JPS58109842A - Apparatus for measuring evaporation weight and evaporation heat value simultaneously - Google Patents

Abstract

PURPOSE:To shorten the necessary time of measurement, by hanging a sample vessel stored in a heating furnace to a weight detection mechanism provided to the outside of the heating furnace through connection parts and measuring the heat value of evaporation and weight of evaporation at the same time. CONSTITUTION:A sample vessel 6 stored in a heating furnace 5 is hung or mounted to a weight detection mechanism 8 provided to the ouside of the furnace 5 through an introducing pipe 7 to be a connection member. Reaction gas or carrier gas is introduced into the vessel 6 through the pipe 7 and also, a heater 20 and the first temperature sensor 21 detecting the temperature of the sample are provided in the vessel 6 and moreover, the second temperature sensor 22 detecting the atomsphere temperature is provided in the neighborhood of the outside of the vessel 6. In case when the detection temperature of the sensor 21 is lower than that of the sensor 22, electricity is conducted to the heater 20 to keep the difference of both detection temperatures zero and compensation electric power of this current conductor time and the variation quantity of the weight of the sample by the mechanism 8 are measured at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a simultaneous thermogravimetric and evaporative heat amount measuring device that can simultaneously measure the weight change that occurs in a sample heated to a constant temperature and the amount of heat of evaporation per unit weight of the sample at that temperature.

Measuring the heat of evaporation per unit weight of a sample heated to a certain temperature is often done as a means of obtaining data necessary for determining the design conditions of chemical plants, etc. Conventionally, for example, a differential scanning calorimeter (Differ-rent scanning calorimetry needle)
Measurements are being carried out using a combination of a ning Calorimeter) and a balance.

As is well known in the calorimeter, a container containing a sample and a container containing a reference sample are simultaneously heated at a constant rate under the same conditions, and the temperature difference between the two is detected by a tube. The electric power supplied to the heaters separately provided in the two containers is automatically adjusted so as to maintain the power at zero, and the difference between the nine electric powers added to the two containers, that is, the compensation power ΔW, is recorded with respect to time t. If evaporation begins when the sample is heated to a constant temperature, the latent heat of vaporization will be removed from the sample, and while this evaporation continues,
A peak appears for the base fin on the ΔW vs. curve (DECgram) drawn correspondingly. By the way, there is heat exchange between the sample and the surroundings, but it is considered to be the same size in the two containers, so
The amount of compensation heat, that is, the amount of heat of evaporation is determined by measuring and converting the area between the D80 gram base fin and the base fin. On the other hand, the change in electrolytic corrosion of the sample before and after this measurement (
In this case, the weight loss) is measured separately using a chemical balance. This is a method of determining the amount of heat of evaporation (-1) per unit weight at a constant heating temperature of the sample from these two measured values.

The measurement method described above has drawbacks such as complicated operation and a long time required for measurement when it is necessary to repeat the measurement with different set heating temperatures.

This invention was made in view of the above-mentioned current situation, and eliminates the conventional drawbacks in measuring the heat of evaporation per unit weight of a sample heated to a certain temperature at that temperature, and allows measurement to be performed easily and in a short time. The purpose of this device is to provide a thermogravimetric analyzer that allows a sample container housed in a heating furnace to be suspended or mounted on a weight detection mechanism provided outside the heating furnace via a connecting member. A reactant gas or a carrier gas is introduced into the container through a gas introduction pipe, and a heater and a first temperature sensor for detecting the sample temperature are provided in the container, and the ambient temperature is controlled near the outside of the container. A second temperature sensor is provided to detect the first temperature.
When the temperature detected by the second temperature sensor becomes lower than the temperature detected by the second temperature sensor, the heater is energized so as to keep the rain detection temperature difference to zero, and the compensation power and the weight when energized are This device is a simultaneous thermogravimetric and evaporative heat amount measuring device that can measure both the amount of change in sample weight and the amount of change seen by the detection mechanism at the same time.

The following are the 5Is related to this invention! An example device will be described in detail with reference to the drawings. FIG. 1 shows the main unit of this embodiment device. FIG. 3 is a side view schematically showing the section.

The cylindrical pressure-resistant container (1) installed in the lead 1 is divided into an upper sample chamber (2), a lower weight measurement chamber (3), and a weight measurement chamber (3).
), and a heating furnace (for example, an electric furnace) (5) is formed on the outer periphery of the sample chamber (2).
is provided. The interior of the sample chamber (2) is filled with a sample, and a sample container (6) is connected to the bottom of the connecting member (gas introduction pipe) (7) via the weight detection mechanism of the weight measurement chamber (3). For example, a load cell (8) is mounted on a rack so as to be located approximately in the center of the sample chamber (2). The gas inlet tube (7) is filled into the expanding sample container (6), and the load cell (8) is used to accurately measure changes in the weight of the sample.
) It serves as a connecting member with rigidity capable of transmitting K, and also serves as an introduction path for the reaction gas or carrier gas to be brought into contact with the sample.For example, a thin tube made of stainless steel is used, and the sample chamber (2) The gas inlet pipe (7) is fitted to a circular guide plate (9) provided below the guide plate (9) to reduce friction therebetween and not to affect the transmission of weight by the gas introduction pipe (7)K. The gas introduction pipe (7) is provided with a branch part α1, and a flexible connecting pipe I made of a thin tube made of polypropylene material, for example, is connected to the branch part Ql, which is buried horizontally inside the branch chamber (4). One end is connected. The other throat is connected to a desired gas source (not shown) and connected to a pipe introduced into the branch chamber (4) via a flow rate regulating valve. This connecting pipe aυ has a gas inlet pipe (
7) Minimize interference with weight transmission via
It has flexibility to the extent that it does not affect the detection sensitivity of the lead cell (8). There is a flow rate adjustment valve al in the sample chamber (2).
The branch chamber (4) is provided with an exhaust port I and a pressure gauge a, and an exhaust port aη with an on-off valve is provided in the branch chamber. A gas introduction pipe (7) connected to the bottom of the sample container (6) extends above the filling level of the sample;
A mantle tube with a blind lid (18 is attached coaxially to it,
An opening is provided near the bottom of the sample container (6). In addition, a small heater ■ and a first temperature sensor Qυ for detecting the sample temperature are provided inside the sample container (6), and a second temperature sensor for detecting the ambient temperature is provided near the outside of the sample container (6). A temperature sensor (2) is provided. And these temperature sensors @1. (2), for example, uses a chromesy alumel thermocouple, which is differentially connected to the DC amplifier (2) as shown in the temperature control circuit diagram of the electric furnace and heater in FIG. In the temperature control circuit shown in Figure 2, (Found) is the power guarantee circuit, (To) is the recording needle, and (To) is the power guarantee circuit.
is a temperature controller, and (21/) is a temperature sensor consisting of a thermocouple for controlling the temperature of the electric furnace (5).

When performing an experiment by heating the sample to a high temperature by using the sample contained in the sample container (6), radiant heat from the sample chamber (2)
In order to keep the temperature sensor r21 warm, a thin-walled pipe made of, for example, gold or platinum and having an open top and bottom is provided as a thermal barrier (2).

Next, a case will be described in which the measurement using this apparatus is carried out using nitrogen as a carrier gas and measuring the amount of heat of evaporation per unit weight of a sample heated to a constant temperature.

First, the flow rate adjustment valve a3 is closed, the opening/closing valve and the flow rate adjustment valve a'at- are opened, and nitrogen is sent as a carrier gas into the sample container (6) via the connecting pipe aυ and the gas introduction pipe (7). This gas flows into the sample from the opening through the small hole and the mantle tube side, flows out from the opening of the sample container (6), fills the inside of the pressure container (1), and is exhausted from the exhaust port αη. Ru. During this time, sample container (6) and pressure container (1
) is replaced by carrier gas and these containers are cleaned. Next, close the on-off valve ae, adjust the flow rate adjustment valve (13, (lit?), and adjust the pressure gauge ti9.
Confirm that the pressure in the sample chamber (2) is maintained at the set value. The carrier gas that has passed through the sample is discharged from the exhaust port a4, and in this state, the electric furnace (5) is energized to heat the sample.

During this heating, the temperature controller (to) is set at a constant heating rate and the ultimate heating temperature (ambient temperature measured by the temperature sensor (22'))'@: while the temperature controller (to) performs program control. , the electric furnace (5) is operated so that the ambient temperature remains at the set stagnation temperature. This electric furnace (5
), the atmospheric temperature in the sample chamber (2) is gradually raised, and the sample in the sample container (6) is accordingly heated, increasing its temperature. In this case, the sample chamber (2
) is also detected by a thermocouple (2), and the temperature T8 of the sample in the sample container (6) is detected by a thermocouple Qυ.

Since the carrier gas is made to flow continuously through the sample, when the small heater is not in operation, there is a difference of 1 between the ambient temperature Tm and the sample temperature T8, and there is a time lag between the two during the heating process. However, in a stable state where the ambient temperature Tm is maintained at a constant optical film temperature, the female temperature Tm and the temperature Ts become equal. In the process of reaching this stable state, the output based on the detected temperature difference of the thermocouple (2m, @) is input to the power guarantee circuit @ via the amplifier @, and the small heater (2) is energized. Since heat is applied to the sample and the temperature difference is reduced to zero, the round tube constant state described above is reached in a fairly short time.

Now, if the evaporated components of the sample begin to evaporate at this set temperature, the evaporated gas will be carried out of the container (6) by the carrier gas. During the subsequent evaporation, the evaporated components are removed from the sample in this way, so that the sample weight changes accordingly, and the amount of change is transferred to the load cell (8) via the gas inlet pipe (7)'t-. The signal transmitted and outputted from it is recorded on the recorder (c) along with time t. (This circuit is omitted in Figure 2.) On the other hand, while evaporation is occurring, the latent heat of evaporation is removed from the sample, so the sample temperature T8 naturally becomes lower than the ambient temperature Tm. A temperature difference occurs between the two.

Therefore, the above-mentioned operation is performed again, and the small heater (2) is energized so as to make the temperature difference between the two zero, and while the evaporation continues, the small heater (2) is turned on.
The electric power ΔW supplied to is recorded on the recorder (c) every moment, and a Δw'Mt curve corresponding to the D8C gram described above is obtained. Therefore, by measuring and converting the area surrounded by the curve and the base fin to the ΔW pair of
The amount of compensation heat due to the temperature, that is, the amount of heat of evaporation at the set temperature of this sample is determined. As mentioned above, the weight change of the sample is recorded along with the time t, so if we calculate this time axis and the heat of evaporation and calculate 9Δw jI by keeping the time axis of the curves common, we can calculate the weight loss of the sample due to evaporation, The amount of friend heat required for its evaporation, that is, the amount of heat of evaporation, can be accurately measured, and from this measured value, the amount of heat of evaporation (-beak) per unit weight of the sample at the set heating temperature can be determined.

The sample container (6) is a sample chamber (
2), the flow rate adjustment valve α3. (By adjusting the opening degree of 11, the sample can be pressurized within the pressure range of the carrier gas source.

Therefore, the heat of vaporization per unit weight of the sample described above can be measured using both pressure and temperature as a buff meter.

In addition, if the small analyzer (2) and its control circuit are kept inactive, this device can be used as a thermogravimetric analyzer.

As is clear from the above explanation, the thermogravimetric and evaporative heat amount simultaneous measuring device according to the present invention uses a conventional method such as a differential scanning calorimetry needle and a balance to measure the evaporative heat amount of the sample and the corresponding evaporative weight. Compared to the method of measuring the heat of evaporation per unit weight of the sample at a constant temperature by measuring them separately, it is possible to measure the heat of evaporation and the weight of evaporation at the same time, which simplifies the measurement operation and makes it easier to measure. The time required can be shortened. This is particularly effective when it is necessary to repeat measurements with different set heating temperatures for the sample. In addition, this apparatus can be configured so that the sample container is housed in a pressure-resistant container and the sample is heated while pressurizing it. Therefore, in this apparatus configured in this way, pressure and temperature are measured using a buff meter, and the temperature is measured per unit weight of the sample. The heat of evaporation can be measured at Harushima.

[Brief explanation of the drawing]

FIG. 1 shows the main structure of the dormitory embodiment device according to the present invention. FIG. 2, which is a side sectional view schematically showing the parts, is an example of a temperature control circuit diagram of this device. (1)・・・・・・Pressure container, (2)・・・・・・
...Sample room, (3)...Four weight measurement room, (5)
・・・・・・Heating furnace (electric furnace), (6)・・
-・Curved trial container. (7)......Connection member (gas introduction pipe),
(8)...Weight measurement mechanism (load cell), (11 questions...Heater, (2 tons...)
111 temperature sensor (thermocouple), (2)...
・Second temperature sensor (thermocouple)

Claims (1)

[Claims] 1. A sample container housed in a heating furnace is suspended or placed on a weight detection mechanism provided outside the heating furnace via a connecting member, and a reaction gas or a carrier gas is supplied to the sample container. The sample is introduced through an introduction tube, and a heater and a tenth temperature sensor for detecting the sample temperature are provided in the container.
Additionally, a second sensor is installed near the outside of this container to detect the ambient temperature.
temperature sensor is provided, and when the temperature detected by the first temperature sensor becomes lower than the temperature detected by the third temperature sensor, K1ff is set to keep the rain detection temperature difference to zero.
A simultaneous measurement device for thermogravimetry and evaporative heat quantity, which is capable of energizing the heater and measuring at the same time the compensation power when the heater is energized and the amount of change in sample weight seen from the weight detection mechanism. 2. The thermogravimetric/evaporative heat amount simultaneous measuring device according to claim 1, wherein the chamber for accommodating the sample container is a pressure-resistant container.