JPH02144102A - Method and device for vacuum freeze drying - Google Patents

Abstract

PURPOSE:To reduce the amt. of an unfrozen material discharged by separating many vacuum freeze driers into the blocks wherein the number of the driers is gradually decreased in accordance with the ratio of the supply amt. of a liq. material to be dried to the cylindrical body in a drying chamber to the amt. of the unfrozen liq. material to be discharged. CONSTITUTION:Many vacuum freeze driers A are separated into the blocks B1-B4 wherein the number of driers is gradually decreased in accordance with the ratio of the supply amt. of a liq. material to be dried to the cylindrical body 1 provided in the drying chamber (b) to the amt. of the unfrozen liq. material to be discharged. The liq. material is supplied to the drier A in the block b1 wherein the largest number of driers are set, and prefrozen. The unfrozen liq. material is then supplied to the drier A in the block B2 wherein the second largest number of driers are set, and prefrozen. The unfrozen liq. material is successively supplied to the driers A in the succeeding blocks, and prefrozen. As a result, the absolute amt. of the unfrozen liq. material to be discharged is minimized.

Description

Detailed Description of the Invention The present invention involves freezing a liquid material to be dried on a cooling surface that also serves as a heating surface, sublimating moisture while maintaining a normal degree of vacuum, and condensing it in a trap. The present invention relates to a freeze-vacuum drying device.

More specifically, when freeze-drying a liquid material to be dried or a liquid material to be dried, as shown in FIG. Cylindrical body 1 with cooling surface a in the vertical direction
and housed in parallel in a drying chamber surrounded by a partition wall 2 so as to maintain a normal degree of vacuum, and the drying chamber maintains a vacuum by collecting water vapor sublimated from the material to be dried. The present invention relates to an improvement in a freeze-vacuum drying means when drying is carried out by a freeze-vacuum dryer A configured to communicate with a trap chamber C containing a trap (steam condenser) 3.

Freeze-vacuum drying of a material to be dried using the above-described freeze-vacuum dryer A is performed by first supplying a liquid or liquefied material to be dried from a supply pipe 10 into a drying chamber in a large number of lines arranged in parallel. The cylindrical bodies L... are supplied to the insides of the cylindrical bodies L until they reach a predetermined level, and then, in this state, the cylindrical bodies L... The liquid material to be dried is frozen on the inner circumferential surface of the cylindrical body l by circulating an antifreeze heat medium fluid around it, and when the freezing progresses in a cylindrical shape, the unfrozen material is released from the supply pipe 10. The remaining material liquid to be dried is discharged in the opposite direction, and the unfrozen portion of the material liquid to be dried located on the axis side within each cylinder 1 is dropped, and thereby each cylinder I
...with a frozen layer Z of the material to be dried frozen in a ring shape in the cross section left in a tube shape,
Next, in this state, the refrigerant liquid is circulated through the trap 3 through its supply port 30 and discharge port (not shown in the drawing), and the trap chamber C is circulated through its 4j9. wall 4
Each cylindrical body l...
The frozen drying material layer Z is circulated around the cooling surface a, which also serves as a heating surface, formed by 100 surfaces of the cylindrical body l. This is done by supplying heat to the limit that does not cause melting, sublimating the moisture from the layer of the material to be dried, without condensing and collecting it in the trap 3.

By the way, when freeze-vacuum drying is performed in this manner, the unfrozen material liquid to be dried taken out from each cylinder I in the drying chamber is coated with a frozen layer of material to be dried on the inner surface of each cylinder 1. Since the purpose is to form a wide sublimation surface in the frozen layer by leaving it in the shape of a hollow tube, it is made to have approximately half the internal volume of the cylinder l. That is, when the freezing progresses to approximately half the level of the liquid material to be dried in the cylindrical body 1, the unfrozen liquid material to be dried is dropped. For this reason, half of the liquid material to be dried that has been supplied to the freeze-vacuum dryer A is taken out in excess, which poses a problem in that its processing is troublesome.

As a countermeasure to this problem, i1! Continuously supplied material'#
In the case of liquid, as shown in Fig. 282, multiple freeze-vacuum dryers A... are installed in parallel, and the unfinished liquid is taken out from the first freeze-vacuum dryer fiA and collected in the collection tank T1. The frozen liquid material to be dried is sent to the supply tank t that supplies the liquid material to be dried to the second freeze-vacuum dryer A, and half of the new liquid material to be dried is supplied to the supply tank t to combine them. , is supplied to the cylindrical body l... in the drying chamber of the second freeze-vacuum dryer A, and this is supplied to the third and fourth cylindrical bodies l...
By repeating the cycle of supplying the first and second freeze-vacuum dryers A to the first and second freeze-vacuum dryers A, the ratio of the unfrozen material liquid to be taken out to the whole can be reduced. I try to keep it sufficiently low. However, if the raw material liquid is supplied in batches at a fixed rate and mixing of the next batch with the product is not allowed, or if the life of the liquid material is short at low temperatures, the above method is inappropriate. It is.

The uninvented invention was made to solve the above-mentioned problems occurring in the freeze-drying means performed using the freeze-vacuum dryer A of the above-mentioned form, and the invention was made in order to solve the above-mentioned problems occurring in the freeze-drying means using the freeze-vacuum dryer A of the above-mentioned form. It is an object of the present invention to provide a new means that can minimize the absolute amount of the unfrozen material liquid to be taken out in order to freeze the supplied material to be dried into a hollow tube shape. As a means to achieve this objective, a vertical freeze-vacuum dryer is used in which the cooling surface, which also serves as a heating surface for supplying heat to the material liquid to be dried, is a vertical cylinder. In the freeze-vacuum drying method in which the liquid is pre-frozen in a frozen layer and vacuum-dried, a large number of freeze-vacuum dryers are used to supply the liquid material to be dried to cylinders installed in their drying chambers, leaving the liquid unfrozen. The liquid material to be dried is divided into blocks whose base number decreases by 81i according to the ratio of the discharge amount of the liquid material to be dried to be discharged, and the liquid material to be dried is supplied to the freeze-vacuum dryer of the block with the largest number of bases for preliminary freezing. The material liquid to be dried, which is left unfrozen and discharged, is then supplied to the freeze-vacuum dryer of the block with a large number of bases and pre-frozen. A freeze-vacuum drying method characterized by sequentially supplying the material to a dryer and pre-freezing it, and a vertical freeze-vacuum dryer in which the cooling surface that also serves as a heating surface for supplying heat to the liquid material to be dried is a vertical cylinder. In a freeze-vacuum drying method in which a liquid material to be dried is pre-frozen in a tube-shaped frozen layer and then vacuum-dried, the liquid material to be dried is discharged from the freeze-vacuum dryer while remaining unfrozen. Furuzuke of the cylindrical body in the drying chamber is Mf according to the ratio of the supply amount of the liquid material to be dried to the cylindrical body provided in the drying chamber and the discharge amount of the liquid material to be dried which is left unfrozen and discharged.
The present invention proposes a freeze-vacuum drying method characterized in that pre-freezing is performed by sequentially supplying the liquid to a freeze-vacuum dryer in which the temperature is reduced.

Next, embodiments will be described in detail with reference to the drawings. Note that the same reference numerals in the drawings as in the previous means are used for components having the same effect.

Figure 3 shows the freeze-vacuum drying bag (d
In the same figure, A... is a freeze-vacuum dryer, L is a supply line that supplies liquid material to be dried to them, and M is a drainage liquid that discharges unfrozen liquid material to be dried from them. Show the line.

The freeze-vacuum dryer A... is shown in a symbolic form in Figure 3, but each has the structure shown in Figure 1 above, or has a configuration with the same effect. The structure is equipped with That is, as shown in FIG. 1, the vertical cylindrical bodies 1 . A drying chamber b is housed in rows and surrounded by a partition wall 2 to maintain a normal degree of vacuum 17, and is formed between the inner circumferential surface of the partition wall 2 of the drying chamber and the outer circumferential surface of the cylindrical body 1. A circulation path for an antifreeze heat medium fluid, and a brine nozzle 20φ21 for circulating and supplying the antifreeze heat medium fluid to the circulation path. The cylindrical body 1...
A trap chamber C1 that accommodates the toe and tube 3 that condenses and collects moisture from the frozen material to be dried on the inner circumferential surface of the trap chamber C1, which blocks and controls communication between the trap chamber C and the drying chamber. An on-off valve 6 provided in the communication passage, a vacuum exhaust system connected to an exhaust pipe 40 provided on the a wall 4 of the trap chamber C so as to maintain the inside of the trap chamber C at a normal degree of vacuum, and a vacuum exhaust system connected to the exhaust pipe 40 provided in the a wall 4 of the trap chamber C to maintain the inside of the trap chamber C at a normal degree of vacuum. 8 is circulated from the supply port 30 and the discharge port, and the cylindrical body 1...
A supply pipe 10 for supplying a liquid material to be dried to the inner cavity of the cylindrical body 1 and discharging an unfrozen liquid material to be dried;
- A take-out o 22 for taking out the material to be dried frozen in a tube shape from the drying chamber after it has been dried, a bottom lid 23 for freely opening and closing the take-out port 22, and a bottom thereof. An operating member 24 that opens and closes the lid 23;
A hopper 5 for taking out dried products surrounding the second part 423 and continuing below the take-out port 22, and a shutter 51 provided under the hopper 5 [150] so as to be openable and closable.
This is a vertical freeze-vacuum dryer equipped with a container for collecting dried products disposed below the lower opening 50 of the hopper 5. However, in these freeze-vacuum dryers A..., the entire volume (l!: is,
It is set much smaller than that of each freeze-vacuum dryer A used in the freeze-vacuum dryer shown in FIG. 2.

These freeze-vacuum dryers A... are connected to supply pipes 10, which are designed to supply the material liquid to be dried, to the cylindrical bodies l... in their respective drying chambers. When connecting the supply lines L of the freeze-vacuum dryers A, which are installed in parallel,
. . , the number corresponding to the ratio of the amount of the liquid material to be dried to be supplied and the discharge j- to be left unfrozen and discharged is summarized in the first block B1. Here, since the ratio +:ji is set to 1/2, approximately 1/2 of the number of freeze-vacuum dryers 4j of the parallel freeze-vacuum dryers A...
1. A... are collected into a first block B1, and this first blow.

Half the number of freeze-vacuum dryers A... of the second block B1 are combined as a second block B2, and further, half the number of freeze-vacuum dryers A... of this second block B2 are combined into a third block. B3. Half the number is used as the fourth block B4, and the number is successively reduced to half, so that the last remaining freeze-vacuum dryer A is used as the final block Bn.

The supply line L is connected only to the supply pipe 10 of each freeze-vacuum dryer A of the first block B1, and is connected only to the supply pipe 10 of each freeze-vacuum dryer A of the second block B2. is each freeze-vacuum drying fiA of the first block B1.
A drainage line M is connected to collect the unfrozen dried material liquid drawn from..., and each block B3 of the third, fourth, etc.
Supply pipe 10 of each freeze vacuum dryer A of mB4...
. . ., each has a drain line M that collects the unfrozen dry material liquid drawn from the block located at the electrical position 1.
Let's connect it.

In addition, in Fig. 3, ■... indicates each freeze-vacuum dryer A.
This is a switching valve for switching the supply pipe 10 between the supply line L (or the drain line M of the preceding block) and the drain line M for communication.

Therefore, the drying material liquid to be vacuum dried is
The amount of freeze-vacuum drying 4jIA... of block B] is adjusted to fill the entire cylindrical body l... in the drying chamber of block B], and this is fed by the supply line L to the 4. Freeze-vacuum drying of Pronku B1. 't A cylindrical body 1・
...supplied within. Then, in this state, a pre-freezing step is performed to freeze the liquid material to be dried as a frozen layer Z having a predetermined thickness on the inner circumferential surface of the cylindrical body 1.

Next, when the preliminary freezing of this drying material liquid is completed,
The switching pulp V... is operated to drain the material liquid to be dried, which remains unfrozen, to the drain line M.

At this time, each freeze-vacuum dryer A/in the second block Bz
... operates the switching valve V... so that each of the supply pipes IO is connected to and communicates with the drain line M of the rij block. The unfrozen drying material liquid is in a second block B,
The cylindrical body 1 of each freeze-vacuum dryer A is filled with excess and insufficient amounts.

Next, in this state, a pre-freezing process is performed for each freeze-vacuum drying fiA of the second block B2. At this time, the first block B1 may be controlled to shift to a drying process.

Next, when the pre-freezing process in the second block B2 is completed, the switching valve ■... is operated to switch to νJ, and the remaining unfrozen material liquid to be dried is drained into the drain line M.
This is then transferred to the freeze-vacuum dryer A of the third block B3.
... and perform the same preliminary freezing process.Then, by performing this step in sequence, the final professional block freeze-vacuum dryer A is supplied to the previous block freeze-vacuum dryer By supplying the drawn unfrozen material liquid to be dried, freezing it, and drawing out the unfrozen liquid material to be dried, drying for all freeze-vacuum dryers A... The step of pre-freezing the material liquid is completed.

Freeze vacuum dryer A for each block after pre-freezing...
may move to the drying process at each point C, but since the time required for pre-freezing is much shorter than the time required for the drying process, once all the pre-freezing for each block is completed, all The freeze-vacuum dryer A may be controlled to simultaneously shift to the drying process.

When freeze-drying the material liquid to be dried in this way, in the above-mentioned freeze-vacuum dryer, for example, the number of parallel freeze-vacuum dryers A is 15, and the first block B1 has 82t! The total capacity of the cylindrical body l of each drying chamber of the freeze-vacuum dryer A in the above-mentioned method shown in FIG. If the cylindrical body l of the drying chamber is made to have the same capacity as 41, then the maximum is V! The amount of unfrozen liquid material to be dried discharged from the freeze-vacuum dryer A of block Bn is one-eighth of that in the case of the means shown in FIG.

Next, FIG. 4 shows that the above-mentioned example is a cylindrical body l...
Freeze vacuum dryers A with the same capacity ω are arranged in parallel in blocks, the number of which gradually decreases according to the ratio of the supply amount of the material liquid to be dried and the discharge amount unfrozen. The cylindrical body of the drying chamber
Freeze-vacuum dryers A1, A2, etc., whose capacities are gradually decreased according to the ratio between the supply amount and the discharge amount.
This is an example in which one set of A3... is combined.

That is, in FIG. 5, A1 and A2φA3A4 are freeze-vacuum dryers having the configurations shown in FIG. 1, and A is the first block B1 in the freeze-vacuum dryer shown in FIG. This is a freeze-vacuum dryer corresponding to the entire freeze-vacuum dryer A..., and the capacity of the cylindrical body 1... (the number of cylinder bodies l...) in the drying chamber is made large. ing. Further, A2 is a second freeze-vacuum dryer corresponding to the second block B2 in the example shown in FIG. 1/2 the capacity of freeze-vacuum dryer A (the capacity of each cylinder 1 is the same, but the number of cylinders is 1/2)
A3 is the third freeze-vacuum dryer, and the capacity of its cylindrical body (number of bottles) is ) is the capacity of the second freeze-vacuum dryer A2 (number of cylinders l)
The number of containers (number of cylindrical bodies 1) of A4 is one half of that of the third freeze-vacuum dryer A3.

These freeze vacuum dryers A1, A2...
A drain line M that guides the unfrozen material liquid to be dried drawn out via a switching valve V from a supply pipe 10 provided in the drying chamber of the second freeze-vacuum dryer A1 is used for drying in the second freeze-vacuum dryer A2. The supply line L for supplying the liquid material to be dried to the supply pipe 10 of the chamber is connected to the supply line L through the supply tank t or directly. In addition, this second freeze-vacuum dryer A
The drain line M that draws out the unfrozen material to be dried from the supply pipe 10 of the second drying chamber is connected and communicated with the supply line L of the third freeze-vacuum dryer A3 in the same way as described above. Repeating this, the drain line M of the preceding freeze-vacuum dryer is connected to the supply line L of the final freeze-vacuum dryer An via the supply tank t or directly.

In the freeze-vacuum drying apparatus configured in this way, the amount of the liquid material to be dried that remains unfrozen in the cylinder 1 during pre-freezing and is discharged is such that the amount of the liquid material to be dried remaining unfrozen in the cylindrical body 1 is equal to the amount of the liquid material to be dried that is discharged. A freeze-vacuum dryer At φA2 is arranged in parallel in multiple stages so as to supply the liquid material to be dried to the drying chamber.
・If the number of parallel stages is 4 when discharged from the freeze-vacuum dryer An at the crossroads, it will be 1/8th as in the method shown in Fig. 3 above. If the number of cylindrical bodies 1 provided in the drying chamber of the final freeze-vacuum dryer An is one, the amount will be extremely small, which is half the capacity of that cylindrical body 1.

FIG. 5 is a modification of the means shown in FIG. 4 described above. In this example, a large number of freeze-vacuum dryers Al- Az...A
n are arranged in parallel in multiple stages so that the unfrozen material liquid to be dried discharged from the preceding freeze-vacuum dryer Al is supplied to the next freeze-vacuum dryer A2 whose capacity is gradually reduced. The method of combining them is the same as the means shown in Fig. 4 above, but the height positions at which they are installed are also different.
It is arranged so that it descends step by step.

With this means, when extracting the unfrozen material liquid to be dried from the preceding freeze-vacuum dryer Al, it is possible to supply it to the next freeze-vacuum dryer A2 with a head difference. Therefore, the supply tank t and pump P can be omitted.

In addition, in the means shown in FIG. 5, under each hopper 5 of the parallel freeze vacuum dryer At
Container h for taking out dried products placed below 150
... is to connect and communicate the upper end side of the chute 7..., which communicates with the large container H for taking out dried products provided separately in each army []50... So it can be omitted.

As explained above, the freeze-vacuum dryer stage of the present invention is a vertical freeze-vacuum dryer in which the cooling surface that also serves as a heating surface that supplies heat to the liquid material to be dried is a vertical cylinder. In the freeze-vacuum dryer method, in which a liquid is pre-frozen in a tube-shaped frozen layer and vacuum-dried, a large number of freeze-vacuum dryers are used to supply four liquids of the material to be dried to a cylindrical body installed in their drying chambers. The liquid material to be dried is divided into blocks whose number of bases gradually decreases according to the ratio between the supply amount and the discharge t of the liquid material to be dried which is left unfrozen and discharged, and the liquid material to be dried is supplied to the freeze-vacuum dryer of the block with the largest number of bases to make a reserve. After freezing, the liquid material to be dried to be discharged unfrozen is supplied to the freeze-vacuum dryer of the block with the next highest number of bases and pre-frozen. Since the material to be dried is pre-frozen by sequentially supplying blocks to the freeze-vacuum dryer in which the amount gradually decreases, when pre-freezing the material to be dried, the liquid material to be dried supplied to the vertical cylindrical body in the drying chamber of the freeze-vacuum dryer is Since the material is frozen in the form of a hollow tube, the amount of unfrozen material to be dried that is left unfrozen and discharged can be significantly reduced.

In addition, the freeze-vacuum dryer A... does not have to be made in many different types, but is made with the same structure, and when freezing,
It becomes possible to reduce the amount of liquid material to be dried that is left unfrozen and extracted.

In addition, the amount of supply of the material liquid to be dried, which is left unfrozen from the freeze-vacuum dryer and evaporated, to the cylindrical body provided in the drying chamber of the freeze-vacuum dryer and the amount of unfrozen material to be dried, The volume of the cylindrical body in the drying chamber is gradually reduced according to the ratio of the discharged amount of the liquid material to be dried, which is left as it is.When pre-freezing is to be carried out by sequentially supplying the drying chamber to a freeze-vacuum dryer, the material is removed from the final freeze-vacuum dryer. The amount of unfrozen material to be dried can be reduced to a desired level L^.

In addition, the capacity of the vertical cylindrical body provided in the drying chamber of the freeze-vacuum drying apparatus is gradually reduced according to the ratio between the supply amount of the material to be dried and the discharge amount of the material liquid to be dried, which is left unfrozen and discharged. A plurality of freeze-vacuum dryers formed in this manner are arranged in a stepwise manner from a high place to a low place according to the order in which the capacity thereof gradually decreases, and the unfrozen and dried material is extracted from the high-position freeze-vacuum dryers. The freeze-vacuum dryer is connected and communicated so that the material liquid is supplied to the lower-level freeze-vacuum dryer, and the freeze-vacuum dryer AI/A2 is arranged in parallel in multiple stages.
The unfrozen liquid material to be dried can be extracted and supplied from An without using the pump P.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a vertical freeze-vacuum dryer used in the method of the present invention, Fig. 2 is an explanatory diagram of the mean of the present invention, and Fig. 3 is a schematic plan view of the freeze-vacuum dryer used in carrying out the method of the present invention. 4 is a longitudinal sectional front view of the freeze-vacuum drying apparatus according to the present invention, and FIG. 5 is a longitudinal sectional front view of another embodiment of the same. Explanation of drawing symbols A-A, ~An...Freeze vacuum dryer n...Block B1-B H...Container M...Drain line T1...Collection tank 2...Frozen layer b ... Drying room h ... Container 1 ... Cylindrical body 2 ... Partition wall 22 ... Removal [1 24 ... Operating member 30 ... Supply port 40 ... Exhaust pipe 50 ... Lower port 6... Opening/closing valve f L... Supply line P... Pump ■... Switching valve a... Cooling surface C... Trap chamber t... Supply tank io... Supply pipe 21...Brine nozzle 23...Bottom 3...Trap 4...Machine wall 5...Hopper 51...Shutter 7...Chute Fig. 2 Fig.

Claims (3)

[Claims] (1) The liquid material to be dried is pre-frozen into a tube-shaped frozen layer using a vertical freeze-vacuum dryer in which the cooling surface, which also serves as a heating surface for supplying heat to the liquid material to be dried, is a vertical cylinder. In the freeze-vacuum drying method of vacuum drying, a large number of freeze-vacuum dryers are used to discharge the material liquid to be dried, leaving the supplied amount and unfrozen material liquid to the cylinders installed in their drying chambers. The material to be dried is divided into blocks whose number of bases gradually decreases according to the ratio to the discharge amount of The liquid is then supplied to the freeze-vacuum dryer of the block with a large number of bases for pre-freezing, and the liquid material to be dried, which is discharged unfrozen, is sequentially supplied to the freeze-vacuum dryer of blocks with a gradually decreasing number of bases for preliminary freezing. A freeze-vacuum drying method characterized by freezing. (2) The liquid material to be dried is pre-frozen into a tube-shaped frozen layer using a vertical freeze-vacuum dryer in which the cooling surface, which also serves as a heating surface for supplying heat to the liquid material to be dried, is a vertical cylinder. In the freeze-vacuum drying method of vacuum drying, the liquid material to be dried is discharged from the freeze-vacuum dryer while remaining unfrozen, and the liquid material to be dried is supplied to a cylindrical body provided in the drying chamber of the freeze-vacuum dryer. Pre-freezing is carried out by sequentially supplying the drying chamber to a freeze-vacuum dryer in which the capacity of the cylindrical body of the drying chamber is gradually reduced according to the ratio between the supply amount and the discharge amount of the material liquid to be dried, which is left unfrozen and discharged. Freeze-vacuum drying method. (3) A plurality of cylinders formed in the drying chamber so that the capacity of the vertical cylindrical body gradually decreases according to the ratio between the supply amount of the material to be dried and the discharge amount of the material liquid to be dried, which is left unfrozen and discharged. Freeze-vacuum dryers are arranged in a stepwise manner from a high place to a low place according to the order in which the capacity thereof gradually decreases, and the unfrozen drying material liquid to be extracted from the high-order freeze-vacuum dryer is placed in a lower place. A freeze-vacuum dryer that is connected and communicated so as to be supplied to a freeze-vacuum dryer.