JPS63177012A - Surface area measuring apparatus - Google Patents

Abstract

PURPOSE:To enhance not only the efficiency of measuring work but also measuring accuracy, by providing an apparatus main body, a control apparatus and an order/ operation apparatus to continuously and automatically perform each process of a surface area measuring method and processing a plurality of specimens in parallel. CONSTITUTION:Gas supply sources 6, 7 for supplying the pretreating adsorbing and desorbing gas of a specimen and the transport gas thereof, a gas flow rate control system 5 for mixing said gases in a definite ratio to transport the same and gas flow passage selecting cocks 10a-10d for selectively performing the opening and closing of the gas flow passages to specimen pipes 9 (9a-9h) are provided to an apparatus main body. Further, an electric furnace 13 for heating the specimen pipes 9 a liquid nitrogen receiver 14, a water receiver 15, a heat conductive detector 26 for detecting the amount of the gas adsorbed by or desorbed from the specimen and an adsorbing/ desorbing amount calibration system 23 for calibrating the amount of the adsorbed or desorbed gas are provided. All of the processes of the specimen due to a surface area measuring method are automatically and collectively performed inclusive of the pretreatment of the specimen and a large number of specimens are measured by parallel operation and a measuring time is shortened and the working quantity of a measuring person is reduced and working content can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a surface area measuring device that can automatically measure the surface area of a sample by applying the BET specific surface area measuring method.

(Prior art) As a conventional method for measuring the surface area of samples such as catalysts, [
The 3ET specific surface area measurement method is well known, and various devices are commercially available for measuring the surface area of a sample by applying this measurement method.

However, the above-mentioned device uses the BET specific surface area measurement method to measure the surface area of a sample in each process, namely: - Sample weighing - Sample pretreatment - Measurement of gas particles adsorbed to or desorbed from the sample - Volume of the gases listed on the left. There has never been a method that completely automatically performs the following processes: - Verification - Precise weighing of the sample - Squeezing out the surface area of the sample.

(Problems to be Solved by the Invention) Conventionally, in each process of measuring the surface area of a sample as described above, a large number of samples were not completely automatically processed, so the measurement required a long amount of time. In addition, there were problems in that the amount of work required by the measuring operator was large and the work was quite sloppy.

(Means for Solving the Problems) In order to solve the above problems, the present invention continuously and automatically performs each process of the surface area measurement method, and enables parallel processing of a plurality of samples. This system aims to streamline measurement work and improve measurement accuracy, and includes two gas supply sources that supply gas for sample pretreatment, adsorption/desorption gas, and transportation gas, and a system that mixes both gases at a fixed ratio. A gas flow control system to be transported, a gas flow path selection mechanism that selectively closes gas flow paths to multiple sample tubes, a sample tube installation section that installs multiple sample tubes, and a sample tube installation section that installs multiple sample tubes; A heating furnace that heats, cools, and warms the tube, a liquid nitrogen receiver and a water receiver, a drive system that rotates them and moves them up and down independently, and a heat source that detects the amount of gas adsorbed to or attached to the sample. A device body equipped with a conductivity detector, an adsorption/desorption wI open calibration system that calibrates the amount of adsorbed or desorbed gas, a W control device in the device body, and control commands to the device body and information transferred from the device body. This provides a surface area measuring device 1A consisting of an 8Ilin device and instructions for calculating measurement data.

<Example> As an example of the present invention, a surface area measuring device having a configuration in which eight sample tubes can be installed will be described.

FIG. 1 is a schematic configuration diagram of a surface area measuring device according to an embodiment of the present invention. As shown in FIG. configured.

The configuration of the device main body 2 will be explained below.

FIG. 2 is a system diagram of the main body of the device.

The gas flow ffl i, II control system 5 is supplied from a helium gas source 6 and a nitrogen gas source 7. The flow rates of helium gas for transportation and nitrogen gas for pretreatment and adsorption/desorption are controlled by mass flow controller 1 cola 8, and each sample tube 9a to 9h is mixed as a mixed gas with a predetermined mixing ratio. It is intended to be transported to

Gas flow f! 1 selection cocks 10a to 10d correspond to each sample tube 9a to 9h,! : Dedicated! 11, and selectively opens and closes the gas flow path so that the mixed gas transported from the gas flow rate control system flows into a designated sample tube.

As shown in FIG.
It is designed to be installed in the sample tube installation section 12 of .

Below the sample tube installation part 12, there are four electric furnaces 13, liquid nitrogen receivers 14, and water receivers 15! It is placed on the stand 16.

The liquid nitrogen receiver 14 is connected to the liquid nitrogen supply source 1 via a conduit 17.
8 so that liquid nitrogen is automatically supplied from a liquid nitrogen supply source 18.

Further, the temperature of the electric furnace 13 and the liquid level of liquid nitrogen in the liquid nitrogen receiver 14 are controlled to respective designated positions by a command and arithmetic unit W14.

Furthermore, the mounting body 16 can be rotated by a drive motor 19, and the electric furnace 13, liquid nitrogen receiver 14, and water receiver 15 can each be moved up and down independently by their respective drive systems 20, 21, and 22. ing.

The adsorption/desorption amount calibration system 23 calibrates the amount of nitrogen gas adsorbed to or desorbed from the sample, and includes a hanging pipe 24
, rotary valve 25, etc.

The thermal conductivity detector 26 is a thermal conductivity detector 26 that detects the amount of nitrogen gas adsorbed to or desorbed from the sample.
By using , it is possible to measure the surface area of a sample with an accuracy of 0°0'l''/(l.

The control device 3 will be explained.

FIG. 3 is a system diagram that does not show the control system of the main body of the apparatus.

The control device 3 commands the control of each drive system of the device main body 2,
This is done by switching the built-in relay 27 in accordance with a control command from the arithmetic unit 4.

The command and performance device 4 is comprised of a computer 28, a display 29, and a printer 30, as shown in FIG.

The computer 28 issues control commands to the device main body 2,
8# numbing is performed using the measurement data transferred from the apparatus main body 2, and the sieving value of the surface area of the sample is displayed on the display 29 or output to the printer 30.

Next, a method for measuring the surface area of a sample using this measuring device will be described in accordance with the order of the measurement process.

First, a weighed sample is inserted into each of the sample tubes 9a to 9h, and the sample tubes are placed in the sample Fl tube installation section 12 shown in FIG.

Next, the measurement conditions are inputted into the instruction and execution device 4, and the device main body 2 is started.

In the apparatus main body 2, a sample tube 9a to which a gas flow path selection cock 10a is designated by a command or a start command from the arithmetic unit 4 is installed.
The mixed gas flows from the gas flow layer control system 5 into the sample tube 9a.

The inflowing mixed gas then passes through the gas flow path selection cock 10.
It is discharged through d.

Subsequently, the mounting body 16 is rotated, and the electric furnace 13 is moved to the sample tube 9a.
The electric furnace 13 is then moved upward and the sample tube 9a is inserted thereinto.

The sample tube 9a is heated at a predetermined temperature by the electric furnace 13.

The bag and the electric furnace 13 are moved downward for a predetermined period of time, and the sample tube 98 is discharged from the electric furnace 13 and cooled.

When the sample tube 9a is cooled to room temperature, the gas flow path to the sample tube 9a is opened by the gas flow path selection cocks 10b and 10C, and the gas flow path connecting the sample Fl tube 9a and the thermal conductivity detector 26 is opened. is asked.

Subsequently, the mounting body 16 is rotated, and the liquid nitrogen receiver 14 is moved and positioned below the sample tube 9a, and the liquid nitrogen receiver 114 is further moved upward to insert the sample tube 9a and cool it for a predetermined period of time.

At this time, the thermal conductivity detector 26 detects the peak value of nitrogen gas adsorption to the sample filled in the sample tg9a.

This detection (1 (+ is a command, transferred to performance equipment M4.

After a predetermined time, the liquid nitrogen receiver 14 moves downward, and then, due to the rotation of the mounting body 16, the water receiver 1 is placed below the sample tube 9a.
5 is located, the sample tube 9a is similarly moved upward, and the sample tube 9a, which has been cooled 7J1 to the temperature of liquid nitrogen, is heated.

Due to the heating, nitrogen is desorbed from the sample, and at this time the thermal conductivity detector 26 detects the peak value of the nitrogen desorption gloss from the sample.

This detected value is also transferred to the instruction and focusing device 4 in the same way.

The above series of operations are sequentially repeated for the sample tubes 9b to 9h.

Here, this measuring device can perform two processes at the same time, such as the sample tube 9a being inserted into the liquid nitrogen receiver 14 and the sample tube 9bl:lt being inserted into the electric furnace 13 at the same time. Since the operation mode is changed, the measurement time is significantly shortened.

When the series of operations described above is completed for all sample tubes 98 to 9h, a predetermined amount of nitrogen gas is transported from the adsorption/desorption suspension calibration system 23 to the thermal conductivity detector 26, and the peak value of the amount of nitrogen gas transported is determined. Detected.

This detected value is also transferred to the command and control device 4.

When all the operations of the device body 2 are completed, the command, fief
In the 1g device 4, data is transferred from the device main body 2, and calculations are performed based on the measured data values, and the surface area of the sample is also calculated.

The surface area value can be displayed on the display 29 or output to the printer 30.

Xi like the above! The time required to measure the surface area of a sample is greatly shortened by the configuration and operation of the i-position, and automation also greatly reduces the amount of work performed by the measurement operator, making the content of each task more i-simplified.

Furthermore, measurement automation eliminates measurement errors that depend on the measurement operator, making objective and highly reliable measurements possible.

In addition, by adopting a thermal conductivity detector, 0.01llI2/
(We were also able to achieve extremely high precision measurement of J.

(Effects of the invention) All steps of the method for measuring the surface area of a sample, including pretreatment of the sample, are automatically performed all at once, and the device is configured to be able to measure multiple samples in parallel, thereby reducing the time required for measurement. This greatly reduces the amount of work required for measurement workers, and greatly simplifies the work involved.

Furthermore, measurement automation has eliminated measurement errors that depend on the measurement operator, making it possible to perform objective measurements with high reproducibility, and the adoption of a thermal conductivity detector has also made it possible to achieve highly accurate measurements.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of the surface area measuring device of the present invention, FIG. 2 is a system diagram of the main body of the measurement Vt device, and FIG. 3 is a conceptual diagram showing the control system of the main body of the measuring device F1. DESCRIPTION OF SYMBOLS 1... Main measuring device, 2... Apparatus main body, 3... Control device, 4... Command, calculation device, 5... Gas flow rate control system, 6... Helium gas supply source, 7 ...Nitrogen gas supply source, 8...Mass flow controller, 93~9h・
...Sample tube, 10a-10d...Cock for gas flow path selection, 13...Electric furnace, 14...Liquid nitrogen receiver, 15
...Water receiver, 23...Adsorption/desorption@monitor calibration system, 26.
・Thermal conductivity detector.

Claims (1)

[Claims] Both gas supply sources supply gas for sample pretreatment, adsorption/desorption gas, and transport gas, gas flow control system that mixes both gases at a fixed ratio and transports them, and gas flow paths to multiple sample tubes. a gas flow path selection mechanism that selectively opens and closes the sample tube, a sample tube installation section that installs a plurality of sample tubes, a heating furnace that heats, cools, and warms the sample tubes, a liquid nitrogen receiver, and a water receiver; A drive system that rotates and independently moves them up and down, a thermal conductivity detector that detects the amount of gas adsorbed to or desorbed from the sample, and an adsorption/desorption amount calibration system that calibrates the amount of gas adsorbed or desorbed. A surface area measuring device comprising: a device main body equipped with the device; a control device for the device main body; and a command and arithmetic device for calculating control commands to the device main body and measurement data transferred from the device main body.