Stainless steel PTFE tank

Stainless steel PTFE tank, the inner liner is made of PTFE material, also known as high-pressure digestion tank, high-pressure tank, synthesis reactor, etc.

The stainless steel PTFE tank is an extension of the autoclave, hereinafter referred to as the tank, as shown in Figure 22-30

Figure 22-30 Stainless steel PTFE tank and its assembly

The original intention of designing the stuffy tank was to use it as a closed pressure vessel for decomposing insoluble substances, so it is called a high-pressure digestion tank

The stuffy tank is lined with polytetrafluoroethylene (commonly known as plastic king, melting point is 327℃), with excellent sealing performance.

(1) Use

After placing the reaction sample, close the lid inside the cup tightly

(2) Safety instructions

(1) The temperature is inversely proportional to the strength of the lining polytetrafluoroethylene.

(2) Safety pressure: Although the manufacturer promises that the allowable pressure value of the new tank is 4-10MPa, with repeated use, it is easy to fatigue or age, and the pressure resistance will gradually decrease, so the recommended pressure should be below 4MPa

There have been many explosion accidents of the stuffy tank, so before the high temperature and high pressure reaction, the physical and chemical properties of the reactants, the reaction solvent, the volume of the reaction liquid, the volume of the space, and the maximum calculated according to the ideal gas state equation should be checked.

In particular, prevent possible exothermic reactions

(3) Before use, check whether the stainless steel tank body and lid have any visible deformation, damage or cracks, observe whether the thread at the screw mouth is damaged, and whether the stainless steel gasket is deformed

(4) Before use, check whether the cup body and lid of the PTFE inner cup are deformed, damaged or cracked visually, and the tightness of the inner cup should be checked preliminarily: put the inner cup and the jar together in the stainless steel tank, and then Lift the PTFE lid gently by hand.

(5) If the oil bath is used for heating, be careful not to directly touch the electric heating ring at the bottom of the tank, so as to avoid the danger of local heating at the bottom of the tank

(6) It is forbidden to use stuffy tanks as hazardous reactions to explosives such as substances with high nitrogen content, peroxides, etc.

(7) It is forbidden to use stuffy tanks for violent and exothermic dangerous reactions such as easy polymerization and decomposition at high temperature.

(8) All the stuffy tank reactions need to be isolated by a baffle, and the operation must be carried out with the fume hood door pulled to the end

(9) Filling factor: The total volume of the reaction liquid generally does not exceed 50% of the total effective volume.

(10) When heating, the temperature should be raised to the required reaction temperature according to the specified heating rate, which is less than the specified safe use temperature
.
It takes at least 0.
5h to gradually raise the temperature to 100°C.
On this basis, the temperature can be raised to the required temperature after 1h of constant temperature
.

(11) At the end of the reaction, the temperature should not drop sharply.
It should be operated strictly in accordance with the specified cooling rate to facilitate safety and prolong the service life of the stuffy tank
.
First take out the stuffy pot from the oil bath and cool it in the air for more than 0.
5h, then water cooling, and finally ice water cooling
.
After fully cooling and confirming that the temperature of the polytetrazolium inner cup material in the label is lower than the boiling point of the reactants and the solvent, the lid of the kettle can be opened for subsequent operations
.

(12) A temperature controller should be used during heating to strictly control the reaction temperature to avoid runaway
.

(3) Scrap

(1) If a large area of ​​the inner wall or outer wall of the steel tank is found to be black and yellow and the threaded mouth is rusted, it shall be scrapped
.

(2) If the stainless steel tank body and lid are found to be deformed, damaged or cracked, or the thread at the screw mouth is damaged, or the stainless steel upper and lower gaskets are warped, deformed or have small cracks, they should be scrapped immediately
.

(3) If the cup body and lid of the PTFE inner cup are found to be deformed, damaged or cracked, they should be scrapped immediately
.
If the sealing is not good, you should find the reason for repair, if it still can not be sealed, it must be resolutely discarded
.

(4) If the wall of the lining cup is blackened by more than 2/3 due to high temperature for a long time, extremely blackened, or there is residue that cannot be cleaned up, it should be discarded immediately
.

(5) If any user or manager has sufficient reason to believe that it should be scrapped, it should be scrapped decisively
.