JP5779753B2 - Volatile substance extraction device in soil - Google Patents

Description

The present invention relates to a method and a measuring device for measuring the concentration of volatile substances contained in soil by a quick and simple method at a soil contamination investigation site without adversely affecting the environment.

Some volatile substances of soil pollutants include, for example, petroleum hydrocarbons. These petroleum hydrocarbons are derived from petroleum products handled in petroleum-related facilities, such as gasoline, kerosene, light oil, A heavy oil, C heavy oil, lubricating oils (mineral oil, synthetic oil), crude oil, etc. Is a hydrocarbon compound. Currently, it is obliged to report the results of soil contamination surveys when changing the intended use of land, and as part of this, it is necessary to examine the content of petroleum hydrocarbon components in the soil.

As a conventional analysis method, petroleum hydrocarbon components in soil are extracted and separated with n-hexane, n-hexane is evaporated by heating, and the weight of the residue is measured (n-hexane extraction-weight Method), extracting and separating petroleum hydrocarbon components in soil with carbon tetrachloride, and performing infrared absorption spectroscopy (IR) analysis of the carbon tetrachloride extract to measure the component content (carbon tetrachloride extraction) -IR method), extraction and separation of petroleum hydrocarbon components in soil with carbon disulfide, analysis of carbon disulfide extract with gas chromatography (GC, detection device FID), chart area ratio Further, a method of measuring the component content (carbon disulfide extraction-GC method) or the like is known (for example, see Non-Patent Document 1). Also known is a method (tetrachloroethylene extraction-IR method) for extracting petroleum hydrocarbon components in soil with tetrachloroethylene, performing IR analysis of the extract, and measuring the component content (for example, patents) Reference 1).

Moreover, the instrument which extracts the hydrocarbon of the soil extract | collected as a simple hydrocarbon analyzer in soil with an extraction solvent, and measures hydrocarbon content from the turbidity of an extract is marketed.

In addition, as a method of measuring the oil content in water, after extracting the oil content in water with an extraction solvent, volatilizing the extraction solvent from the oil extract and measuring the oil content from carbon dioxide generated by burning the residue Is disclosed (for example, see Patent Document 2).

However, these methods all use extracts that cause air pollution or soil contamination. Therefore, if these extracts are discharged as they are, environmental pollution will occur and these extracts will be rendered harmless. It takes a lot of money and effort.

On the other hand, as a method that does not use the extract, light hydrocarbon fractions in the soil are evaporated by heating, trapped (purge and trap, PT), analyzed by GC, and from the area ratio of the chart A method for measuring the oil content (PT-GC method) is known (for example, see Non-Patent Document 1).

However, this method is applied when the petroleum hydrocarbon component contained in the soil is a light fraction. When the medium heavy fraction is included in addition to the light fraction, Employs a carbon disulfide extraction-GC method (PEC method) using the above extract. Therefore, extraction methods using organic solvents that cause air pollution or soil contamination have been used in the conventional methods for soils containing a wide range of petroleum hydrocarbon components from light fractions to medium heavy fractions.

In addition, as a method for easily measuring the content of petroleum hydrocarbon components without requiring an extraction operation with an organic solvent for soil containing a wide range of petroleum hydrocarbon components from light fractions to medium heavy fractions, The soil containing the petroleum hydrocarbon component was loaded into the sample chamber of the heating unit and heat-treated to vaporize the component contained in the soil, and the sample chamber was vaporized by introducing a mixed gas of oxygen and nitrogen. Petroleum hydrocarbon component content in soil, wherein the component is fed into a reaction chamber and burned, the amount of carbon dioxide generated thereby is measured, and the content of the component contained in soil is measured Is disclosed (for example, see Patent Document 3).

Further, based on these findings, the soil containing the petroleum hydrocarbon component is loaded into the vaporizer and heat-treated to vaporize the component contained in the soil, and the vaporizer also has a mixed gas of oxygen and nitrogen. The vaporized component introduced into the reaction tube filled with the oxidation catalyst and burned, the amount of carbon dioxide generated thereby is measured, and the content of the component contained in the soil is determined from the amount of carbon dioxide. In the measurement method, a method of measuring the content of petroleum hydrocarbon components in soil using a platinum catalyst as the oxidation catalyst is disclosed (see, for example, Patent Document 4 and Patent Document 5).

JP 2003-294617 A JP 2003-302316 A JP 2007-171049 A JP 2008-281212 A JP 2008-304316 A

Technical development report on purification of oil-contaminated soil, Japan Petroleum Industry Activation Center, March 2003, P8-P28.

However, these findings and soil containing petroleum hydrocarbon components are loaded into a vaporizer and heat-treated to vaporize the components contained in the soil, and a mixed gas of oxygen and nitrogen is supplied to the vaporizer. The introduced and vaporized components are sent to a reaction tube filled with an oxidation catalyst and burnt, and the amount of carbon dioxide generated thereby is measured, and the content of the components contained in the soil is measured from the amount of carbon dioxide In the method, the soil and the air that heats the soil are heated when trying to produce a product based on the method disclosed in the method of measuring the content of petroleum hydrocarbon components in the soil using a platinum catalyst as the oxidation catalyst. Therefore, a large heating furnace (such as an electric furnace) is required. Therefore, it takes several hours to reach a stable temperature necessary for heating, and measurement cannot be started during that time. In addition, the heating furnace needs to always maintain a temperature close to 300 ° C., and heat is transferred to the outside of the apparatus, and there is a risk of burns when touching the apparatus with bare hands. At the time of measurement, protective gloves and goggles for preventing burns are required. Furthermore, all the gas burned by the catalyst must be collected (collected) in a dedicated bag. Thus, a series of measurement procedures is complicated, and it is difficult to measure in a short time while ensuring the safety of the measurer at the site where the contamination investigation is performed.

The apparatus for extracting volatile substances in soil according to the present invention includes a storage space for storing the soil to be measured, a delivery means for feeding a mixed gas of oxygen and nitrogen to the soil, and the accommodation space by heating the mixed gas. Heating means to be introduced into the soil, combustion means for burning the gas whose petroleum-based hydrocarbon concentration contained in the soil is vaporized by the heating means, a combustion gas concentration measuring means for measuring the concentration of the combustion gas, and soil A lifting device that automatically lifts and lowers the container to and from the housing space; a temperature sensor that monitors the temperature of the housing space; and a lock control device that controls the lifting and lowering of the lifting device, wherein the soil container is the mixed gas Characterized by having an inlet and an outlet for passing through.

It is preferable that cooling means for cooling the gas burned by the combustion means is provided. Moreover, it is preferable that the said lock control apparatus controls the raising / lowering of the said raising / lowering apparatus by the information of the said temperature sensor.

The soil container is preferably provided with a metal mesh filter at the inlet. The soil container is preferably provided with a metal mesh filter at both the inlet and the outlet.

The lifting device includes an arm portion to which the soil container is attached, a slider portion that supports the arm portion, a holding portion that is provided on the arm and holds the soil container , and a drive portion that lifts and lowers the arm. Is preferred.

The housing space preferably includes a soil container housing space for housing the soil container and a heat insulating space for insulating heat from the housing space.

The heat insulation space preferably includes preheating means preheated by the heating means.

According to the present invention, a mixed gas of oxygen and nitrogen used for vaporizing volatile substance components contained in soil can be rapidly heated only when measuring, and the amount of heat necessary for heating as in an electric furnace can be reduced. Measurement is possible in a short time without requiring time to obtain. Therefore, the energy can be reduced during measurement.

In addition, the mixed gas in a room temperature state is passed through one side of the accommodation space that accommodates the soil to be measured having at least two spaces shielded by the inner wall, and the accommodation space has a surface exposed to the outside of the measurement device. By passing the mixed gas heated by the heating means through the other space containing the soil inside, it is difficult to transmit the heat of the rapidly heated mixed gas to the external surface of the apparatus where the accommodation space is exposed. It is possible to prevent burns even if the accommodation space touches the surface exposed to the outside of the measuring apparatus with bare hands, and the safety of the measurement operator is achieved. Furthermore, when the mixed gas in a room temperature state is passed through one housing space having a surface exposed to the outside of the measuring device and then used to heat the mixed gas, a so-called preheating effect can be obtained. This makes it possible to reduce energy during measurement.

By measuring the soil to be measured using a capsule-like container fitted with a filter, it becomes easy to exchange the measurement sample while preventing the discharge of fine dust from the capsule to the outside of the capsule. Even if the mixed gas is allowed to pass through, fine dust in the soil is not discharged outside the capsule, so that clogging inside the piping can be prevented, and maintenance of the measuring apparatus can be reduced.

Combustion gas concentration measuring means is provided, and the mixed gas before heating is passed through a combustion gas concentration meter, and the concentration of carbon dioxide contained in the mixed gas is measured in advance, so that the concentration of the combustion gas By subtracting the carbon dioxide concentration of the mixed gas before heating from the measured value, it is possible to remove the influence of the concentration of carbon dioxide (so-called background) contained in the mixed gas before heating. Is improved. Furthermore, since hydrocarbon compounds such as kerosene, light oil, A heavy oil, and C heavy oil have different vaporization temperatures, the flow rate of the mixed gas is controlled to be constant, and the concentration change of the burned gas is measured in time series. By measuring the volatile substance concentration, the type of hydrocarbon compounds contained in the soil can be determined simultaneously with the volatile substance concentration in the soil. Thereby, the time required for the determination can be shortened by making it possible to determine the type of the hydrocarbon compounds that have conventionally been taken back and analyzed at the contamination investigation site.

The measuring device is equipped with a plurality of temperature sensors, which can perform optimal temperature control and abnormality monitoring in each process of heating-vaporization-combustion-cooling-measurement, prevent abnormal heating, and containment space during heating Safety design such as opening / closing stop can be performed, and the safety of the measurement device, measurement work, and measurement operator can be ensured.

It is a block diagram of the vaporization / combustion part of the volatile substance extraction apparatus in soil which concerns on embodiment of this invention. It is a block diagram of the whole volatile substance extraction apparatus in soil. It is sectional drawing which shows the state in which the accommodation raising / lowering apparatus is accommodated in the accommodation space. It is sectional drawing which shows the state from which the accommodation raising / lowering apparatus was taken out from the accommodation space. It is a perspective view which shows the state which opened the capsule-shaped sample container.

The details of the structure relating to vaporization and combustion of the soil volatile substance extraction device according to the embodiment of the present invention will be described with reference to FIG. The vaporization / combustion unit 1 includes a vaporization container 116 having a storage space 118 therein, a capsule-shaped sample container 115 for storing soil as a sample to be measured, the sample device 115 and the sample loading chamber lid 145. In order to accommodate the sample, the sample container 115 and the sample raising / lowering device 3 for automatically raising and lowering the sample loading chamber lid 145 are provided. Further, the vaporization container 116 is configured to divide the accommodation space 118 into two spaces by accommodating the sample container 115 and the sample loading chamber lid 145. One end of the housing space 118 (the side through which the heated mixed gas passes) accommodates the sample container 115 and passes a heated gas through which the heated mixed gas (for example, 250 to 300 degrees Celsius) passes. A mixed gas inlet 2a for introducing a mixed gas of oxygen and nitrogen at normal temperature (for example, 0 to 40 degrees Celsius) is provided on the other side of the space 119 and the accommodation space 118 (the side through which the mixed gas at normal temperature passes). The room temperature gas passage space 120 provided is formed. The vaporization container 116 includes a mixed gas pipe 2c that connects the room temperature gas passage space 120 and an in-line heater 113 (details will be described later) and allows the room temperature mixed gas to pass therethrough.

Further, the vaporization / combustion unit 1 includes an in-line heater 113 that heats the mixed gas at room temperature that has passed through the mixed gas pipe 2c, an in-line heater temperature measurement sensor 121 that measures the temperature of the mixed gas in the in-line heater 113, A heated mixed gas pipe 2d connected to the inline heater 113 and the heated gas passage space 119 and through which the mixed gas heated by the inline heater 113 passes is provided.

The in-line heater 113 includes a heater for heating in a metal circular tube and heats a gas passing through the circular tube rapidly (for example, within a few seconds to several minutes) to a high temperature (for example, about 600 degrees Celsius). it can. Moreover, the heat generation temperature can be controlled by controlling the power supply to the built-in heater (for example, adjusting the voltage).

As a result, the heated gas passage space 119 becomes a high temperature state (for example, 250 degrees Celsius to 300 degrees Celsius) by the heated mixed gas that has passed through the mixed gas pipe 2d. Thereby, the hydrocarbon compound component contained in the soil of the said sample container 115 accommodated in the heating gas passage space 119 vaporizes.

The vaporization / combustion unit 1 includes a vaporized gas temperature measurement sensor 147 for measuring the temperature of the heated gas passage space 119, a vaporized gas pipe 2e connected to the heated gas passage space 119 and a catalyst container 117 filled with an oxidation catalyst, The catalyst container 117 for burning the heated mixed gas containing the vaporized component that has passed through the vaporized gas pipe 2e, the catalyst 158 filled in the catalyst container 117, and the catalyst container 117 for preheating the catalyst 158 are attached. The catalyst heater 157, the catalyst container lid 149 that opens and closes when the catalyst container 117 is filled with the catalyst 158, the catalyst temperature measurement sensor 159 that measures the temperature of the catalyst heater 157, and the catalyst container 117 are attached. And the heated mixed gas containing carbon dioxide generated by combustion in the catalyst container 117 is discharged. A combustion gas outlet 2b, and the combustion gas temperature measurement sensor 161 for measuring the temperature of the heating gas mixture containing carbon dioxide, further comprising a. With this catalyst container 117, the vaporized mixed gas can be replaced with carbon dioxide to be measured.

Next, the detail of the structure which concerns on the whole volatile substance extraction apparatus in soil is demonstrated in FIG. A volatile substance extraction device 2 (hereinafter referred to as device 2) in soil includes, as an air supply system, a housing 10 of the device 2, an outside air introduction port 101 attached to the housing 10, and the outside air introduction port 101. A pump 105 that introduces a mixed gas of oxygen at normal temperature and nitrogen introduced into the vaporization / combustion unit 1 into the inside of the housing 10 and sends it in, and an air filter 103 that removes dust from the mixed gas that is sent in The flow rate control device 107 that controls the flow rate of the mixed gas that has been fed in, the feeding temperature measurement sensor 108 that measures the temperature of the mixed gas, and the mixed gas that has been introduced from the outside air inlet 101. A flow path switching electromagnetic valve 109 that switches a flow path to be sent to or detoured to the vaporization / combustion unit 1 and a direction in which the flow path switching electromagnetic valve 109 is fed to the vaporization / combustion unit 1 are switched. It is the mixed gas comprises an air pipe 155 which passes through.

Further, the device 2 is connected to the combustion gas outlet 2b as an exhaust system, and the combustion gas pipe 135 through which the heated mixed gas containing the carbon dioxide discharged from the vaporization / combustion unit 1 passes, and the carbon dioxide. The cooling device 123 that cools the contained heated mixed gas to a temperature that can be measured by the gas concentration detector 133 (for example, 5 to 30 degrees Celsius), and the heated mixed gas that contains the carbon dioxide in the cooling device 123 Passing through the cooling unit 125, the cooling unit gas inlet temperature measurement sensor 129 for measuring the temperature of the heated mixed gas containing carbon dioxide passing through the inlet of the cooling unit 125, and the outlet of the cooling unit 125 The cooling section gas outlet temperature measurement sensor 163 that measures the temperature of the mixed gas after cooling that includes the carbon dioxide and the flow path switching solenoid valve 109 are bypassed. As a result of detecting the mixed gas temperature after cooling by the backflow preventing solenoid valve 141 that prevents the normal temperature mixed gas that has passed through the gas pipe 111 from flowing back to the cooling unit 125, and the cooling unit gas outlet temperature measurement sensor 163, The heated mixed gas is connected to the forced exhaust port 139 in order to protect the gas concentration detection unit 133 when the heated mixed gas after cooling cannot be cooled to a temperature that can be measured by the gas concentration detection unit 133. A forced exhaust solenoid valve 131 that switches the flow path to the forced exhaust pipe 165, and a gas concentration measurement pipe through which the mixed gas containing carbon dioxide cooled to a temperature that can be measured by the gas concentration detector 133 by the cooling unit 125 passes. 167, a dehumidifying part 127 for adjusting the humidity of the mixed gas containing carbon dioxide that passes through the gas concentration measuring pipe 167, and the carbon dioxide Comprising a gas concentration detecting portion 133 for measuring the concentration of the mixed gas, the exhaust port 137 which is attached to the housing 10 for discharging the mixed gas containing the carbon dioxide measured by the gas concentration detection unit 133 to the outside.

Further, the device 2 includes, as a control system, an operation unit 13 that performs operations necessary for the measurement of the device 2, a display unit 14 that displays items necessary for operations, setting values, measurement results, the pump 105, and the A flow control unit 17 that controls the flow control device 107, a temperature measurement unit 19 that measures the temperature of a plurality of temperature measurement sensors attached to the inside of the housing 10, and a lock control that controls the opening and closing of the storage lifting device 3. Unit 23, measurement control unit 21 that measures and controls the concentration of gas concentration detection unit 133, and calculation control unit 15 that performs calculation control based on signals from flow rate control unit 17, temperature measurement unit 19, and measurement control unit 21. The input / output signal line 143 that connects the flow control unit 17, the temperature measurement unit 19, the lock control unit 23, the measurement control unit 21, the calculation control unit 15, the operation unit 13, and the display unit 14. The Obtain.

Note that the vaporization / combustion unit 1 is a heat shield wall 11 in order to protect a device (for example, a measurement unit or a control unit such as the calculation control unit 15 or the temperature measurement unit 19) that interferes with measurement control due to the temperature effect. Surrounded.

The housing lifting / lowering device 3 for inserting / removing the sample container 115 and the sample loading chamber lid 145 into / from the housing space 118 of the vaporization container 116 will be described with reference to FIGS. FIG. 3 shows a state in which the sample container 115 is stored in the storage space 118 formed inside the vaporization container 116. FIG. 4 shows a state in which the sample container 115 is outside the storage space 118. The container lifting / lowering device 3 includes a motor 153 that automatically lifts and lowers the sample container 115 and the sample loading chamber lid 145 to be housed or taken out from the housing space 118, and a motor pulley 303 that is driven by the motor. The belt 305 that transmits the power of the motor pulley 303 to the shaft pulley 307, the ball screw 309 that is attached to the shaft pulley 307 and rotates by the power transmitted by the belt 305, and the shaft pulley 307 is rotated by the rotation of the ball screw 309. An arm mounting base 311 that moves in the mounting direction or in the reverse direction, the slide arm 151 that is mounted on the arm mounting base 311, a sample loading chamber lid 145 that is mounted on the sliding arm 151, and the sample loading chamber lid 145 The connecting rod 313 is attached, and the connecting rod 313 is attached. A shielding wall 315 that shields the accommodation space 118 into two spaces (the heated gas passage space 119 and the room temperature gas passage space 120) by being inserted into the accommodation space 118, and a sample container mounting base attached by the connecting rod 313. 317.

Further, the storage lifting device 3 includes a support column 301 attached to the housing 10, a slide rail 325 attached to the support column 301, a slider 323 that moves along the slide rail 325, and the support column 301 or the slide rail 325. Are provided with an upper position sensor 319 for detecting the position of the slider 323 and a lower position sensor 321. The slider 323 is connected to the arm mount 311 and moves along the slide rail 325 in conjunction with the arm mount 311.

Further, the sample container 115 is set on the sample container mounting base 317 of the storage lifting device 3.

Further, a storage space 118 formed inside the vaporization container 116 of the storage lifting device 3 is shielded at a predetermined position substantially in the middle by the shielding wall 315, and the room temperature gas passage space 120, the heating gas passage space 119, and the like. Is formed. The heated gas passage space 119 is brought to a high temperature state by a high temperature mixed gas, and vaporizes hydrocarbon compound components contained in the soil put in the sample container 115. On the other hand, a normal temperature mixed gas passes through the normal temperature gas passage space 120 shielded by the shielding wall 315. That is, by making the inner side (lower side) of the vaporization container 116 a high-temperature vaporization space and the outer side (upper side) a hierarchical space structure of a normal temperature cooling space, the high-temperature heat of the heated gas passage space 119 is as follows: It is cooled by the shielding wall 315 and the room temperature gas passage space 120 so that it is not transmitted to the outside of the vaporization vessel 116 in a high temperature state. As a result, the measurer can work safely without being exposed to high-temperature heat.

Next, an embodiment of the capsule-shaped soil sample container will be described in detail with reference to FIG. FIG. 5 shows a state in which the measurement soil 503 is placed in a capsule-like sample container 115. The capsule-like sample container 5 is composed of a sample container receiver 115b in which the soil 503 to be measured is placed, and a sample container lid 115a that covers the sample container 115b.

Further, the capsule-shaped sample container 5 allows the mixed gas heated by the in-line heater 113 in the accommodation space 118 to pass through the soil 503 placed in the sample container 115, and the soil 503 is outside the sample container 115. A fine mesh filter 501 is attached to the sample container lid 115a and the sample container receiver 115b so as not to flow out.

Next, the usage method (measurement method) of this apparatus 2 is demonstrated. In a predetermined storage device (for example, ROM) of the arithmetic control unit 15 of the apparatus 2, operations of respective units necessary for measurement and operation described below are built in as a program in advance. The built-in program is executed in response to an operation command from the operator's operation unit 13. The built-in program displays the operation items, the state during measurement, the measurement result, and the like on the display unit 14. Thereby, the operator can perform an appropriate operation at an appropriate timing by looking at the displayed information, and can perform highly accurate measurement in a short time.

The soil 503 containing the volatile substance component is put in the sample container receiver 115b of the capsule-shaped sample container 115, and the sample container lid 115a is covered. The housing lifting / lowering device 3 is driven by the operation unit 13 of the device 2 and the sample container mounting base 317 is taken out of the housing 10 from the housing space 118 so that the sample container 115 can be set as shown in FIG. After the sample container 115 is set, as shown in FIG. 3, the accommodation lifting device 3 is driven again by the operation unit 13 to accommodate the sample container 115 in the accommodation space 118. In the storage device 3, a method of taking out the sample container 115 from the storage space 118 using the motor 153 and the ball screw 309 is disclosed, but other drive devices may be used manually.

As shown in FIG. 3, the sample container 115 is set in the accommodation space 118, and the measurement start operation is performed by the operation unit 13 of the apparatus 2. In accordance with a command sent from the operation unit 13 to the calculation control unit 15, the calculation control unit 15 automatically executes the control operation of the apparatus 2 according to the following procedure based on a control program stored in advance.

The pump 105 is driven and a mixed gas of oxygen and nitrogen at normal temperature is sucked from the outside air inlet 101 attached to the housing 10, and dust and dust contained in the mixed gas are removed by the air filter 103. Next, the mixed gas is sucked into the pump 105 and then discharged and sent to the flow control device 107. At this time, the mixed gas is controlled to a constant flow rate by the flow rate control device 107 in accordance with a signal from the flow rate control unit 17.

The mixed gas controlled to have a constant flow rate is sent to the gas concentration measurement pipe 167 from the bypass pipe 111 with the flow path controlled by the flow path switching solenoid valve 109, the backflow prevention solenoid valve 141, and the forced exhaust solenoid valve 131. After being dehumidified by the dehumidifying unit 127, it is sent to the gas concentration detecting unit 133. At this time, the mixed gas is controlled in the flow path and does not flow into the air pipe 155, the forced exhaust pipe 165 and the combustion gas pipe 135.

The gas concentration detector 133 measures the carbon dioxide concentration of the mixed gas. The measured carbon dioxide concentration of the mixed gas is stored in a predetermined storage area of the arithmetic control unit 15 as a background value of the mixed gas.

While measuring the carbon dioxide concentration of the mixed gas as the background value, the catalyst 158 placed in the catalyst container 117 is heated by the catalyst heating heater 157 of the vaporization / combustion unit 1. At this time, the arithmetic control unit 15 uses the catalyst temperature measurement sensor 159 attached to the catalyst container 117 to control the catalyst temperature of the catalyst container 117 to a temperature suitable for the catalytic effect (for example, 250 degrees to 300 degrees Celsius). The temperature of the container 117 is detected. The detected temperature (temperature signal) of the catalyst container 117 is subjected to signal conversion processing by the temperature measuring unit 19. The arithmetic control unit 15 controls the catalyst heating heater 157 based on the temperature signal subjected to the signal conversion process, and controls the temperature of the catalyst container 117 to be constant.

After the temperature of the catalyst temperature measuring sensor 159 reaches a specified value, the mixed gas discharged from the pump 105 and controlled at a constant flow rate is controlled in flow path by the flow path switching electromagnetic valve 109 and is bypassed. The pipe 111 is switched to the air pipe 155 and sent. At this time, the mixed gas does not flow into the bypass pipe 111. The introduced mixed gas at normal temperature is sent into the normal temperature gas passage space 120 shielded by the shielding wall 315 from the mixed gas inlet 2a attached to the vaporization vessel 116, and further into the normal temperature gas passage space 120. It passes through the connected mixed gas piping 2c and is sent to the in-line heater 113 having a built-in heater.

The in-line heater 113 starts heating at the same time as the mixed gas is switched to the air pipe 155 and is heated, and the mixed gas at room temperature is heated when it passes through the in-line heater 113. The heated mixed gas passes through the heated mixed gas pipe 2d and is sent into the heated gas passage space 119 shielded by the shielding wall 315. At this time, the temperature of the heater built in the in-line heater 113 is controlled to a temperature suitable for vaporizing the contained volatile substance (for example, 250 to 300 degrees Celsius). Specifically, the arithmetic control unit 15 further converts the temperature signal detected by the in-line heater temperature measurement sensor 121 and further converts the heater signal built in the in-line heater 113 on the basis of the temperature signal obtained by signal conversion processing by the temperature measurement unit 19. The temperature is controlled to be constant within a predetermined temperature range.

The mixed gas fed into the heated gas passage space 119 passes through the mesh filter 501 attached to the sample container 115 set on the sample container mounting base 317 to heat the soil 503 in the sample container 115. To do. And the volatile substance contained in the soil 503 is vaporized. The vaporized volatile substance passes through the vaporized gas pipe 2e together with the mixed gas, is sent to the catalyst 158 in the catalyst container 117, and is burned by the catalyst 158 to become carbon dioxide gas.

Carbon dioxide gas generated by combustion in the catalyst 158 (hereinafter referred to as combustion gas) is attached to the cooling device 123 through the combustion gas pipe 135 from the combustion gas outlet 2b attached to the catalyst container 117. After being cooled to room temperature by the cooling unit 125, the flow path is controlled by the backflow prevention solenoid valve 141 and the forced exhaust solenoid valve 131, the gas is sent to the gas concentration measurement pipe 167, and after dehumidification by the dehumidification unit 127, the gas concentration detection unit To 133. At this time, the combustion gas is controlled in the flow path and does not flow through the bypass pipe 111 and the forced exhaust pipe 165.

The measured value of the carbon dioxide concentration of the combustion gas measured by the gas concentration detector 133 is stored in the arithmetic control unit 15 as the value of the carbon dioxide concentration of the combustion gas in time series from the measurement start time to the end time. . The measurement is ended after a measurement start operation is performed at the operation unit 13 of the apparatus 2 and a predetermined time has elapsed. The measurement time may be arbitrarily set, but when the carbon dioxide concentration of the combustion gas becomes equal to the value stored in the arithmetic control unit 15 as the background value of the mixed gas measured in advance. The measurement can also be terminated. This is because it is determined that the vaporization of the volatile substance contained in the soil 503 has ended.

Some volatile substances of soil pollutants include, for example, petroleum hydrocarbons. For example, when petroleum hydrocarbons are completely burned, the calculation control unit 15 applies the following reaction formula (1) programmed in the calculation control unit 15 so that the calculation control unit 15 can generate The content of the volatile substance contained in is calculated and the measurement result is displayed on the display unit.

CmHn + (m + n / 4) O ₂ → mCO ₂ + n / 2H ₂ O (1)

When the pollutant component contained in the soil is known in advance, for example, in the case of light oil, if the measurer inputs from the operation unit 13 as m = 1 and n = 1.8, the calculation The control unit 15 can calculate the content of the pollutant more accurately by using the reaction formula (1).

Furthermore, since hydrocarbon compounds such as kerosene, light oil, A heavy oil, C heavy oil have different vaporization temperatures, the gas concentration detection unit 133 controls the concentration change of the burned gas by controlling the flow rate of the mixed gas constant. By measuring in series, the calculation control unit 15 can determine the types of hydrocarbon compounds contained in the soil at the same time as the concentration of volatile substances in the soil. When the correct values of m and n are input from the operation unit 13, the calculation control unit 15 can calculate the content of pollutants more accurately by using the reaction formula (1).

The measurement data obtained as described above can be stored in a predetermined storage area (for example, RAM) of the arithmetic control unit 15. Further, the measurement data can be copied from the calculation control unit 15 to an electronic storage medium or the like, or can be copied by connecting a personal computer or the like directly to the calculation control unit 15.

The arithmetic control unit 15 ends the measurement when it is determined that a measurement start operation is performed according to a built-in program and a certain time has elapsed or the vaporization of the volatile substance contained in the soil 503 is completed. Simultaneously with the end of the measurement, the arithmetic control unit 15 stops the heating of the in-line heater 113. The mixed gas at room temperature passes through the inline heater 113 whose heating has been stopped, and the heater built in the inline heater 113 is rapidly cooled. Further, the heated gas passage space 119, the sample container 115, the sample container mounting base 317, the connecting rod 313, and the shielding wall 315 are cooled by the mixed gas that has passed through the in-line heater 113. At this time, the temperature signals from the vaporized gas temperature measurement sensor 147 and the feed temperature measurement sensor 108 attached to the heated gas passage space 119 are subjected to signal conversion processing by the temperature measurement unit 19, and the temperature of the two sensors is adjusted by the arithmetic control unit 15. If they are equal, the mixed gas controlled to have a constant flow rate is controlled in flow path by the flow path switching solenoid valve 109, the backflow prevention solenoid valve 141, and the forced exhaust solenoid valve 131, and passes through the forced exhaust pipe 165. The mixed gas is discharged from a forced exhaust port 139 attached to the housing 10. At this time, the mixed gas does not flow through the gas concentration measurement pipe 167 and the bypass pipe 111.

Next, when measuring another soil, the sample container mounting is performed so that the storage container 3 can be set as shown in FIG. The table 317 is taken out of the housing space 118 from the housing space 118, the sample container 115 which has been measured is removed, and the soil 503 to be measured next is put into the capsule-shaped sample container 115, and the sample container mounting table. After setting to 317, the same operation as the previous time is repeated.

When all the measurements are completed, the measurer inputs the end again at the operation unit 13 of the device 2. Upon receiving the end command, the arithmetic control unit 15 automatically executes the following operations according to the built-in program. First, the arithmetic control unit 15 stops heating the in-line heater 113 and the catalyst heating heater 157. The mixed gas at room temperature passes through the inline heater 113 whose heating has been stopped, and the heater built in the inline heater 113 is rapidly cooled. Further, the heated gas passage space 119, the sample container 115, the sample container mounting base 317, the connecting rod 313, and the shielding wall 315 are also cooled by the mixed gas that has passed through the in-line heater 113. Further, the mixed gas also cools the catalyst container 117 and the catalyst 158. At the same time as the heating is stopped, the flow path is controlled by the backflow prevention solenoid valve 141 and the forced exhaust solenoid valve 131, and the forced exhaust port 139 attached to the casing 10 through the forced exhaust pipe 165. The mixed gas is discharged. At this time, the mixed gas does not flow through the gas concentration measurement pipe 167 and the bypass pipe 111.

Next, the temperature from the vaporized gas temperature measurement sensor 147, the supply temperature measurement sensor 108, the combustion gas temperature measurement sensor 161, the catalyst temperature measurement sensor 159, and the cooling unit gas inlet temperature sensor 129 attached to the heated gas passage space 119. The signal is subjected to signal conversion processing by the temperature measuring unit 19, and when the temperatures of these five sensors become equal by the arithmetic control unit 15, the pump 105 is stopped and the end is displayed on the display unit 14 to notify the measurer.

In short, the soil 503 to be measured is set in the vaporization container 116 (accommodating space), and the mixed gas of oxygen and nitrogen fed to the soil by the pump 105 (feeding means) is supplied by the in-line heater 113 (heating means). When rapidly heated and introduced into the vaporization container 116 (accommodating space), volatile substances contained in the soil are vaporized by the in-line heater 113 (heating means), and the vaporized gas is further converted by the catalyst 158 (combustion means). After burning, the soil is obtained by cooling with the cooling device 123 and the cooling unit 125 (cooling unit) to obtain a normal temperature gas again, and then measuring the concentration of the gas with the gas concentration detecting unit 133 (gas concentration measuring unit). Medium volatile substance concentration can be measured. According to this method, heating and cooling only need to be performed at the time of measurement, and it is not necessary to use an electric furnace, and energy can be reduced at the time of measurement. In addition, measurement with an electric furnace takes about several hours to reach the optimum temperature required for measurement, but this method enables measurement in a short time (for example, the time for measuring one sample is about 10 minutes). It is possible to quickly measure at the site where contamination is to be investigated.

The soil 503 can be stored in the sample container 115 (capsule container) and stored in the vaporization container 116 (storage space). As a result, sample exchange for each measurement can be easily performed.

A fine mesh filter 501 is attached to the sample container 115 to prevent fine dust in the soil 503 from flowing out of the sample container 115 when the mixed gas passes, and the mixed gas passes. The vaporization container 116 (accommodating space), the catalyst 158, and the like are not polluted, so that the maintainability is improved, and the convenience at the soil contamination site where many samples are to be measured in a short time can be improved.

The storage lifting device 3 (lifting means) that automatically lifts and lowers the sample container 115 (capsule container) simply stores the sample container 115 (capsule container) in the vaporization container 116 (storage space). It also serves as a safety device. For example, in order to vaporize the volatile substances contained in the soil 503, the mixed gas at a high temperature (for example, 300 degrees Celsius) is used. However, the sample container 115 (capsule container) is The gasification container 116 (accommodating space) is accommodated and cannot be directly touched from the outside of the device 2. Further, it is possible to raise the housing lifting / lowering device 3 on the condition that the temperature of the vaporized gas temperature measuring sensor 147 attached to the vaporizing container 116 (accommodating space) is the same level as the temperature of the feeding temperature measuring sensor 108. Therefore, it is possible to prevent the measurer from touching the sample container 115 (capsule container) in a high temperature state and protect the measurer from burns. As a matter of course, it is also possible to set conditions in combination with temperature monitoring of other temperature sensors in the apparatus 2, signals of the upper position sensor 319 and the lower position sensor 321, and operations of the inline heater 113 and the like. is there.

The storage elevating device 3 (elevating means) includes the slide arm 151 (arm portion) to which the sample container 115 (capsule container) is attached, the arm mounting base 311 that supports the slide arm 151 (arm portion), and the slider 323. The (slider part), the sample container mounting base 317 for setting the sample container 115 (capsule container), the connecting rod 313 and the shielding wall 315 (holding part) are interlocked with the driving force of the motor 153 (driving part). By operating, the sample container 115 (capsule container) can be easily taken out from the vaporization container 116 (accommodating space).

The vaporization container 116 (accommodation space) is a room temperature that insulates the heat of the vaporization container 116 and the heated gas passage space 119 (capsule accommodation space) that accommodates the sample container 115 (capsule container) shielded by the inner wall. It has two spaces, a gas passage space 120 (heat insulating space), a mixed gas of oxygen and nitrogen at normal temperature is passed through the normal temperature gas passage space 120, and the soil 503 is accommodated in the heated gas passage space 119. The mixed gas heated by the in-line heater 113 (heating means) is allowed to pass through. That is, by making the inner side (lower side) of the vaporization container 116 a high-temperature vaporization space and the outer side (upper side) a hierarchical space structure of a normal temperature cooling space, the high-temperature heat of the heated gas passage space 119 is as follows: The apparatus 2 is cooled by the shielding wall 315 and the room temperature gas passage space 120 and can be cooled to near room temperature. As a result, the heat of the gas mixture rapidly heated is exposed to the vaporization container 116 (accommodation space). It is possible to make it difficult to convey to the external surface, and it is possible to prevent the vaporization container 116 (accommodating space) from being burned even if the surface exposed to the outside of the device 2 is touched with bare hands. Is planned.

The room temperature gas passage space 120 (heat insulating space) is transferred to the room temperature gas passage space 120 by the in-line heater 113 (heating means), but the mixed gas passes through the room temperature gas passage space 120 at the same time. The heat is taken away. That is, the mixed gas in the normal temperature state introduced into the normal temperature gas passage space 120 can obtain a so-called preheating effect at the same time as the effect of cooling the normal temperature gas passage space 120, thereby reducing energy during measurement. .

As described above, according to the present invention, the mixed gas of oxygen and nitrogen used for vaporizing volatile substance components contained in the soil can be rapidly heated only when measuring, and is necessary for heating like an electric furnace. Measurement is possible in a short time without requiring time to obtain a large amount of heat. Therefore, the energy can be reduced during measurement. Furthermore, by rapidly heating the mixed gas at room temperature that has passed through one of the accommodation spaces blocked by the two spaces and introducing it into the other space containing the soil, It is possible to ensure the safety of the measurer who takes heat away from one space and does not release it outside the device. Further, by measuring the gas obtained by burning the vaporized volatile substance component in a time series by the gas concentration detector, it is possible to detect the contamination concentration and discriminate the contaminant component.

The present invention can be widely used in the field of measuring the concentration of volatile substances contained in soil. In particular, it can be used in the field of measuring the concentration of volatile pollutants in soil.

1 Vaporization / combustion unit 2 Soil volatile substance extraction device (device)
2a Mixed gas inlet 2b Combustion gas outlet 2c Mixed gas pipe 2d Heated mixed gas pipe 2e Vaporized gas pipe 3 Accommodating elevating device 5 Capsule sample container 10 Housing 11 Heat shield wall 13 Operation unit 14 Display unit 15 Calculation control unit 17 Flow rate control Unit 19 Temperature measurement unit 21 Measurement control unit 23 Lock control unit 101 Outside air introduction port 103 Air filter 105 Pump 107 Flow rate control device 108 Inflow temperature measurement sensor 109 Channel switching solenoid valve 111 Bypass piping 113 Inline heater 115 Sample container 115a Sample container Lid 115b Sample container receiver 116 Vaporization container 117 Catalytic container 118 Storage space 119 Heated gas passage space 120 Room temperature gas passage space 121 In-line heater temperature measurement sensor 123 Cooling device 125 Cooling unit 127 Dehumidifying unit 129 Cooling unit gas inlet temperature sensor 131 Forced exhaust electricity Valve 133 Gas concentration detector 135 Combustion gas piping 137 Exhaust port 139 Forced exhaust port 141 Backflow prevention solenoid valve 143 Input / output signal line 145 Sample loading chamber lid 147 Vaporized gas temperature measurement sensor 149 Catalyst container lid 151 Slide arm 153 Motor 155 Air piping 157 Catalyst heating heater 158 Catalyst 159 Catalyst temperature measurement sensor 161 Combustion gas temperature measurement sensor 163 Cooling section gas outlet temperature measurement sensor 165 Forced exhaust pipe 167 Gas concentration measurement pipe 301 Strut 303 Motor pulley 305 Belt 307 Shaft pulley 309 Ball screw 311 Arm mounting Base 313 Connecting rod 315 Shielding wall 317 Sample container mounting base 319 Upper position sensor 321 Lower position sensor 323 Slider 325 Slide rail 501 Mesh filter 503 Soil

Claims (8)

A storage space for storing the soil to be measured;
A feeding means for feeding a mixed gas of oxygen and nitrogen into the soil;
Heating means for heating the mixed gas and introducing it into the accommodation space;
Combustion means for burning a gas having a petroleum hydrocarbon concentration contained in the soil vaporized by the heating means with a catalyst;
A combustion gas concentration measuring means for measuring the concentration of the combustion gas;
A lifting device that automatically lifts and lowers the soil container into the accommodation space;
A temperature sensor for monitoring the temperature of the accommodation space;
A lock control device for controlling the lifting and lowering of the lifting device;
The soil container has an inlet and an outlet for allowing the mixed gas to pass therethrough.   The apparatus for extracting volatile substances in soil according to claim 1, further comprising cooling means for cooling the gas burned by the combustion means.   3. The soil volatile substance extraction device according to claim 1, wherein the lock control device controls the lifting and lowering of the lifting device based on information of the temperature sensor. The soil container is
The volatile substance extraction device in soil according to any one of claims 1 to 3, wherein a metal mesh filter is attached to the inlet. The soil container is
The volatile substance extraction device in soil according to any one of claims 1 to 4, wherein a metal mesh filter is attached to both the inlet and the outlet. The lifting device is
An arm portion for attaching the soil container;
A slider portion for supporting the arm portion;
A holding part that is provided in the arm part and holds the soil container;
The volatile substance extraction device in soil according to any one of claims 1 to 5, further comprising a drive unit that moves the arm unit up and down. The accommodating space is
A soil container housing space for housing the soil container;
The volatile substance extraction device for soil according to any one of claims 1 to 6, further comprising a heat insulating space for insulating heat of the housing space.   The said heat insulation space is provided with the preheating means preheated by the said heating means, The volatile substance extraction apparatus in soil of Claim 7 characterized by the above-mentioned.

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