Chapter 607

Agust pointed to a complex set of experimental equipment not far from the glass house and said, "chief, this is the freeze-drying extraction equipment we developed according to your instructions. You see, this is the decompression tank, this is the air drying equipment, this is the low temperature freezing equipment, this is the continuous heating equipment, this is... "

Here, Agust seems very excited, here is his territory, everything here is condensed with all his efforts.

Here, he is the real master.

Stone Bear looked at it and nodded with satisfaction.

Although he attaches great importance to Yanhuang Academy of science and technology, he does not care about the cost of investment for the Academy of science and technology, but his usual work is too much, which makes him seldom have time to inspect the Academy of science and technology. Moreover, the Academy of science and technology is not only a medical park, but also many other science and technology parks.

So although Shi Xiong has been to the Academy of science and technology several times, this is his second visit to the medical park. The last time he came to the medical park, it didn't have so many facilities or so many people. The current medical park is very different from the last time he came here.

"Chief, according to your suggestion, we started with the three-phase point test." There was a wry smile on Agust's face. "We have known the three phases of water, solid state, liquid state and gas state for a long time. We also know what sublimation and sublimation are. But it takes us a lot of effort and time to find the real three-phase point. But fortunately, after finding the temperature and pressure data of the three-phase point, our freeze-drying extraction method is 80% complete. "

Of course, the stone bear is clear about the three-phase point mentioned by Agust. He told Agust about this term.

The three forms of water, solid state, liquid state and gas state, have been known by many scientists and alchemists in Europe for a long time. They also know that when water is in liquid state, as long as it is heated to a certain temperature, it will boil and then turn into gas state. Well, this temperature refers to the degree centigrade just mentioned for more than 30 years. The specific figure is 100 degrees centigrade.

On the contrary, the liquid water is cooled to a certain temperature, that is, 0 ℃, then the liquid water will become solid ice.

It is well known that water changes in three phases by heating or cooling.

Similarly, the sublimation from solid state to gas state and the transformation from gas state to ancient sublimation are also known by most scientists in this era.

But the three-phase point of sublimation condensation point, evaporation condensation point and melting solidification point, which are combined into one, is unknown in this era, and no one can think that through the change of air pressure and temperature, liquid water can present a state of solid, liquid and gas coexisting at the same time.

The three-phase point of water, which was discovered and put forward in the 20th century, has been regarded as the only reference point of thermodynamic temperature in later generations. But in this era, the triple point of water has not been found.

Although Shi Xiong was a liberal arts student in his previous life, he still knew the most basic thermodynamic physical unit, and he also knew how to obtain the three-phase point of water. He also knew that if he wanted to purify penicillin, he had to use freeze-drying to achieve it.

The front of freeze-drying method is to find the three-phase point of water.

Finding the triple point of water, if in later generations, is a very easy thing. But now, it's one thing to know. It's very difficult to find the triple point of water.

As we all know, atmospheric pressure is another factor that affects the phase state of water at constant temperature. For example, at sea level, basically at atmospheric pressure, water needs to be heated to 100 degrees Celsius to boil.

But if the altitude rises, the pressure will decrease and the boiling point of water will decrease. At the altitude of 3650 meters, the sunshine city in Huaxia Tibetan area, where the water boils as long as it is heated to 92 ℃.

This is because the change of air pressure leads to the decrease of boiling point of water.

Therefore, if the pressure drops to a certain level, water can boil at room temperature.

On the contrary, if the pressure continues to rise, the boiling point of water will continue to rise at the same temperature. It's faster to cook things in a pressure cooker because the pressure inside the pressure cooker is much higher than that outside, so the boiling point of water will rise a lot, and the things cooked in the cooker will be easier to cook.

Although Galileo discovered air pressure more than 130 years ago, and later Torricelli invented the barometer, even in this era, the use of air pressure in the scientific community is not very much.

Now maybe many people know that the change of air pressure and temperature will have different effects on liquid water, but it's still a long time before the three-phase point of water can be found.

But for the stone bear's tips and instructions, Agust would not know how to deal with the three-phase point of water.

But with the stone bear's tips and instructions, Agust and his team finally spent a long time to find the three-phase point of water. At 0.01 ℃ and 0.61 atmospheric pressure, pure water will present the coexistence of solid state, liquid state and gas state.

"Chief, you said that penicillin is not resistant to high temperature. It must be purified at low temperature. So when we found the triple point of water, we frozen the culture medium for penicillin. Then we put the frozen culture medium into the vacuum tank, which is the device Agust pointed to the sealing device made of thick glass.

"After the frozen culture medium is put into the vacuum tank, we start to extract the air from the tank. Because the air in the decompression tank is continuously pumped out, the air pressure in the decompression tank will be reduced accordingly. At the same time, we will keep lowering the temperature of the vacuum tank. When the temperature reaches 0.01 ℃ and the air pressure drops to 0.61 atmospheric pressure, the water in the culture medium will continue to sublimate into gas, leaving behind the first purified penicillin powder. "

The stone bear nodded with satisfaction. In fact, this is the hint and direction he gave to Agust. This method is also the freeze-drying extraction method used by Ernst chann to purify penicillin.

It is not easy for French alchemists to purify penicillin in this way in this era.

"However, after the first purification, the penicillin powder still contains about 10% water. In these powders, some water is attached to the penicillin powder in the form of crystal water. Once the temperature and air pressure change, the crystal water will become liquid, which makes the penicillin powder damp, leading to the deterioration of the penicillin powder. So after the first purification, we use micro heating and continue to reduce the atmospheric pressure for secondary purification. The water content of penicillin powder purified in this way is only about 2%! Such penicillin powder can be preserved for a long time. The penicillin powder stored in the vial you see is the penicillin after secondary purification! "