JPH02218949A - Apparatus for heating and cooling thermally analyzing sample - Google Patents

Abstract

PURPOSE:To permit the temperature of sample to vary over a wide range including higher and lower temperatures than the ambient temperature by a method wherein a jacket for cooling is wound around the exterior of a heating furnace with sample contained to have it coupled to a cooling fluid source with two conduit tubes while a heat exchanger is provided between them. CONSTITUTION:When a pump 10 is operated, alcohol 11 cooled by dry ice 13 flows in a jacket 5 from a conduit tube 7 and returns to a vessel 12 via a conduit tube 8. Therefore a heating furnace 2, sample 3 inside it and standard sample 4 are cooled. In addition with current flowed in a heating wire 1 and by increasing the current gradually, the temperature inside the furnace 2 rises at a desired rate to have the sample 3 heated. Therefore, differential scanning thermal analysis is performed in this process. As the temperature of the furnace 2 rises, the temperature of the alcohol 11 fed out from the jacket 5 rises simultaneously to be fed into a heat exchanger 9. Therefore, the conduit tube 7 is heated and the temperature of coolant to the jacket 5 also rises, thereby decreasing function for cooling the furnace 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a heat flux type differential scanning calorimeter, etc.
The present invention particularly relates to the configuration of a cooling device for use in observing thermal characteristics at each temperature by changing the sample temperature from a range lower than room temperature to a range higher than room temperature.

When using such a thermal analyzer to analyze samples such as synthetic resin materials, liquid crystals, moisture in living bodies, amorphous metals, etc., the temperature of the sample should be adjusted from below room temperature, for example -70 degrees to +300 degrees, or higher. It needs to vary continuously over a temperature range. Therefore, the furnace body that heats the sample to a temperature higher than room temperature is housed in a cooling jacket, and a cooling liquid such as alcohol, which has been cooled with a refrigerator such as dry ice or a Freon type, is passed through the jacket. A heating device is used. However, in order to cool the sample to a low temperature, it is necessary to place the cooling jacket in close contact with the outside of the heating furnace, so when heating the sample, the amount of heat is absorbed by the cooling jacket, which limits the heating temperature. At the same time, the consumption of dry ice and the like becomes extremely large, and a refrigerator with a significantly large capacity must be used. In addition, in order to increase the cooling capacity according to the temperature of the sample, it is necessary to change the state of contact between the furnace body and the cooling jacket, and this variation causes disturbances in the measurement curve. Furthermore, if a heating device is installed for the cooling fluid flowing through the jacket, and its temperature is controlled according to changes in the furnace temperature, the consumption of dry ice, etc. will increase significantly, and the temperature curve will change due to mutual interference with the furnace temperature. It has drawbacks such as causing disturbance. Accordingly, the present invention provides an apparatus which allows the sample temperature to be varied over a wide range above and below room temperature without such drawbacks.

In the present invention, a cooling jacket is wound around the outside of a heating furnace containing a sample, and both ends of the cooling jacket are connected to a cooling fluid source through first and second conduits, and heat is heated between the eleventh and second conduits. It is equipped with an exchanger. That is, when the heating furnace is put into a rest state, the sample is cooled by the cooling fluid flowing through the jacket. Furthermore, when the heating furnace inside the jacket is operated in this state, the sample is heated and its temperature increases. At the same time, since the jacket is heated, the temperature of the cooling fluid flowing inside it also increases. However, as mentioned above, by providing a heat exchanger between the first and second conduits connected to opposite ends of the jacket, the incoming fluid is heated by the fluid exiting the jacket. That is, this heat exchange lowers the temperature of the fluid returned to the cooling fluid source, reduces the power requirement of the cooling source or the consumption of refrigerant such as dry ice, and reduces the required capacity of the cooling device. At the same time, the temperature of the fluid flowing into the jacket also increases as the furnace temperature increases, so the furnace is not excessively cooled and its temperature does not reach 300 degrees or more, and the measured curve It has the advantage that there are no defects that would disturb the baseline.

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, in which a sample 3 for differential scanning calorimetry, for example, is placed inside a cylindrical heating furnace 2 made of a material with good thermal conductivity and around which a heating wire I is wound. and its standard sample 4 are arranged.

A cylindrical body 6 formed with a spiral cooling jacket 5 is tightly fitted to the outside of the heating furnace 2, and a first conduit 7 is connected to the upper end of the jacket 5, and a second conduit 8 is connected to the lower end. A heat exchanger 9 is formed by connecting a large diameter portion formed in a part of the conduit 8 and a part of the conduit 7 coaxially. Further, the tip of the conduit 7 is connected to the outlet of the pump IO, the inlet of the pump is connected to the lower part of the container 12 of alcohol 11, for example, and the tip of the large diameter portion formed at the lower end of the conduit 8 is connected to the upper part of the container 12. It is open to the public. In addition, for example, pieces of dry ice 13. for cooling are included in the alcohol 11.
13... is mixed.

In the above device, when the pump 10 is operated, alcohol II cooled with dry ice 13 flows through the jacket 5 from the conduit 7 and returns to the container I2 via the conduit 8. Therefore, the furnace 2 and the sample 3 and standard sample 4 inside it are cooled to, for example, about -70 degrees. Further, when a current is passed through the heating wire I and the current is gradually increased, the temperature of the heating furnace 2 rises at a desired rate, and the sample can be heated to a temperature of several hundred degrees, for example. Therefore, in this process, for example, differential scanning calorimetry of sample 3 is performed.

In the above device, when the current of the heating wire 1 is gradually increased, the temperature inside the furnace 2 gradually rises, and at the same time, the temperature of the refrigerant alcohol 11 sent out from the jacket 5 also rises, and this alcohol flows into the heat exchanger 9. sent. Therefore, the first conduit 7 passing through the jacket 5 is heated, and the temperature of the refrigerant fed into the jacket 5 also rises, so that the effect of cooling the heating furnace 2 by the refrigerant is reduced. Therefore, the amount of power required to be applied to the heating wire 1 to raise the temperature of the furnace 2 to above room temperature can be reduced. Moreover, since the temperature of the refrigerant returning from the conduit 8 to the container 12 is lowered by the heat exchanger 9, the amount of dry ice 13 consumed is also reduced.

Figure 2 is a diagram showing the above operation, where the horizontal axis l is the heat exchanger 9.
, and the vertical axis T is the temperature,
Alcohol If delivered from container 12 by pump IO
temperature T rises in the heat exchanger 9 as indicated by arrow p and is fed into the jacket 5. While flowing through this jacket, the alcohol temperature T of the refrigerant further rises and is sent to the heat exchanger 9 through the conduit 8. Therefore, the heat is taken away by the conduit 7, the temperature decreases as shown by the arrow q, and it returns to the container a 12.

In this way, the device of the invention can reduce the consumption of a coolant, such as dry ice, since the temperature of the coolant returned to the coolant container through the cooling jacket is lower. Moreover, when the heating power source is cut off to cool the sample to room temperature or below, the amount of heat exchanged in the heat exchanger becomes extremely small, so that a decrease in cooling efficiency is prevented and efficient cooling is performed. Moreover, since there is no part where the amount of change changes suddenly during temperature change, highly accurate analysis can be performed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the operation of the present invention. In the figure, 1 is a heating wire, 2 is a heating furnace, 3 is a sample, 4 is a standard sample, 5 is a jacket, 9 is a heat exchanger, 10 is a pump, 11 is alcohol as a refrigerant, and 13 is dry ice.

Claims (1)

[Claims] a first conduit for supplying a sample cooling fluid to a cooling jacket wrapped around the outside of a heating furnace for accommodating and heating a sample for thermal analysis to a temperature above room temperature;
A heating and cooling device for a thermal analysis sample, characterized in that a second conduit is provided for discharging cooling fluid from the jacket, and a heat exchanger is provided between the first conduit and the second conduit.