JP2552153B2 - Thermal analysis sample cooling device - Google Patents

Description

The present invention relates to a cooling device for cooling a sample for thermal analysis to a desired temperature or continuously changing the temperature to measure its thermal characteristics.

In various types of thermal analysis such as differential thermal analysis, differential scanning calorimetry, thermogravimetric analysis, etc., when the sample is cooled to a low temperature below room temperature, the container surrounding the sample etc. is conventionally placed in liquid nitrogen or the like. Means have been taken such as immersing in nitrogen, or circulating low-temperature nitrogen obtained by evaporating liquid nitrogen to the sample portion. However, all of them have the drawbacks that the sample cannot be rapidly cooled to a desired temperature because the cooling efficiency is low and the consumption of the refrigerant is great.

Therefore, the present invention is intended to obtain a cooling device which does not have the above-mentioned drawbacks and whose temperature can be easily controlled. For example, one end of a cooling rod having a high thermal conductivity is connected to the sample holding portion to, for example, liquid nitrogen or The sample is cooled by heat conduction by fitting a cooling cylinder cooled with a fluorocarbon refrigerant or the like at an arbitrary position of the cooling rod. Therefore, there is an operation effect that the sample temperature can be easily controlled by utilizing the change of the heat conduction resistance and the consumption of the refrigerant is small.

FIG. 1 is a vertical cross-sectional view of an embodiment of the present invention, in which an arbitrary sample is housed inside a sample holder 1, a probe for detecting a sample temperature and other desired physical quantity is provided, and fine adjustment of the temperature or the temperature thereof is performed. A heating wire 2 used when continuously changing from a low temperature to a high temperature above room temperature is attached to the outside of the holding portion 1. The sample holder 1 is held by a support 4 on a base 3 and the outside is covered by a heat insulating tube 5.
The lower surface of the sample holder 1 is made of a metal having a high thermal conductivity, such as silver or copper, and the vertically arranged cooling rod 6 is brought into close contact with its upper end, and its lower end has the same sectional shape as this cooling rod. The porcelain and other heat insulating rods 7 having the above are connected, and the lower end of the heat insulating rod is fixed to the base 8. Further, a cooling cylinder 9 is slidably fitted to the cooling rod 6 and the heat insulating rod 7 so that the sliding contact surfaces thereof are as close as possible, and a cooling pipe 10 is wound inside the cooling cylinder. A heat insulating material 11 is filled in the outer gap, and both ends of the cooling pipe 10 are connected to a cooling fluid source by flexible tubes 12.
The fluid source is, for example, a methanol, ethanol or chlorofluorocarbon refrigerant, and the latent heat accompanying the evaporation thereof causes the cooling cylinder 9
Is cooled to several tens to one hundred and several tens of degrees, and the evaporated refrigerant is liquefied by being compressed by a pump (not shown) and returned to the fluid source. Further, since the rack 13 is fixed to the cooling cylinder 9 and the pinion gear 14 is meshed with the rack, the cooling cylinder 9 is rotated by rotating this gear with a motor.
Can be moved vertically along the cooling rod 6 and the insulating rod 7. Also, bellows 17 and 18 connect between the lid plate 15.16 fixed to the upper end of the cooling rod and the lower end of the heat insulating rod and both ends of the cooling pipe 9, and a small hole 19 is provided in a portion near the center of the cooling pipe 9. The insides of the two bellows are connected. Inside the bellows 17.18, water is attached to the surfaces of the cooling rod 6 and the heat insulating rod 7 by evacuating the bellows 17.18 to keep it in a vacuum state or enclosing a dry gas, and the cooling tube 9 is cooled by the freezing. It prevents the movement of the animals from being hindered. Moreover, low temperature grease is applied to the surface of the cooling rod to facilitate the movement of the cooling cylinder 9 and to reduce the heat transfer resistance.

In the above-mentioned apparatus, when the cooling cylinder 9 is moved upward and arranged at the cooling rod 6 as shown by the solid line in FIG. 1, the heat of the sample holder 1 is transferred to the cooling cylinder 9 via this cooling rod. The sample holder 1 is cooled to be deprived. In addition, as the cooling rod 6 is disposed above the cooling rod 6, the heat conduction resistance is reduced and the cooling efficiency is improved. Therefore, the sample holder 1 can be maintained at a desired temperature by disposing the cooling cylinder 9 at an appropriate position. However, by further controlling the current applied to the heating wire 2, the temperature of the sample holder 1 can be controlled precisely and quickly to a desired temperature. The chain line 9'in FIG.
When the cooling cylinder 9 is arranged at the position of the heat insulating rod 7 as shown in FIG. 3, the cooling rod 6 is hardly cooled by this cooling cylinder, so that the temperature of the sample holder 1 is set to an arbitrary temperature higher than room temperature by the electric current of the heating wire 2. Can be held at. Further, it goes without saying that automatic measurement is also possible by performing the above-described movement of the cooling cylinder 9 and the current of the heating wire 2 by feedback program control.

FIG. 2 is a longitudinal cross-sectional view of a part of another embodiment of the present invention, in which the cooling cylinder 9 is integrally formed of a material having good heat conduction and slidable on the cooling rod 6 and the heat insulating rod 7. Along with fitting, axial grooves 20 are formed on these side surfaces. The groove
A hook 21 is slidably fitted and the tip of the hook is bonded to the cooling cylinder 9. That is, the groove 20 forms a gas flow passage inside the bellows 17.18 and acts as a guide for the key 21. The liquid nitrogen containing such a cooling rod 6, adiabatic rod 7 and cooling cylinder 9 in a container 22. Refrigerant like
Soaked in 23.

Therefore, when the cooling cylinder 9 is arranged at the position of the cooling rod 6 as shown by the solid line, the heat quantity of the sample holding portion is efficiently transferred to the cooling cylinder 9 cooled by the refrigerant 23 via the cooling rod 6 having high thermal conductivity. Since it is often robbed, the holding part is cooled to a low temperature.
Further, when the lower end of the key 21 is pulled to move the cooling cylinder 9 to the position of the heat insulating rod 7 as shown by the chain line 9 ″, the cooling rod 6 is arranged in the space inside the bellows 17 and the heat conduction is prevented. As a result, the temperature of the sample holder 1 rises as in the device of Fig. 1. Therefore, by moving the cooling cylinder 9 to a desired position as in the device of Fig. 1, the sample holder is moved to the desired position. It can be cooled to any temperature.

As described in the above embodiments, the apparatus of the present invention connects one end of a cooling rod having good heat conduction to the sample holder, inserts / removes a cooling tube cooled to a low temperature into the cooling rod, or By arranging the sample holder at a position to change the cooling efficiency of the sample holder, it is cooled to a desired temperature. Therefore, the cooling temperature of the sample can be controlled easily, quickly and precisely, and the consumption of the refrigerant is small.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention, and FIG. 2 is a partial vertical sectional view of another embodiment of the present invention. In the figure, 1 is a sample holder, 6 is a cooling rod, 9 is a cooling tube, 17.18 is a bellows, 10 is a cooling pipe, and 23 is a refrigerant.

Claims (4)

(57) [Claims] 1. A thermal analysis characterized in that one end of a cooling rod having a high thermal conductivity is connected to a sample holding portion, and a cooling cylinder cooled to a low temperature is removably fitted into the cooling rod. Sample cooling device 2. A bellows is fitted to a cooling rod between the cooling cylinder and the sample holder, and both ends of the bellows are bonded to the base end of the cooling rod and the cooling cylinder to form the sample holder and the cooling cylinder. The thermal analysis sample cooling device according to claim 1, wherein the cooling rod between the two is sealed by the bellows. 3. A thermal analysis sample cooling device according to claim 1, wherein a cooling pipe is provided inside the cooling cylinder, and the cooling pipe is connected to a cooling fluid source. 4. The thermal analysis sample cooling device according to claim 1, wherein the cooling cylinder is immersed in a refrigerant to cool it.