Evolved gas analyzer and method for analyzing evolved gas
Disclosed herein are an evolved gas analyzer and a method for analyzing evolved gas, the apparatus cooling a sample holder in a short time without using excessive cooling performance and without providing the entire apparatus in an excessively large size, thereby enhancing analysis work efficiency. The apparatus 200 includes: a sample holder 20 holding a sample S; a heating unit 10 receiving the sample holder therein, and evolving a gas component G by heating the sample; a detecting means 110 detecting the gas component; a sample holder supporting unit 204 L movably supporting the sample holder to move the sample holder to predetermined outer and inner positions of the heating unit; and a cooling unit 30 provided at an outside of the heating unit, and cooling the sample holder by being in direct or indirect contact with the sample holder, when the sample holder is moved to a discharging position.
1. An evolved gas analyzer, comprising:
a sample holder, holding a sample;
a heating furnace, receiving the sample holder therein, and evolving a gas component by heating the sample;
a detecting means detecting the gas component evolved by the heating furnace;
a sample holder supporting unit supporting the sample holder so as to enable moving the sample holder to given positions inside and outside of the heating furnace; and
a cooling unit placed outside of the heating furnace, cooling the sample holder by direct or indirect contact with the sample holder, when the sample holder is moved to a discharging position at which the sample can be put in or taken out,
wherein the cooling unit comprises a cooling block in contact with the sample holder, an air cooling fan, air cooling fins and a fan duct, cooling the cooling block,
the air cooling fins are connected to a floor portion and a side surface of the cooling block,
the air cooling fan is placed at a lower part of the air cooling fin connected to the floor portion of the cooling block, and
the fan duct extends from the air cooling fan towards outside of the air cooling fin connected to the side surface of the cooling block, and forms an air guiding plate guiding cooling air from the air cooling fan to the air cooling fins.
2. The apparatus of claim 1 , wherein the cooling block comprises:
a contact portion being in contact with the sample holder at the discharging position; and
a protruding portion extending more towards the heating furnace to form a recess in the cooling block to surround the sample holder.
3. The apparatus of claim 1 , wherein a ratio (C1/C2) of a heat capacity (C1) of the cooling block to a heat capacity (C2) of the sample holder is between 5 and 20.
4. The apparatus of claim 1 , wherein the heating furnace comprises a heating furnace heater heating inside of the heating furnace to a given temperature, and
the sample holder comprises a sample heater heating the sample.
5. The apparatus of claim 1 , further comprising:
an autosampler automatically putting in or taking out the sample to or from the sample holder from outside; and
a sample holder moving unit, moving the sample holder in conjunction with the autosampler,
wherein the sample holder moving unit comprises:
a first spring part elastically pressuring the sample holder in a direction towards the cooling unit, when the sample holder is close to the discharging position; and
a second spring part elastically pressuring the sample holder in a direction towards the heating furnace, when the sample holder is received inside the heating furnace and close to a measuring position at which measurement is performed.
6. The apparatus of claim 1 , wherein a part of an inner wall of the heating furnace around the sample held in the sample holder expands towards outside, forming a recess,
the recess comprising a first recess portion, which is located upstream of direction of flow of the gas component inside the heating furnace, and a second recess portion, which is located downstream compared to the first recess portion in the direction of flow direction and meeting the inner wall, as an integral body, and,
when viewed from a cross section of the heating furnace along the direction of flow, an outline of the second recess portion is located more upstream of the direction of flow than a normal line of the inner wall at a contact point between the second recess portion and the inner wall.
7. A method for analyzing evolved gas, the method comprising:
supporting a sample holder holding a sample so as to enable moving the sample holder to given positions inside or outside of a heating furnace;
receiving the sample holder in the heating furnace to heat the sample;
detecting evolved gas components; and
cooling the sample holder by bringing the sample holder into contact with a cooling block of a cooling unit, placed outside of the heating furnace, when the sample holder is moved to a discharging position at which the sample can be put in or taken out to or from the sample holder,
wherein the cooling unit further comprises an air cooling fan, air cooling fins and a fan duct, cooling the cooling block,
the air cooling fins are connected to a floor portion and a side surface of the cooling block,
the air cooling fan is placed at a lower part of the air cooling fin connected to the floor portion of the cooling block, and
the fan duct extends from the air cooling fan towards outside of the air cooling fin connected to the side surface of the cooling block, and forms an air guiding plate guiding cooling air from the air cooling fan to the air cooling fins.