JPH0633343Y2 - Freeze dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) This invention relates to a freeze-drying apparatus.

(Prior Art) In general, freeze-drying is an established drying method, whereby, for example, drugs such as vaccines, vitamin agents, and antibiotics are dried and stored. The water-soluble product undergoing drying is initially frozen and then placed under vacuum. Under such a condition, the water content of the product directly changes from ice to steam without passing through an intermediate liquid stage. If a large amount of this sublimation steam condenses in the oil, and the oil is immediately contaminated, the performance of the oil rotary vacuum pump is deteriorated and the degree of vacuum required for freeze-drying cannot be maintained.

In order to avoid this, in the conventional means, a condenser having an adsorbent is provided between the drying chamber and the vacuum pump so that sublimation steam generated during the drying process is collected by the condenser.

(Problems to be solved by the invention) As described above, the sublimation steam generated from the frozen sample during freeze-drying is sequentially collected by the adsorbent of the condenser. After stopping, it is necessary to evaporate the adsorbed water by heating or the like to regenerate the adsorbent.

However, since the saturated state of the adsorbent cannot be visually confirmed, the conventional means uses a timer to stop the freeze-drying operation at a set time.

Therefore, although the adsorbent is regenerated after the drying operation is stopped, the adsorbent is managed by the timer. In this case, the set time of the timer is set based on the experimental data in which the adsorbent becomes saturated, but in practice, the number of frozen samples set in the drying chamber may be large or small. In the former case, the adsorbent becomes saturated before the set time of the timer is reached. In such a case, there is a risk that water vapor will be sucked by the vacuum pump.

In the latter case, the operation is stopped before the adsorbent becomes saturated, so that the efficiency is poor and there is a problem that the adsorbent is regenerated in a usable state.

Then, this invention aims at provision of the freeze-drying apparatus which can regenerate a condenser efficiently.

[Configuration of Device] (Means for Solving the Problem) In order to achieve the above-mentioned object, in the present invention, a connection passage is provided in a connection passage that connects a drying chamber in which a frozen sample is set and a vacuum pump. In a freeze-drying device equipped with a control valve that opens and closes and a condenser that collects water generated in a drying chamber, a detection signal is output to the condenser when a vacuum degree in the condenser is close to a saturated state is detected. A detection sensor for outputting is provided, and the control valve is closed based on the detection signal from the vacuum sensor to shut off the passage between the condenser and the vacuum pump.

(Operation) In the freeze-drying apparatus, the frozen sample set in the drying chamber is placed under vacuum by the vacuum pump to perform freeze-drying. Sublimation steam generated during the freeze-drying is collected by the adsorbent of the condenser. The degree of vacuum gradually decreases in proportion to the collection rate by the adsorbent, and when the vacuum sensor detects the degree of vacuum in a state close to saturation, the control signal is closed by the detection signal and the vacuum pump and the condenser are closed. Cut off the communication passage. Therefore, when the condenser reaches the saturated state, the freeze-drying operation is surely stopped.

Embodiment An embodiment of the present invention will be described in detail below with reference to FIG.

In the figure, 1 is a drying chamber in which a frozen sample 3 can be set, and 5 is a vacuum pump. The drying chamber 1 and the vacuum pump 5 are connected and communicated with each other by the first connecting passage 7 and the second connecting passage 9, and the condensers 11, 13 are provided in the first and second connecting passages 7, 9, respectively.
Is provided.

One of the condensers 11 and 13 provided in the first and second connection passages 7 and 9 is for standby and can be used alternately by switching by solenoid valves V ₁ and V ₂ described later. ing.

That is, each of the condensers 11 and 13 has a first communication port 15 that communicates with the drying chamber 1 side and a second communication port 17 that communicates with the vacuum pump 5 side, and connects the communication ports 15 and 17 together. In the crank-shaped passage,
The adsorbent 19 is arranged in series. Therefore, in the condensers 11 and 13, the sublimation steam is guided from the first communication port 15 to the second communication port 17 side as shown by the arrow. Further, the adsorbent 19 employs a reproducible molecular sheep.

The first and second solenoid valves V ₁ and V ₂ for switching the condensers 11 and 13 are
It is provided in each of connection passages 7 and 9 between the drying chamber 1 and the condensers 11 and 13.

On the other hand, connection passages 7 and 9 between the condensers 11 and 13 and the vacuum pump 5 are provided with _third and _fourth solenoid valves V ₃ and V ₄ , respectively. In addition, chambers 21 and 21 are provided inside the condensers 11 and 13 and on the upper side of the second communication ports 17 and 17, respectively, and these chambers 21 and 21 communicate with the vacuum gauge sensor 23 for sampling. It is connected to the passages 25, 25.

The vacuum gauge sensor 23 detects the degree of vacuum that changes in proportion to the collection rate of water in the condensers 11 and 13. The chamber 21 is provided near the second communication port 17 which is the final position. is there. As a result, the state of collection of the final region of the adsorbent 19 can be confirmed, and efficient detection is possible. Fifth and sixth solenoid valves V ₅ and V ₆ are provided in sampling passages 25 and 25 that connect the vacuum sensor 23 and the chamber 21, respectively.

A seventh solenoid valve V ₇ is provided above the condenser 11 to release steam during regeneration, and an eighth solenoid valve V ₇ is provided above the condenser 13.
V ₈ are provided respectively, and around the condensers 11 and 13, heaters 29 and 3 that are connected to a power source (not shown) and generate hot air are provided.
1 is provided for each.

The first solenoid valve V ₁ to the eighth solenoid valve V including the heaters 29 and 31
₈ is controlled by the control unit 35.

That is, the control unit 35 controls the first solenoid valve V ₁
Of the solenoid valves V _8, for example, first, third, fifth, seventh solenoid valves V _1, V _3,
When V _{5 is} open and 7th solenoid valve V ₇ is closed, the other 2nd, 4th, 4th
6, 8 solenoid valve _{V 2, V 4, V 6} , V 8 is controlled to the closed in the standby state. In addition, the second, fourth, and sixth solenoid valves V ₂ , V ₄ ,
When V _{6 is} opened and the 8th solenoid valve V ₈ is closed, the other 1st, 3rd and 5th solenoid valves V ₁ , V ₃ and V ₅ are controlled to be closed and the 7th solenoid valve V ₇ is controlled to be opened. ,
Continuous operation is possible.

Further, the seventh and eighth solenoid valves V ₇ and V ₈ are kept closed while the condensers 11 and 13 are operating, and the heaters 29 and 3 are
When the condensers 11 and 13 in which 1 is turned on are controlled to be open at the time of regeneration, steam at the time of regeneration is allowed to escape to the atmosphere.

The heaters 29 and 31 are controlled to be turned on by inputting a detection signal from the vacuum sensor 23 to the control unit 25.

In the freeze-drying device configured in this way, the flask
The frozen sample 3 set in 31 is put in a vacuum state by making the inside of the drying chamber 1 into a vacuum by the vacuum pump 5, and thereby freeze-drying is performed.

Sublimation steam generated during the freeze-drying is guided into the condenser 11 through the first communication port 15 and is sequentially adsorbed by the adsorbent 19. The saturation state due to this adsorption gradually expands from the first communication port 15 to the second communication port 17.

When the saturation state expands, the degree of vacuum inside the condenser 11 gradually decreases. When the vacuum gauge sensor 23 detects that the set vacuum degree has been reached, the detection signal is sent to the control unit 35.
To enter. Accordingly, the solenoid valves V _1, V _3, V ₅ is closed, enters the operating state each of the electromagnetic valves V ₂ was waiting, V _4, V ₆ is opened.
At the same time, the seventh solenoid valve V ₇ is opened and the heater 29 is turned on. As a result, the condenser 11 is reliably regenerated when it reaches a saturated state.

The action when the condenser 13 is used is the same as the action when the condenser 11 is used.

[Advantages of the Invention] As described above, according to the freeze-drying apparatus of the present invention, the saturation state in the condenser is detected by the vacuum gauge sensor, so that the condenser can be efficiently regenerated. You can

[Brief description of drawings]

The attached drawings are overall explanatory views showing the freeze-drying apparatus of the present invention. 1 ...... drying chamber 3 ...... frozen samples 5 ...... vacuum pump 11, 13 ...... condenser V _1, V ₂ ...... solenoid valve (control valve) 23 ...... vacuum sensor

Claims (1)

[Scope of utility model registration request] 1. Freeze-drying comprising a control passage for opening and closing the connection passage and a condenser for collecting water generated in the drying chamber, in a connection passage connecting a drying chamber in which a frozen sample is set and a vacuum pump. In the apparatus, the condenser is provided with a vacuum sensor that outputs a detection signal when the degree of vacuum inside the condenser is close to a saturated state is provided, and the control valve is closed based on the detection signal from the vacuum sensor. A freeze-drying device, characterized in that the passage between the vacuum pump and the vacuum pump is blocked.