JP2014219229A - Chemical substance collection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical substance collection apparatus configured to reduce the time to stabilize a dissipation state of chemical substances emitted from a sample.SOLUTION: On receipt of an instruction from an operator to start ventilation, a CPU drives a fan at predetermined diffusion rotation speed higher than predetermined measurement rotation speed, to allow clean air with diffusion flow rate larger than predetermined measurement flow rate to flow into a sample installation space. When a dissipation state of the emitted chemical substances becomes steady, the rotation speed of the fan is changed to the measurement rotation speed, to allow the clean air with the predetermined measurement flow rate to flow into the sample installation space.

Description

  The present invention relates to an apparatus used for measuring the concentration of chemical substances emitted from materials and parts.

  Japanese Patent Application Laid-Open No. 2010-38700 describes a device for measuring the amount of emission, which measures the amount of emission of a semi-volatile organic compound (SVOC) emitted from an object to be measured. In this apparatus, an object to be measured is installed in a chamber to generate a vertical laminar airflow at a predetermined wind speed (for example, 0.04 m / s) to dissipate SVOC from the object to be measured in the chamber. The air is collected and the amount of SVOC emitted is measured.

  Japanese Patent Laid-Open No. 2006-242791 measures the concentration of volatile organic compounds (VOC) in indoor air, and regulates the VOC concentration in indoor air by discharging the VOC in indoor air to the outdoors. A VOC removal system is described that reduces below the value. In this apparatus, a blower and a VOC sensor are provided in an outdoor air discharge path, and when the VOC concentration is reduced, the output of the blower is reduced to save power consumption.

JP 2010-38700 A JP 2006-242791 A

  In general, the concentration and amount of chemical substances emitted from a sample such as VOC and SVOC should be measured when the state of chemical emission from the sample is stable in order to obtain highly accurate measurement values. Is preferred.

  However, in the apparatus described in Patent Document 1, since the airflow in the chamber is a very low-speed vertical laminar flow from start to finish, it takes a long time to stabilize the chemical substance from the sample.

  Further, in the system described in Patent Document 2, the ventilation amount is changed by controlling the blower according to the concentration of the chemical substance. However, the change in the ventilation amount is performed in order to stabilize the emission state of the indoor chemical substance or the emission state. This is not done to shorten the time until it stabilizes.

  Then, this invention aims at provision of the chemical substance collection apparatus which can shorten time until the diffusion state of the chemical substance from a sample is stabilized.

  In order to achieve the above object, the chemical substance collecting apparatus according to the first aspect of the present invention includes a chamber, a chemical substance concentration detecting means, an air flow generating means, and a control means. A sample is set in the chamber. The chemical substance concentration detection means detects the concentration of the chemical substance released from the sample. The airflow generating means causes clean air to flow into the chamber. In the non-stationary period until the concentration of the chemical substance detected by the chemical substance concentration detection means becomes stable, the control means determines the amount of clean air that the air flow generation means flows into the chamber by the chemical substance concentration detection means. The second air amount is controlled to be larger than the first air amount to be introduced during a steady period in which the concentration of the detected chemical substance is stable.

  In addition, a volatile organic compound (VOC: Volatile Organic Compounds) and a semi-volatile organic compound (SVOC: Semi Volatile Organic Compounds) are contained in a chemical substance. Further, the first air amount may be a flow rate capable of stabilizing the airflow in the chamber, and is not limited to being a fixed amount. Further, the second air amount means an air amount larger than the first air amount, and is not limited to being a fixed amount.

  In the above configuration, during a non-stationary period until the concentration of the chemical substance is stabilized, clean air having a second air amount larger than the first air amount to be introduced during the steady period where the concentration of the chemical substance is stable is provided. Let it flow into the chamber. For this reason, the chemical substance diffused from the sample can be diffused into the chamber at an early stage, and the time until the chemical substance concentration from the sample is stabilized and the chemical substance emission state from the sample is stabilized can be shortened. . In addition, the chemical substance can be reliably diffused from the sample and diffused into the chamber, and a stable measurement value can be obtained regardless of the diffusing property of the sample.

  Further, the chemical substance collection device of the second aspect of the present invention is the chemical substance collection device of the first aspect, wherein the air flow generating means allows clean air to flow into the chamber from a single direction, The control means controls the air flow generating means to flow in clean air from a single direction during the non-steady period, and controls the air flow generating means to control the air amount to flow into the chamber during the steady period. Clean air is introduced from the same direction as the non-stationary period.

  In the above configuration, the inflow direction of the clean air into the chamber is a single direction in the unsteady period and the steady period. For this reason, even in a chamber having a structure in which clean air can flow into the inside only from a single direction, the time until the chemical emission state is stabilized can be shortened without changing the structure of the chamber itself, and Stable measurement values can be obtained.

  Moreover, the chemical substance collection device according to the third aspect of the present invention is the chemical substance collection device according to the first aspect, wherein the air flow generating means flows clean air into the chamber from a single direction or a plurality of directions. In the non-steady period, the control means controls the air flow generating means to flow clean air from a plurality of directions, and in the steady period, controls the air flow generating means to control the amount of clean air to flow into the chamber. The amount of air is 1 and clean air is introduced from a single direction.

  In the above configuration, in the non-steady period, the second amount of clean air is divided into a plurality of directions to flow into the chamber, and in the steady period, the first amount of clean air flows into the chamber from a single direction. Let For this reason, even if the sample has properties that make it difficult for chemical substances to dissipate in one direction of airflow, the chemical substance can be reliably diffused from the sample and diffused into the chamber until the chemical emission state is stabilized. And a stable measurement value can be obtained.

  Moreover, the chemical substance collection apparatus of the 4th aspect of this invention is the said 1st-3rd chemical substance collection apparatus, Comprising: A chemical substance density | concentration detection means is a semiconductor sensor.

  In the above configuration, a general-purpose semiconductor sensor is used as chemical substance concentration detection means for detecting the chemical substance concentration. For this reason, the concentration of the chemical substance can be sequentially detected without requiring a special detection means.

  According to the present invention, it is possible to shorten the time until the chemical substance is released from the sample.

It is sectional drawing of the chemical substance collection apparatus of 1st Embodiment. It is a flowchart which shows the ventilation volume adjustment process which CPU performs. It is sectional drawing of the chemical substance collection apparatus of 2nd Embodiment.

  Hereinafter, the chemical substance collection apparatus 1 of 1st Embodiment of this invention is demonstrated with reference to drawings. FIG. 1 is a cross-sectional view of a chemical substance collecting apparatus 1 according to the first embodiment. FIG. 2 is a flowchart showing ventilation amount adjustment processing executed by the CPU. In the following description, the up, down, left, and right directions indicate the respective directions when the chamber 3 is viewed from the front (opening / closing door side). Moreover, the arrow in a figure has shown the flow direction of air.

  As shown in FIG. 1, the chemical substance collection apparatus 1 of the present embodiment includes a volatile organic compound (VOC) and a semi-volatile organic compound (SVOC) emitted from a sample 2. The air for collecting the emission amount and concentration of the chemical substance is collected, and includes a chamber 3, a chemical substance concentration detection sensor 21, an air cleaning unit 22, an exhaust unit 24, and a control unit 27.

  The chamber 3 includes a front wall surface (not shown) and a rear wall surface 4 that stand oppositely in the front-rear direction, a left wall surface 5 and a right wall surface 6 that stand oppositely in the left-right direction, an upper ceiling surface 7, and a lower floor surface. 8 and is provided with an opening / closing door (not shown) for inserting and removing the sample 2 on the front wall surface.

  The surfaces 4 to 8 of the chamber 3 are formed by an outer plate 9 and an inner plate 10 that are arranged apart from each other. The outer plate 9 is formed of a heat-resistant metal material or resin material having a low thermal conductivity. The inner plate 10 is disposed inside the outer plate 9 and is formed of a heat-resistant metal material having high thermal conductivity. In the case where the inner plate 10 is made of stainless steel, it is desirable that the surface is subjected to an inactivation treatment (for example, silico steel treatment) that reduces the reactivity with chemical substances.

  An upper partition plate 11 and a lower partition plate 12 are provided inside the chamber 3. The upper partition plate 11 and the lower partition plate 12 have a desired strength and are formed in the same size and shape as the inner plate 10 of the ceiling surface 7 and the floor surface 8 by a heat-resistant metal material or the like. A large number of ventilation holes 13 are formed. The upper partition plate 11 is provided substantially parallel to the ceiling surface 7 above the chamber 3. The lower partition plate 12 is provided in the lower portion of the chamber 3 substantially in parallel with the floor surface 8. That is, the upper partition plate 11 and the lower partition plate 12 divide the interior of the chamber 3 into three, that is, a supply space 14, a sample installation space 15, and a discharge space 16, while allowing air to flow. Specifically, the upper surface of the upper partition plate 11 partitions the supply space 14 together with the ceiling surface 7 of the chamber 3 and the inner plates 10 of the wall surfaces 4 to 6, and the lower surface of the upper partition plate 11 and the upper surface of the lower partition plate 12 are The sample installation space 15 is defined together with the inner plate 10 of the wall surfaces 4 to 6, and the lower surface of the lower partition plate 12 defines the discharge space 16 together with the floor surface 8 and the inner plates 10 of the wall surfaces 4 to 6. The supply space 14 is provided with an air purification unit 22 described later, the sample installation space 15 is provided with the sample 2, and the exhaust space 16 is provided with an exhaust unit 24 and a chemical substance concentration detection sensor 21 described later. ing. In addition, when the upper partition plate 11 and the lower partition plate 12 are formed of stainless steel, it is desirable that the surface be subjected to an inactivation process, like the inner plate 10. Moreover, in this embodiment, although the sample 2 is directly installed on the lower partition plate 12, you may use an installation stand according to a magnitude | size or a shape.

  Further, the chamber 3 is formed with an air inlet 17 that connects the supply space 14 and the outside of the chamber 3 on the ceiling surface 7, and an exhaust port that connects the discharge space 16 and the outside of the chamber 3 below the right side wall surface 6. 18 and a collection port 19 are formed. The collection port 19 is connected to a measuring device A that collects the air in the discharge space 16 and measures the amount of chemical substance diffused from the sample 2.

  Furthermore, the chamber 3 is provided with a heater 20 for heating the sample installation space 15. The heater 20 generates heat when energized, and is provided along the inner plate 10 between the outer plate 9 and the inner plate 10 of the wall surfaces 4 to 6 that define the sample installation space 15. The energization amount of the heater 20 is controlled by the control unit 27.

  The chemical substance concentration detection sensor 21 is a semiconductor sensor and is provided in the vicinity of the exhaust port 18 of the discharge space 16 of the chamber 3. The chemical substance concentration detection sensor 21 detects the concentration of the chemical substance in the air in the discharge space 16 every predetermined time, and outputs the detected concentration of the chemical substance to the control unit 27. That is, the chemical substance concentration detection sensor 21 functions as a chemical substance concentration detection unit that detects the concentration of the chemical substance released from the sample 2.

  The air cleaning unit 22 has a blower fan 23 whose operation is controlled by a control unit 27, and is provided in the supply space 14 of the chamber 3. When the blower fan 23 is driven, the air purification unit 22 takes in air having a flow rate corresponding to the rotational speed of the blower fan 23 from the outside of the chamber 3 through the intake port 17 and cleans it. Air (clean air) is caused to flow into the sample installation space 15 through the vent hole 13 of the upper partition plate 11.

  The exhaust unit 24 includes an exhaust fan 25 whose operation is controlled by the control unit 27, and is provided in the exhaust space 16 of the chamber 3. When the exhaust fan 25 is driven, the exhaust unit 24 takes in air having a flow rate corresponding to the number of rotations of the exhaust fan 25 from the sample installation space 15 through the vent hole 13 of the lower partition plate 12 and exhausts the exhaust port. It is discharged to the outside of the chamber 3 through 18. That is, the vent hole 13, the air cleaning unit 22, and the exhaust unit 24 of the upper partition plate 11 and the lower partition plate 12 of the chamber 3 function as airflow generating means for allowing clean air to flow into the sample installation space 15 from a single direction. To do.

  The input panel 26 is provided outside the chamber 3 and receives various instructions related to the operation of the chemical substance collection apparatus 1 from an operator. The various instructions include a start instruction for starting ventilation in the chamber 3 and a set temperature instruction for setting the temperature in the chamber 3. When various instructions are input from the operator, the input panel 26 outputs the input various instructions to the control unit 27.

  The control unit 27 includes a storage unit 28 and a CPU (Central Processing Unit) 29.

  The storage unit 28 is configured by a recording medium such as a RAM (Random Access Memory). The storage unit 28 stores a control program and various data for the CPU 29 to execute various processes. The various data includes a fan rotation speed map showing the set rotation speeds of the blower fan 23 and the exhaust fan 25 corresponding to the absolute value of the chemical substance concentration change rate (hereinafter referred to as the concentration change rate). It is. The fan rotation speed map shows a set rotation speed corresponding to a density change rate that is greater than or equal to a predetermined first change rate and less than a predetermined second change rate, and the set rotation speed is determined from a predetermined measurement rotation speed. It is set so as to increase stepwise as the density change rate increases within a range that is larger than a predetermined rotational speed for diffusion. The storage unit 28 is set with a storage area in which various types of information are stored in a readable and writable manner. A ventilation control information table and a flag setting area are set in the storage area. In the ventilation control information table, a concentration storage area in which the concentration of the chemical substance detected by the chemical substance concentration detection sensor 21 is stored in time series and a concentration change rate storage area corresponding to the concentration storage area are set. In the flag setting area, a steady process flag and a first unsteady process flag that can be set to an on state and an off state are set.

  The CPU 29 functions as an information receiving unit 30, a concentration change rate calculating unit 31, a state determining unit 32, a ventilation control unit 33, and a temperature control unit 34 by reading and executing the control program stored in the storage unit 28.

  The information receiving unit 30 receives the concentration of the chemical substance output from the chemical substance concentration detection sensor 21, stores the received concentration of the chemical substance in the concentration storage area of the ventilation control information table of the storage unit 28 in time series, Various instructions output from the input panel 26 are received.

  When the information receiving unit 30 receives the concentration of the chemical substance, the concentration change rate calculating unit 31 uses a predetermined number of consecutive concentrations including this concentration (latest concentration) to change the concentration change rate (chemical Calculate the absolute value of the change rate of the substance concentration. After calculating the concentration change rate, the concentration change rate calculation unit 31 stores the calculated concentration change rate in the concentration change rate storage area corresponding to the latest concentration in the ventilation control information table.

  When the change rate calculation unit 31 calculates the concentration change rate, the state determination unit 32 is stable from an unsteady state where the chemical substance emission state from the sample 2 is not stable based on the calculated concentration change rate. It is determined whether it is in a steady state. When it is determined that the state is unsteady, it is determined whether the first unsteady state having a large degree of instability or the second unsteady state having a small degree of instability.

  Specifically, the state determination unit 32 determines whether or not the density change rate is equal to or higher than a predetermined first change rate, and determines that the state is an unsteady state when the density change rate is equal to or higher than the first change rate. If it is less than the first rate of change, it is determined that it is in a steady state. If it is determined that the concentration change rate is equal to or higher than the first change rate and is in the unsteady state, the state determination unit 32 further determines whether or not the concentration change rate is equal to or higher than a predetermined second change rate, If it is equal to or higher than the second rate of change, it is determined that the state is the first unsteady state, and if it is less than the second rate of change, it is determined that the state is the second unsteady state.

  The ventilation control unit 33 controls the operation of the blower fan 23 of the air cleaning unit 22 and the exhaust fan 25 of the exhaust unit 24 according to the reception information of the information reception unit 30 and the determination result of the state determination unit 32. .

  Specifically, the ventilation control unit 33 executes a ventilation start process when the information receiving unit 30 receives a start instruction from the input panel 26. In the ventilation start process, the ventilation control unit 33 drives the blower fan 23 and the exhaust fan 25 at a predetermined diffusion rotation speed, and the first unsteady process set in the flag setting area of the storage unit 28. Set the flag to the on state.

  Moreover, when the state determination part 32 determines with it being a 1st unsteady state, the ventilation control part 33 determines whether the 1st unsteady process flag of the memory | storage part 28 is set to the ON state, and is turned off. If the state is set, the first process is executed. In the first process, the ventilation control unit 33 changes the rotation speeds of the blower fan 23 and the exhaust fan 25 to the diffusion rotation speed, and sets the first unsteady process flag of the storage unit 28 to the on state.

  Moreover, when the state determination part 32 determines with it being a 2nd unsteady state, the ventilation control part 33 determines whether the 1st unsteady process flag of the memory | storage part 28 is set to an ON state, and is ON. If it is set to the state, it is set to the off state and the second process is executed. If it is set to the off state, the second process is executed. In the second process, the ventilation control unit 35 determines the set rotational speeds of the blower fan 23 and the exhaust fan 25 corresponding to the latest density change rate with reference to the fan rotational speed map, and the ventilation fan 23 and the exhaust air The rotational speed of the fan 25 is changed to the determined rotational speed.

  Moreover, when the state determination part 32 determines with it being a steady state, the ventilation control part 33 determines whether the steady process flag set to the flag setting area | region of the memory | storage part 28 is set to the ON state. If it is set to the off state, the third process is executed. In the third process, the ventilation control unit 33 changes the rotational speeds of the blower fan 23 and the exhaust fan 25 to a predetermined measurement rotational speed, and sets the steady process flag of the storage unit 28 to an on state.

  In other words, the ventilation control unit 33 waits until the state determination unit 32 determines that it is in the second unsteady state (unsteady period) after the information reception unit 30 receives the start instruction (unsteady period). The fan 25 is driven at the rotational speed for diffusion. Also, during the period from when the state determination unit 32 determines that it is in the second unsteady state to when it is determined to be in the steady state (unsteady period), the blower fan 23 and the exhaust fan 25 are set to the latest concentration change rate. Is driven at a set rotational speed corresponding to (a rotational speed smaller than the rotational speed for diffusion and larger than the rotational speed for measurement). Further, after the state determination unit 32 determines that the state is in a steady state (steady period), the blower fan 23 and the exhaust fan 25 are driven at the measurement rotational speed. When the state determination unit 32 determines that the first unsteady state is determined again after determining that the state is the second unsteady state, the state determination unit 32 continues to determine that the state is the second unsteady state. Meanwhile, the blower fan 23 and the exhaust fan 25 are driven at the rotational speed for diffusion.

  Thus, when an instruction to start ventilation is received from the worker, clean air having a predetermined diffusion flow rate (second air amount) larger than the predetermined measurement flow rate (first air amount) is supplied to the chamber 3. From the space 14 into the sample installation space 15 and out to the discharge space 16, a downward laminar air flow is generated in the sample installation space 15. When the chemical substance diffusion state becomes the second unsteady state, the flow rate of the clean air flowing into the sample installation space 15 is a flow rate corresponding to the concentration change rate within a range that is less than the diffusion flow rate and exceeds the measurement flow rate ( 2nd air amount). Further, when the chemical substance is released to a steady state, the amount of clean air flowing into the sample installation space 15 is reduced to a predetermined measurement flow rate.

  That is, the concentration change rate calculation unit 31, the state determination unit 32, and the ventilation control unit 33 allow clean air having a flow rate larger than the measurement flow rate to flow from a single direction in the non-steady period, and in the steady period, the measurement flow rate. It functions as a control means for flowing clean air from a single direction.

  The temperature control unit 34 controls the energization amount of the heater 20 based on the set temperature instruction received from the input panel 26 by the information receiving unit 30.

  Next, various processes (ventilation volume adjustment process) executed by the CPU 29 to adjust the ventilation volume will be described with reference to FIG. This process is repeatedly executed at predetermined time intervals for receiving the chemical substance concentration output from the chemical substance concentration detection sensor 21.

  When this process is started, the concentration change rate (absolute value of the change rate of the chemical substance concentration) within a predetermined time is calculated using a predetermined number of consecutive concentrations including the latest chemical substance concentration (step) S1).

  Next, it is determined whether or not the calculated density change rate is equal to or higher than a predetermined first change rate (step S2).

  When the calculated concentration change rate is equal to or higher than the first change rate (step S2: YES), it is determined that the chemical substance emission state from the sample 2 is an unsteady state, and this concentration change rate is a predetermined second change. It is further determined whether or not the rate is greater than or equal to the rate (step S3).

  When the calculated concentration change rate is equal to or higher than the second change rate (step S3: YES), it is determined that the chemical substance emission state from the sample 2 is the first unsteady state having a large degree of instability, and the first It is determined whether or not the unsteady processing flag is set to the on state (step S4).

  When the first unsteady process flag is set to the on state (step S4: YES), this process ends.

  On the other hand, when the first unsteady processing flag is set to the OFF state (step S4: NO), the rotation speeds of the blower fan 23 and the exhaust fan 25 are changed to the diffusion rotation speed, and the first unsteady state is set. The processing flag is set to the on state (step S5), and this processing is terminated.

  Further, when the calculated concentration change rate is less than the second change rate (step S3: NO), it is determined that the chemical substance emission state from the sample 2 is the second unsteady state with a small degree of instability, It is determined whether or not the first unsteady process flag is set to an on state (step S6).

  When the first unsteady process flag is set to the on state (step S6: YES), the first unsteady process flag is set to the off state (step S7).

  When the first unsteady process flag is set to the off state (step S6: NO) and when the first unsteady process flag is set to the off state (step S7), the air flow corresponding to the calculated concentration change rate The set rotational speeds of the fan 23 and the exhaust fan 25 are determined, the rotational speeds of the blower fan 23 and the exhaust fan 25 are changed to the determined rotational speeds (step S8), and this process is terminated.

  If the calculated concentration change rate is less than the first change rate (step S2: NO), the chemical substance emission state from the sample 2 is determined to be a steady state, and the steady process flag is set to an on state. It is determined whether or not (step S9).

  When the steady process flag is set to the on state (step S9: YES), this process ends.

  On the other hand, when the steady process flag is set to the off state (step S9: NO), the rotational speed of the blower fan 23 and the exhaust fan 25 is changed to the rotational speed for measurement, and the steady process flag is turned on. Set (step S10), the process is terminated.

  In the chemical substance collecting apparatus 1 configured as described above, when an instruction to start ventilation is received from an operator, clean air having a predetermined diffusion flow rate flows into the sample installation space 15 from the supply space 14 of the chamber 3. Then, the gas flows out into the discharge space 16, and a downward laminar airflow is generated in the sample installation space 15. When the chemical substance emission state from the sample 2 becomes the second unsteady state, the flow rate of clean air into the sample installation space 15 becomes a concentration change rate within a range that is less than the diffusion flow rate and exceeds the measurement flow rate. Decrease to the corresponding flow rate. Furthermore, when the chemical substance is released to a steady state, the amount of clean air flowing into the sample installation space 15 is reduced to the measurement flow rate. That is, more clean air flows into the sample installation space 15 until the chemical substance emission state from the sample 2 is stabilized (unsteady period) than after it is stabilized (steady period), and the ventilation rate is increased. Will increase.

  Further, when an instruction for the set temperature in the chamber 3 is received from the operator, the heater 20 is energized and heated according to the set temperature, and the sample installation space 15 is heated via the inner plate 10 of each wall surface 4-6. The

  Note that the measuring apparatus A collects air in the chamber 3 during a steady period, and measures the amount of chemical substance released from the sample 2 and the like.

  As described above, according to the chemical substance collecting apparatus 1 of the present embodiment, during the non-stationary period, more clean air is allowed to flow into the sample installation space 15 than the measurement flow rate that flows in during the stationary period. The chemical substance diffused from can be diffused in the sample installation space 15 at an early stage, and the time until the chemical substance concentration is stabilized can be shortened. In addition, the chemical substance can be reliably diffused from the sample 2 and diffused into the sample installation space 15, and a stable measurement value can be obtained regardless of the diffusion property of the sample 2.

  In addition, since the inflow direction of the clean air into the sample installation space 15 is a single direction in the non-stationary period and the steady period, even in a chamber having a structure in which the clean air can only flow into the inside from a single direction, Without changing the structure of the chamber, it is possible to shorten the time until the concentration of the chemical substance is stabilized and to obtain a stable measurement value.

  Moreover, since a general-purpose semiconductor sensor is used as the chemical substance concentration detecting means for sequentially detecting the chemical substance concentration, the chemical substance concentration can be sequentially detected without requiring a special device.

  The shape of the chamber 3 is not limited to the above, and may be a cylindrical shape or the like.

  Further, the chemical substance concentration detection sensor 21 for detecting the chemical substance concentration is not limited to a semiconductor sensor as long as it can sequentially detect the chemical substance concentration.

  Moreover, the airflow generated in the chamber 3 is not limited to the above, and may be an upward laminar flow, a swirl flow, or the like.

  Further, the airflow generation means for generating the airflow in the chamber 3 is not limited to the above, and the fan may be any one of the blower fan 23 of the air cleaning unit 22 and the exhaust fan 25 of the exhaust unit 24. Moreover, the structure which generate | occur | produces an airflow without using a fan may be sufficient.

  In addition, the amount of clean air that flows into the sample installation space 15 in the stationary period is not limited to a constant value as long as the airflow in the sample installation space 15 can be stabilized.

  In addition, before the transition from the unsteady period to the steady period (during the second unsteady state), the inflow amount of clean air is not limited to the stepwise decrease as described above, but is continuously decreased. May be. Further, the flow rate is not decreased until it is determined to be in a steady state, that is, the inflow amount during the non-steady period may be constant, for example, at a predetermined diffusion flow rate.

  Next, the chemical substance collection apparatus 51 of 2nd Embodiment of this invention is demonstrated with reference to drawings. FIG. 3 is a cross-sectional view of the chemical substance collecting apparatus 51 of the second embodiment. The present embodiment is different from the first embodiment in that clean air is allowed to flow from a plurality of directions into the sample installation space 55 in which the sample 2 is installed in an unsteady state. In addition, the same code | symbol is attached | subjected to the structure similar to the said 1st Embodiment, and the detailed description is abbreviate | omitted.

  Inside the chamber 3, a left partition plate 52 and a right partition plate 53 are provided. The left partition plate 52 and the right partition plate 53 are substantially the same width as the inner plate 10 of the side wall surfaces 5 and 6 and the length between the upper partition plate 11 and the lower partition plate 12 by a heat-resistant metal material or the like. It is formed in a rectangular shape having a length, and a large number of vent holes 13 are formed in the entire area. The left partition plate 52 is provided on the left side in the chamber 3 and between the upper partition plate 11 and the lower partition plate 12 so as to be substantially parallel to the left wall surface 5. The right partition plate 53 is provided on the right side in the chamber 3 and between the upper partition plate 11 and the lower partition plate 12 so as to be substantially parallel to the right wall surface 6. That is, the left partition plate 52 and the right partition plate 53 divide a space defined by the wall surfaces 4 to 6, the upper partition plate 11, and the lower partition plate 12 in a state in which air circulation is allowed, The sample is divided into three, a sample installation space 55 and a second diffusion supply space 56. In the present embodiment, the sample 2 is installed in the sample installation space 55.

  Dampers 57 and 58 are provided outside the left partition plate 52 and the right partition plate 53, respectively. The dampers 57 and 58 can be set to a closed state or an open state, and are set to any state by the control unit 27. When the dampers 57 and 58 are set in an open state, the left and right partition plates 52 between the first diffusion supply space 54 and the sample installation space 55 and between the second diffusion supply space 56 and the sample installation space 55 are set. , 53 is allowed to flow and is set in a closed state, the vent holes 13 of the left and right partition plates 52, 53 are closed to form a space between the first diffusion supply space 54 and the sample installation space 55 and the second. The flow of air through the left and right partition plates 52 and 53 between the diffusion supply space 56 and the sample installation space 55 is blocked. That is, the vent holes 13 and the dampers 57 and 58 of the left partition plate 52 and the right partition plate 53 of the chamber 3 are the vent holes 13 of the upper partition plate 11 and the lower partition plate 12 of the chamber 3, the air cleaning unit 22 and the exhaust unit. 24 functions as an airflow generating means for flowing clean air into the sample installation space 55 from a single direction or a plurality of directions.

  The ventilation control unit 33 of the CPU 29 controls the operation of the blower fan 23 and the exhaust fan 25 according to the reception information of the information reception unit 30 and the determination result of the state determination unit 32, and changes the states of the dampers 57 and 58. Set. Specifically, when the information receiving unit 30 receives a start instruction from the input panel 26, the ventilation control unit 33 sets the dampers 57 and 58 to an open state, and determines that the state determining unit 32 is in a steady state. At this time, the dampers 57 and 58 are set in a closed state.

  As a result, when an instruction to start ventilation is received from the worker, the flow of air through the left and right partition plates 52 and 53 is allowed, and the clean air having a predetermined diffusion flow rate is supplied to the supply space 14 of the chamber 3 and the first diffusion air. The sample flows into the sample installation space 55 from the supply space 54 and the second diffusion supply space 56 and flows out to the discharge space 16. When the chemical substance from the sample 2 is diffused into the second unsteady state, the amount of clean air flowing into the sample installation space 55 while allowing air to flow through the left and right partition plates 52 and 53 is allowed. Decreases to a flow rate corresponding to the rate of change in concentration within a range below the flow rate for diffusion and above the flow rate for measurement. Further, when the chemical substance is released to a steady state, the amount of clean air flowing into the sample installation space 55 is reduced to the measurement flow rate, and the flow of air through the left and right partition plates 52 and 53 is interrupted to provide clean air. Flows only from the supply space 14, and the air flow in the sample installation space 55 changes to a downward laminar flow.

  Thus, according to the chemical substance collecting apparatus 51 of the present embodiment, during the non-stationary period, clean air larger than the measurement flow rate is caused to flow into the sample installation space 55 from three directions. Even if the sample has properties that make it difficult for chemicals to dissipate in the air stream, the chemicals can be reliably diffused from the sample 2 and diffused into the sample installation space 55, and the time until the concentration of the chemicals becomes stable can be increased. Shortened and stable measurement values can be obtained.

  In the unsteady state, the inflow direction of the clean air into the sample installation space 55 of the chamber 3 is not limited to three directions and may be two directions or four or more directions. Furthermore, the structure which changes an inflow direction or the structure which increases / decreases may be sufficient according to the diffusion state of a chemical substance.

  Further, the configuration for flowing clean air into the sample installation space 55 from a plurality of directions is not limited to the above. For example, the first diffusion supply space 54 and the second diffusion supply space 56 are also provided with fans. Also good. In this case, in the non-stationary period, the amount of clean air flowing into the sample installation space 55 is provided for the fan provided in the first diffusion supply space 54 and the second diffusion supply space 56 together with the blower fan 23 and the exhaust fan 25. Is driven at a rotational speed that provides an air amount larger than the measurement flow rate, and in a steady period, the fans provided in the first diffusion supply space 54 and the second diffusion supply space 56 are stopped, and the blower fan 23 and the exhaust are exhausted. The fan 25 is driven at the rotational speed for measurement.

  The above embodiment is an example of the present invention and can be changed without departing from the present invention.

  INDUSTRIAL APPLICABILITY The present invention is effective for measuring the amount of chemical substances released from materials and parts used in houses, automobiles, aircraft, and the like.

1, 51: Chemical substance collection device 2: Sample 3: Chamber 13: Vent (air flow generating means)
21: Chemical substance concentration detection sensor (chemical substance concentration detection means)
22: Air purification unit (air flow generation means)
24: Exhaust unit (airflow generating means)
29: CPU
31: Density change rate calculation unit (control means)
32: State determination unit (control means)
33: Ventilation controller (control means)
57, 58: damper (airflow generating means)

Claims (4)

A chamber in which the sample is placed;
Chemical substance concentration detection means for detecting the concentration of the chemical substance diffused from the sample;
An air flow generating means for flowing clean air into the chamber;
In the non-stationary period until the concentration of the chemical substance detected by the chemical substance concentration detection means becomes stable, the amount of clean air that the airflow generation means flows into the chamber is changed by the chemical substance concentration detection means. And a control means for controlling the second air amount to be larger than the first air amount to be introduced during a steady period in which the concentration of the detected chemical substance is stable. . The chemical substance collecting apparatus according to claim 1,
The air flow generating means allows clean air to flow into the chamber from a single direction,
The control means controls the air flow generating means to flow clean air from a single direction during the unsteady period, and controls the air flow generating means to flow into the chamber during the steady period. A chemical substance collecting apparatus characterized in that clean air is introduced from the same single direction as that of the unsteady period while the amount of air is the first air amount. The chemical substance collecting apparatus according to claim 1,
The air flow generating means allows clean air to flow into the chamber from a single direction or a plurality of directions,
In the non-steady period, the control means controls the air flow generating means to flow clean air from a plurality of directions, and in the steady period, controls the air flow generating means to flow clean air to flow into the chamber. A chemical substance collecting apparatus, wherein the amount of air is set to the first amount of air and clean air is introduced from a single direction. The chemical substance collecting apparatus according to any one of claims 1 to 3,
The chemical substance collecting apparatus, wherein the chemical substance concentration detecting means is a semiconductor sensor.

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