JP2014202429A - Device and method for monitoring dried state of material to be dried that is adapted for frozen drying machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for monitoring a dried state of material to be dried for a frozen drying machine capable of monitoring a dried state of material to be dried during a secondary drying step without using any temperature sensor and completely eliminating a dangerous state of collapsing of the material to be dried.SOLUTION: Control means PLC stores control programs for a dry warehouse DC, a cold trap CT and degree of vacuum adjusting means, a required calculation program and some required formulae. When material to be dried enters a secondary drying period, the control means PLC changes a dry warehouse degree of vacuum Pdc as it is, and calculates an average product temperature Tm and an average dehumidifying speed Qm of the material to be dried at the secondary drying period in reference to measured data including the dry warehouse degree of vacuum Pdc across the change, a cold trap degree of vacuum Pct and a rack temperature Th detected by rack temperature detecting means. The calculated average product temperature Tm and average dehumidifying speed Qm are recorded in recording means (e).

Description

  The present invention is applied to a freeze dryer that is a product obtained by drying raw material liquids such as foods and pharmaceuticals to a predetermined moisture content by freeze drying, and a dry state monitoring device for monitoring a freeze dried state of a material to be dried and a dry state It relates to the monitoring method.

  For freeze-drying of pharmaceuticals, etc., containers such as trays and vials filled with materials to be dried are loaded into the drying chamber of a freeze dryer automatically controlled by a control panel, and the materials to be dried in each container are predetermined. It is performed by drying until the water content becomes. The freeze-drying process of the material to be dried using this type of freeze-dryer generally includes a primary drying process for removing moisture contained in the ice-like material to be dried until the material to be dried becomes a dry solid, and a primary drying process. It comprises a secondary drying step of removing a trace amount of antifreeze water contained in the material to be dried that has become a dry solid through the process, and drying the material to be dried until a predetermined moisture content is obtained.

  The applicant of the present application does not directly measure the sublimation surface temperature of the material to be dried using a temperature sensor, but calculates the sublimation surface temperature of the material to be dried from the measured values of other parameters. Thus, an apparatus and a method for monitoring the dry state of the material to be dried during the primary drying process have been proposed (for example, see Patent Document 1). According to the technique described in Patent Document 1, since the temperature sensor is not inserted into the material to be dried, there are inconveniences caused by using the temperature sensor, for example, (1) all the objects to be charged in the drying chamber. Cannot determine the sublimation surface temperature for dry materials, (2) Cannot be applied to aseptic preparations because bacteria are likely to be mixed into the dry materials, (3) Automatic to automatically load dry materials into the drying cabinet It is possible to eliminate problems such as being unable to be applied to a freeze dryer equipped with a loading device. Further, the apparatus and method previously proposed by the applicant of the present application, in the primary drying step of the material to be dried, drives the vacuum degree adjusting means to change the direction of temporarily increasing the degree of vacuum in the drying cabinet, and at least From the measurement data including the degree of vacuum in the drying chamber and the degree of vacuum in the cold trap before and after the change, the average sublimation surface temperature, average bottom part temperature, and sublimation rate of the material to be dried in the primary drying period are calculated. As a result, when measuring data is collected, the degree of vacuum in the drying chamber changes in a direction higher than the vacuum control value, and the sublimation surface temperature is lowered. Therefore, unlike the conventional MTM (Manometric Temperature Measurement) method, the material to be dried The risk of collapsing can be completely eliminated.

WO2012 / 108470A1 brochure

  However, the invention described in Patent Document 1 relates to an apparatus and method that can monitor the drying state of the material to be dried during the primary drying process, and does not consider the secondary drying process. As described above, since the freeze-drying process of the material to be dried includes the primary drying process and the secondary drying process, the material to be dried in the secondary drying process is more accurately monitored in order to more accurately monitor the drying state of the material to be dried. Development of an apparatus and a method capable of monitoring the dry state of the food is desired. Of course, this apparatus and method are required not to use a temperature sensor and to completely eliminate the risk of the material to be dried collapsing.

  The present invention has been made in order to meet such a demand. The object of the present invention is to monitor the drying state of the material to be dried during the secondary drying process without using a temperature sensor, and the material to be dried is collapsed. It is an object of the present invention to provide a dry state monitoring device and a dry state monitoring method for a freeze dryer that can completely eliminate the risk of occurrence.

  In order to solve the above-mentioned problems, the present invention relates to a dry state monitoring method, which is generated from a drying cabinet (DC) in which a material to be dried is charged and a material to be dried charged in the drying chamber (DC). A cold trap (CT) for condensing and collecting water vapor, a main pipe (a) communicating the drying chamber (DC) and the cold trap (CT), and a main valve (MV) for opening and closing the main pipe (a) A vacuum degree adjusting means for adjusting a vacuum degree in the drying cabinet (DC), a vacuum detecting means for detecting an absolute pressure in the drying cabinet (DC) and an absolute pressure in the cold trap (CT), and Automatic operation of the shelf temperature detecting means for detecting the temperature (Th) of the shelf installed in the drying cabinet (DC), the drying cabinet (DC), the cold trap (CT), and the vacuum degree adjusting means. Freezing with control means (PLC) to control In the dry condition monitoring method applied to the dryer, the control means (PLC) includes a control program for the drying chamber (DC), the cold trap (CT) and the vacuum degree adjusting means, a required calculation program, The required relational expression is stored, and when the material to be dried enters the secondary drying period, the degree of vacuum (Pdc) in the drying cabinet (DC) is changed according to the course, and before and after the change Measurement data including the degree of vacuum (Pdc) in the drying cabinet (DC), the degree of vacuum (Pct) in the cold trap (CT), the temperature (Th) of the shelf detected by the shelf temperature detecting means, and From the relational expression, the average product temperature and average dehumidification rate of the material to be dried in the secondary drying period are calculated, and the calculated average product temperature and average dehumidification rate of the material to be dried are recorded in the recording means (e). To do The features.

  Further, in the dry state monitoring method having the above-described configuration, the opening degree adjuster (C) is provided in the main pipe (a) as the vacuum degree adjusting means, and the relational expression is provided in the control means (PLC). The relationship between the dehumidification rate (Qm) due to water load in the state where the main valve (MV) is fully opened, the opening angle (θ) of the opening controller (C), and the main pipe resistance R (θ) is as follows: The material to be dried stored in the drying cabinet (DC) enters the secondary drying period, and the opening degree adjuster (C) starts to rotate in the fully open direction. The PLC) includes an opening angle (θ) of the opening controller (C), a degree of vacuum (Pdc) in the drying cabinet (DC), and a vacuum in the cold trap (CT) at predetermined time intervals. Material to be dried in the secondary drying period from the measurement data of the degree (Pct) and the temperature (Th) of the shelf board And calculates an average product temperature and average dehumidification rate.

  In the dry state monitoring method having the above-described configuration, the vacuum control circuit (f) with a leak control valve (LV) is used as the vacuum degree adjusting means, the drying chamber (DC), the cold trap (CT), and Provided in any of the vacuum systems including the main pipe (a), and the control means (PLC) has a dehumidification rate (Qm) due to water load in the state where the main valve (MV) is fully opened as the relational expression. And the steam flow resistance coefficient (Cr) of the main pipe (a) are stored, and after the material to be dried placed in the drying chamber (DC) enters the secondary drying period, the control means (PLC) drives the leak control valve (LV) to control the degree of vacuum (Pdc) in the drying cabinet (DC) to a set value, or closes the leak control valve (LV), and then At a predetermined time interval, the drying cabinet (D ), The degree of vacuum (Pct) in the cold trap (CT), and the measured data of the shelf temperature (Th), the average product temperature and average of the material to be dried in the secondary drying period The dehumidifying rate is calculated.

  On the other hand, with respect to the dry state monitoring device, a drying chamber (DC) in which the material to be dried is charged, and a cold trap that condenses and collects water vapor generated from the material to be dried charged in the drying chamber (DC) ( CT), a main pipe (a) communicating with the drying cabinet (DC) and the cold trap (CT), a main valve (MV) for opening and closing the main pipe (a), and the inside of the drying cabinet (DC) The vacuum degree adjusting means for adjusting the degree of vacuum, the vacuum detecting means for detecting the absolute pressure in the drying chamber (DC) and the absolute pressure in the cold trap (CT), and the drying chamber (DC). A shelf temperature detecting means for detecting the temperature (Th) of the shelf board, and a control means (PLC) for automatically controlling the operation of the drying chamber (DC), the cold trap (CT) and the vacuum degree adjusting means. Comprising the control means (PLC) It stores a control program for the drying cabinet (DC), the cold trap (CT) and the vacuum degree adjusting means, a required calculation program, and a required relational expression, and the material to be dried enters the secondary drying period. The degree of vacuum (Pdc) in the drying chamber (DC) is changed according to circumstances, the degree of vacuum (Pdc) in the drying chamber (DC) before and after the change, and in the cold trap (CT) From the measurement data including the degree of vacuum (Pct), the shelf temperature detected by the shelf temperature detecting means (Th), and the relational expression, the average product temperature and the average desorption of the material to be dried in the secondary drying period are obtained. The humidity rate is calculated, and the calculated average product temperature and average dehumidification rate of the material to be dried are recorded in the recording means (e).

  In the dry condition monitoring apparatus having the above-described configuration, the opening degree adjuster (C) is provided in the main pipe (a) as the vacuum degree adjusting means, and the control means (PLC) includes the relational expression. The relationship between the dehumidification rate (Qm) due to water load in the state where the main valve (MV) is fully opened, the opening angle (θ) of the opening controller (C), and the main pipe resistance R (θ) is as follows: The material to be dried stored in the drying cabinet (DC) enters the secondary drying period, and the opening degree adjuster (C) starts to rotate in the fully open direction. The PLC) includes an opening angle (θ) of the opening controller (C), a degree of vacuum (Pdc) in the drying cabinet (DC), and a vacuum in the cold trap (CT) at predetermined time intervals. Material to be dried in the secondary drying period from the measurement data of the degree (Pct) and the temperature (Th) of the shelf board And calculates an average product temperature and average dehumidification rate.

  Further, in the dry state monitoring apparatus having the above-described configuration, the vacuum control circuit (f) with a leak control valve (LV) is used as the vacuum degree adjusting unit, the drying cabinet (DC), the cold trap (CT), and Provided in any of the vacuum systems including the main pipe (a), and the control means (PLC) has a dehumidification rate (Qm) due to water load in the state where the main valve (MV) is fully opened as the relational expression. And the steam flow resistance coefficient (Cr) of the main pipe (a) are stored, and after the material to be dried placed in the drying chamber (DC) enters the secondary drying period, the leak control is performed. The valve (LV) is closed, and then at a predetermined time interval, the degree of vacuum (Pdc) in the drying chamber (DC), the degree of vacuum (Pct) in the cold trap (CT), and the shelf temperature ( From the measured data of Th), secondary drying And calculates an average product temperature and average dehumidification rate of the dried material in.

  According to the present invention, since the average product temperature Tm and the average dehumidification rate Qm in the secondary drying period for all the materials to be dried charged in the drying cabinet can be obtained by calculation, the average product in the primary drying period By combining with the calculation of the temperature Tm and the average sublimation rate Qm, the freeze-dried state of the material to be dried from the start to the end of the freeze-drying process can be consistently monitored. Therefore, the collapse of the product to be dried can be avoided, and the productivity of the freeze-dried product can be increased.

It is a lineblock diagram of a freeze-dryer of a channel opening vacuum control system to which a monitoring device and a monitoring method concerning a 1st embodiment are applied. It is a flowchart of channel opening degree vacuum control. It is a block diagram of the freeze-dryer of the leak type vacuum control system to which the monitoring apparatus and monitoring method which concern on 2nd Embodiment are applied. It is a flowchart of leak type vacuum control. It is a graph of the average product temperature of the to-be-dried material in the secondary drying period computed by a flow-path opening degree vacuum control system. It is a graph of the average product temperature of the material to be dried in the secondary drying period calculated by the leak type vacuum control method.

  Hereinafter, a dry state monitoring apparatus and a dry state monitoring method according to the present invention will be described for each embodiment with reference to the drawings.

[First Embodiment]
The dry state monitoring apparatus and the dry state monitoring method according to the first embodiment are for adjusting the degree of vacuum in the drying chamber in the main pipe connecting the drying chamber and the cold trap, as shown in FIGS. 1 and 2. The present invention is applied to a freeze-dryer of a flow path opening vacuum control system provided with an opening controller (damper).

<Configuration of freeze dryer>
That is, as shown in FIG. 1, the freeze dryer W1 according to the first embodiment generates a drying chamber DC in which a material to be dried is charged and water vapor generated from the material to be dried charged in the drying chamber DC. Cold trap CT that condenses and collects in the trap coil ct, main pipe a that communicates the drying chamber DC with the cold trap CT, a main valve MV that opens and closes the main pipe a, and a damper-type opening provided in the main pipe a The regulator C, the inlet valve V attached to the cold trap CT, the vacuum pump P connected to the inlet valve V, and the vacuum for detecting the absolute pressure in the drying chamber DC and the absolute pressure in the cold trap CT A meter (vacuum detection means) b, a temperature sensor (shelf temperature detection means) S for detecting the temperature (shelf temperature) of the shelf board B for placing the material to be dried installed in the drying cabinet (DC), and the above-mentioned A control panel CR that automatically controls the operation of each unit It is configured in La main. In this example, a sequencer PLC and a recorder (recording means) e are incorporated in the control panel CR, and the sequencer PLC has a dehumidifying speed Qm and an opening degree controller due to water load when the main valve MV is fully opened. A relational expression between the opening angle θ of C and the main pipe resistance R (θ) and a required calculation program are stored in advance. Instead of the configuration using the control panel CR, a personal computer in which the above relational expressions and calculation programs are recorded can be used. Further, instead of the configuration in which the vacuum gauge b for detecting the absolute pressure is provided in each of the drying cabinet DC and the cold trap CT, a differential pressure for detecting the differential pressure between the absolute pressure in the drying cabinet DC and the absolute pressure in the cold trap CT. A vacuum gauge can also be provided. The opening angle θ refers to the rotation angle of the opening adjuster C from the fully open state (0 °).

  When the drying state of the material to be dried enters the secondary drying period, the sequencer PLC changes the degree of vacuum Pdc in the drying chamber DC according to the actual condition, and the degree of vacuum Pdc in the drying chamber DC before and after the change, From the measurement data including the degree of vacuum Pct in the cold trap CT, the shelf temperature Th detected by the temperature sensor S, and the relational expression, the average product temperature and average dehumidification rate of the material to be dried in the secondary drying period are calculated. Then, the calculated average product temperature and average dehumidification rate of the material to be dried are recorded on the recorder e. The operator can monitor the freeze-dried state of the material to be dried by checking the average product temperature and the average dehumidification rate of the material to be dried recorded in the recorder e. Hereinafter, a method for calculating the average product temperature Tm and the dehumidification rate Qm in the flow path opening vacuum control method will be described.

<Calculation method of average product temperature Tm and dehumidification rate Qm by channel opening vacuum control method>
The dehumidification rate Qm is calculated from the degree of vacuum Pdc in the drying chamber DC and the degree of vacuum Pct in the cold trap CT measured by the vacuum gauges b attached to the drying chamber DC and the cold trap CT of the freeze dryer W1, respectively. According to this method, since it is not necessary to provide an expensive measuring instrument other than the vacuum gauge e, the dehumidification rate Qm can be calculated easily and at low cost.

  The water vapor dehumidified from the material to be dried flows from the drying chamber DC through the main pipe a into the cold trap CT and is condensed and collected by the trap coil Ct. In the case of the channel opening degree vacuum control method, the opening degree adjuster C rotates in the fully open direction when the secondary drying process is started. Even if the opening controller C rotates in the fully open direction, the flow of water vapor in the main pipe a is in a jet state during the period of Pct / Pdc <0.53, so the dehumidification rate Qm from the material to be dried is When the main pipe resistance is R, it can be calculated by the following equation.

Qm = 3.6 × Pdc / R
When the opening degree adjuster C further rotates in the fully open direction and Pct / Pdc> 0.53, the flow of water vapor in the main pipe a becomes a viscous flow state. In this case, the dehumidifying rate Qm from the material to be dried can be calculated by the following equation, where R is the main pipe resistance.

Qm = 3.6 × (Pdc−Pct) / R
The main pipe resistance R is obtained by measuring or calculating the amount of sublimation from the material to be dried when a water load is applied. If the main pipe resistance R is obtained, the dehumidifying rate Qm can be obtained from the measurement data of the degree of vacuum Pdc in the drying cabinet DC and the degree of vacuum Pct in the cold trap CT as described above.

  Specifically, with the material to be dried placed in the drying cabinet DC, the freeze dryer W1 shown in FIG. 2 is operated, the shelf temperature is set to Th, and the degree of vacuum Pdc in the drying cabinet DC is set. Freeze drying of the material to be dried is started by setting the control value with the opening controller C. After the start of freeze-drying, first, a primary drying process is entered, and moisture contained in the ice-like material to be dried is removed until the liquid material to be dried becomes a dry solid. After the completion of the primary drying process, a small amount of antifreeze water contained in the material to be dried that has entered the secondary drying process and became a dry solid through the primary drying process is removed, and the material to be dried has a predetermined moisture content. Dried until.

  When entering the secondary drying step, almost no water vapor is dehumidified from the material to be dried, so that the opening degree adjuster C suddenly rotates in the fully open direction. At this time, the sequencer PLC performs the opening angle θ of the opening controller C, the degree of vacuum Pdc in the drying chamber DC, the degree of vacuum Pct in the cold trap CT at a constant time interval (for example, every 1 to 5 minutes). The shelf temperature Th is taken in and recorded on the recorder e. The sequencer PLC calculates the average product temperature Tm and the average dehumidification rate Qm of the entire material to be dried in the secondary drying according to the following procedure in accordance with the calculation program stored in the sequencer PLC.

(1) The main pipe resistance R is calculated from the relational expression between the main pipe resistance R (θ) measured by the water load and the opening angle θ of the opening adjuster C.

(2) In the state of Pct / Pdc <0.53 in which the water vapor flow in the main pipe a becomes a jet state,
The average dehumidification rate is calculated using the formula Qm = 3.6 × Pdc / R.

  In the state of Pct / Pdc> 0.53 in which the water vapor flow in the main pipe a is in a viscous flow state, the average dehumidification rate is calculated by the calculation formula of Qm = 3.6 × (Pdc−Pct) / R.

(3) The bottom part temperature Tm is calculated from the relational expression between the main pipe resistance R (θ) measured by the water load and the opening angle θ of the opening controller C.

  In the freeze-dryer W1 of the flow path opening vacuum control system, the main pipe resistance R (θ) of water vapor flowing through the main pipe a and the opening degree controller C communicating with the drying chamber DC and the cold trap CT is R (θ) = It is expressed by (Pdc−Pct) / Qm, and when Pct / Pdc <0.53, the flow of water vapor becomes a jet. Therefore, the main pipe resistance R (θ) of water vapor can be calculated by R (θ) = Pdc / Qm. The calculation method is shown below.

(1) the inlet of the main pipe a, the resistance of the main valve MV and main a R1 (theta) from the viscous flow equations Pdc-P1 = Cr × ρ × u 2/2 of the pressure drop, Pdc-P1 = R1 ( θ) × Qm, R1 (θ) = Cr × R × T / (2 × Pdc × M × A0 ² ) × Qm.

(2) The resistance R2 (θ) of the opening controller C becomes a jet when the pressure ratio Pct / Pl before and after the opening controller C becomes 0.53 or less, and the calculation formula of the jet is
Qm = ρ × A ′ × u ′.

However, u ′ is the local sound velocity, and u ′ = (K × R × T / M) ^1/2 .

  A ′ is a contraction area, and A ′ = 0.6 to 0.7 × A.

Therefore, when the calculation formula of the jet is set as R2 (θ) = (R × T / (K × M)) ^1/2 / A ′,
Qm = P1 × A ′ × [K × M / (R × T)] ^1/2 = P1 / R2 (θ)
It can be rewritten as

(3) On the other hand, the main pipe resistance R (θ) is
R (θ) = R1 (θ) + R2 (θ)
= [[C0 + (R2 (θ) / 2) ² ] ^1/2 + R2 (θ) / 2
It is represented by

However, C0 = Cr × R × T / (2 × Pdc × M × A0 2) = 3408.65,
R2 (θ) = 2223.7 / A,
The sectional area A (cm ² ) of the opening controller C is as follows: D is the inner diameter of the main pipe a, d1 is the diameter of the opening controller C, and t is the thickness of the opening controller C.
^{A = 0.01 × (π × D} 2/4-d1 × t × cosθ-π × d1 2/4 × sinθ)
Calculated by

An example of the calculation result is shown in Table 1 below.

<Derivation of relational expression between opening angle θ of opening controller C and main pipe resistance R (θ)>
In calculating the average product temperature Tm and the average dehumidification rate Qm of the material to be dried in the secondary drying, the dry load Qm (Kg / hr), the degree of vacuum Pdc in the drying cabinet DC, and the cold trap CT are calculated beforehand with water The degree of vacuum Pct is measured, and a relational expression between the opening angle θ of the opening controller C and the main pipe resistance R (θ) is obtained. In that method, a product temperature sensor is attached to the bottom of the tray, water is added to the tray, frozen to −40 ° C., shelf temperature is set during primary drying, and the degree of vacuum in the drying chamber is changed from 26.7 Pa to 6.7 Pa. Until the shelf temperature Th and the bottom part temperature Tb are measured, and the internal pressure Pdc and the CT pressure Pct are measured by the absolute pressure vacuum gauge b. The opening angle θ of the opening controller C at each vacuum control value is also measured.

  There are two methods for determining the drying load Qm (Kg / hr): a method of obtaining a drying amount from a difference in weight of materials to be dried before and after drying, and a method of analyzing from a heat input calculation. In the case of analysis from the heat input calculation, the heat transfer coefficient α from the shelf to the bottom of the tray is calculated at the degree of vacuum Pdc in the drying cabinet DC, and then Q = A1 × α × (Th−Tb) The heat flow to the bottom of the tray is calculated by the equation, and the drying load Qm is obtained from the ice sublimation latent heat of 2850 KJ / Kg by the calculation equation Qm = Q / 2850. Thereby, the relational expression between the opening angle θ of the opening controller C and the main pipe resistance R (θ) is obtained.

  Next, when freeze-drying the material to be dried according to the freeze-drying program, the opening angle θ of the opening controller C, the degree of vacuum Pdc in the drying cabinet DC, the degree of vacuum Pct in the cold trap CT, and the shelf temperature Th Is measured and recorded, the product temperature of the individual container is measured from the relational expression between the opening angle θ of the opening controller C and the water vapor resistance R (θ) obtained by the water load measurement described above. In addition, the overall average product temperature Tm and average dehumidification rate Qm in the secondary drying period can be monitored.

  Hereinafter, a specific embodiment for deriving a relational expression between the opening angle θ of the opening controller C and the main pipe resistance R (θ) will be described.

  First, in the water load test, a relational expression between the opening angle θ of the opening controller C and the main pipe resistance R (θ) is obtained. The water load test is performed by inserting a tray filled with water into the drying chamber DC and controlling the freeze dryer W1 in the same procedure as that for lyophilization of a normal material to be dried. As an example, the water in the tray is frozen to −45 ° C., the shelf temperature Th is set to −20 ° C. during primary drying, and the degree of vacuum Pdc in the drying cabinet DC is 4 Pa, 6.7 Pa, 10 Pa, 13.3 Pa, Control was performed at 20 Pa, 30 Pa, 40 Pa, and 60 Pa, and each was held for 3 hours, and a total of 8 water load tests were performed. At that time, the opening angle θ of the opening controller C, the shelf temperature Th, the ice temperature Tb at the bottom of the tray, the degree of vacuum Pdc in the drying cabinet DC, and the degree of vacuum Pct in the cold trap CT are measured respectively. recorded in e.

The ice drying load Qm (Kg / h) was determined by measuring the amount of drying and calculating the amount of heat input, and the relational expression between the opening angle θ of the opening controller C and the main pipe resistance R (θ) was obtained. Table 2 shows the relationship between the opening angle θ of the opening controller C and the main pipe resistance R (θ) obtained by calculation, and the main pipe resistance obtained by the opening angle θ of the opening controller C and measurement. The relationship with R (θ) is shown.

Next, from the data in Table 2, a calculation formula for the main pipe resistance R (θ) and a calculation formula for the cross-sectional area A (cm ² ) of the opening controller C were obtained as follows.

R (θ) = [3408.65+ (2223.7 / A) ² ] ^1/2 + 2223.7 / A,
^{A = 0.01 × (π × D} 2/4-d1 × t × cosθ-π × d1 2/4 × sinθ)
Where D is the inner diameter of the main pipe a, d1 is the diameter of the opening controller C, and t is the thickness of the opening controller C.

  With the above procedure, a relational expression among the opening angle θ of the opening controller C, the main pipe resistance R (θ), and the drying load Qm is obtained in the water load test.

[Second Embodiment]
As shown in FIGS. 3 and 4, the dry state monitoring device and the dry state monitoring method according to the second embodiment include a leak type vacuum control in which the dry chamber has a leak valve for adjusting the degree of vacuum in the dry chamber. This is applied to the freeze dryer of the type.

<Configuration of freeze dryer>
As shown in FIG. 3, the freeze dryer W2 according to the second embodiment traps the steam generated from the drying chamber DC charged with the material to be dried and the material to be dried loaded into the drying chamber DC. A cold trap CT that condenses and collects at ct, a main pipe a that communicates the dryer DC with the cold trap CT, a main valve MV that opens and closes the main pipe a, and a vacuum with a leak control valve LV connected to the dryer DC The control circuit f, the inlet valve V attached to the cold trap CT, the vacuum pump P connected to the inlet valve V, and the vacuum for detecting the absolute pressure in the dryer DC and the absolute pressure in the cold trap CT A meter (vacuum detection means) b, a temperature sensor (shelf temperature detection means) S for detecting the temperature (shelf temperature) of the shelf board B for placing the material to be dried installed in the drying cabinet (DC), and the above-mentioned That automatically controls the operation of each part of the machine It is mainly composed of a CR. In this example, a sequencer PLC and a recorder (recording means) e are incorporated in the control panel CR, and the sequencer PLC has a dehumidification rate Qm and a main pipe due to a water load obtained when the main valve MV is fully opened. A relational expression with the steam flow resistance coefficient Cr in a and a required calculation program are stored in advance. Since others are the same as those of the freeze dryer W1 according to the first embodiment, the corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The sequencer PLC opens or closes the leak control valve LV to control the degree of vacuum Pdc in the drying cabinet DC to a control value or closes the leak control valve LV when the drying state of the material to be dried enters the secondary drying period. Then, the degree of vacuum Pdc in the drying cabinet DC is changed depending on the course. Then, from the measurement data including the degree of vacuum Pdc in the drying cabinet DC before and after the change, the degree of vacuum Pct in the cold trap CT, the shelf temperature Th detected by the temperature sensor S, and the relational expression, the secondary drying period The average product temperature and the average dehumidification rate of the material to be dried are calculated, and the calculated average product temperature and the average dehumidification rate of the material to be dried are recorded on the recorder e. The operator can monitor the freeze-dried state of the material to be dried by checking the average product temperature and the average dehumidification rate of the material to be dried recorded in the recorder e. Hereinafter, a method for calculating the average product temperature Tm and the dehumidification rate Qm in the leak vacuum control method will be described.

<Calculation method of average product temperature Tm and average dehumidification rate Qm by leak vacuum control method>
As described above, the water vapor dehumidified from the material to be dried in the secondary drying period flows from the drying chamber DC into the cold trap CT through the main pipe a, and is condensed and collected by the trap coil Ct. In the case of the leak vacuum control method, the flow of water vapor in the main pipe a is a viscous flow, and therefore the dehumidification rate Qm from the material to be dried can be calculated by the following equation.

Qm = 3.6 × (Pdc−Pct) /R=3.6×ΔP/R
In the above equation, Pdc is the degree of vacuum in the drying cabinet DC (drying chamber vacuum level)
Pct is the degree of vacuum in the cold trap CT (cold trap vacuum degree)
ΔP is the pressure difference between the drying chamber vacuum Pdc and the cold trap vacuum Pct R is the main pipe resistance.

  The differential pressure ΔP is expressed as follows from the calculation formula of the pipe pressure drop of the viscous flow.

ΔP = Cr / 2 × ρ × u ² = Cr / 2 × ρ × [Qm / (3600 × A × ρ)] ²
However, Cr is the water vapor flow resistance coefficient of the main pipe flow path ρ is a value represented by the equation of state of ideal gas ρ = P × M / (R × T) (P is the pressure of the gas, M is the molecular weight of the gas, and R is Gas constant, T is gas temperature)
A is the flow passage area of the main pipe a.

Substituting the ideal gas equation of state ρ = P × M / (R × T), molecular weight M = 18, gas constant R = 8314, gas temperature T = 288, ΔP = Pdc−Pct into the above ΔP equation, and dehumidifying When converted to the equation of speed Qm,
Qm = A × [(Pdc ² −Pct ² ) / (8314 × 288 / (18 × 36002) × Cr)] ^1/2 .

  After entering the secondary drying process, the leak control valve LV is opened and closed to control the degree of vacuum Pdc in the drying cabinet DC to a control value, or the leak control valve LV is closed to set the degree of vacuum Pdc in the drying cabinet DC. Change it depending on the outcome. When the measured value of the degree of vacuum Pdc in the drying chamber DC before and after this change is Pdc1, and the measured value of the degree of vacuum Pct in the cold trap CT is Pct1, the dehumidification rate Qm of the material to be dried can be expressed by the following equation. .

Qm = A × [(Pdc1 ² −Pct1 ² ) / (0.0103 × Cr)] ^1/2
<Derivation of Relation between Dehumidification Rate Qm and Steam Flow Resistance Coefficient Cr of Main Pipe Channel>
The steam flow resistance coefficient Cr of the main pipe flow path can be obtained by two methods, that is, a method of measuring an actual dry amount with a water load and a method of calculation.

In the case of obtaining by calculation, since the flow path area A of the main pipe a is known, the above-mentioned Qm = A × [(Pdc ² −Pct ² ) / (8314 × 288 / (18 × 36002) × Cr)] ^{1 / 2}
If the water vapor flow resistance coefficient Cr of the main pipe flow path is obtained from the above equation, the dehumidification rate Qm can be calculated by measuring the degree of vacuum Pdc in the drying chamber DC and the degree of vacuum Pct in the cold trap CT. Note that a high-precision vacuum gauge b is required to measure the degree of vacuum Pdc in the drying cabinet DC and the degree of vacuum Pct in the cold trap CT.

  Specifically, the material to be dried is charged into the drying cabinet DC, the shelf temperature is set to Th, and the freeze dryer W2 shown in FIG. 4 is operated, and the drying state of the material to be dried is in the secondary drying period. When entering, the degree of vacuum Pdc in the drying cabinet DC is set to a control value by opening and closing the leak control valve LV, or the leakage control valve LV is closed and the degree of vacuum Pdc in the drying cabinet DC is changed. . In this state, the degree of vacuum Pdc in the drying cabinet DC, the degree of vacuum Pct in the cold trap CT, and the shelf temperature Th are recorded by the recorder e at regular time intervals (for example, at intervals of 1 to 5 minutes). Then, the measurement data is taken into the sequencer PLC, and the overall average product temperature Tm and dehumidification rate Qm of the material to be dried in the secondary drying are calculated according to the following procedure according to the calculation program stored in the sequencer PLC.

(1) From the relational expression between the steam flow resistance coefficient Cr of the main pipe a measured at the water load and the dehumidification rate Qm, the water vapor flow resistance coefficient Cr value at the time of measurement and the cross-sectional area A of the main pipe flow path are converted into a sequencer (PLC). take in.

(2) Formula for calculating pipe pressure drop of viscous flow ΔP = Cr / 2 × ρ × u ² = Cr / 2 × ρ × [Qm / (3600 × A × ρ)] ²
From this, the dehumidification rate Qm at the time of secondary drying is calculated by the following equation.

Qm = A × [(Pdc1 ² −Pct1 ² ) / (0.0103 × Cr)] ^1/2
(3) The average product temperature Tm is calculated.

  Next, a flow resistance coefficient Cr of water vapor flowing through the main pipe a communicating with the drying cabinet DC and the cold trap CT is obtained. The steam flow resistance coefficient Cr is the sum of the steam flow resistance coefficients of the respective sections from the inlet to the outlet of the main pipe a. In this test example, the main pipe a is defined as the main pipe inlet, the main pipe outlet, the elbow portion, and the main valve MV. Is divided into five sections where the flow is sufficiently developed, excluding the inlet section of the main pipe a and the inlet section of the main pipe a (the run-up section of the steam flow), the flow resistance coefficient Cr1 = 0.5 at the main pipe inlet, and the flow resistance at the main pipe outlet The coefficient Cr2 = 0.5, the flow resistance coefficient Cr3 = 1.2 at the elbow location, and the flow resistance coefficient Cr4 = 1.7 at the location where the main valve MV is installed.

  It should be noted that the flow resistance coefficient Cr3 at the elbow location is determined by 1.13 × n (90 ° × n location). In this test example, the opening degree controller C is provided in the main pipe a connecting the drying chamber DC and the cold trap CT (see FIG. 1), and the drying chamber DC is used for adjusting the degree of vacuum in the drying chamber DC. Since a freeze dryer equipped with a leak valve LV (see FIG. 3) was used, Cr3 = 1.2 as a flow resistance corresponding to an elbow.

  The flow resistance coefficient Cr5 of the section where the flow is sufficiently developed excluding the inlet section of the main pipe a (water vapor flow running section) is Cr5 = λ × L / D + ξ (where ξ = 2.7, L is the length of the main pipe) , D is the main pipe inner diameter, λ is the friction coefficient), the friction coefficient λ is obtained by λ = 64 / Re (where Re is the Reynolds number), and the Reynolds number Re is Re = u × D / ν≈ 40 × Qm / D (where Qm is the sublimation speed and D is the inner diameter of the main pipe a).

  In the testing machine of this example, when L = 0.7 m and Qm = 0.05 Kg / hr, Cr = 6.6 + 1.6 × 0.7 / 0.05 = 29.

  On the other hand, when the relational expression of the steam flow resistance coefficient Cr and the dehumidification rate Qm of the main pipe flow path is obtained by measurement, a product temperature sensor is attached to the bottom of the tray, water is put into the tray, frozen to −40 ° C., and the primary The shelf temperature is set during the drying period, the degree of vacuum in the drying cabinet is sequentially controlled from 26.7 Pa to 6.7 Pa, the shelf temperature Th and the bottom component temperature Tb are measured, and the degree of vacuum Pdc in the drying cabinet DC And the degree of vacuum Pct in the cold trap CT is recorded with an absolute pressure gauge.

  The dehumidification rate Qm (Kg / hr) can be determined by two methods: a method for obtaining a dry amount from a weight difference between materials to be dried before and after drying, and a method for analyzing from a heat input calculation. In the case of analysis, the heat transfer coefficient α from the shelf to the bottom of the tray is calculated at the degree of vacuum Pdc in the drying cabinet DC, and then to the bottom of the tray by the calculation formula of Q = A1 × α × (Th−Tb). The dehumidification rate Qm is obtained from the ice sublimation latent heat 2850 KJ / Kg by the calculation formula Qm = Q / 2850. As a result, a relational expression between the steam flow resistance coefficient Cr of the main channel and the dehumidification rate Qm is obtained.

  In the leak type vacuum control system, when actually setting a freeze-drying program and freeze-drying the material to be dried, if the vacuum degree Pdc in the drying chamber and the vacuum degree Pct in the CT are measured and recorded, Using the relational expression between the water vapor resistance coefficient Cr of the main pipe channel obtained by the load measurement and the dehumidification rate Qm, the water vapor flow rate dehumidified during the secondary drying is obtained, and the dehumidification rate can also be calculated.

  Hereinafter, more specific examples of the calculation method and the calculation apparatus of the average product temperature Tm and the average dehumidification rate Qm of the material to be dried in the secondary drying period applied to the freeze-type dryer W2 of the leak type vacuum control system will be described. Show.

<Derivation of relational expression between steam flow resistance coefficient Cr and dehumidification rate Qm>
First, in a water load test, a relational expression between the steam flow resistance coefficient Cr of the main pipe channel and the dehumidification rate Qm is obtained. The water load test is performed by controlling the operation of the freeze dryer W2 by the control panel CR and executing a predetermined drying process in a state where a tray filled with water is loaded in the drying cabinet DC. In this example, at the time of primary drying after freezing the water in the tray to −45 ° C., the shelf temperature Th is set to −20 ° C. and the degree of vacuum Pdc in the drying cabinet DC is set to 6.7 Pa. Held for hours. Further, the shelf temperature Th was set to −10 ° C., and the degree of vacuum Pdc in the drying cabinet DC was controlled to 6.7 Pa, 13.3 Pa, and 20 Pa, and held for 3 hours, respectively. Further, the shelf temperature Th was set to 5 ° C., and the degree of vacuum Pdc in the drying cabinet DC was controlled to 6.7 Pa and 13.3 Pa, and held for 3 hours. Further, the shelf temperature Th was set to 20 ° C., and the degree of vacuum Pdc in the drying cabinet DC was controlled to 6.7 Pa and 13.3 Pa, and held for 3 hours, respectively. While carrying out the water load test of the above nine conditions, the shelf temperature Th, the tray bottom component temperature Tb, the degree of vacuum Pdc in the drying cabinet DC, and the degree of vacuum Pct in the cold trap CT were measured and recorded. Furthermore, from these measurement results, the dehumidification rate Qm (Kg / h) and the steam flow resistance coefficient Cr of the main pipe channel were obtained. Table 3 shows the shelf temperature Th obtained in the water load test, the degree of vacuum Pdc in the drying cabinet DC, the degree of vacuum Pct in the cold trap CT, the dehumidification rate Qm, and the steam flow resistance coefficient Cr of the main pipe channel. .

The graph showing the relationship between the steam flow resistance coefficient Cr of the main pipe flow path created based on the data of Table 3, and the dehumidification rate Qm is shown. From this graph,
Cr = 5.4 + 0.85 / Qm ^1.25
The following relational expression was obtained.

In this embodiment, since the length of the main pipe a is relatively short, the entire main pipe a is an entrance section (running section), and the calculation formula Cr = 6.6 + 1 in a section where the flow of water vapor is sufficiently developed. Compared to .6 × L / Qm, the steam flow resistance coefficient Cr is inversely proportional to the drying speed Qm ^1.25 .

<Calculation method of average product temperature Tm>
The average product temperature Tm of the entire material to be dried in the secondary drying period can be calculated from the following equation.

  First, the heat transfer equation of the dried product is expressed by the following equation.

C × dTm / dt = Qh + Qr−Qm × ΔHs
However, in this formula, C is the heat capacity of the material to be dried, Tm is the average product temperature, Qh is the amount of heat input from the shelf through the gas conduction to the bottom of the container, Qr is the amount of heat input from the drying chamber wall to the entire container, Qm is the dehumidification rate and ΔHs is the latent heat of evaporation.

  First, the amount of heat input Qh from the shelf due to gas conduction to the bottom of the container is calculated by the following equation.

Qh = Ae × K × (Th−Tm)
However, Ae is an effective heat transfer area (m ² ), K is a heat transfer coefficient from the shelf stage to the container bottom by gas conduction, Th is the shelf temperature (° C.), and Tb is the bottom part temperature (° C.).

The effective heat transfer area Ae can be calculated by Ae = 2 / (1 / Av + 1 / At),
The heat transfer coefficient K (W / m ² ° C) from the shelf to the bottom of the container by gas conduction is
K = 16.86 / (δ + 2.12 × 29 × 0.133 / Pdc).

In the calculation formula of the effective heat transfer area Ae, Av is the container bottom area (m ² ), and At is the tray frame area (m ² ).

The container bottom area Av can be calculated by Av = π / 4 × n1 × d ² (where n1 is the number of vials and d is the vial diameter), and the tray frame area At is At = n2 × W × L (where n2 Is the number of frames; W is the width of the frame, and L is the length of the frame).

  Moreover, in the calculation formula of the heat transfer coefficient K from the shelf to the container bottom by gas conduction, δ is the gap at the container bottom and the unit is mm.

  On the other hand, the width incident heat quantity Qr from the drying cabinet wall to all containers is obtained from the following equation.

Qr = 5.67 × ε × Ae × [(Tw / 100) ⁴ − (Tm / 100) ⁴ ]
However, in the equation, ε is a radiation coefficient, Tw is a drying cabinet wall temperature, and Tm is an average product temperature.

  Further, the width incident heat quantity Qr from the drying chamber wall to all containers can be approximately calculated by the following equation.

Qr = Ae × Kr × (Tw−Tm)
However, Kr are equivalent heat transfer coefficient due to radiation heat input, Kr = 0.7W / ^{m 2} ℃ in tester can be approximated as Kr = 0.2W / ^{m 2} ℃ production machine.

  When the formula for calculating the heat input is included in the heat transfer equation, the following formula is established.

C x dTm / dt
= Ae * K * (Th-Tm) + Ae * Kr * (Tw-Tm) -Qm * [Delta] Hs
However, ΔHs is latent heat of vaporization, and ΔHs = 2850 KJ / Kg.

  The average product temperature of the material to be dried during the secondary drying period can be calculated by the following formula.

C × (Tm−Tm0) / Δt
= Ae * K * (Th-Tm) + Ae * Kr * (Tw-Tm) -Qm * [Delta] Hs
Tm = (Tm0 + a1 × Th + a2 × Tw−a3) / (1 + a1 + a2)
a1 = K × Ae × Δt / C,
a2 = Kr × Ar × Δt / C,
a3 = Qm × ΔHs × Δt / C
Where C is the heat capacity of the material to be dried.

  Therefore, if the dehumidification rate Qm is measured in the secondary drying period, the average product temperature Tm of the entire material to be dried can be calculated from the above formula.

<Calculation method of heat capacity C of material to be dried>
When entering the secondary drying step, the shelf temperature is raised to the set temperature for secondary drying. Thereby, the antifreeze water in the material to be dried is dehumidified, and the product temperature is also increased. The heat capacity C of the material to be dried includes the heat capacity Ct of the tray, the heat capacity Cv of the vial and the rubber stopper, the heat capacity Cs of the medicine, and the heat capacity Cw of the antifreeze water.

(1) The heat capacity Ct of the tray is calculated by Ct = csus × Wt. csus is the specific heat of stainless steel. Wt is the tray weight, and is the total value of the extraction tray and the bottomed tray.

(2) The heat capacity Cv of the vial and the rubber stopper is calculated by Cv = cv × Wv + cc × Wc. cv is the specific heat of the vial, Wv is the weight of the vial, cc is the specific heat of the rubber stopper, and Wv is the weight of the rubber stopper.

(3) The heat capacity Cs of the medicinal component is calculated by Cs = cs × Ws. cs is the specific heat of the chemical, and Ws is the chemical weight.

(4) The heat capacity Cw of the antifreeze water is calculated by Cw = cw × Ww. cw is the specific heat of the antifreeze water, and Ww is the weight of the antifreeze water.

(5) Therefore, the heat capacity C of the material to be dried is C = Ct + Cv + Cs + Cw.

<Calculation results of average product temperature Tm and dehumidification rate Qm>
In the following, a freeze-drying test using an actual load is performed for each of the cases where the freeze-dryer W1 of the flow path opening vacuum control system and the freeze-dryer W2 of the leak vacuum control system are used. The calculation result of the average product temperature Tm of the whole to-be-dried material in the secondary drying period calculated | required by (2), and the dehumidification rate Qm is shown.

<When using freeze-dryer W1 with flow path opening vacuum control>
The freeze dryer W1 is loaded with 660 vials in which a 10% aqueous solution of sucrose (molecular formula: C ₁₂ H ₂₂ O ₁₁ ), which is a material to be dried, is dispensed in a drying cabinet DC, and is controlled by a control panel CR. Then, a predetermined drying process is started. In order to verify the suitability of the calculation method and the calculation apparatus according to the present invention, a product temperature sensor is inserted into the three vials inserted in the center of the shelf, and the dispensed material is dispensed into the vials. The product temperature (product temperature 1, product temperature 2, product temperature 3) of the dried material sucrose was measured. The solution is frozen at −45 ° C. for 3 hours, the shelf temperature Th is set to −20 ° C. at the time of primary drying, and the degree of vacuum Pdc in the drying chamber DC is adjusted to 10 by adjusting the opening angle θ of the opening controller C. The material to be dried was lyophilized by controlling to 0.0 Pa. In secondary drying, the shelf temperature is raised from −20 ° C. to 30 ° C. in one hour, the vacuum degree adjusting means is driven to change the degree of vacuum Pdc in the drying cabinet DC, and the opening degree controller C is It was rotated in the fully open direction. During the secondary drying period, the opening angle θ of the opening controller C, the degree of vacuum Pdc in the drying cabinet DC, the degree of vacuum Pct in the cold trap CT, and the shelf temperature Th are measured and recorded, respectively. The average product temperature Tm and average dehumidification rate Qm of the material to be dried were calculated using calculation software stored in the sequencer PLC. FIG. 5 shows the calculation result.

  FIG. 5 is a graph of the average product temperature Tm and the dehumidification rate Qm of the material to be dried in the secondary drying period according to the channel opening degree vacuum control method calculated under the above conditions. As is clear from this figure, the calculated average product temperature Tm of the material to be dried is well equal to the product temperature of the material to be dried (product temperature 1, product temperature 2, product temperature 3) detected by the product temperature sensor. I'm doing it. Thereby, it was possible to verify the appropriateness of the calculation method and the calculation apparatus according to the present invention. The data shown in FIG. 5 is recorded on a recorder e provided in the control panel CR. The operator of the freeze dryer W1 can know the secondary drying state of the material to be dried by monitoring the data of the average product temperature Tm and the data of the dehumidification rate Qm recorded in the recorder e.

<When using leak vacuum control freeze dryer W2>
The freeze dryer W2 is loaded with 660 vials into which a 10% aqueous solution of mannitol (Mannitol, molecular formula: C ₆ H ₁₄ O ₆ ), which is a material to be dried, is dispensed, and is controlled by the control panel CR. Then, a predetermined drying process is started. In order to verify the suitability of the calculation method and the calculation apparatus according to the present invention, a product temperature sensor is inserted into the three vials inserted in the center of the shelf, and the dispensed material is dispensed into the vials. The product temperature (product temperature 1, product temperature 2, product temperature 3) of the dried material mannitol was measured. The solution is frozen at −45 ° C. for 3 hours, the shelf temperature Th is set to 0 ° C. during the primary drying, and external air is freeze-dried via the variable leak valve and the leak control valve LV provided in the vacuum control circuit f. By introducing into the machine W2, the degree of vacuum Pdc in the drying cabinet DC was controlled to 10 Pa, and the material to be dried was freeze-dried. In the secondary drying, the shelf temperature was raised from 0 ° C. to 20 ° C. in 1 hour, the degree of vacuum Pdc in the drying cabinet DC was controlled from 10 Pa to 1 Pa in 1 hour, and then the vacuum was achieved. During the secondary drying period, the degree of vacuum Pdc of the drying cabinet DC, the degree of vacuum Pct of the cold trap CT, and the shelf temperature Th are measured and recorded, respectively, and calculated using the calculation software stored in the sequencer PLC. The average product temperature Tm and the dehumidification rate Qm of the material were calculated. Table 4 and FIG. 6 show the calculation results.

  FIG. 6 is a graph of the average product temperature Tm and dehumidification rate Qm of the material to be dried in the secondary drying period by the leak-type vacuum control method calculated under the above conditions. As is clear from this figure, the calculated average product temperature Tm of the material to be dried is well equal to the product temperature of the material to be dried (product temperature 1, product temperature 2, product temperature 3) detected by the product temperature sensor. I'm doing it. Thereby, it was possible to verify the appropriateness of the calculation method and the calculation apparatus according to the present invention. The data shown in FIG. 6 is recorded on a recorder e provided in the control panel CR. The operator of the freeze dryer W2 can know the secondary drying state of the material to be dried by monitoring the data of the average product temperature Tm and the data of the dehumidification rate Qm recorded in the recorder e.

  The present invention can be used for a freeze dryer used for freeze drying of foods, medicines and the like.

C Opening controller CT Cold trap CR Control panel DC Dryer MV Main valve P Vacuum pump PLC Sequencer V Inlet valve W Freeze dryer a Main pipe b Vacuum gauge ct Trap coil (plate)
e Recorder f Vacuum control circuit

Claims (6)

A drying chamber (DC) for charging the material to be dried, a cold trap (CT) for condensing and collecting water vapor generated from the material to be dried charged in the drying chamber (DC), and the drying chamber (DC) ) And the cold trap (CT), a main pipe (a), a main valve (MV) for opening and closing the main pipe (a), and a vacuum degree adjusting means for adjusting the degree of vacuum in the drying chamber (DC) And a vacuum detecting means for detecting an absolute pressure in the drying cabinet (DC) and an absolute pressure in the cold trap (CT), and a temperature (Th) of a shelf board installed in the drying cabinet (DC). It is applied to a freeze dryer having a shelf temperature detecting means for detecting, and a control means (PLC) for automatically controlling the operation of the drying chamber (DC), the cold trap (CT) and the vacuum degree adjusting means. In the dry condition monitoring method,
The control means (PLC) stores a control program for the drying chamber (DC), the cold trap (CT) and the vacuum degree adjusting means, a required calculation program, and a required relational expression. When the desiccant material enters the secondary drying period, the degree of vacuum (Pdc) in the drying chamber (DC) is changed as desired, and the degree of vacuum (Pdc) in the drying chamber (DC) before and after the change. ), Measurement data including the degree of vacuum (Pct) in the cold trap (CT), the temperature (Th) of the shelf board detected by the shelf temperature detecting means, and the relational expression, The average product temperature and average dehumidification rate of the dried material are calculated, and the calculated average product temperature and average dehumidification rate of the material to be dried are recorded in the recording means (e). Dry state Method. The opening degree adjuster (C) is provided in the main pipe (a) as the vacuum degree adjusting means, and the control means (PLC) includes water in a state where the main valve (MV) is fully opened as the relational expression. Storing a relational expression between a dehumidifying speed (Qm) by a load, an opening angle (θ) of the opening controller (C), and a main pipe resistance R (θ);
After the material to be dried charged in the drying chamber (DC) enters the secondary drying period, and the opening controller (C) starts to rotate in the fully open direction, the control means (PLC) , The opening angle (θ) of the opening controller (C), the degree of vacuum (Pdc) in the drying cabinet (DC), and the degree of vacuum (Pct) in the cold trap (CT) at predetermined time intervals. ) And the measurement data of the temperature (Th) of the shelf board, the average product temperature and average dehumidification rate of the material to be dried in the secondary drying period are calculated. The dry condition monitoring method applied to. A vacuum control circuit (f) with a leak control valve (LV) is provided as any one of the vacuum systems including the drying chamber (DC), the cold trap (CT), and the main pipe (a) as the vacuum degree adjusting means. In addition, the control means (PLC) includes, as the relational expression, a dehumidification rate (Qm) due to a water load in a state where the main valve (MV) is fully opened, and a steam flow resistance coefficient (Cr) of the main pipe (a). Remember the relational expression with
After the material to be dried placed in the drying chamber (DC) enters the secondary drying period, the control means (PLC) drives the leak control valve (LV) to drive the drying chamber (DC). The degree of vacuum (Pdc) in the inside is controlled to a set value or the leak control valve (LV) is closed, and thereafter, the degree of vacuum (Pdc) in the drying chamber (DC) at predetermined time intervals, The average product temperature and average dehumidification rate of the material to be dried in the secondary drying period are calculated from the measurement data of the degree of vacuum (Pct) in the cold trap (CT) and the shelf temperature (Th). A dry state monitoring method applied to the freeze dryer according to claim 1. A drying chamber (DC) for charging the material to be dried, a cold trap (CT) for condensing and collecting water vapor generated from the material to be dried charged in the drying chamber (DC), and the drying chamber (DC) ) And the cold trap (CT), a main pipe (a), a main valve (MV) for opening and closing the main pipe (a), and a vacuum degree adjusting means for adjusting the degree of vacuum in the drying chamber (DC) And a vacuum detecting means for detecting an absolute pressure in the drying cabinet (DC) and an absolute pressure in the cold trap (CT), and a temperature (Th) of a shelf board installed in the drying cabinet (DC). A shelf temperature detecting means for detecting, and a control means (PLC) for automatically controlling the operation of the drying chamber (DC), the cold trap (CT) and the vacuum degree adjusting means,
The control means (PLC) stores a control program for the drying chamber (DC), the cold trap (CT) and the vacuum degree adjusting means, a required calculation program, and a required relational expression. When the desiccant material enters the secondary drying period, the degree of vacuum (Pdc) in the drying chamber (DC) is changed as desired, and the degree of vacuum (Pdc) in the drying chamber (DC) before and after the change. ), Measurement data including the degree of vacuum (Pct) in the cold trap (CT), the temperature (Th) of the shelf board detected by the shelf temperature detecting means, and the relational expression, The average product temperature and average dehumidification rate of the dried material are calculated, and the calculated average product temperature and average dehumidification rate of the material to be dried are recorded in the recording means (e). Dry state Apparatus. The opening degree adjuster (C) is provided in the main pipe (a) as the vacuum degree adjusting means, and the control means (PLC) includes water in a state where the main valve (MV) is fully opened as the relational expression. Storing a relational expression between a dehumidifying speed (Qm) by a load, an opening angle (θ) of the opening controller (C), and a main pipe resistance R (θ);
After the material to be dried charged in the drying chamber (DC) enters the secondary drying period, and the opening controller (C) starts to rotate in the fully open direction, the control means (PLC) , The opening angle (θ) of the opening controller (C), the degree of vacuum (Pdc) in the drying cabinet (DC), and the degree of vacuum (Pct) in the cold trap (CT) at predetermined time intervals. And an average product temperature and an average dehumidification rate of the material to be dried in the secondary drying period are calculated from the measurement data of the temperature (Th) of the shelf board. Dry condition monitoring device applied to. A vacuum control circuit (f) with a leak control valve (LV) is provided as any one of the vacuum systems including the drying chamber (DC), the cold trap (CT), and the main pipe (a) as the vacuum degree adjusting means. In addition, the control means (PLC) includes, as the relational expression, a dehumidification rate (Qm) due to a water load in a state where the main valve (MV) is fully opened, and a steam flow resistance coefficient (Cr) of the main pipe (a). Remember the relational expression with
After the material to be dried placed in the drying chamber (DC) enters the secondary drying period, the control means (PLC) drives the leak control valve (LV) to drive the drying chamber (DC). The degree of vacuum (Pdc) in the inside is controlled to a set value or the leak control valve (LV) is closed, and thereafter, the degree of vacuum (Pdc) in the drying chamber (DC) at predetermined time intervals, The average product temperature and average dehumidification rate of the material to be dried in the secondary drying period are calculated from the measurement data of the degree of vacuum (Pct) in the cold trap (CT) and the shelf temperature (Th). The dry condition monitoring apparatus applied to the freeze dryer according to claim 4.