CN102645096A - Method for judging vacuum freeze-drying end points - Google Patents
Method for judging vacuum freeze-drying end points Download PDFInfo
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- CN102645096A CN102645096A CN2012101245083A CN201210124508A CN102645096A CN 102645096 A CN102645096 A CN 102645096A CN 2012101245083 A CN2012101245083 A CN 2012101245083A CN 201210124508 A CN201210124508 A CN 201210124508A CN 102645096 A CN102645096 A CN 102645096A
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Abstract
The invention discloses a method for judging vacuum freeze-drying end points. When the temperature of materials at a primary (secondary) drying stage is close to that of a shelf, a separation valve t2 between a drying chamber and a cold trap is periodically closed every t1 minute, a dew point rise value is measured, finishing of primary (secondary) drying is judged if the dew point rise value is equivalent to that in idle load. Otherwise, drying is continued until the dew point rise value is equivalent to that in idle load, and then primary (secondary) drying is finished. The method can be used for reflecting drying conditions of samples in batch, process change is obvious, the freeze-drying end points can be accurately judged, freeze-drying time is saved, and energy consumption is reduced.
Description
Technical field
The present invention relates to a kind of determination methods of dry end point, relate in particular to a kind of method of judging vacuum freeze drying primary drying and redrying end point.
Background technology
Vacuum freeze drying is with the material that is rich in water, is cooled to its eutectic point earlier or below the glass transition temperature, and water congeals into ice to make major part in the material, and remaining moisture and material component form eutectic or amorphous state (glassy state).Under low temperature and vacuum condition, frozen material is heated then, so that the distillation of the ice in the material; Realize lyophilization (primary drying); After lyophilization finished, rising temperature of charge (as rising to 30 ℃) heated material under vacuum condition; To remove adsorbed water, realize adsorption stripping and dry (redrying).
Because freeze drying is under low temperature and vacuum condition, material to be carried out heat drying, so very time-consuming and power consumption.The general temperature method that adopts is judged once (secondary) freeze-drying end point in the actual freeze-drying production technology, in order to guarantee the quality of product, often leaves bigger empirical coefficient in time, has so just increased freeze-drying time, and causing consuming energy further raises.Therefore how to guarantee under the product quality premise, shorten freeze-drying time and become key issue, and freeze-drying time is being directly related with the judgement of freeze-drying end point.Therefore, seeking a kind of method that can judge the freeze-drying end point accurately and effectively, thereby realize saving freeze-drying time, cut down the consumption of energy, is one of problem demanding prompt solution in the current freeze drying.
At present, the method for known judgement freeze-drying end point has temperature-responsive method, pressure rising method, dew point method and weight method.The temperature-responsive method can only reflect the drying regime of individual samples, needs to keep enough safety (time) coefficients; Pressure rising method is higher to the sealing requirements of hothouse, and under the lower situation of drying chamber pressure, can't accurately judge the redrying end point; Dew point method is judged redrying end point effect not as good as judging that an end point is accurate; The rule of weighing exists mass sensor that comparatively difficulty is installed, and is not suitable for the mass industrial production problem.
Summary of the invention
Technical problem to be solved by this invention is: a kind of method of judging the vacuum freeze drying end point is provided, can effectively solves existing freeze dryer and can't accurately judge the freeze-drying end point and cause that energy consumption of freeze drying is big, consuming time for a long time, product cost is high and problem such as quality instability.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of method of judging the vacuum freeze drying end point is characterized in that, said method is monitored in the freeze-drying process moisture increment through the dew point method lift-off value and changed, thereby judges lyophilization end point and secondary adsorption stripping and dry end point; Said method comprises the steps:
Step S1, the unloaded dew point lift-off value of measurement; By the freeze-drying program that configures, carry out freeze-drying process, respectively in primary drying and redrying stage, every in the closing of t1 time cycle property at a distance from the valve t2 time, record dew point lift-off value obtains primary drying, the unloaded dew point lift-off value of redrying respectively;
Step S2, carry out material sample freeze-drying process, measure the dew point lift-off value, judge primary drying, redrying end point; Put the material sample well, carry out actual freeze-drying process; With thermocouple record shelf temperature and temperature of charge, when temperature of charge during near shelf temperature, every in the closing of t1 time cycle property at a distance from the valve t2 time, measure the dew point lift-off value; When primary drying dew point lift-off value and unloaded primary drying suitable, be judged as primary drying and finish, the conversion freeze-drying gets into the redrying stage; When the unloaded redrying of redrying dew point lift-off value and secondary suitable, be judged as redrying and finish, that is to say whole freeze-drying end point, shut down and finish freeze-drying.
As a kind of preferred version of the present invention, among the step S1, every at a distance from 10 minutes periodically close at a distance from valve 60 seconds, record dew point lift-off value obtains primary drying, redrying zero load dew point lift-off value respectively;
Among the step S2, with thermocouple record shelf temperature and temperature of charge, when temperature of charge during near shelf temperature, every at a distance from 10 minutes periodically close at a distance from valve 60 seconds, measurement dew point lift-off value.
Beneficial effect of the present invention is: the method for the judgement vacuum freeze drying end point that the present invention proposes; Can judge that the method for vacuum freeze drying end point can react the drying regime of sample by the gross; Process changes obviously; Can accurately judge the freeze-drying end point, realize saving freeze-drying time, cut down the consumption of energy.
Description of drawings
Fig. 1 is the method device for carrying out said structural representation that dew point rising method of the present invention is judged a lyophilization and secondary adsorption stripping and dry end point;
Fig. 2 is that dew point rising method of the present invention is judged 2% sweet mellow wine dew point rising curve map in the method for a lyophilization and secondary adsorption stripping and dry end point.
The specific embodiment
Specify the preferred embodiments of the present invention below in conjunction with accompanying drawing.
Embodiment one
See also Fig. 1, the present invention has disclosed a kind of device for carrying out said of judging the vacuum freeze drying end point, this device comprise control module 1, hothouse 2, at a distance from valve 3, cold-trap 4, dew point transducer 5, material and shelf temperature thermocouple probe 6,7.
Dew point transducer 5 is fixed through clip, inserts from hothouse 2 tops, and the signal of collection is sent to control module 1, and control module 1 is measured and passed to material and shelf temperature through temperature thermocouple probe 6 and 7, separated valve 3 in hothouse 2 and cold-trap 4 middle being provided with.
Equipment requirements and type selecting:
A: dew point transducer requires the probe can be environment temperature-40 ℃～80 ℃, work below the environmental pressure 100Pa, temperature measurement accuracy≤0.2 ℃; Dew point scope-80 ℃～80 ℃, dew point precision≤± 1 ℃, the response time was less than 10 seconds.As can select for use the DMT340 of Vaisala Oy serial.
B: control module requires agile and all-purpose, and reliability is high, and antijamming capability is strong, and wiring is simple, and is low in energy consumption.As can select Omron CJ1W series for use.
The principle of the invention: dew point is (refer to not situation about contacting with wet stock with water) unsaturation humid air cooling humid air that reaches capacity under certain steam partial pressure Pv, and the temperature when promptly bearing dewdrop is represented with td.Dew point can be measured with dew point hygrometer, records td and is equivalent to measure Pv, i.e. t
d=f (p
v).Steam partial pressure and dew point are relation one to one.The variation of the interior dew point of hothouse is exactly the variation of steam partial pressure (water vapour content) in the freezing dry process, and drying chamber pressure is to not influence of dew point.Freezing dry process is the constantly process of migration of a moisture.Steam comes out to get into hothouse from material, normal freeze-drying process steam gets into cold-trap from hothouse, and hothouse steam partial pressure (water vapour content) remains unchanged basically.
The primary drying stage, central at a distance from valve when closing, can not in time get into cold-trap from the steam of material (distillation); Cause steam partial pressure to increase; Regular time at interval in, recruitment has reflected the amount of the steam that distillation is come out in the material, can raise through dew point measure out.Along with the carrying out of primary drying, the steam that distils out in the material is fewer and feweri, thereby causes that steam partial pressure constantly reduces in the hothouse, in closing behind valve the dew point lift-off value constantly reduce.When the dew point lift-off value is reduced to when being equivalent to zero load, explain that ice crystal has distilled fully in the material, show that primary drying finishes.
In the redrying stage, the dew point lift-off value presented ever-reduced trend when dew point curve was in plateau.When the dew point lift-off value is reduced to when being equivalent to zero load, explain that the desorb degree is very little in the material, show that redrying finishes.
During near end point, at a distance from valve, the dew point lift-off value has reflected the drying regime of sample by the gross in closing in freeze drying.
When temperature of charge is near shelf temperature in the freezing dry process, at a distance from valve, measure the dew point lift-off value in periodically closing, if the dew point lift-off value, thinks then that freeze-drying finishes near unloaded; Otherwise, continue drying, near unloaded, finish freeze-drying process up to the dew point lift-off value.Method step is:
(1), measures unloaded dew point lift-off value.By the freeze-drying program that configures, carry out freeze-drying process, respectively in primary drying and redrying stage, every at a distance from 10 minutes periodically close at a distance from valve 60 seconds, write down the dew point lift-off value, obtain once (secondary) dry unloaded dew point lift-off value;
(2), carry out material sample freeze-drying process, measure the dew point lift-off value, judge once (secondary) dry end point.Put the material sample well, carry out actual freeze-drying process.With thermocouple record shelf temperature and temperature of charge, when temperature of charge during near shelf temperature, every at a distance from 10 minutes periodically close at a distance from valve 60 seconds, measurement dew point lift-off value.When primary drying dew point lift-off value and unloaded primary drying suitable, be judged as primary drying and finish (F point among Fig. 2), the conversion freeze-drying gets into the redrying stage; When the unloaded redrying of redrying dew point lift-off value and secondary suitable, be judged as redrying and finish (J point among Fig. 2), that is to say whole freeze-drying end point, shut down and finish freeze-drying.
In sum, the method for the judgement vacuum freeze drying end point that the present invention proposes can judge that the method for vacuum freeze drying end point can be reacted the drying regime of sample by the gross; Process changes obviously; Can accurately judge the freeze-drying end point, realize saving freeze-drying time, cut down the consumption of energy.
Here description of the invention and application is illustrative, is not to want with scope restriction of the present invention in the above-described embodiments.Here the distortion of the embodiment that is disclosed and change are possible, and the replacement of embodiment is known with the various parts of equivalence for those those of ordinary skill in the art.Those skilled in the art are noted that under the situation that does not break away from spirit of the present invention or substantive characteristics, and the present invention can be with other form, structure, layout, ratio, and realize with other assembly, material and parts.Under the situation that does not break away from the scope of the invention and spirit, can carry out other distortion and change here to the embodiment that is disclosed.
Claims (2)
1. a method of judging the vacuum freeze drying end point is characterized in that, said method is monitored in the freeze-drying process moisture increment through the dew point method lift-off value and changed, thereby judges lyophilization end point and secondary adsorption stripping and dry end point; Said method comprises the steps:
Step S1, the unloaded dew point lift-off value of measurement; By the freeze-drying program that configures, carry out freeze-drying process, respectively in primary drying and redrying stage, every in the closing of t1 time cycle property at a distance from the valve t2 time, record dew point lift-off value obtains primary drying, the unloaded dew point lift-off value of redrying respectively;
Step S2, carry out material sample freeze-drying process, measure the dew point lift-off value, judge primary drying, redrying end point; Put the material sample well, carry out actual freeze-drying process; With thermocouple record shelf temperature and temperature of charge, when temperature of charge during near shelf temperature, every in the closing of t1 time cycle property at a distance from the valve t2 time, measure the dew point lift-off value; When primary drying dew point lift-off value and unloaded primary drying suitable, be judged as primary drying and finish, the conversion freeze-drying gets into the redrying stage; When unloaded suitable of redrying dew point lift-off value and redrying, be judged as redrying and finish, that is to say whole freeze-drying end point, shut down and finish freeze-drying.
2. the method for judgement vacuum freeze drying end point according to claim 1 is characterized in that:
Among the step S1, every at a distance from 10 minutes periodically close at a distance from valve 60 seconds, record dew point lift-off value obtains primary drying, redrying zero load dew point lift-off value respectively;
Among the step S2, with thermocouple record shelf temperature and temperature of charge, when temperature of charge during near shelf temperature, every at a distance from 10 minutes periodically close at a distance from valve 60 seconds, measurement dew point lift-off value.
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| CN2012101245083A CN102645096A (en) | 2012-04-25 | 2012-04-25 | Method for judging vacuum freeze-drying end points |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104154712A (en) * | 2014-08-25 | 2014-11-19 | 济南康众医药科技开发有限公司 | Drying method of lamiophlomis rotata |
| CN110530921A (en) * | 2019-09-09 | 2019-12-03 | 江苏省原子医学研究所 | A kind of judgment method of external hanging type vacuum freeze drying degree |
Citations (5)
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| WO1995030118A1 (en) * | 1994-05-03 | 1995-11-09 | Institut National De La Recherche Agronomique | Method and device for controlling vacuum lyophilization |
| CN2352909Y (en) * | 1998-08-28 | 1999-12-08 | 张祯儒 | Freezing type drying machine |
| CN1470856A (en) * | 2003-06-26 | 2004-01-28 | 上海理工大学 | Pressure thermometering method during lyophilizing process |
| CN2651678Y (en) * | 2003-06-26 | 2004-10-27 | 上海俊乐制冷自控元件有限公司 | Multifunctional experimental refrigerating drier |
| CN101419015A (en) * | 2008-09-02 | 2009-04-29 | 上海理工大学 | Method for judging once lyophilization drying end point and secondary drying end point |
-
2012
- 2012-04-25 CN CN2012101245083A patent/CN102645096A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995030118A1 (en) * | 1994-05-03 | 1995-11-09 | Institut National De La Recherche Agronomique | Method and device for controlling vacuum lyophilization |
| CN2352909Y (en) * | 1998-08-28 | 1999-12-08 | 张祯儒 | Freezing type drying machine |
| CN1470856A (en) * | 2003-06-26 | 2004-01-28 | 上海理工大学 | Pressure thermometering method during lyophilizing process |
| CN2651678Y (en) * | 2003-06-26 | 2004-10-27 | 上海俊乐制冷自控元件有限公司 | Multifunctional experimental refrigerating drier |
| CN101419015A (en) * | 2008-09-02 | 2009-04-29 | 上海理工大学 | Method for judging once lyophilization drying end point and secondary drying end point |
Non-Patent Citations (1)
| Title |
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| 周国燕等: "《真空冷冻干燥残余水分监测方法概述》", 《低温工程》, 31 August 2009 (2009-08-31) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104154712A (en) * | 2014-08-25 | 2014-11-19 | 济南康众医药科技开发有限公司 | Drying method of lamiophlomis rotata |
| CN110530921A (en) * | 2019-09-09 | 2019-12-03 | 江苏省原子医学研究所 | A kind of judgment method of external hanging type vacuum freeze drying degree |
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Application publication date: 20120822 |