaned with a bag filled with clean gas prepared in advance as described above. Had been implemented using. Also, in the measurement using an automatic sampling device for mounting and selecting multiple samples, the history of the previous sample is excluded before the next sample measurement. In this case, a bag filled with a clean gas was used. For this reason, it is necessary to fill a clean bag with clean gas in advance before measurement, and then attach and clean the bag immediately after removing the sample cylinder, which makes the preparation and cleaning operations such as gas filling and storage complicated. Met.

  In addition, there are restrictions on the flow rate and time of the cleaning gas, and the cleaning gas is mixed with the cleaning gas at the beginning of cleaning. Since the remaining sample again flows through the piping in the apparatus, the cleaning effect is impaired and the reliability of cleaning is lowered. In addition, one or more of the sample attachment ports can be used exclusively for attaching the cleaning bag for the convenience of cleaning the piping in the automatic sampling apparatus, but in this case, the number of attached samples must be reduced. It was. An object of the present invention is to provide means for solving such problems.

  In order to solve the above problems, the odor identification device provided by the present invention is provided with one or a plurality of gas sensors, and is introduced from a sample inlet using a pressurized gas from a high pressure cylinder or a compressor as a carrier gas. In the odor discriminating apparatus for performing the measurement of odor gas, a carrier gas backflow means for backflowing the carrier gas to the sample suction port is provided, and the sample suction port and its surrounding piping are cleaned by the backflow of the carrier gas. An automatic sampling device having a sample attachment port capable of attaching and selecting a plurality of samples, connected to the sample suction port of the odor identification device by a pipe, and introducing a sample introduced from the sample attachment port into the odor identification device And a means for cleaning the sample attachment port of the automatic sampling device through the sample suction port of the odor identification device. During sample measurement by the odor discriminator, the carrier gas that has flowed back is introduced into the common pipe portion in the automatic sampling device through the sample inlet of the odor discriminator, and the common pipe portion is cleaned. Means.

  According to the present invention, it is possible to clean the sample suction port, the sample mounting port of the automatic sampling device and the common piping part without using a cleaning bag, simplifying the preparation and cleaning work, and providing sufficient cleaning time and Since the flow rate is secured, the cleaning effect is also improved.

  This will be described with reference to the illustrated example. FIG. 1 shows a first embodiment provided by the present invention. The piping system including the valve V1, the six-way valve 3, the valve V2, and the pump 5 constitutes a preparation system for measuring the sample (smell gas), and the valves V21, V22, V23 and the valve V21 to the valve V22 are arranged. An intervening piping system that reaches the six-way valve 3 is a carrier gas back flow system that cleans the suction port 2 by causing the carrier gas to flow back to the suction port 2, which is a feature of the present invention. FIG. 1 shows the state of the cleaning process of the suction port 2 performed after measurement of the sample. In the case of measurement, the sample container 1 is connected to the measurement system via the suction port 2 as shown in FIG. It is joined. In FIG. 1, the structure and operation of components having the same reference numerals as those in FIG. 3 are the same as those in FIG.

  A system for sample measurement and a cleaning process system will be described below. In the first step of collecting odorous components in the sample, the valves V21, V22 and V23 are all placed in the omnidirectionally closed position, and the sample container 1 is connected to the inlet 2 as shown in FIG. Connected to the measurement system. The positions of other valves and the like are the same as the positions described in FIG. The sample in the sample container 1 passes through the path of the suction port 2 -valve V 1 -hexagonal valve 3 -collection tube 4 -valve V 2 -pump 5, and the odor gas component is adsorbed on the collection tube 4. After the collection of odor components, the selection direction of the valve V1 is switched, the direction of the suction port 2 is closed, a path from the direction of the valve V21 to the direction of the six-way valve 3 is opened via the valve V1, and the valve V21 is a filter. Only the path from the F1 direction to the valve V1 direction is communicated. Valve V22 continues to be closed.

  In the above operation, the nitrogen gas from the nitrogen cylinder 6 passes through the device through the route of valve V3-filter F1-valve V21-valve V1-hexagonal valve 3-collecting pipe 4-valve V2-flow path A-first exhaust port. Then, residual samples, residual moisture, etc. in this path are removed. At this time, the odor component in the sample adsorbed on the collection tube 4 at room temperature or at an arbitrary temperature, for example, 40 ° C. is continuously adsorbed on the collection tube 4 and only the residual moisture in the collection tube 4 is removed. Is done. During the measurement period, the six-way valve 3, the flow cell 8 and the path from the six-way valve 3 to the flow cell 8 are kept at a temperature of, for example, 40 ° C. by a heater (not shown). Is prevented from adhering to the inner wall of the path.

  Next, the six-way valve 3 is operated to switch the position of the communication path, and the measurement operation is performed. In this case, the valve V23 is opened and the nitrogen gas from the nitrogen cylinder 6 is switched to the route of the valve V3-valve V23-filter F2-hexagonal valve 3-collecting pipe 4-hexagonal valve 3-flow cell 8-second exhaust port. The collector tube 4 starts to be heated at a rising rate of, for example, 10 ° C./second, and the odor components in the collector tube 4 are sequentially detected for measurement.

  After completion of the measurement, the sample container 1 is removed from the suction port 2, the position of the six-way valve 3 is returned, the valve V23 is closed, the valve V21 is opened only in the direction from the filter F1 to the valve V22, and nitrogen gas from the nitrogen cylinder 6 is supplied to the valve V3. -Filter F1-Valve V21-Valve V22-Hexway valve 3-Valve V1-Discharge from the suction port 2 through the route of suction port 2, forcibly wash the suction port 2 and the piping near the suction port 2, and measure the next sample Prepare for. In FIG. 1, black arrows indicate the flow of nitrogen gas in this cleaning step.

  Only the main part of the second embodiment provided by the present invention is shown in FIG. In this embodiment, an automatic sampling device or an apparatus called “autosampler” is used. That is, the odor discriminating device includes an autosampler S through the suction port 2. In the illustrated example, five sample containers S1 to S5 are attached to the autosampler S. By opening one of the sample selection valves VS1 to VS5, the sample containers S1 to S5 corresponding thereto are opened. You can make measurements. In FIG. 2, the sample container S1 indicates the position in the cleaning process. For example, during the measurement of the sample in the sample container S1, the sample container S1 is connected to the autosampler S via the sample attachment port S11, and thus via the suction port 2. Connect to odor identification device.

  The operation of the odor discriminating apparatus in the sample measurement and cleaning process is the same as the operation in the first embodiment except that the sample container 1 is replaced with the sample container S1 and the sample selection valve VS1 and the detailed description is omitted. Note that the black arrows in FIG. 2 indicate the flow of nitrogen gas in the cleaning process. In this cleaning step, the sample attachment port S11 and the like are forcibly cleaned with nitrogen gas. Further, the common pipe portion in the autosampler S is cleaned by opening the pipe cleaning valve VS11 which is a means for cleaning the common pipe portion. In the second embodiment, the valves V21, V22, and V23 in FIG. 1 and the piping that reaches the six-way valve 3 from the valve V21 through the valve V22 are supplied with carrier gas from the sample attachment ports S11 to S11 in FIG. This is a carrier gas backflow means for backflowing to any one of S15 and cleaning any one of the sample attachment ports S11 to S15, and the pipe cleaning valve VS11 is a means for cleaning the common pipe portion by the backflow of the carrier gas. is there.

  The characteristics of the odor discriminating apparatus provided by the present invention are as described in detail above, but the present invention is not limited to the above-described embodiments, and various modified embodiments can be given. For example, in Examples 1 and 2, the carrier gas is described as nitrogen gas, but the carrier gas is not limited to nitrogen gas as long as the carrier gas is inert to the sample. Argon or the like may be used. Further, in the first embodiment, as the means for cleaning the sample inlet 2, the valves V21, V22, V23 and the piping that reaches the six-way valve 3 through the valve V22 from the valve V21 are cited. 1 shows one embodiment, and the sample suction port and the sample mounting port are cleaned by using different valves and pipe configurations for odor identification devices of systems other than the odor identification device shown in FIGS. Obviously, means can be provided to do.

  In the first embodiment, the number of sample containers of the odor discriminating apparatus is one, but the odor discriminating apparatus may include a plurality of sample suction ports if necessary. Further, it is obvious that valve operations and the like in the sample measurement and cleaning steps can be automated as necessary. In the illustrated example, the container is shown as a cylinder, but a container such as a plastic bag is also included, and the shape of the container is not limited to the illustrated example. The present invention encompasses all of these.

  The present invention can be applied to an odor discriminating device used in the research and development field related to odors such as foods and fragrances, the quality control field related to odors such as food and chemical product manufacturing, and the odor environment management field.

It is a block diagram of Example 1 of this invention. It is a block diagram of Example 2 of this invention. It is a block diagram of the conventional smell identification apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample container 2 Intake port 3 Six-way valve 4 Collection pipe 5 Pump 6 Nitrogen cylinder 7 Air cylinder 8 Flow cell F1 filter F2 filter F3 filter S Autosampler S1-S5 Sample container S11-S15 Sample attachment port V1 valve V2 valve V4 Valve V4 Valve V21 Valve V22 Valve V23 Valve VS1 to VS5 Sample selection valve VS11 Pipe cleaning valve

Claims (3)

  In an odor discriminating apparatus that includes one or a plurality of gas sensors and uses a pressurized gas from a high-pressure cylinder or a compressor as a carrier gas to measure the odor gas introduced from the sample inlet, the carrier gas is An odor discriminating apparatus comprising a carrier gas backflow means for backflowing the sample suction port, and having a function of cleaning the sample suction port and its surrounding piping by the backflow of the carrier gas.   An automatic sampling device having a sample mounting port capable of mounting and selecting a plurality of samples, connected to the sample suction port of the odor discriminating device by a pipe, and introducing the sample introduced from the sample mounting port to the scent discriminating device In the odor identification apparatus provided, the sample attachment port of the automatic sampling device is washed through the sample suction port of the odor identification device with the backflowed carrier gas.   Means for introducing a back-flowed carrier gas into the common piping portion in the automatic sampling device through the sample inlet of the odor identification device and cleaning the common piping portion during sample measurement by the odor identification device. The odor discriminating apparatus according to claim 2, further comprising:

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