JPS6122943B2 - - Google Patents
Info
- Publication number
- JPS6122943B2 JPS6122943B2 JP56097480A JP9748081A JPS6122943B2 JP S6122943 B2 JPS6122943 B2 JP S6122943B2 JP 56097480 A JP56097480 A JP 56097480A JP 9748081 A JP9748081 A JP 9748081A JP S6122943 B2 JPS6122943 B2 JP S6122943B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- dried
- drying
- collapse
- freeze
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000001035 drying Methods 0.000 claims description 36
- 239000000463 material Substances 0.000 claims description 33
- 238000004108 freeze drying Methods 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 20
- 238000000859 sublimation Methods 0.000 claims description 20
- 230000008022 sublimation Effects 0.000 claims description 20
- 238000007710 freezing Methods 0.000 claims description 5
- 230000008014 freezing Effects 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 235000013351 cheese Nutrition 0.000 description 4
- 230000005686 electrostatic field Effects 0.000 description 4
- 230000018044 dehydration Effects 0.000 description 3
- 238000006297 dehydration reaction Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 2
- 239000006071 cream Substances 0.000 description 2
- 238000007791 dehumidification Methods 0.000 description 2
- 239000000796 flavoring agent Substances 0.000 description 2
- 235000019634 flavors Nutrition 0.000 description 2
- 235000013305 food Nutrition 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 1
- 241001672694 Citrus reticulata Species 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 235000011089 carbon dioxide Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000012520 frozen sample Substances 0.000 description 1
- 235000011389 fruit/vegetable juice Nutrition 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000005457 ice water Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Landscapes
- Freezing, Cooling And Drying Of Foods (AREA)
- Drying Of Solid Materials (AREA)
Description
本発明は凍結乾燥法に関する。更に詳しくは被
乾燥物の品質を良好に保ちつつ、かつ運転コスト
を低く押さえることのできる凍結乾燥を実施する
方法に関する。
被乾燥物を凍結させ高真空下で昇華によつて水
分を蒸発させる凍結乾燥法は、製品品質を低下さ
せずに乾燥処理を行なえるが、製造コストが極め
て高いという問題がある。特に食品の凍結乾燥に
おいては被乾燥物によつて凍結乾燥装置の仕様、
運転条件を選定するというよりは、むしろ装置仕
様によつて被乾燥物を選定するか、あるいはその
組成を変更して凍結乾燥を行うことが多かつた。
これは乾燥温度が低ければ昇華蒸気圧が低下し、
乾燥速度が遅くなるために製造コストが上昇する
ことに基くものである。また、工業的な凍結乾燥
においては、同一の乾燥条件を選定したにもかか
わらず、乾燥製品の品質が必ずしも同一にならな
いことも多かつた。これは乾燥室内の棚温を乾燥
温度とみなして、棚温のみを制御し、被乾燥物の
昇華面温度と棚温との差を充分考慮しなかつたこ
とに起因した。すなわち、昇華面温度が被乾燥物
に固有なコラツプス（Collapse）温度以下であれ
ば昇華脱水が起こるが、それを越える温度になつ
た場合には蒸発脱水が起こるために品質の低下が
生ずるものと考えられる。
本発明者らは被乾燥物のコラツプス温度を測定
し、被乾燥物の昇華面温度を該温度を越えずかつ
できるだけ該温度に近い値に制御しつつ凍結乾燥
を実施すれば、品質が良好で製品コストも低減で
きることに注目して鋭意検討した結果本発明を完
成するに到つた。
すなわち、本発明は、被乾燥物を凍結し、次い
で乾燥層内で乾燥する方法において、乾燥槽内の
被乾燥物の昇華面温度を被乾燥物のコラツプス温
度以下でかつ該コラツプス温度に近い温度に保つ
ように、乾燥槽内の圧力を制御して乾燥を実施す
ることを特徴とする凍結乾燥法である。
本発明を更に詳細に説明する。製品品質に対し
て極めて重大な意味を持つコラツプス温度につい
ては、例えばロンドンのアカデミツクプレス社か
ら出版された“Freeze drying and Advanced
Food Technology”の277頁に掲載されたA.P.
Mackenzieの論文に詳細に記載されている。この
コラツプス温度を測定する方法としては、被乾燥
物の薄片を種々の温度下で凍結乾燥を行ない、顕
微鏡観察により変化が認められた温度と温度の間
の値をコラツプス温度とするという、極めて手間
のかかる方法が知られている。
本発明者らは、このコラツプス温度の測定法に
ついても種々検討した結果、簡便な方法により測
定できることを見い出した。すなわち、被乾燥物
のコラツプス温度は、液体窒素中で−100℃以下
に冷却凍結した被乾燥物を２〜６℃／分の速さで
昇温しながらその直流電気伝導度を測定し、その
対数を絶対温度の逆数に対してプロツトして得ら
れる曲線の外挿変曲点の温度として求めることが
できる。第１図を参照してより具体的に述べる
と、この曲線のコラツプス温度以上の温度での回
帰直線σ１と、コラツプス温度以下の温度での回
帰直線σ２を求め、両直線の交点の温度Ｔがコラ
ツプス温度である。なお、直流電気伝導度は３〜
50V/cmの静電場中での直流電流値より求めた値
である。この新規な測定法は、再現性が良好で、
準備試料も単一片で済み、かつ測定時間も大幅に
短縮することができるので極めて好適な方法であ
る。
本発明は、凍結乾燥において乾燥槽内の圧力を
制御することにより被乾燥物の昇華面温度が１定
に保れつつ昇華乾燥が進行するという発見に基く
ものであるが、何故圧力の制御が昇華面温度を制
御するのかについては、理論的に完全には解明で
きていない。一般に凍結乾燥過程における被乾燥
物への熱の移動は主に輻射及び対流により行われ
ており、熱源からの伝導伝熱、具体的には乾燥槽
内の棚と被乾燥物の接触部分からの伝熱の寄与は
小さいと考えられている。熱源から被乾燥物への
単位時間、単位面積当りの熱の移動量ｑは、熱源
の温度をθ０、被乾燥物の温度をθ、熱伝達率を
α（ｐ）とすれば、温度差θ０−θが極端に大き
くなく、50〜60℃程度以下であれば下記(1)式が成
立する。
ｑ＝α（ｐ）・（θ０−θ） (1)
ここで気体の熱伝導率は圧力により殆んど影響
を受けないが、熱伝達率α（ｐ）については、ほ
ぼ圧力ｐに比例して変化することが知られてい
る。したがつて(1)式から凍結乾燥における被乾燥
物への熱の移動量は、温度差と共に乾燥槽内の圧
力に依存していると言える。大きな熱容量を持つ
乾燥棚により影響を受ける熱源の温度θは、その
制御応答が遅いのに対し、乾燥槽内の圧力ｐは乾
燥槽内が低圧であることも手伝つて極めて応答の
速い制御が可能である。このことから昇華面の温
度制御に乾燥槽内の圧力を制御することが有効に
働くものと推定される。
本発明の方法を適用するにあたつては、予めコ
ラツプス温度以下に冷却凍結した被乾燥物を乾燥
槽内に静置し、被乾燥物の品温をコラツプス温度
以下に保ちながら、乾燥槽内の空気を排気して圧
力をコラツプス温度の氷の水蒸気圧以下に下げて
実施する。乾燥槽内の圧力を所定の圧力に制御す
る方法としては、コールドドラツプを介して真空
ポンプにより脱気されつつある乾燥槽内に、例え
ば流量可変微少リーク弁等から空気、窒素、ヘリ
ウム等の気体を適宜リークさせることによつて行
うことができる。また、(1)式からも明らかなよう
に、被乾燥物への熱の移動量については熱源の温
度も影響を持つので、本発明の方法においても熱
源の温度制御を併用することは必要である。
被乾燥物の昇華面温度をコラツプス温度以下に
保つための圧力制御の目標値は、試行錯誤的にも
求めることはできるが、例えば熱移動の殆ど無い
測定槽内に試料片を置いて測定した時のコラツプ
ス温度下における平衡蒸気圧の値として求めるこ
とができる。
本発明の方法によれば、凍結乾燥のスタート当
初から、昇華脱水が進行している昇華面の温度を
コラツプス温度以下で、かつコラツプス温度近傍
の狭い温度領域内に保つことができるため、許容
されるほぼ最大限の速度で凍結乾燥を実施するこ
とができ極めて経済効率が高い。加えて昇華面は
常にコラツプス温度以下に保たれているので乾燥
製品の品質は確実に保証される。
以下、実施例によつて本発明を説明する。
実施例 １
温州みかんの生鮮果汁（全固形分8.8％）を液
体窒素中で−100℃以下に冷却、凍結し、約６
℃／分で昇温しながら50V/cmの静電場中での直
流電流値より求めた直流電気伝導度の変化からコ
ラツプス温度−34.5℃を得た。コラツプス温度に
おける直流電気伝導度は3.18×10-7Ω-1ｍ-1であ
つた。
流量可変微少リーク弁を備えた約50容の乾燥
槽に１cm角厚さ２mmの該凍結試料を置いて３つの
異なる温度帯において凍結乾燥を行つた。流量可
変微少リーク弁からは空気をリークさせつつ乾燥
槽内の圧力を所定圧に制御し、昇華面温度を所定
の温度幅内に制御して凍結乾燥を実施した結果は
以下の通りであつた。
The present invention relates to a freeze-drying method. More specifically, the present invention relates to a method of performing freeze-drying that can keep operating costs low while maintaining good quality of the material to be dried. The freeze-drying method, in which the material to be dried is frozen and water is evaporated by sublimation under high vacuum, can perform drying without reducing product quality, but has the problem of extremely high manufacturing costs. Especially when freeze-drying foods, the specifications of the freeze-drying equipment depend on the item to be dried.
Rather than selecting the operating conditions, freeze-drying was often carried out by selecting the material to be dried based on the specifications of the equipment or by changing its composition.
This is because the lower the drying temperature, the lower the sublimation vapor pressure.
This is based on the fact that the drying speed becomes slower, which increases manufacturing costs. Furthermore, in industrial freeze-drying, even if the same drying conditions are selected, the quality of the dried products is often not always the same. This was due to the fact that the shelf temperature in the drying chamber was regarded as the drying temperature, only the shelf temperature was controlled, and the difference between the sublimation surface temperature of the material to be dried and the shelf temperature was not sufficiently considered. In other words, if the sublimation surface temperature is below the collapse temperature specific to the material to be dried, sublimation dehydration will occur, but if the temperature exceeds this temperature, evaporative dehydration will occur, resulting in a decrease in quality. Conceivable. The present inventors determined that the quality would be good if the material to be dried was freeze-dried by measuring the collapse temperature of the material to be dried and controlling the sublimation surface temperature of the material to be as close to the temperature as possible without exceeding that temperature. As a result of intensive studies focusing on the ability to reduce product costs, we have completed the present invention. That is, the present invention provides a method in which a material to be dried is frozen and then dried in a drying layer, in which the sublimation surface temperature of the material to be dried in a drying tank is set to a temperature below the collapse temperature of the material to be dried and close to the collapse temperature. This freeze-drying method is characterized by drying by controlling the pressure inside the drying tank so that the drying temperature is maintained. The present invention will be explained in more detail. The collapse temperature, which has extremely important implications for product quality, is discussed, for example, in “Freeze drying and Advanced
AP published on page 277 of “Food Technology”
This is described in detail in Mackenzie's paper. The method of measuring the collapse temperature is extremely time-consuming and involves freeze-drying thin pieces of the material to be dried under various temperatures, and determining the value between the temperatures at which a change is observed by microscopic observation as the collapse temperature. A method that takes The inventors of the present invention have investigated various methods for measuring this collapse temperature and have found that it can be measured using a simple method. In other words, the collapse temperature of the material to be dried is determined by measuring the DC electrical conductivity of the material that has been cooled and frozen in liquid nitrogen to below -100°C while heating the material at a rate of 2 to 6°C/min. It can be determined as the temperature at the extrapolated inflection point of the curve obtained by plotting the logarithm against the reciprocal of the absolute temperature. To be more specific with reference to Fig. 1, a regression line σ 1 at a temperature above the collapse temperature of this curve and a regression line σ 2 at a temperature below the collapse temperature are calculated, and the temperature at the intersection of both lines is calculated. T is the collapse temperature. In addition, the DC electrical conductivity is 3~
This value was determined from the DC current value in an electrostatic field of 50V/cm. This new measurement method has good reproducibility and
This is an extremely suitable method because only a single sample is required and the measurement time can be significantly shortened. The present invention is based on the discovery that in freeze drying, by controlling the pressure inside the drying tank, the sublimation surface temperature of the material to be dried can be kept constant while sublimation drying proceeds. How the sublimation surface temperature is controlled has not been completely elucidated theoretically. In general, heat transfer to the material to be dried during the freeze-drying process is mainly carried out by radiation and convection, and conductive heat transfer from the heat source, specifically from the contact area of the material to be dried with the shelf in the drying tank. The contribution of heat transfer is thought to be small. The amount of heat transfer q per unit time and unit area from the heat source to the object to be dried is the temperature difference, where θ 0 is the temperature of the heat source, θ is the temperature of the object to be dried, and α (p) is the heat transfer coefficient. If θ 0 −θ is not extremely large and is approximately 50 to 60° C. or less, the following formula (1) holds true. q=α(p)・(θ 0 −θ) (1) Here, the thermal conductivity of gas is hardly affected by pressure, but the heat transfer coefficient α(p) is almost proportional to pressure p. It is known that it changes. Therefore, from equation (1), it can be said that the amount of heat transferred to the material to be dried in freeze-drying depends on the pressure inside the drying tank as well as the temperature difference. The temperature θ of the heat source, which is affected by a drying shelf with a large heat capacity, has a slow control response, but the pressure p inside the drying tank can be controlled with an extremely quick response, partly due to the low pressure inside the drying tank. It is possible. From this, it is presumed that controlling the pressure inside the drying tank is effective in controlling the temperature of the sublimation surface. When applying the method of the present invention, the material to be dried that has been cooled and frozen in advance to below the collapse temperature is placed in a drying tank, and while the temperature of the material to be dried is maintained below the collapse temperature, the material to be dried is placed in the drying tank. This is done by evacuating the air and reducing the pressure below the ice water vapor pressure at the collapse temperature. A method of controlling the pressure inside the drying tank to a predetermined pressure is to introduce gas such as air, nitrogen, helium, etc. from a variable flow rate minute leak valve into the drying tank which is being degassed by a vacuum pump via a cold drape. This can be done by leaking as appropriate. Furthermore, as is clear from equation (1), the temperature of the heat source also has an effect on the amount of heat transferred to the material to be dried, so it is necessary to control the temperature of the heat source in the method of the present invention as well. be. The target value for pressure control to keep the temperature of the sublimation surface of the material to be dried below the collapse temperature can be determined by trial and error, but for example, it is possible to determine the target value for pressure control by placing the sample piece in a measurement tank where there is almost no heat transfer. It can be determined as the value of equilibrium vapor pressure under the collapse temperature at According to the method of the present invention, the temperature of the sublimation surface where sublimation dehydration is progressing can be maintained below the collapse temperature and within a narrow temperature range near the collapse temperature from the beginning of freeze-drying, which is acceptable. Freeze-drying can be carried out at almost the maximum speed possible, making it extremely economically efficient. In addition, the quality of the dried product is guaranteed since the sublimation surface is always kept below the collapse temperature. The present invention will be explained below with reference to Examples. Example 1 Fresh unshiu mandarin juice (total solid content 8.8%) was cooled to below -100°C in liquid nitrogen, frozen, and
A collapse temperature of -34.5°C was obtained from the change in DC electrical conductivity determined from the DC current value in an electrostatic field of 50 V/cm while increasing the temperature at a rate of °C/min. The DC electrical conductivity at the collapse temperature was 3.18×10 -7 Ω -1 m -1 . The frozen sample, 1 cm square and 2 mm thick, was placed in a drying tank of approximately 50 volumes equipped with a variable flow rate minute leak valve, and freeze-dried at three different temperature zones. Freeze-drying was carried out by controlling the pressure inside the drying tank to a predetermined pressure while leaking air from the variable flow rate small leak valve, and controlling the sublimation surface temperature within a predetermined temperature range.The results were as follows. .
【表】
実施例 ２
生鮮カツテージチーズ（全固形分20.2％）を液
体窒素温度迄冷却、凍結した後、約６℃／分で昇
温しながら50V/cmの静電場中の直流電流値より
求めた直流電気伝導度の変化よりコラツプス温度
−9.4℃を得た。コラツプス温度における直流電
伝導度は1.48×10−６Ω-1ｍ-1であつた。
５〜７mm角にカツテングした生鮮カツテージチ
ーズを液体窒素に浸漬し、急速凍結した後乾燥槽
内の圧力を1.4〜1.6Torrに制御し昇華面温度を−
10±0.5℃に制御して凍結乾燥した。乾燥製品は
−10℃前後の比較的高い温度帯で乾燥したにもか
かわらずコラツプス温度以下であつたため、サク
サクした歯ごたえのある良好なテクスチヤーを示
した。
実施例 ３
市販クリームチーズ（全固形分44.3％）につい
て液体窒素温度迄冷却、凍結した後、約２℃／分
で昇温しながら３V/cmの静電場中の直流電流値
より求めた直流電気伝導度の変化より、コラツプ
ス温度−30.0℃を得た。コラツプス温度における
直流電気伝導度は、22.0×10-6Ω-1ｍ-1であつ
た。直径８cm、厚さ３cmの円筒状クリームチーズ
を−80℃の粉末状ドライアイスで急速凍結した
後、乾燥槽内の圧力を0.25〜0.8Torr及び0.06〜
0.2Torrに制御し昇華面温度を−20±５℃及び−
35℃±５℃に制御して凍結乾燥を実施した。コラ
ツプス温度以上の−20±５℃で乾燥した製品は、
乾燥直後に多少のオイルオフと緒小変形が認めら
れ、また脱湿下常温保存で、経時的にオイルオフ
の発生が増加し、風味が劣化した。一方コラツプ
ス温度以下の−35゜±５℃で乾燥した製品は、脱
湿下常温保存６カ月後でもオイルオフの発生は認
められず良好なにクリーム風味及びサクサクした
歯ごたえのある良好なテクスチヤーを示した。
以上の結果より本発明の方法による被乾燥物の
コラツプス温度は、凍結乾燥を実現するための上
限温度に対応しており、乾燥中の昇華面の温度
が、被乾燥物のコラツプス温度より数℃でも上昇
すれば乾燥後の品質が著しく劣化すること及びコ
ラツプス温度以下でさえあれば、必要以上に低温
に保つことなく確実に凍結乾燥が実施できること
が実証された。[Table] Example 2 After cooling and freezing fresh cutlet cheese (total solids content 20.2%) to liquid nitrogen temperature, the DC current value in an electrostatic field of 50 V/cm was determined while heating at a rate of approximately 6°C/min. A collapse temperature of -9.4°C was obtained from the change in DC electrical conductivity. The DC conductivity at the collapse temperature was 1.48 x 10-6 Ω -1 m -1 . Fresh cutlet cheese cut into 5-7 mm squares is immersed in liquid nitrogen, quickly frozen, and then the pressure in the drying tank is controlled to 1.4-1.6 Torr to lower the sublimation surface temperature to -
It was freeze-dried at a controlled temperature of 10±0.5°C. Although the dried product was dried at a relatively high temperature of around -10°C, it was below the collapse temperature, so it had a good crispy texture. Example 3 After cooling commercially available cream cheese (44.3% total solids) to liquid nitrogen temperature and freezing, the DC electricity was determined from the DC current value in an electrostatic field of 3 V/cm while heating at a rate of approximately 2°C/min. A collapse temperature of -30.0°C was obtained from the change in conductivity. The DC electrical conductivity at the collapse temperature was 22.0×10 -6 Ω -1 m -1 . After quickly freezing a cylindrical cream cheese with a diameter of 8 cm and a thickness of 3 cm using powdered dry ice at -80℃, the pressure in the drying tank was adjusted to 0.25 to 0.8 Torr and 0.06 to
Control the sublimation surface temperature to 0.2Torr and -20±5℃ and -
Freeze-drying was carried out at a controlled temperature of 35°C±5°C. Products dried at -20±5℃ above the collapse temperature are
Immediately after drying, some oil-off and small deformation were observed, and when stored at room temperature under dehumidification, the occurrence of oil-off increased over time and the flavor deteriorated. On the other hand, products dried at -35°±5°C, which is below the collapse temperature, showed no oil-off even after being stored at room temperature under dehumidification for 6 months, showing a good creamy flavor and a good texture with crispy texture. Ta. From the above results, the collapse temperature of the material to be dried by the method of the present invention corresponds to the upper limit temperature for realizing freeze-drying, and the temperature of the sublimation surface during drying is several degrees Celsius higher than the collapse temperature of the material to be dried. However, it has been demonstrated that if the temperature rises, the quality after drying will deteriorate significantly, and that as long as the temperature is below the collapse temperature, freeze-drying can be carried out reliably without keeping the temperature unnecessarily low.
第１図は直流電気伝導度の温度変化及びコラツ
プス温度の求め方の一例を示す。横軸は絶対温度
の逆数、縦軸は直流電気伝導度の対数値をそれぞ
れ示す。
σ１及びσ２はそれぞれコラツプス温度以上及
びコラツプス温度以下における直流電気伝導度の
温度変化を示す。σ１及びσ２の回帰直線の交点
の温度Ｔがコラツプス温度を示す。
FIG. 1 shows an example of how the DC electrical conductivity changes with temperature and how the collapse temperature is determined. The horizontal axis shows the reciprocal of absolute temperature, and the vertical axis shows the logarithm of DC electrical conductivity. σ 1 and σ 2 represent temperature changes in DC electrical conductivity above the collapse temperature and below the collapse temperature, respectively. The temperature T at the intersection of the regression lines of σ 1 and σ 2 indicates the collapse temperature.
Claims (1)
る方法において、乾燥槽内の被乾燥物の昇華面温
度を、被乾燥物のコラツプス温度以下でかつ該コ
ラツプス温度に近い温度となるよう乾燥槽内の圧
力を制御して乾燥を実施することを特徴とする凍
結乾燥法。 ２ 乾燥槽内の圧力を、被乾燥物のコラツプス温
度における被乾燥物中の水の平衡蒸気圧以下でか
つ該平衡蒸気圧に近い圧力の範囲となるように制
御する特許請求の範囲第１項記載の凍結乾燥法。 ３ 前記コラツプス温度が、凝固点温度以下に冷
却凍結した被乾燥物の直流電気伝導度の対数値を
絶対温度の逆数に対してプロツトして得られる曲
線の変曲点として求まる温度である特許請求の範
囲第１項記載の凍結乾燥法。[Scope of Claims] 1. A method of freezing a material to be dried and then drying it in a drying tank, in which the temperature of the sublimation surface of the material to be dried in the drying tank is below the collapse temperature of the material to be dried and at the collapse temperature of the material to be dried. A freeze-drying method that is characterized by controlling the pressure inside the drying tank so that the temperature is close to that of the drying tank. 2. The pressure within the drying tank is controlled to a pressure range that is equal to or less than the equilibrium vapor pressure of water in the material to be dried and close to the equilibrium vapor pressure at the collapse temperature of the material to be dried. Lyophilization method as described. 3. The collapse temperature is a temperature determined as the inflection point of a curve obtained by plotting the logarithm of the DC electrical conductivity of the material to be dried, which has been cooled and frozen below the freezing point temperature, against the reciprocal of the absolute temperature. Freeze-drying method according to scope 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56097480A JPS5879A (en) | 1981-06-25 | 1981-06-25 | Freezing drying method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56097480A JPS5879A (en) | 1981-06-25 | 1981-06-25 | Freezing drying method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5879A JPS5879A (en) | 1983-01-05 |
| JPS6122943B2 true JPS6122943B2 (en) | 1986-06-03 |
Family
ID=14193442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56097480A Granted JPS5879A (en) | 1981-06-25 | 1981-06-25 | Freezing drying method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5879A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6389444U (en) * | 1986-12-01 | 1988-06-10 | ||
| JPH0322141U (en) * | 1989-07-14 | 1991-03-06 | ||
| WO2006029467A1 (en) * | 2004-09-16 | 2006-03-23 | Btf Pty Ltd | Rapid freeze drying process |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3301735C2 (en) * | 1983-01-20 | 1986-04-10 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | Transitional storage facility for highly radioactive waste |
| US9121637B2 (en) * | 2013-06-25 | 2015-09-01 | Millrock Technology Inc. | Using surface heat flux measurement to monitor and control a freeze drying process |
-
1981
- 1981-06-25 JP JP56097480A patent/JPS5879A/en active Granted
Non-Patent Citations (5)
| Title |
|---|
| ASPECTS THEORIQUES ET INDUSTRIELS DE LA LYOPHILISATION=1964 * |
| BELLOWS R J AND KING C.J.AICHE SYMP.SER=1973 * |
| FREEZE DRYING OF FOODS AND BIOLOGICALS=1968 * |
| L.REY FUNDAMENTAL ASPECTS OF LYOPHILISATION IN ASPECTS THEORIAUES ET INDUSTRIELS DE LA LYOPHILISATION HERMANN=1964 * |
| RECENT RESEARCH FREEZING AND DRYING=1960 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6389444U (en) * | 1986-12-01 | 1988-06-10 | ||
| JPH0322141U (en) * | 1989-07-14 | 1991-03-06 | ||
| WO2006029467A1 (en) * | 2004-09-16 | 2006-03-23 | Btf Pty Ltd | Rapid freeze drying process |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5879A (en) | 1983-01-05 |
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