JPH03144281A - Freezing drier - Google Patents

Abstract

PURPOSE:To permit the use of a cooling trap as it is upon drying later than second time drying by providing a discharging air flow rate regulating means between a chamber and the cooling trap. CONSTITUTION:A flow rate regulating valve 6 is provided between a chamber 1 and a cooling trap 2 as a discharging air flow rate regulating means. Upon starting the discharging of air in the chamber 1, the air is discharged gradually while dropping an air discharging speed and when a pressure in the chamber 1 has become low sufficiently, the air discharging speed is regulated by the flow rate regulating valve 6 so as to increase the air discharging speed. Accordingly, solvent, arrested in the cooling trap 2, will never be blown off and drying operation may be effected without deteriorating a working time (efficiency) so much until the drying is finished. According to this method, the drying operation can be repeated without removing condensed adhering solvent in the cooling trap 2 at every times.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a freeze-drying device, and particularly to a freeze-drying device that operates under reduced pressure.

[Prior Art] Conventionally, freeze-drying equipment has a cooling trap installed between a sample drying chamber and an exhaust pump to capture moisture and solvent desorbed from the sample to be dried. It is cooled and captured. The moisture and solvent trapped in the cooling trap are removed from the cooling trap each time a new sample is replaced during operation.

In addition, when drying operations are performed continuously, a method is adopted in which two systems of cooling traps are provided and while one cooling trap is in use, the moisture and solvent trapped in the other cooling trap are removed. ing.

[Problems to be Solved by the Invention] The above-mentioned conventional technology does not take into consideration the prevention of the solvent in the cooling trap from being sucked into the exhaust pump, and the operation of the device must be stopped each time the solvent is mixed into the exhaust pump. Since the solvent adhering to the cooling trap must be removed, there is a problem in that work efficiency is poor.

An object of the present invention is to provide a freeze drying apparatus that allows continuous use of such a frozen trap.

[Means for Solving the Problems] The above object of the present invention can be achieved by the following, and the configuration thereof is as follows.

A freeze-drying apparatus having a sample drying chamber that can be evacuated under reduced pressure, an exhaust means for evacuating the inside of the chamber under reduced pressure, and a cooling trap provided between the exhaust means and the chamber, wherein: between the chamber and the cooling trap. A freeze-drying device characterized by being provided with an exhaust flow rate regulating means.

The present invention will be explained with reference to the drawings.

At first, water and solvent (hereinafter simply referred to as solvent) are not condensed and adhered to the cooling trap, so there is no problem even if the pressure is suddenly reduced during the first drying operation.
During the second drying, the solvent desorbed during the first drying is captured and attached to the cooling trap 2. That is, at the end of the first drying operation, the leak valve 8 is open, the opening/closing valve 5 is closed, the cooling trap leak valve 7 is closed, and the inside of the chamber 1 is at atmospheric pressure, and the cooling trap 2 is at atmospheric pressure. The pressure is reduced,
It is in a cooled state.

Next, in the second drying operation, the sample to be dried is introduced into the chamber 1, the leak valve 8 is closed, and the on-off valve 5 is opened to start exhausting the inside of the chamber 1. It enters the cooling trap 2 through valve 5.

At this time, when the exhaust gas from chamber 1 is rapidly introduced into the cooling trap, the solvent condensed and adhered inside the cooling trap by the first drying operation is blown away and sucked into the exhaust pump. , reducing the pumping capacity of the pump.

Further, the solvent sucked into the exhaust pump is also discharged into the atmosphere, which is undesirable as it causes air pollution.

In order to suppress the discharge of the solvent captured by the cooling trap 2, it is conceivable to lower the exhaust speed, but this reduces the drying time and reduces work efficiency.

In order to solve this problem, one aspect of the present invention is to provide a flow rate control valve 6 as an exhaust flow rate control means between the chamber 1 and the cooling trap 2, as shown in FIG.

At the start of evacuation of the chamber 1, the evacuation speed is gradually reduced and the evacuation speed is adjusted by the flow control valve 6 so that the evacuation speed is increased when the pressure inside the chamber 1 becomes sufficiently low. As a result, the drying work can be carried out without blowing off the solvent trapped in the cooling trap and without significantly reducing the working time (efficiency) until the drying is completed. This also allows repeated operations to be carried out without having to remove the condensed adhering solvent in the cooling trap each time.

In addition, the present invention is related to the conventional method of not providing two cooling traps! Although 32 operations could not be performed, one system can be operated, and suction and mixing of the solvent into the exhaust pump 3 can be suppressed.

[Function] The reason why the present invention can continue operation without removing the desorption solvent trapped in the cooling trap each time is due to the action of the exhaust flow rate regulating means provided between the sample drying chamber and the cooling trap. This is because the solvent is no longer blown away.

[Example] [Example 1] An embodiment of the present invention will be described based on FIG.

An on-off valve 5, a flow control valve 6, and a leak valve 7 are connected between the chamber 1 and the cooling trap 2 via an exhaust pipe 4. Further, the chamber 1 is provided with a leak valve 8.

The above-mentioned on-off valve 5 and leak valve 7 are closed, and the exhaust pump 3 is operated to reduce the pressure inside the cooling trap 2. Once the pressure has dropped sufficiently, the cold trap is cooled to lower the temperature. After performing the above preparation operations, the sample to be dried is introduced into the chamber 1, the leak valve 8 is closed, and the on-off valve 5 is opened.

At this time, the meteor control valve 6 is left fully open.

The valve 6 is fully opened only during the first evacuation after the preparatory operation, that is, when no solvent is attached to the inside of the cooling trap 2.

When the drying of the sample is completed, the desorbed solvent is condensed and adhered to the cooling trap 2.

After closing the on-off valve 5, the leak valve 8 is opened to return the inside of the chamber 1 to atmospheric pressure, and the dried sample is taken out.

When drying a new sample subsequently, the operation is performed from the step following the above-mentioned preparatory operation. However, when exhausting, the flow rate adjustment valve 6 is adjusted to gradually exhaust the air.

By doing this, the gas in the chamber 1 passes through the cooling trap 2 one by one, so that the solvent that has adhered to the cooling trap 2 during the first drying process is not blown away, and the solvent that has adhered to the cooling trap is not blown away. It is possible to continue the drying operation without performing an operation to remove it.

Note that since the inside of the cooling chamber only needs to be removed when a large amount of solvent is trapped, the process can be shortened accordingly.

[Example 2] Another embodiment of the present invention will be described based on FIG.

After performing preparation operations to reduce the pressure in the cooling trap 2 and lower the temperature in the same manner as in Example 1, the sample to be dried is introduced into the chamber 1, the leak valve 8 is closed, and the on-off valve 5b is opened to allow the inside of the chamber 1 to flow. Exhaust.

After the first drying is completed, the on-off valve 5a is used for the second and subsequent drying.

After introducing the second sample into the chamber 1, the leak valve 8 is closed and the on-off valve 5a is opened. At this time, it is necessary to restrict the flow rate control valve 6 to such an extent that the solvent condensed on the cooling trap 2 is not blown away.

When the pressure inside the chamber 1 is sufficiently reduced, open/close valve 5b
open and increase the pumping speed. By doing so, the flow rate control valve 6 does not need to be operated every time drying is performed.

[Example 3] Another embodiment of the present invention will be described based on FIG.

In Example 2, after the flow rate control valve 6 was initially adjusted, its throttle amount was fixed.

This embodiment is characterized in that a system having an exhaust resistance equivalent to the exhaust resistance of the valve 6 after the flow adjustment is provided as the flow rate adjustment means.

This can be done by connecting the chamber 1 and the cold trap by exhaust pipes 4a and 4b of different diameters.

Similarly to the above, when performing the second and subsequent drying, the on-off valve 5b provided on the exhaust pipe 4b having a suitable exhaust resistance is opened to exhaust the air through the exhaust pipe 4b. This simplifies the flow rate adjustment operation.

Note that by providing the flow rate regulating means of the present invention, the freeze-drying apparatus can be fully automated.

[Effects of the Invention] The present invention provides a cooling trap on which moisture and solvent desorbed from the sample during the first drying are condensed and adhered.

It has the advantage that it can be used as is even during the second and subsequent drying, and the drying time can be shortened.

Further, there is an effect that the amount of desorption solvent sucked into the exhaust pump can be suppressed, and the life of the exhaust pump can be improved.

[Brief explanation of the drawing]

1 to 3 are exhaust system diagrams of a freeze-drying apparatus according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Chamber, 2... Cooling trap, 3... Exhaust pump, 4... Exhaust pipe, 5... Open/close valve, 6...
...Flow control valve, 7,8...Leak valve. 1... 2... 3... 4... 5... 6... 7.8 Figure 1 Chamber cooling trough exhaust Pump exhaust pipe opening/closing balloon flow rate adjustment balloon nok valve 5a, 5b... opening/closing valve

Claims (1)

[Claims] 1. A freeze-drying apparatus having a sample drying chamber that can be evacuated under reduced pressure, an exhaust means for evacuating the inside of the chamber under reduced pressure, and a cooling trap provided between the exhaust means and the chamber, A freeze-drying apparatus characterized in that an exhaust flow rate regulating means is provided between the chamber and the cooling trap.