High-temperature air-cooled freeze dryer with controllable outlet air temperature

Abstract

This utility model discloses a high-temperature air-cooled refrigerated dryer with controllable outlet air temperature, belonging to the field of dryer technology. The high-temperature air-cooled refrigerated dryer with controllable outlet air temperature includes a refrigeration compressor, an oil separator, an air-cooled condenser, a drying filter, a thermal expansion valve, a high-pressure controller, a hot gas bypass valve, a vaporizer, a high- and low-pressure controller, a low-pressure gauge, a high-pressure gauge, and an air pressure gauge. To solve the problems of increased compressor power consumption, sharp drop in efficiency, and increased risk of icing caused by directly lowering the evaporation temperature, this invention utilizes the lowest temperature gas already present at the evaporator outlet as a cold source. By precisely controlling its bypass ratio, it directly injects the cold gas into the final outlet airflow. This is equivalent to mixing in a cold airflow without power consumption after the reheating process, thereby bypassing the evaporation temperature limit and significantly reducing the final outlet air temperature to a minimum of about 15°C, far superior to traditional models.

Description

Technical Field

[0001] This utility model relates to the field of dryer technology, specifically a high-temperature air-cooled refrigerated dryer with controllable outlet air temperature. Background Technology

[0002] Bottlenecks of traditional freeze dryers: Limited by evaporation temperature, they are usually designed with a dew point of 2 to 10°C, corresponding to a saturated air temperature of 5°C. The outlet air temperature after reheating by the heat exchanger is generally 25 to 40°C. The ambient temperature has a great influence. Although directly reducing the evaporation temperature can reduce the outlet air temperature, it will lead to a sharp increase in compressor power consumption, a sharp drop in efficiency, and an increased risk of icing. Utility Model Content

[0003] The purpose of this invention is to provide a high-temperature air-cooled refrigerated dryer with controllable outlet air temperature. It utilizes the lowest temperature gas already present at the evaporator outlet as a cold source and injects it directly into the final outlet airflow by precisely controlling its bypass ratio. This is equivalent to mixing in a cold airflow without power consumption after the reheating process, thereby bypassing the evaporation temperature limit and significantly reducing the final outlet air temperature to a minimum of about 15°C, which is far superior to traditional models and can solve the problems in the existing technology.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a high-temperature air-cooled refrigerated dryer with controllable outlet air temperature, comprising a refrigeration compressor, an oil separator, an air-cooled condenser, a drying filter, a thermal expansion valve, a high-pressure controller, a hot gas bypass valve, a vaporizer, a high and low pressure controller, a low-pressure gauge, a high-pressure gauge, and an air pressure gauge, and further comprising a heat exchanger, an evaporator, a steam-water separator, an air-cooled precooler, a pneumatic proportional regulating valve, and a temperature probe, wherein one end of the air-cooled precooler is provided with an air inlet, and one end of the heat exchanger is provided with an air outlet.

[0005] Preferably, the pneumatic proportional regulating valve includes a valve body and a diaphragm chamber, with a diaphragm sheet disposed inside the diaphragm chamber, and a spring push rod disposed below the diaphragm chamber, the spring push rod being telescopically connected to the diaphragm chamber.

[0006] Preferably, a travel probe is provided on one side of the spring push rod, and the travel probe is in contact with the spring push rod.

[0007] Preferably, one end of the valve body is provided with an output chamber, and the other end of the valve body is provided with an input chamber.

[0008] Preferably, one end of the spring push rod is provided with a valve core, which extends between the output chamber and the input chamber.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] 1. This utility model utilizes the lowest temperature gas already present at the evaporator outlet as a cold source. By precisely controlling its bypass ratio, it is directly injected into the final outlet gas flow. This is equivalent to mixing in a cold gas flow without power consumption after the reheating process, thereby bypassing the evaporation temperature limit and significantly breaking through to reduce the final outlet gas temperature to a minimum of about 15°C, which is far superior to traditional models.

[0011] 2. This utility model, with its diaphragm drive and spring balance structure, combined with the linear or equal percentage characteristics of the valve core, can achieve a good linear proportional relationship between the input signal and the output flow, resulting in precise control, fewer moving parts, no complex gears or motors, reliable operation in compressed air environment, relatively simple maintenance, and easy maintenance due to the separation of the diaphragm chamber from the valve body. Attached Figure Description

[0012] Figure 1 This is the overall front view of the present invention;

[0013] Figure 2 This is a schematic diagram of the pneumatic proportional regulating valve structure of this utility model;

[0014] Figure 3 This is a schematic cross-sectional view of the pneumatic proportional regulating valve of this utility model.

[0015] In the diagram: 1. Refrigeration compressor; 2. Oil separator; 3. Air-cooled condenser; 4. Dryer filter; 5. Thermal expansion valve; 6. High-pressure controller; 7. Hot gas bypass valve; 8. Vaporizer; 9. High and low pressure controller; 10. Low-pressure gauge; 11. High-pressure gauge; 12. Air pressure gauge; 13. Heat exchanger; 14. Evaporator; 15. Steam-water separator; 16. Air-cooled precooler; 17. Temperature probe; 18. Pneumatic proportional control valve; 1801. Valve body; 1802. Diaphragm chamber; 1803. Stroke probe; 1804. Output chamber; 1805. Input chamber; 1806. Spring push rod; 1807. Valve core. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] To address the issues of increased compressor power consumption, drastic efficiency drop, and increased risk of icing caused by directly lowering the evaporation temperature; please refer to... Figure 1-3 The present invention provides the following solution:

[0018] Reference Figure 1A high-temperature air-cooled refrigerated dryer with controllable outlet air temperature includes a refrigeration compressor 1, an oil separator 2, an air-cooled condenser 3, a dryer filter 4, a thermal expansion valve 5, a high-pressure controller 6, a hot gas bypass valve 7, a vaporizer 8, a high and low pressure controller 9, a low-pressure gauge 10, a high-pressure gauge 11, and an air pressure gauge 12. It also includes a heat exchanger 13, an evaporator 14, a steam-water separator 15, an air-cooled precooler 16, a pneumatic proportional regulating valve 18, and a temperature probe 17. One end of the air-cooled precooler 16 is provided with an air inlet, and one end of the heat exchanger 13 is provided with an air outlet. The above structures are connected in sequence by pipes to form a closed system.

[0019] In this embodiment, a special pipeline layout is adopted, and a pneumatic proportional regulating valve 18 and a temperature probe 17 are added. The low-temperature gas (around 5°C) coming out of the evaporator 14 is separated into gas and water. Part of the gas returns to the outlet through the pneumatic proportional regulating valve 18, and part of the gas returns to the evaporator 14 through the vapor separator. The two parts of gas merge at the outlet and are sent to the gas pipeline network. The temperature of the outlet is monitored by the temperature probe 17. According to the outlet temperature, the opening of the pneumatic proportional regulating valve 18 is controlled. When the temperature is higher than the set temperature, the valve is opened wider, and more cold air flows into the outlet. Conversely, it is closed smaller. In this way, the power of the energy-saving compressor remains unchanged while low-temperature air can be obtained. The low-temperature air can reach as low as 15°C.

[0020] Reference Figure 2-3 The pneumatic proportional control valve 18 includes a valve body 1801 and a diaphragm chamber 1802. A diaphragm is disposed inside the diaphragm chamber 1802. A spring push rod 1806 is disposed below the diaphragm chamber 1802 and is telescopically connected to the diaphragm chamber 1802. A stroke probe 1803 is disposed on one side of the spring push rod 1806 and is in contact with the spring push rod 1806. An output chamber 1804 is disposed at one end of the valve body 1801 and an input chamber 1805 is disposed at the other end of the valve body 1801. A valve core 1807 is disposed at one end of the spring push rod 1806 and extends between the output chamber 1804 and the input chamber 1805.

[0021] In this embodiment, the air pressure control signal issued by the control system acts on the diaphragm chamber 1802. The air pressure signal acts on the diaphragm, generating a downward thrust. This thrust overcomes the upward elastic force of the pre-tensioned spring in the spring push rod 1806, pushing the push rod downward. The lower end of the spring push rod 1806 is connected to the valve core 1807. The downward movement of the push rod causes the valve core 1807 to move downward, gradually increasing the valve opening. This increases the cross-sectional area of ​​the channel connecting the input chamber 1805 and the output chamber 1804, allowing more low-temperature bypass gas from the gas-water separator 15 to enter the output chamber 1804 through the input chamber 1805 and eventually flow to the air outlet. Conversely, when the control signal pressure decreases, the spring force pushes the valve core 1807 upward, reducing the opening and decreasing the bypass flow.

[0022] Working principle: The refrigeration compressor 1 compresses the low-temperature, low-pressure refrigerant gas into a high-temperature, high-pressure gas. The lubricating oil is removed by the oil separator 2, and the gas enters the air-cooled condenser 3. It is cooled and condensed into a high-pressure liquid by ambient air. The liquid flows through the dryer filter 4 to remove moisture and impurities. It is then throttled and depressurized by the thermostatic expansion valve 5, becoming a low-temperature, low-pressure gas-liquid two-phase mixture. It enters the evaporator 14, absorbs heat from the compressed air, and completely evaporates into a low-pressure gas. The gas then returns to the compressor to complete the cycle. The high and low pressure controllers 9, high pressure gauge 11, and low pressure gauge 10 monitor the system pressure for safety. The high pressure controller 6 prevents the condensing pressure from being too high, and the hot gas bypass valve 7 prevents the evaporator from freezing under low load.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-temperature air-cooled refrigerated dryer with controllable outlet air temperature, characterized in that, The system includes a refrigeration compressor (1), an oil separator (2), an air-cooled condenser (3), a dryer filter (4), a thermal expansion valve (5), a high-pressure controller (6), a hot gas bypass valve (7), a vaporizer (8), a high and low pressure controller (9), a low-pressure gauge (10), a high-pressure gauge (11), and an air pressure gauge (12). It also includes a heat exchanger (13), an evaporator (14), a steam-water separator (15), an air-cooled precooler (16), a pneumatic proportional regulating valve (18), and a temperature probe (17). One end of the air-cooled precooler (16) is provided with an air inlet, and one end of the heat exchanger (13) is provided with an air outlet.

2. The high-temperature air-cooled refrigerated dryer with controllable outlet air temperature according to claim 1, characterized in that: The pneumatic proportional control valve (18) includes a valve body (1801) and a diaphragm chamber (1802). A diaphragm is provided inside the diaphragm chamber (1802). A spring push rod (1806) is provided below the diaphragm chamber (1802), and the spring push rod (1806) is telescopically connected to the diaphragm chamber (1802).

3. A high-temperature air-cooled refrigerated dryer with controllable outlet air temperature according to claim 2, characterized in that: A travel probe (1803) is provided on one side of the spring push rod (1806), and the travel probe (1803) is in contact with the spring push rod (1806).

4. A high-temperature air-cooled refrigerated dryer with controllable outlet air temperature according to claim 2, characterized in that: One end of the valve body (1801) is provided with an output chamber (1804), and the other end of the valve body (1801) is provided with an input chamber (1805).

5. A high-temperature air-cooled refrigerated dryer with controllable outlet air temperature according to claim 4, characterized in that: One end of the spring push rod (1806) is provided with a valve core (1807), which extends between the output chamber (1804) and the input chamber (1805).

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