Freeze dryer based on Stirling refrigeration
By using a Stirling refrigerator and a cooling medium circulation pipeline in the freeze dryer to replace HFCs, the greenhouse gas emission problem of the freeze dryer's refrigeration system is solved, achieving an environmentally friendly refrigeration effect.
Patent Information
- Application Number
- CN202423299908.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing freeze dryers use hydrofluorocarbons (HFCs) as refrigerants in their refrigeration systems, resulting in severe greenhouse gas emissions and violating environmental protection requirements.
Stirling refrigerators and cooling medium circulation pipelines are used to replace HFCs. The Stirling refrigerator provides cooling capacity to the drying chamber and cold trap, achieving cooling and constant temperature control.
It effectively reduces greenhouse gas emissions, meets the performance requirements of freeze dryers, and complies with environmental protection requirements.
Smart Images
Figure CN223580424U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to freeze dryer technical field especially is involved in a freeze dryer based on stirling refrigeration. BACKGROUND
[0002] With the development of global economy and the improvement of people's living standards, the demand for high-quality and high-stability products is increasing, which promotes the continuous growth of the freeze dryer market. In the pharmaceutical industry, with the rapid development of biotechnology, the demand for freeze drying technology is increasing. In the process of new drug research and development, freeze dryer has become an indispensable equipment. In the food field, consumers' pursuit of healthy and convenient food promotes the continuous expansion of the freeze-dried food market. In addition, in the field of scientific research, freeze dryer is also widely used in the preparation and preservation of laboratory samples.
[0003] The refrigeration system is one of the most important systems in the freeze dryer. The existing freeze dryer refrigeration system usually uses hydrofluorocarbons (HFCs) as refrigerant, and HFCs is a super greenhouse gas with global warming potential (GWP) of thousands of times of CO2. Under the current environmental protection background, many countries in the world have introduced policies and regulations to strictly limit the use and emission of HFCs, so seeking new environmentally friendly refrigeration methods has become the most urgent work.
[0004] Therefore, the utility model provides a freeze dryer based on stirling refrigeration to solve the above problems. UTILITY MODEL CONTENT
[0005] The utility model aims at providing a freeze dryer based on stirling refrigeration to reduce greenhouse gas emissions.
[0006] To solve the above technical problems, the utility model provides a freeze dryer based on stirling refrigeration, which comprises a first circulation pipeline with a cold medium inside, a stirling refrigerator and a drying box.
[0007] The stirling refrigerator is used to provide cold energy for the cold medium.
[0008] The first circulation pipeline connects the drying box and the stirling refrigerator, and is used to drive the cold medium inside to circulate and conduct between the drying box and the stirling refrigerator, and to circulate and conduct itself in the drying box, so as to reduce and keep the temperature of the drying box.
[0009] Further, the freeze dryer based on stirling refrigeration further comprises a cold trap installed on the drying box and used to capture water vapor inside the drying box.
[0010] The second circulation pipeline with a cold medium inside is arranged between the cold trap and the stirling refrigerator.
[0011] The second circulation pipeline is used for driving the cooling medium in it to circulate between the Stirling refrigerator and the cold trap.
[0012] Further, the second circulation pipeline comprises a cold trap outlet pipeline and a cold trap inlet pipeline.
[0013] The cold trap outlet pipeline is connected with the cooling medium outlet end of the cold trap and the cooling medium inlet end of the Stirling refrigerator, and a cold trap circulating pump, a first ball valve and a defrosting electric heating are sequentially arranged on the cold trap outlet pipeline, and the cold trap circulating pump is close to the cooling medium outlet end of the cold trap.
[0014] The cold trap inlet pipeline is connected with the cooling medium inlet end of the cold trap and the cooling medium outlet end of the Stirling refrigerator, and a second ball valve is arranged on the cold trap inlet pipeline.
[0015] Further, a balance bucket is arranged between the cold trap and the drying box.
[0016] Further, a temperature control electromagnetic valve is arranged between the cooling medium inlet end of the cold trap and the cooling medium outlet end of the drying box.
[0017] Further, the first circulation pipeline comprises a drying box outlet pipeline and a drying box inlet pipeline.
[0018] The drying box outlet pipeline is connected with the cooling medium outlet end of the drying box and the cooling medium inlet end of the Stirling refrigerator, and a drying box circulating pump, a drying box electric heating and a third ball valve are sequentially arranged on the drying box outlet pipeline, and the drying box circulating pump is close to the cooling medium outlet end of the drying box.
[0019] The drying box inlet pipeline is connected with the cooling medium inlet end of the drying box and the cooling medium outlet end of the Stirling refrigerator, and a fourth ball valve is arranged on the drying box inlet pipeline.
[0020] Further, the first circulation pipeline further comprises a self-circulation pipeline.
[0021] The self-circulation pipeline is connected with the drying box outlet pipeline and the drying box inlet pipeline, one end of the self-circulation pipeline is located between the drying box electric heating and the third ball valve, and the other end of the self-circulation pipeline is located between the fourth ball valve and the cooling medium inlet end of the drying box, and a fifth ball valve is arranged on the self-circulation pipeline.
[0022] Compared with the prior art, the utility model has at least the following beneficial effects:
[0023] The freeze dryer based on Stirling refrigeration provided by the utility model adopts Stirling refrigerators to refrigerate, and can abandon the use of HFCs under the premise of meeting the performance requirements of the freeze dryer, effectively reduces the emission of greenhouse gases, and is more friendly to the environment. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a whole structure schematic view of the freeze dryer based on Stirling refrigeration in the utility model embodiment.
[0025] In the drawing: 1, Stirling refrigerator; 2, defrosting electric heating; 3, first ball valve; 4, second ball valve; 5, fourth ball valve; 6, fifth ball valve; 7, third ball valve; 8, cold trap circulating pump; 9, cold trap; 10, drying cabinet; 11, balance bucket; 12, drying cabinet circulating pump; 13, drying cabinet electric heating; 14, temperature control electromagnetic valve; 15, first circulating pipeline; 16, second circulating pipeline. DETAILED DESCRIPTION
[0026] The freeze dryer based on Stirling refrigeration of the utility model will be described in more detail below in conjunction with the schematic view, wherein the preferred embodiment of the utility model is represented, and it should be understood that the utility model described herein can be modified by those skilled in the art, and the advantageous effects of the utility model can still be achieved. Therefore, the following description should be understood as extensive knowledge for those skilled in the art, and not as a limitation on the utility model.
[0027] The utility model will be described in more detail in the following paragraphs with reference to the drawings. The advantages and features of the utility model will be more apparent according to the following description. It should be noted that the drawings are very simplified and all use non-precise proportions, only to facilitate, clearly assist in the purpose of explaining the utility model embodiment.
[0028] As Figure 1 shown, the utility model embodiment proposes a freeze dryer based on Stirling refrigeration, including the first circulating pipeline 15 with the internal load cold medium, Stirling refrigerator 1 and drying cabinet 10;The Stirling refrigerator 1 is used to provide the cold quantity for the load cold medium;The first circulating pipeline 15 is connected the drying cabinet 10 and Stirling refrigerator 1, is used to drive the load cold medium in its inside to carry out circulation conduction between the drying cabinet 10 and Stirling refrigerator 1 and in the drying cabinet 10 carries out self circulation conduction, to make the internal cooling and constant temperature of the drying cabinet 10 keep.
[0029] In the above embodiment, specifically, the first circulation pipeline 15 comprises a drying box outlet pipeline, a drying box inlet pipeline and a self-circulation pipeline; the drying box outlet pipeline connects the cold medium outlet end of the drying box 10 and the cold medium inlet end of the Stirling refrigerator 1, and the drying box outlet pipeline is sequentially provided with a drying box circulation pump 12, a drying box electric heater 13 and a third ball valve 7, and the drying box circulation pump 12 is close to the cold medium outlet end of the drying box 10; the drying box inlet pipeline connects the cold medium inlet end of the drying box 10 and the cold medium outlet end of the Stirling refrigerator 1, and the drying box inlet pipeline is provided with a fourth ball valve 5; the self-circulation pipeline connects the drying box outlet pipeline and the drying box inlet pipeline, one end of the self-circulation pipeline is located between the drying box electric heater 13 and the third ball valve 7, and the other end of the self-circulation pipeline is located between the fourth ball valve 5 and the cold medium inlet end of the drying box 10; and the self-circulation pipeline is provided with a fifth ball valve 6.
[0030] In a preferred embodiment, the Stirling refrigeration-based freeze dryer further comprises a cold trap 9 installed on the drying box 10 for capturing water vapor inside the drying box 10; a second circulation pipeline 16 with cold medium inside is arranged between the cold trap 9 and the Stirling refrigerator 1; and the second circulation pipeline 16 is used to drive the cold medium inside to circulate and conduct between the Stirling refrigerator 1 and the cold trap 9.
[0031] In the above preferred embodiment, specifically, the second circulation pipeline 16 comprises a cold trap outlet pipeline and a cold trap inlet pipeline; the cold trap outlet pipeline connects the cold medium outlet end of the cold trap 9 and the cold medium inlet end of the Stirling refrigerator 1, and the cold trap outlet pipeline is sequentially provided with a cold trap circulation pump 8, a first ball valve 3 and a defrosting electric heater 2, and the cold trap circulation pump is close to the cold medium outlet end of the cold trap; the cold trap inlet pipeline connects the cold medium inlet end of the cold trap 9 and the cold medium outlet end of the Stirling refrigerator 1, and the cold trap inlet pipeline is provided with a second ball valve 4.
[0032] Further, a balance bucket 11 is arranged between the cold trap 9 and the drying box 10 to prevent the pressure fluctuation of the pipeline caused by the thermal expansion and contraction of the cold medium. The specific structure and installation method of the balance bucket belong to the prior art, and will not be described here.
[0033] Further, a temperature control electromagnetic valve 14 is arranged between the cold medium inlet end of the cold trap 9 and the cold medium outlet end of the drying box 10 for temperature control of the cold medium during the sublimation process of the drying box 10.
[0034] In the above embodiments, the cold required for both the drying cabinet 10 and the cold trap 9 is provided by a Stirling cryocooler 1. A Stirling cryocooler is a type of refrigeration device that utilizes the principle of closed-cycle regenerative refrigeration. It is mainly based on the Stirling cycle, which is a thermodynamic cycle consisting of two isothermal processes and two isochoric processes, with key components including a compressor, an expander, a regenerator, and so on. In one complete cycle of the Stirling cycle, the working gas (usually helium or hydrogen) first expands isothermally at a high-temperature heat source, absorbing heat. Then, through an isochoric process, the gas is transported to a low-temperature region, followed by isothermal compression at a low-temperature heat source, releasing heat. Finally, through another isochoric process, the gas returns to the high-temperature region, starting the next cycle. In this process, by controlling the expansion and compression of the working gas and the exchange of heat, a refrigeration effect is achieved. Stirling cryocoolers have the following advantages:
[0035] High efficiency and energy saving: Due to the presence of the regenerator in the Stirling cycle, heat can be effectively recovered and reused, making the Stirling cryocooler theoretically have high efficiency. Compared with traditional refrigeration machines (such as vapor compression refrigeration machines), it can achieve lower energy consumption in certain working conditions, especially in small temperature difference refrigeration and low temperature refrigeration fields.
[0036] Compact structure: The overall structure of the Stirling cryocooler is relatively compact, and its main components can be integrated through reasonable design. This makes it have advantages in space-limited application scenarios, such as portable refrigerators, small low-temperature experimental devices, etc.
[0037] Environmentally friendly working medium: Common working gases such as helium and hydrogen are environmentally friendly gases that do not damage the ozone layer or cause serious greenhouse effects like some traditional refrigerants (such as Freon). This conforms to modern environmental protection concepts and has great application potential in fields with high environmental protection requirements (such as aerospace, green data centers, etc.).
[0038] Wide working temperature range: Stirling cryocoolers can achieve refrigeration in a wide temperature range. It can be used for ordinary refrigeration temperatures (for example, 0-10℃), and can also be used for low temperature or even ultra-low temperature environments (such as liquid helium temperature levels, close to absolute zero), depending on the design parameters and application requirements of the cryocooler.
[0039] Fast startup and simple operation: The Stirling cryocooler has a relatively fast startup speed and does not require long preheating or precooling like some complex refrigeration systems. At the same time, its operation is relatively simple, and the refrigeration capacity and temperature can be adjusted by controlling the working frequency, power, etc. of the compressor and expander, making it easy for users to use and maintain.
[0040] The working process of the freeze dryer based on Stirling refrigeration provided in the embodiments of the utility model is roughly as follows:
[0041] The pre-freezing stage of the drying box 10: the Stirling refrigerator 1 and the drying box circulating pump 12 are started, the fourth ball valve 5 and the third ball valve 7 are opened, the first ball valve 3, the second ball valve 4 and the fifth ball valve 6 are closed, and the drying box electric heating 13 is also closed. The cooling medium is cooled in the Stirling refrigerator 1 and is delivered to the plate layer of the drying box 10 through the pipeline. The cooling medium enters the plate layer and takes away the heat of the plate layer, so that the inside of the drying box 10 is cooled.
[0042] The sublimation stage of the drying box 10: the drying box circulating pump 12 is started, the drying box electric heating 13 is started, the ball valve 6 is opened, and the fourth ball valve 5 and the third ball valve 7 are closed. The power output of the drying box electric heating 13 and the on-off frequency of the temperature control electromagnetic valve 14 are controlled to realize the constant temperature control of the inlet end temperature of the cooling medium of the drying box 10.
[0043] The cooling stage of the cold trap 9: the cold trap circulating pump 8 is started, the Stirling refrigerator 1 is started, the first ball valve 3 and the second ball valve 4 are opened, and the fourth ball valve 5, the fifth ball valve 6 and the third ball valve 7 are closed. The cooling medium is cooled in the Stirling refrigerator 1 and is delivered to the coil of the cold trap 9, so that the cold trap 9 is cooled.
[0044] The defrosting stage of the cold trap 9: the defrosting electric heating 2 is opened, the Stirling refrigerator 1 is closed, the cooling medium is gradually heated, and the heated cooling medium is delivered to the coil of the cold trap 9, so that the defrosting is realized.
[0045] In summary, compared with the prior art, the utility model has at least the following advantages:
[0046] The freeze dryer based on Stirling refrigeration provided by the utility model adopts the Stirling refrigerator to realize refrigeration. On the premise of meeting the performance requirements of the freeze dryer, the use of HFCs can be abandoned, the emission of greenhouse gases is effectively reduced, and the environment is more friendly.
[0047] 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 equivalent technologies, the utility model also intends to include these modifications and variations.
Claims
1. A freeze dryer based on Stirling refrigeration, characterized in that, It includes a first circulation pipeline (15) with a cooling medium inside, a Stirling refrigerator (1) and a drying oven (10); The Stirling refrigerator (1) is used to provide cooling capacity for the cooling medium; The first circulation pipeline (15) connects the drying chamber (10) and the Stirling refrigerator (1) to drive the cooling medium inside to circulate between the drying chamber (10) and the Stirling refrigerator (1) and to circulate within the drying chamber (10) so as to cool and maintain the temperature inside the drying chamber (10).
2. The freeze dryer based on Stirling refrigeration as described in claim 1, characterized in that, It also includes a cold trap (9), which is installed on the drying chamber (10) to capture water vapor inside the drying chamber (10); A second circulation pipeline (16) with a cooling medium inside is provided between the cold trap (9) and the Stirling refrigerator (1); The second circulation pipe (16) is used to drive the internal cooling medium to circulate between the Stirling refrigerator (1) and the cold trap (9).
3. The freeze dryer based on Stirling refrigeration as described in claim 2, characterized in that, The second circulation pipeline (16) includes a cold trap outlet pipeline and a cold trap inlet pipeline; The cold trap outlet pipe connects the cold trap (9) outlet end of the cooling medium and the Stirling refrigerator (1) inlet end of the cooling medium. The cold trap outlet pipe is sequentially equipped with a cold trap circulation pump (8), a first ball valve (3) and a defrost electric heater (2). The cold trap circulation pump (8) is close to the cold trap (9) outlet end of the cooling medium. The cold trap inlet pipe connects the inlet end of the cold trap (9) and the outlet end of the cold medium of the Stirling refrigerator (1), and a second ball valve (4) is provided on the cold trap inlet pipe.
4. The freeze dryer based on Stirling refrigeration as described in claim 2, characterized in that, A balance tank (11) is provided between the cold trap (9) and the drying box (10).
5. The freeze dryer based on Stirling refrigeration as described in claim 2, characterized in that, A temperature control solenoid valve (14) is provided between the inlet end of the cooling medium of the cold trap (9) and the outlet end of the cooling medium of the drying box (10).
6. The freeze dryer based on Stirling refrigeration as described in claim 1, characterized in that, The first circulation pipeline (15) includes a drying oven outlet pipeline and a drying oven inlet pipeline; The drying chamber outlet pipe connects the cooling medium outlet end of the drying chamber (10) and the cooling medium inlet end of the Stirling refrigerator (1). The drying chamber outlet pipe is sequentially equipped with a drying chamber circulation pump (12), a drying chamber electric heater (13) and a third ball valve (7). The drying chamber circulation pump (12) is close to the cooling medium outlet end of the drying chamber (10). The inlet pipe of the drying box is connected to the inlet end of the cooling medium of the drying box (10) and the outlet end of the cooling medium of the Stirling refrigerator (1). A fourth ball valve (5) is provided on the inlet pipe of the drying box.
7. The freeze dryer based on Stirling refrigeration as described in claim 6, characterized in that, The first circulation pipeline (15) also includes a self-circulating pipeline; The self-circulating pipe connects the outlet pipe and the inlet pipe of the drying chamber. One end of the self-circulating pipe is located between the electric heater (13) of the drying chamber and the third ball valve (7), and the other end of the self-circulating pipe is located between the fourth ball valve (5) and the inlet of the cooling medium of the drying chamber (10). A fifth ball valve (6) is provided on the self-circulating pipe.