Condensing system of vacuum drier

Abstract

The invention relates to the technical field of condensation systems of vacuum dryers, and discloses a condensation system of a vacuum dryer, which comprises a vacuum maintaining module, a condensation trapping module, a refrigeration cycle module and a control module, the vacuum maintaining module comprises a vacuum main pump, a front-stage roots pump, an auxiliary vacuum pump, a stainless steel corrugated pipe, a vacuum valve and a vacuum pipeline, the condensation trapping module comprises a condenser, a heat exchanger and a cold trap, and the refrigeration cycle module comprises a refrigeration compressor, an expansion valve, an evaporator and a condensing coil; the roots pump is connected with the vacuum main pump in series through a stainless steel corrugated pipe, the cold trap is connected with the condenser in series, and an air inlet of the vacuum main pump is connected with an outlet of the condenser through a vacuum pipeline; by means of the system, interruption of the drying process can be avoided, the drying effect is guaranteed, and condensation trapping is optimized.

Description

Technical Field

[0001] This invention belongs to the technical field of condensation systems for vacuum dryers, specifically a condensation system for a vacuum dryer. Background Technology

[0002] Vacuum drying technology is widely used in the pharmaceutical, food, and chemical industries. Its core principle is to directly sublimate the moisture in materials through a low-temperature and low-pressure environment. However, traditional systems have the following technical bottlenecks: 1. Insufficient vacuum stability: Single-stage vacuum pumps are prone to vacuum fluctuations under high loads, leading to localized overheating or uneven drying of materials.

[0003] 2. Low condensation efficiency: In conventional single-stage cold traps, the collection efficiency decreases as the ice layer thickens during continuous operation, requiring frequent shutdowns for defrosting. Some systems have attempted to add pre-cooling devices, but direct connection between the cold trap and the drying chamber can cause temperature backflow, affecting the quality of material crystallization.

[0004] 3. Insufficient level of automation; most equipment relies on manual adjustment of valves and pump sets, resulting in long vacuum build-up times, a lack of real-time energy consumption monitoring, and low efficiency in troubleshooting. Therefore, we propose a condensation system for a vacuum dryer. Summary of the Invention

[0005] The purpose of this invention is to provide a condensation system for a vacuum dryer in order to avoid interruption of the drying process, ensure the drying effect, and optimize condensation collection.

[0006] The technical solution adopted in this invention is as follows: A condensation system for a vacuum dryer includes a vacuum maintenance module, a condensation collection module, a refrigeration cycle module, and a control module; The vacuum maintenance module includes a main vacuum pump, a backing Roots pump, an auxiliary vacuum pump, a stainless steel bellows, vacuum valves, and vacuum piping; the condensation trap module includes a condenser, a heat exchanger, and a cold trap; and the refrigeration cycle module includes a refrigeration compressor, an expansion valve, an evaporator, and a condensing coil. The Roots pump and the main vacuum pump are connected in series via the stainless steel bellows. The cold trap and the condenser are connected in series. The inlet of the main vacuum pump is connected to the outlet of the condenser via the vacuum pipeline to pump out uncondensed gas and water vapor and maintain the system vacuum. The vacuum valve is installed on the vacuum pipeline to control the gas flow path in the vacuum pipeline. The auxiliary vacuum pump is connected to the outlet of the condenser via an independent pipeline. The cold trap is connected to the drying chamber via a hydraulic mushroom valve. Sublimated water vapor enters the cold trap through this valve and condenses into ice. The heat exchanger is connected to the product shelf and circulates heat-conducting silicone oil to the metal shelf in the drying chamber through a closed pipeline to achieve material temperature control.

[0007] In a preferred embodiment of the invention, the exhaust port of the refrigeration compressor is directly connected to the inlet of the condenser coil via a high-pressure resistant metal pipeline, and the outlet of the condenser coil is connected to the inlet of the expansion valve after passing through a liquid receiver dryer.

[0008] In a preferred embodiment of the invention, the expansion valve outlet is connected to the bottom inlet of the evaporator via an insulated pipe, and the evaporator outlet is inclined upwards to connect to the cold trap inlet.

[0009] In a preferred embodiment of the invention, the control module includes a PLC control box, an electrical control box, a control panel, a temperature sensor, and a pressure sensor.

[0010] In a preferred embodiment of the invention, the number of temperature sensors is several, and the temperature sensors are installed on the inner wall of the drying chamber, the outlet of the condenser coil, and the surface of the cold trap, and the temperature sensors are electrically connected to the PLC control box.

[0011] In a preferred embodiment of the invention, the number of pressure sensors is several, and the pressure sensors are installed in the vacuum pump inlet pipe, the compressor outlet of the refrigeration compressor, the evaporator inlet and the cold trap outlet, and the pressure sensors are electrically connected to the PLC control box.

[0012] In a preferred embodiment of the invention, the PLC control box is electrically connected to the main vacuum pump, the forestage Roots pump, the auxiliary vacuum pump, and the refrigerated compressor.

[0013] In a preferred embodiment of the invention, the output terminal of the electrical control box is electrically connected to the PLC control box, the main vacuum pump, the forestage Roots pump, the auxiliary vacuum pump, and the refrigerated compressor, and the control panel is disposed on the outer surface of the PLC control box.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In this invention, a Roots pump and a main vacuum pump are connected in series and connected flexibly with a stainless steel bellows to reduce vibration interference, achieve stable maintenance of high vacuum, reduce the load on the main pump, and at the same time, an auxiliary vacuum pump is added to quickly restore vacuum in case of sudden leakage or defrosting, avoid interruption of the drying process, and ensure drying effect.

[0015] 2. In this invention, the condensation trap is optimized by connecting the cold trap and the condenser in series. When water vapor sublimates, it first sublimates into ice in the cold trap and then is captured a second time by the condenser, which improves the capture efficiency. At the same time, the flow is controlled by a hydraulic mushroom valve to avoid temperature fluctuations caused by direct connection between the cold trap and the drying chamber, making the sublimation process more stable.

[0016] 3. In this invention, through multi-sensor closed-loop feedback, the temperature of the drying chamber, cold trap, and condenser coil is monitored in real time to dynamically adjust the refrigeration power and shelf heating, and the vacuum pump inlet pressure sensor triggers staged start and stop to improve the vacuum response speed. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The following will combine Figure 1 A detailed description is provided of the condensation system of a vacuum dryer according to an embodiment of the present invention. Example 1

[0020] Reference Figure 1 A condensation system for a vacuum dryer includes a vacuum maintenance module, a condensation trapping module, a refrigeration cycle module, and a control module. The vacuum maintenance module includes a main vacuum pump, a backing Roots pump, an auxiliary vacuum pump, a stainless steel bellows, vacuum valves, and vacuum piping. The condensation trapping module includes a condenser, a heat exchanger, and a cold trap. The refrigeration cycle module includes a refrigeration compressor, an expansion valve, an evaporator, and a condensing coil. Specifically, the main vacuum pump is a Leybold pump from Germany, the Roots pump is a Bassmann corrosion-resistant stainless steel rotor Roots pump, and the auxiliary vacuum pump is a Bassmann stainless steel vacuum pump. The Roots pump and the main vacuum pump are connected in series and flexibly connected using a stainless steel bellows to reduce vibration interference, achieve stable maintenance of a high vacuum, reduce the load on the main pump, and the additional auxiliary vacuum pump can quickly restore the vacuum in case of sudden leakage or defrosting, avoiding interruption of the drying process and ensuring the drying effect.

[0021] Reference Figure 1The Roots pump and the main vacuum pump are connected in series via a stainless steel bellows, and the cold trap and condenser are connected in series. The inlet of the main vacuum pump is connected to the outlet of the condenser via a vacuum pipeline to pump out uncondensed gas and water vapor, maintaining the system vacuum. A vacuum valve is installed on the vacuum pipeline to control the gas flow path within the pipeline, and an auxiliary vacuum pump is connected to the condenser outlet via an independent pipeline. The cold trap is connected to the drying chamber via a hydraulic mushroom valve. Sublimated water vapor enters the cold trap through this valve and condenses into ice. The heat exchanger is connected to the product shelf and circulates the heat-conducting silicone oil to the metal shelf in the drying chamber through a closed pipeline to achieve material temperature control. Specifically, the condensation and collection process is optimized by connecting the cold trap and condenser in series. When water vapor sublimates, it first condenses into ice in the cold trap and then is collected a second time by the condenser, improving collection efficiency. At the same time, the flow is controlled by a hydraulic mushroom valve to avoid temperature fluctuations caused by direct connection between the cold trap and the drying chamber, making the sublimation process more stable. Example 2

[0022] Reference Figure 1 The refrigeration compressor discharge port is directly connected to the condenser coil inlet via a high-pressure resistant metal pipeline. The condenser coil outlet is connected to the expansion valve inlet after passing through a liquid receiver dryer. The expansion valve outlet is connected to the bottom inlet of the evaporator via an insulated pipeline. The evaporator outlet is connected to the cold trap inlet at an upward angle. Specifically, the refrigerant is reused repeatedly in a closed loop, avoiding operational interruptions and cooling losses caused by refrigerant replenishment in the open-loop system. The heat absorbed by the evaporator is recovered through secondary condensation in the cold trap, resulting in high energy recycling efficiency and reduced operating energy consumption.

[0023] Reference Figure 1 The control module includes a PLC control box, an electrical control box, a control panel, temperature sensors, and pressure sensors. Several temperature sensors are installed on the inner wall of the drying chamber, the outlet of the condenser coil, and the surface of the cold trap, and are electrically connected to the PLC control box. Several pressure sensors are installed on the vacuum pump inlet pipe, the compressor outlet of the refrigeration compressor, the evaporator inlet, and the cold trap outlet, and are also electrically connected to the PLC control box. The PLC control box is connected to the main vacuum pump, the backing Roots pump, and the auxiliary vacuum pump. The system is electrically connected to the refrigeration compressor. The output of the electrical control box is electrically connected to the PLC control box, the main vacuum pump, the forestage Roots pump, the auxiliary vacuum pump, and the refrigeration compressor. The control panel is located on the outer surface of the PLC control box. Specifically, the microcontroller inside the PLC control box is the main control chip, model STC89C51. Through multi-sensor closed-loop feedback, it uses real-time monitoring of the temperature of the drying chamber, cold trap, and condenser coil to dynamically adjust the refrigeration power and shelf heating. It also triggers the vacuum pump inlet pressure sensor to start and stop in stages, thereby improving the vacuum response speed.

[0024] It should be noted that, in this document, relational terms such as "first" and "second" are used merely 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0025] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A condensation system for a vacuum dryer, characterized in that: It includes a vacuum maintenance module, a condensation trapping module, a refrigeration cycle module, and a control module; The vacuum maintenance module includes a main vacuum pump, a Roots pump, an auxiliary vacuum pump, a stainless steel bellows, vacuum valves, and vacuum pipelines; the condensation trap module includes a condenser, a heat exchanger, and a cold trap; and the refrigeration cycle module includes a refrigeration compressor, an expansion valve, an evaporator, and a condensing coil. The Roots pump and the main vacuum pump are connected in series via the stainless steel bellows. The cold trap and the condenser are connected in series. The inlet of the main vacuum pump is connected to the outlet of the condenser via the vacuum pipeline to pump out uncondensed gas and water vapor and maintain the system vacuum. The vacuum valve is installed on the vacuum pipeline to control the gas flow path in the vacuum pipeline. The auxiliary vacuum pump is connected to the outlet of the condenser via an independent pipeline. The cold trap is connected to the drying chamber via a hydraulic mushroom valve. Sublimated water vapor enters the cold trap through this valve and condenses into ice. The heat exchanger is connected to the product shelf and circulates heat-conducting silicone oil to the metal shelf in the drying chamber through a closed pipeline to achieve material temperature control.

2. The condensation system of a vacuum dryer as described in claim 1, characterized in that: The exhaust port of the refrigeration compressor is directly connected to the inlet of the condenser coil through a high-pressure resistant metal pipeline, and the outlet of the condenser coil is connected to the inlet of the expansion valve after passing through a liquid receiver dryer.

3. The condensation system of a vacuum dryer as described in claim 2, characterized in that: The expansion valve outlet is connected to the bottom inlet of the evaporator via an insulated pipe, and the evaporator outlet is inclined upwards to connect to the cold trap inlet.

4. The condensation system of a vacuum dryer as described in claim 1, characterized in that: The control module includes a PLC control box, an electrical control box, a control panel, a temperature sensor, and a pressure sensor.

5. The condensation system of a vacuum dryer as described in claim 4, characterized in that: The number of temperature sensors is several. The temperature sensors are installed on the inner wall of the drying chamber, the outlet of the condenser coil, and the surface of the cold trap, and the temperature sensors are electrically connected to the PLC control box.

6. The condensation system of a vacuum dryer as described in claim 4, characterized in that: The pressure sensors are multiple in number and are installed in the vacuum pump inlet pipe, the refrigeration compressor outlet, the evaporator inlet, and the cold trap outlet. The pressure sensors are also electrically connected to the PLC control box.

7. The condensation system of a vacuum dryer as described in claim 4, characterized in that: The PLC control box is electrically connected to the main vacuum pump, the forestage Roots pump, the auxiliary vacuum pump, and the refrigeration compressor.

8. The condensation system of a vacuum dryer as described in claim 7, characterized in that: The output terminal of the electrical control box is electrically connected to the PLC control box, the main vacuum pump, the pre-stage Roots pump, the auxiliary vacuum pump, and the refrigeration compressor, and the control panel is located on the outer surface of the PLC control box.

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