Freeze drying process monitoring device based on TDLAS

Abstract

The utility model discloses a freeze-drying process monitoring device based on TDLAS (tunable diode laser absorption spectroscopy). The freeze-drying process monitoring device comprises a drying chamber, a condensation chamber and a detection channel connected with the drying chamber and the condensation chamber, the laser emitting device is arranged on one side of the detection channel and is used for emitting specific wavelength laser corresponding to a characteristic absorption spectrum of water molecules; the reflection light path system is used for forming an X-shaped cross light path; and the laser receiving device is arranged on the other side of the detection channel. According to the utility model, the laser emitting device and the laser receiving device are arranged in the detection channel between the drying chamber and the condensation chamber, and are matched with the X-shaped cross light path system, so that non-contact water vapor concentration monitoring is realized, interference caused by direct contact of a probe in a traditional monitoring device is avoided, and the monitoring precision is remarkably improved; meanwhile, the device compactly integrates a laser emission system, a laser reflection system and a laser receiving system, so that the system stability is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to freeze drying technical field, especially, it relates to a freeze drying process monitoring device based on TDLAS (tunable diode laser absorption spectroscopy). BACKGROUND

[0002] Freeze drying technology is widely used in pharmaceutical, food and biotechnology field, especially in the occasion that needs to keep product biological activity and structure. In freeze drying device, monitoring system is the key component of guaranteeing product quality and process efficiency.

[0003] At present, mainstream freeze drying device adopts multiple monitoring components to constitute monitoring system. Among them, temperature monitoring device is mainly composed of thermocouple and platinum resistance temperature probe, needs to insert probe into the inside of the penicillin bottle or the inside of the liquid tray, and this structural design makes the measuring point be affected by temperature gradient and position limitation. Although weighing monitoring device can measure product weight change, its structural design makes it impossible to realize continuous, stable online monitoring. Pressure monitoring device adopts the structure form that interval closes the partition valve, not only leads to discontinuous measurement, but also when measuring amorphous product, this structure can make product reabsorb moisture.

[0004] These monitoring devices have common defects in structure: first, the monitoring components need direct contact with the measured object, which affects the measurement accuracy; second, the integration degree between the components of the monitoring system is low, and it is difficult to realize stable and reliable measurement; third, in the complex freeze drying environment, the existing structural design is difficult to ensure the stable operation of the monitoring device. These structural problems seriously restrict the monitoring effect of the freeze drying device. UTILITY MODEL CONTENT

[0005] The utility model aims at overcoming the insufficient in prior art, provides a freeze drying process monitoring device based on TDLAS.

[0006] In order to realize the above-mentioned purpose, the utility model provides a freeze drying process monitoring device based on TDLAS, comprising:

[0007] Drying chamber, condensing chamber and detection channel connecting drying chamber and condensing chamber;

[0008] Laser emitting device is arranged at one side of detection channel and is used for emitting specific wavelength laser corresponding to the characteristic absorption spectrum of water molecule;

[0009] Reflection light path system is used for forming X type cross light path; And

[0010] Laser receiving device is arranged at the other side of detection channel;

[0011] The laser emitted by the laser emitting device is reflected by the reflection optical path system and received by the laser receiving device.

[0012] Optionally, the drying chamber is provided with multiple layers of shelves arranged horizontally and at intervals, and each of the shelves is provided with a temperature control device for placing the drying objects.

[0013] Optionally, the condensing chamber is provided with a refrigeration coil.

[0014] Optionally, the detection channel is provided with a sealing connection structure between the drying chamber and the condensing chamber.

[0015] Optionally, the reflection optical path system comprises a first mirror group and a second mirror group arranged oppositely in the detection channel, and the reflection surfaces of the first mirror group and the second mirror group are opposite to each other.

[0016] Optionally, the first mirror group and the second mirror group comprise an angle fine-tuning mechanism.

[0017] Optionally, the included angle between the reflection surfaces of the first mirror group and the second mirror group and the laser incidence direction is 30-60 degrees.

[0018] Optionally, the laser emitting device comprises a tunable semiconductor laser and a laser controller.

[0019] Optionally, the detection channel is provided with light-transmitting windows at both ends, and the light-transmitting windows are made of waterproof and anti-fog materials.

[0020] Optionally, the laser receiving device is a photoelectric detector.

[0021] Compared with the prior art, the freeze drying process monitoring device based on TDLAS provided by the utility model realizes non-contact water vapor concentration monitoring through the laser emitting device and the laser receiving device arranged in the detection channel between the drying chamber and the condensing chamber, cooperates with the X-shaped cross light path system, completely avoids the interference caused by the direct contact of the probe in the traditional monitoring device, significantly improves the monitoring precision, and compactly integrates the laser emitting, reflecting and receiving systems, and improves the system stability. Through the real-time monitoring of the water vapor concentration by the device, the drying end point can be accurately judged, and the production efficiency is significantly improved.

[0022] Further, the freeze drying process monitoring device based on TDLAS provided by the utility model is provided with a sealing connection structure between the detection channel and the drying chamber and the condensing chamber, and in combination with the adjustable mirror group and the angle fine-tuning mechanism, the monitoring device can adapt to the complex freeze drying environment, and the reliability of the measurement result is ensured; the setting of the multiple layers of temperature control shelves further optimizes the overall performance of the device, and effectively improves the monitoring effect of the freeze drying process. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structure schematic diagram of a freeze-drying process monitoring device based on TDLAS in the embodiment of the present application.

[0024] In the figure, 1, drying chamber; 2, condensing chamber; 3, detection channel; 31, laser emitting device; 32, laser receiving device. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present application will be described below with reference to the accompanying drawings, wherein the preferred embodiments of the present application are represented, and it should be understood that those skilled in the art can modify the present application described herein while still achieving the advantageous effects of the present application. Therefore, the following description should be understood as extensive knowledge for those skilled in the art, and not as a limitation on the present application.

[0026] In this paper, the serial number of the component itself, such as "first", "second" and so on, is only used to distinguish the described object, and has no any order or technical meaning. And the "connection" and "coupling" in this application, unless otherwise specified, include direct and indirect connection (coupling). In the description of the present application, it should be understood that the orientation or position relationship indicated by the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0027] In the present application, unless otherwise specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0028] The present application will be described in more detail in the following paragraphs with reference to the accompanying drawings. The advantages and features of the present application will be more apparent according to the following description. It should be noted that the drawings are very simplified and use non-precise proportions, only for the purpose of facilitating and clearly assisting the description of the embodiments of the present application.

[0029] AsFigure 1 The utility model provides a freeze drying process monitoring device based on TDLAS, which comprises a drying chamber 1, a condensing chamber 2 and a detection channel 3 connecting the drying chamber 1 and the condensing chamber 2. A laser emitting device 31 is arranged on one side of the detection channel 3 for emitting laser of a specific wavelength corresponding to the characteristic absorption spectrum of water molecules. A reflection light path system is arranged in the detection channel 3 for forming an X-shaped cross light path. A laser receiving device 32 is arranged on one side of the detection channel 3. The laser emitted by the laser emitting device 31 is reflected by the reflection light path system and received by the laser receiving device 32.

[0030] The specific wavelength corresponds to the characteristic absorption spectrum of water molecules. The laser emitted by the laser emitting device is reflected by the reflection light path system and received by the laser receiving device, and the water vapor concentration is measured by detecting the absorption change of laser energy. The freeze drying process monitoring device based on TDLAS is particularly suitable for monitoring the primary drying stage in the freeze drying process. Through real-time monitoring of the water vapor concentration, the drying endpoint can be accurately determined, and the production efficiency is significantly improved.

[0031] The drying chamber 1 is provided with multiple layers of shelves arranged horizontally and at intervals. Each layer of the shelves is provided with a temperature control device, which can control the temperature in the range of -40 DEG C to 20 DEG C. The shelves are arranged at equal intervals to facilitate the placement of the vials.

[0032] In one specific example, the temperature control device comprises a media conduit and a temperature sensor. The media conduit is arranged inside the shelf for introducing silicon oil for cooling and heating. The temperature sensor is a PT100 platinum resistance, which is inserted at the inlet and outlet of the silicon oil. The temperature measurement range is -50 DEG C to +400 DEG C, the temperature measurement accuracy is B grade, and the temperature control accuracy is ±0.5 DEG C. All contact surfaces of the shelf are polished with 316L stainless steel mirror. In one specific example, the size of the shelf is 960mm x 905mm x 22mm, and the distance between adjacent shelves is 100mm. The shelf can accommodate 1550 vials of 15R specification at the same time.

[0033] The condensing chamber 2 is provided with a refrigeration coil for capturing sublimated water vapor.

[0034] In one specific example, the refrigeration coil is made of 316L stainless steel. The size of the coil is related to the area of the shelf, and the ice-capturing capacity is about 20kg / m 2 When the inlet temperature reaches -75 DEG C, the refrigeration coil starts to work.

[0035] In one specific example, the detection channel 3 has a rectangular cross-section, and sealing connection structures are provided between the detection channel 3 and the drying chamber 1 and the condensation chamber 2 respectively, to ensure the airtightness of the entire system.

[0036] In one specific example, flange connection interfaces are provided at both ends of the detection channel 3, and the inner wall of the channel is polished to reduce scattering.

[0037] In one specific example, the sealing connection structure adopts an O-ring, and the moving parts are connected by a 316 bellows.

[0038] The reflected light path system includes a first mirror group and a second mirror group arranged oppositely in the detection channel 3, and the reflecting surfaces of the first mirror group and the second mirror group are opposite.

[0039] The first mirror group and the second mirror group are fixed in the detection channel 3 by mounting seats, and the mounting seats are provided with the angle fine adjustment mechanism for adjusting the angle of the mirror group during assembly.

[0040] In one specific example, the mounting seat is provided with an angle fine adjustment mechanism, including adjustment bolts in horizontal and vertical directions, for adjusting the angle of the mirror group during assembly. After adjustment is completed, it is fixed by locking structure to ensure the stability of the angle of the mirror group.

[0041] In another specific example, the angle fine adjustment mechanism includes a three-point adjustment structure, specifically, three adjustment screws are arranged on the mounting seat at intervals of 120 degrees, each adjustment screw is pre-tightened by a spring, and the angle of the mirror group is adjusted by adjusting the screw-in depth of the three screws. After adjustment is completed, it is fixed by a locking nut to ensure the long-term stability of the angle of the mirror group.

[0042] Further, a laser emitting device 31 is arranged on one side of the detection channel 3, and the laser emitting device 31 includes a tunable semiconductor laser and a laser controller. The tunable semiconductor laser is used to emit a specific wavelength laser corresponding to the characteristic absorption spectrum of water molecules, and the specific wavelength covers the absorption spectrum of water molecules. The laser controller is used to adjust the temperature and current of the laser to ensure the stability of the laser wavelength and the stability of the spectral scanning.

[0043] In one specific example, the center wavelength of the tunable semiconductor laser covers the water molecule absorption spectrum, the output power meets the detection requirements, and has the characteristics of narrow line width.

[0044] In another specific example, a scanning frequency of 2kHz is adopted, and wavelength tuning is performed near the water molecule absorption spectrum to realize accurate scanning of the water molecule absorption spectrum.

[0045] The detection channel 3 is provided with light transmission windows at both ends, which are made of waterproof and anti-fog materials to ensure the stability of laser transmission.

[0046] The other side of the detection channel 3 is provided with a laser receiving device 32 for receiving the laser signal transmitted through the X-shaped cross light path. The laser receiving device 32 is a photodetector.

[0047] The working process of the monitoring device is as follows:

[0048] S1. System debugging:

[0049] Turn on the laser, set the working temperature, and inject the current;

[0050] Calibrate the system under standard environment (20 DEG C, 1 atm).

[0051] S2. Pre-freezing stage:

[0052] Place the products to be dried (such as 20 bottles of 15ml vials) on the shelf;

[0053] Control the shelf temperature to drop to-40 DEG C and keep for more than 2 hours;

[0054] Start the cold trap refrigeration system at the same time, and make the cold trap temperature drop to-60 DEG C.

[0055] S3. First drying stage:

[0056] Drop the cavity pressure to below 10Pa;

[0057] Control the shelf temperature to rise to-20 DEG C at a rate of 0.5 DEG C / min;

[0058] Start collecting data, detect the water vapor concentration in real time through the X-shaped reflective light path, and record the water vapor concentration change;

[0059] When the water vapor concentration drops to below 1% of the initial value, determine that the first drying is completed.

[0060] S4. Second drying stage:

[0061] Raise the shelf temperature to 20 DEG C and maintain the vacuum degree;

[0062] Continue to monitor the water vapor concentration change until the signal is stable at the background value level.

[0063] In conclusion, the device provided by the utility model has high measurement precision, the optical path length is obviously increased through the X-shaped cross light path design, the sensitivity of water vapor concentration measurement is improved, and the water detection precision of ppm level can be realized. The detection channel is located between the drying chamber and the condensing chamber, directly monitors the water molecule sublimation channel, avoids the errors caused by the temperature gradient and the probe position in the traditional method, and can capture the rapid water vapor concentration change. The waterproof and anti-fog design of the light transmission window ensures the stability of the light path and improves the measurement accuracy. The overall structure design is compact, the system integration degree is high, and the operation and maintenance are convenient. Modular design is adopted, the key components are convenient to replace and maintain, and the use cost is reduced.

[0064] Obviously, those skilled in the art can make various modifications and variations to the utility model without departing from the spirit and scope of the utility model. Thus, if these modifications and variations of the utility model belong to the scope of the utility model claims and their equivalent technologies, the utility model also intends to include these modifications and variations.

Claims

1. A TDLAS-based freeze-drying process monitoring device, characterized in that, include: Drying chamber (1), condensation chamber (2), and detection channel (3) connecting the drying chamber (1) and condensation chamber (2); A laser emitting device (31) is disposed on one side of the detection channel (3) and is used to emit a laser of a specific wavelength corresponding to the characteristic absorption spectrum of water molecules; A reflective optical path system for forming an X-shaped cross-beam optical path; and A laser receiver (32) is located on the other side of the detection channel (3); The laser emitted by the laser emitting device (31) is reflected by the reflection optical path system and then received by the laser receiving device (32).

2. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The drying chamber (1) is equipped with multiple shelves arranged horizontally at intervals. Each shelf is equipped with a temperature control device for placing items to be dried.

3. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The condenser chamber (2) is equipped with a refrigeration coil.

4. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The detection channel (3) is provided with a sealed connection structure between itself and the drying chamber (1) and the condensation chamber (2).

5. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The reflected light path system includes a first reflector group and a second reflector group disposed opposite each other in the detection channel (3), with the reflecting surfaces of the first reflector group and the second reflector group facing each other.

6. The TDLAS-based freeze-drying process monitoring device according to claim 5, characterized in that, The first reflector group and the second reflector group include an angle fine-tuning mechanism.

7. The TDLAS-based freeze-drying process monitoring device according to claim 6, characterized in that, The angle between the reflecting surfaces of the first and second reflector groups and the incident direction of the laser is 30-60 degrees.

8. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The laser emitting device (31) includes a tunable semiconductor laser and a laser controller.

9. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The detection channel (3) is provided with light-transmitting windows at both ends, and the light-transmitting windows are made of waterproof and anti-fog materials.

10. The TDLAS-based freeze-drying process monitoring device according to claim 1, characterized in that, The laser receiving device (32) is a photodetector.

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