CN217236131U - Refrigerating system for freeze dryer and freeze dryer - Google Patents

Abstract

The application relates to the technical field of freeze dryers, and discloses a refrigeration system for a freeze dryer and the freeze dryer. A refrigeration system for a lyophilizer comprising: an evaporating coil; the compressor is communicated with the evaporation coil; and one end of the air return pipe is communicated with the air outlet of the evaporation coil pipe, the other end of the air return pipe is communicated with the air inlet of the compressor, and the highest point of the air return pipe is higher than the air inlet of the compressor. In the embodiment of the disclosure, the highest point of the air return pipe is higher than the air inlet of the compressor, that is, the air return pipe comprises a descending section, the descending section is communicated with the highest point of the air return pipe and the air inlet of the compressor, and the lubricating oil flows in the descending section from top to bottom. When the compressor is stopped, the lubricating oil flows into the compressor by utilizing the gravity of the compressor, so that the lubricating oil is prevented from being driven to reversely flow by the low-pressure environment in the evaporating coil, and the lubricating oil is sucked into the evaporating coil again and sucked out of the compressor.

Description

Refrigerating system for freeze dryer and freeze dryer

Technical Field

The present application relates to the field of freeze dryers, for example to a refrigeration system for a freeze dryer and a freeze dryer.

Background

At present, a freeze dryer is widely applied to the fields of pharmacy, food, biology, chemical industry and the like, a refrigerating system in the freeze dryer is an important component of the freeze dryer, and the guarantee of the normal operation of the refrigerating system is one of the core problems to be considered for designing the freeze dryer.

The prior art discloses a vapor return and liquid return protection device which is externally arranged on a condensing coil of a condenser of a freeze dryer refrigeration system and comprises a liquid collecting pipe buffer, a horizontal pipe, a U-shaped bent pipe of a cold trap, a vertical pipe, a second U-shaped bent pipe, a vapor return buffer pipe, a capillary pipe, two cooling valves, two expansion valves and a liquid feeding pipe. The inlet end of the liquid collecting tube buffer is connected with the outlet end of the condensing coil, the inlet end of the horizontal tube is connected with the outlet end of the liquid collecting tube buffer, the inlet end of the U-shaped bent tube of the cold trap is connected with the outlet end of the horizontal tube, the inlet end of the vertical tube is connected with the outlet end of the U-shaped bent tube of the cold trap, the inlet end of the second U-shaped bent tube is connected with the outlet end of the vertical tube, the inlet end of the steam return buffer tube is connected with the outlet end of the second U-shaped bent tube, the outlet end of the steam return buffer tube is connected with a compressor, the outlet end of the compressor is connected with a water condenser, the outlet end of the water condenser is connected with a liquid outlet tube, the inlet end of the capillary tube is connected with the liquid outlet tube, the outlet end of the capillary tube is connected with the steam return buffer tube, the capillary tube is provided with a steam return cooling control valve, the two cooling valves are connected with the outlet end of the liquid outlet tube in parallel, and each expansion valve is connected with one cooling valve in one-to-one correspondence, the inlet end of the liquid feeding pipe is connected with the two expansion valves, and the outlet end of the liquid feeding pipe is connected with the inlet end of the condensing coil pipe.

In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

after the compressor is stopped, because the temperature and the pressure in the condensing coil are lower, the oil return phenomenon of the refrigeration oil (lubricating oil) is easy to occur, so that the refrigeration oil (lubricating oil) reversely flows in the pipeline.

SUMMERY OF THE UTILITY MODEL

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview nor is intended to identify key/critical elements or to delineate the scope of such embodiments but rather as a prelude to the more detailed description that is presented later.

The embodiment of the disclosure provides a refrigeration system for a freeze dryer and the freeze dryer, so as to solve the problem of reverse flow of lubricating oil after a compressor is stopped.

According to a first aspect of the present application, there is provided a refrigeration system for a freeze dryer comprising: an evaporating coil; the compressor is communicated with the evaporation coil; and one end of the air return pipe is communicated with the air outlet of the evaporation coil pipe, the other end of the air return pipe is communicated with the air inlet of the compressor, and the highest point of the air return pipe is higher than the air inlet of the compressor.

Optionally, the muffler comprises: one end of the first air return pipe is communicated with an air outlet of the evaporation coil pipe; one end of the second air return pipe is communicated with the other end of the first air return pipe, and the other end of the second air return pipe is communicated with an air inlet of the compressor; the connection part of the one end of the second air return pipe and the other end of the first air return pipe is bent, and the highest point of the air return pipe comprises the highest point of the bending.

Optionally, an included angle between a straight line of the first air return pipe and a straight line of the air outlet of the evaporation coil is in a range from 0 degree to 70 degrees.

Optionally, the slope of the second muffler is greater than the slope of the first muffler.

Optionally, the second gas return pipe extends at least partially vertically downward in the refrigerant flow direction.

Optionally, the first return pipe extends upward in a refrigerant flow direction.

Optionally, a communication part between the one end of the second air return pipe and the other end of the first air return pipe is arc-shaped.

Optionally, the highest point of the air return pipe is lower than the liquid inlet of the evaporation coil.

Optionally, the liquid inlet of the evaporation coil is higher than the gas outlet of the evaporation coil.

According to a second aspect of the present application, there is provided a freeze dryer comprising: cold trap; in the refrigeration system for a freeze dryer according to any of the above claims, the evaporation coil is disposed in the cold trap or wound outside the cold trap.

The refrigeration system for the freeze dryer and the freeze dryer provided by the embodiment of the disclosure can realize the following technical effects:

one end of the air return pipe is communicated with the air outlet of the evaporation coil pipe, the other end of the air return pipe is communicated with the air inlet of the compressor, and the compressor is communicated with the evaporation coil pipe through the air return pipe. The refrigerant and the lubricating oil in the evaporating coil flow to the compressor through the return pipe. The highest point of the return air pipe is higher than the air inlet of the compressor. That is, the muffler includes a descending section communicating the highest point of the muffler with the air inlet of the compressor, and the lubricating oil flows in the descending section in a direction from the top (highest point of the muffler) to the bottom (air inlet of the compressor). When the compressor is stopped, the lubricating oil flows into the compressor by utilizing the gravity of the compressor, so that the lubricating oil is prevented from being driven to reversely flow by the low-pressure environment in the evaporating coil, and the lubricating oil is sucked into the evaporating coil again and sucked out of the compressor. Therefore, after the compressor is stopped, lubricating oil still flows into the compressor, and the amount of the lubricating oil in the compressor is increased. The lubricating oil volume in the compressor increases, can carry out better lubrication to compressor inner structure, improves the life of compressor. Meanwhile, the compressor has good performance when being restarted, and stable operation of the refrigerating system is guaranteed.

The foregoing general description and the following description are exemplary and explanatory only and are not restrictive of the application.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the accompanying drawings and not in limitation thereof, in which elements having the same reference numeral designations are shown as like elements and not in limitation thereof, and wherein:

fig. 1 is a schematic view of a portion of a refrigeration system for a freeze dryer according to an embodiment of the present disclosure;

fig. 2 is a schematic cross-sectional view of a freeze dryer provided in an embodiment of the present disclosure;

FIG. 3 is a schematic cross-sectional view of a cold trap provided in embodiments of the present disclosure;

fig. 4 is a schematic structural diagram of a cold trap provided in an embodiment of the present disclosure.

Reference numerals:

10. an evaporating coil; 20. a compressor; 30. an air return pipe; 31. a first gas return pipe; 32. a second muffler; 33. bending; 40. cold trap; 410. a vacuum pumping port; 420. a gap; 50. a baffle plate; 510. and (4) notches.

Detailed Description

So that the manner in which the features and advantages of the embodiments of the present disclosure can be understood in detail, a more particular description of the embodiments of the disclosure, briefly summarized above, may be had by reference to the appended drawings, which are included to illustrate, but are not intended to limit the embodiments of the disclosure. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may be practiced without these details. In other instances, well-known structures and devices may be shown in simplified form in order to simplify the drawing.

The terms "cold-trap," "second," and the like in the description and claims of embodiments of the present disclosure and in the foregoing drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the present disclosure described herein may be made. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.

In the embodiments of the present disclosure, the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the disclosed embodiments and their examples and are not intended to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation. Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meanings of these terms in the embodiments of the present disclosure can be understood by those of ordinary skill in the art as appropriate.

In addition, the terms "disposed," "connected," and "secured" are to be construed broadly. For example, "connected" may be a fixed connection, a detachable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. Specific meanings of the above terms in the embodiments of the present disclosure can be understood by those of ordinary skill in the art according to specific situations.

The term "and/or" is an associative relationship that describes objects, meaning that three relationships may exist. For example, a and/or B, represents: a or B, or A and B.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

As shown in fig. 2, embodiments of the present disclosure provide a lyophilizer that includes a cold trap 40 and a refrigeration system for the lyophilizer. The refrigeration system for the freeze dryer includes an evaporation coil 10, the evaporation coil 10 being disposed within the cold trap 40 or wound outside the cold trap 40.

With this alternative embodiment, the evaporator coil 10 is disposed in the cold trap 40 or wound outside the cold trap 40, and can transfer the cold energy generated by the refrigeration system into the cold trap 40, so that the cold trap 40 freezes the material.

As shown in fig. 1, 2 and 4, a refrigeration system for a freeze dryer provided by the embodiment of the present disclosure includes an evaporation coil 10, a compressor 20 and a return air pipe 30. Compressor 20 is in communication with evaporator coil 10. One end of the air return pipe 30 is communicated with the air outlet of the evaporation coil 10, the other end of the air return pipe 30 is communicated with the air inlet of the compressor 20, and the highest point of the air return pipe 30 is higher than the air inlet of the compressor 20.

The compressor 20 is a core component of the refrigeration system, which can be said to be a heart of the refrigeration system, and ensuring the normal operation of the compressor 20 is one of the core problems to be considered in designing the refrigeration system. The compressor 20 needs to have a sufficient amount of oil to ensure lubrication of the internal components of the compressor 20 during operation. Inside the compressor 20, the refrigerant is mixed with the lubricating oil, and the compressor 20 discharges the refrigerant while taking up the lubricating oil. When the compressor 20 is stopped, the refrigerant and the lubricant oil cannot be provided with power to the inside of the compressor 20 any more, and the temperature and the air pressure of the evaporation coil 10 are low, so that the lubricant oil moves into the evaporation coil 10 and cannot return to the inside of the compressor 20. The dynamic balance of the lubricant in the entire refrigeration system is maintained only if this portion of the discharged lubricant can be carried back to the compressor 20, otherwise the compressor 20 would be damaged by the lack of lubricant. Therefore, it is important to allow the lubricating oil outside the compressor 20 in the refrigeration system to flow into the compressor 20.

With this alternative embodiment, one end of the air return pipe 30 is connected to the air outlet of the evaporation coil 10, the other end of the air return pipe 30 is connected to the air inlet of the compressor 20, and the compressor 20 is connected to the evaporation coil 10 through the air return pipe 30. The refrigerant and lubricant oil in the evaporator coil 10 flow through the return air pipe 30 to the compressor 20. The highest point of the return air pipe 30 is higher than the intake port of the compressor 20. That is, the muffler 30 includes a descending section communicating the highest point of the muffler 30 and the intake port of the compressor 20, and the lubricating oil flows in the descending section in a direction from the top (the highest point of the muffler 30) to the bottom (the intake port of the compressor 20). When the compressor 20 is stopped, the lubricating oil flows into the compressor 20 by its own gravity, so as to prevent the low-pressure environment in the evaporating coil 10 from driving the lubricating oil to flow in the reverse direction, suck the lubricating oil into the evaporating coil 10 again, and suck the lubricating oil out of the compressor 20. This allows the lubricant to flow into the compressor 20 after the compressor 20 is stopped, thereby increasing the amount of lubricant in the compressor 20. The amount of lubricant in the compressor 20 is increased, which can better lubricate the internal structure of the compressor 20 and improve the service life of the compressor 20. Meanwhile, the compressor 20 has good performance when being started again, and stable operation of the refrigerating system is ensured.

As shown in fig. 1, in some alternative embodiments, muffler 30 includes a first muffler 31 and a second muffler 32. One end of the first air return pipe 31 is communicated with the air outlet of the evaporation coil 10. One end of the second muffler 32 communicates with the other end of the first muffler 31, and the other end of the second muffler 32 communicates with the intake port of the compressor 20. Wherein, a bent part 33 is formed at the communication position of one end of the second air return pipe 32 and the other end of the first air return pipe 31, and the highest point of the air return pipe 30 comprises the highest point of the bent part 33.

The joint between one end of the second muffler 32 and the other end of the first muffler 31 forms a bend 33, and the highest point of the muffler 30 includes the highest point of the bend 33. The first air return pipe 31 is at least partially an ascending section, and the second air return pipe 32 is at least partially a descending section. When the compressor 20 is stopped, the lubricant in the second muffler 32 flows into the compressor 20 by its own weight, so as to prevent the lubricant from flowing reversely under the low-pressure environment in the evaporating coil 10, which causes the lubricant to be sucked into the evaporating coil 10 again and the lubricant to be sucked out from the compressor 20.

In some alternative embodiments, the angle between the line of the first return air pipe 31 and the line of the evaporation coil 10 at the air outlet is in the range of 0 to 70 degrees.

The refrigerant and the lubricating oil flow from the outlet of the evaporating coil 10 to the first return pipe 31. If the range of the included angle between the first air return pipe 31 and the straight line at the air outlet of the evaporation coil 10 is too large, the refrigerant and the lubricating oil need to turn at the joint of the first air return pipe 31 and the evaporation coil 10, so that a large resistance is brought to the flow of the refrigerant and the lubricating oil. The greater the resistance, the greater the power provided by the compressor 20, thereby increasing the burden on the compressor 20. By adopting the optional embodiment, the included angle between the straight line of the first air return pipe 31 and the straight line of the air outlet of the evaporation coil 10 is in the range of 0-70 degrees, so that the resistance of the joint of the first air return pipe 31 and the evaporation coil 10 to the refrigerant and the lubricating oil is reduced, the burden of the compressor 20 is reduced, and the service life of the compressor 20 is prolonged.

Optionally, the pipe wall at the connection between the first return pipe 31 and the air outlet of the evaporation coil 10 is an arc-shaped pipe wall. This reduces the flow resistance of the refrigerant and the lubricant oil at the connection between the first return pipe 31 and the outlet of the evaporating coil 10, and reduces the operation load of the compressor 20.

In some alternative embodiments, the slope of second muffler 32 is greater than the slope of first muffler 31.

With this alternative embodiment, the second return pipe 32 has a greater slope than the first return pipe 31. When the refrigerant and the lubricating oil flow in the second muffler 32, the slope of the second muffler 32 is large, and the refrigerant and the lubricating oil can flow downward by using the self-gravity, so that the refrigerant and the lubricating oil are driven by the driving force of the compressor 20 and are driven by the self-driving force. The refrigerant and the lubricating oil are stressed to be increased, the flow speed of the refrigerant and the lubricating oil is higher, or the driving force for driving the refrigerant and the lubricating oil to flow in the second air return pipe 32 is reduced. The gravity of the refrigerant and the lubricant itself may also be used to provide a driving force to facilitate the flow of the refrigerant and the lubricant into the compressor 20 when the compressor 20 is stopped. Meanwhile, the slope of the first return pipe 31 is small, and the driving force for driving the refrigerant and the lubricating oil to flow in the first return pipe 31 can be reduced.

In some alternative embodiments, second muffler 32 extends at least partially vertically downward in the direction of refrigerant flow.

With this alternative embodiment, second muffler 32 extends at least partially vertically downward, and refrigerant and lubricant flow vertically downward in the vertical section. Thus, the gravity of the refrigerant and the lubricant oil are used to provide driving force, and the refrigerant and the lubricant oil are convenient to flow into the compressor 20 when the compressor 20 is stopped.

In some alternative embodiments, the first return pipe 31 extends upward in the refrigerant flow direction.

With this alternative embodiment, the first gas return pipe 31 extends upward, and the first gas return pipe 31 is prevented from being angled, thereby increasing the flow resistance of the refrigerant and the lubricant oil in the first gas return pipe 31.

In some alternative embodiments, the connection between one end of the second air return pipe 32 and the other end of the first air return pipe 31 is arc-shaped.

With this alternative embodiment, the connection between one end of the second air return pipe 32 and the other end of the first air return pipe 31 is arc-shaped, and the connection between one end of the second air return pipe 32 and the other end of the first air return pipe 31 is bent 33. Therefore, the wall of the bend 33 is arc-shaped, and the refrigerant and the lubricant smoothly flow from the first muffler 31 to the second muffler 32. Thus, the resistance of the communication part (bend 33) to the refrigerant and the lubricating oil is reduced, thereby reducing the load of the compressor 20 and prolonging the service life of the compressor.

Optionally, the bend 33 has an arc of 90 degrees (none) to 180 degrees (none).

In some alternative embodiments, the highest point of the muffler 30 is lower than the inlet of the expansion coil 10.

By adopting the alternative embodiment, the refrigerant and the lubricating oil enter the evaporating coil 10 from the liquid inlet of the evaporating coil 10, and the refrigerant transfers the cold energy to the cold trap 40 and then flows out from the air outlet of the evaporating coil 10 and flows into the air return pipe 30. Refrigerant and lubricant are left in the muffler 30 and the evaporator coil 10 when the compressor 20 is stopped. The highest point of the air return pipe 30 is lower than the liquid inlet of the evaporating coil 10, and the highest point of the air return pipe 30 is higher than the air inlet of the compressor 20. Due to the pressure difference, the refrigerant and the lubricant oil in the evaporating coil 10 above the highest point of the muffler 30 in the evaporating coil 10 flow from the evaporating coil 10 to the compressor 20. This allows more lubricant to flow into the compressor 20, which provides better lubrication of the internal structure of the compressor 20 and increases the life of the compressor 20. The compressor 20 has good performance when it is restarted, ensuring smooth operation of the refrigeration system.

In some alternative embodiments, the liquid inlet of the evaporator coil 10 is higher than the air outlet of the evaporator coil 10.

By adopting the alternative embodiment, the refrigerant and the lubricating oil enter the evaporating coil 10 from the liquid inlet of the evaporating coil 10, and the refrigerant transmits the cold energy to the cold trap 40 and then flows out from the air outlet of the evaporating coil 10. The liquid inlet of the evaporation coil 10 is higher than the gas outlet of the evaporation coil 10, the refrigerant and the lubricating oil can provide a driving force for flowing downwards by utilizing the gravity action of the refrigerant and the lubricating oil, the driving force provided by the compressor 20 for the refrigerant and the lubricating oil is reduced, the burden of the compressor 20 is reduced, and the service life of the compressor 20 is prolonged.

The freeze dryer provided by the embodiment of the present disclosure includes any one of the refrigeration systems for the freeze dryer.

The freeze dryer provided by the embodiment of the present disclosure includes the refrigeration system for a freeze dryer in any one of the above embodiments, so that all the beneficial effects of the refrigeration system for a freeze dryer in any one of the above embodiments are achieved, and details are not described herein again.

In some alternative embodiments, as shown in fig. 3 and 4, with the expansion coil 10 disposed within the cold trap 40, there is a gap 420 between the expansion coil 10 and the inside wall of the cold trap 40.

With this alternative embodiment, the evaporator coil 10 is disposed in the cold trap 40, and a gap 420 is formed between the evaporator coil 10 and the inner sidewall of the cold trap 40. Thus, during the freezing phase, both sides of the evaporating coil 10 are in contact with the air in the cold trap 40, increasing the transfer area of the cold. The transfer area of the cold energy is increased, thereby improving the transfer efficiency of the cold energy and enabling the cold trap 40 to reach the freezing temperature faster. In the drying stage, the water vapor sublimated from the material can contact with the two sides of the evaporation coil 10, so that the contact area of the water vapor and the evaporation coil 10 is increased, and the water capturing capacity of the cold trap 40 is improved.

Alternatively, in the case where the evaporating coil 10 is wound outside the cold trap 40, the evaporating coil 10 abuts against the outside wall of the cold trap 40.

By adopting the alternative embodiment, the efficiency of transferring cold energy from the evaporating coil 10 to the cold trap 40 can be improved by abutting the evaporating coil 10 against the outer side wall of the cold trap 40.

As shown in fig. 3 and 4, the lyophilizer optionally further comprises a baffle 50. The side walls of cold trap 40 are provided with evacuation ports 410 to evacuate the interior of cold trap 40. The evaporation coil 10 is arranged in the cold trap 40 and corresponds to the side wall of the cold trap 40, a gap 420 is formed between the evaporation coil 10 and the inner side wall of the cold trap 40, and the vacuum-pumping port 410 is communicated with the gap 420. The baffle 50 is disposed in the gap 420, and at least a portion of the baffle 50 covers the vacuum-pumping port 410, the baffle 50 is provided with a gap 510, and the vacuum-pumping port 410 is communicated with the gap 420 through the gap 510, so that the gas flows around the evaporation coil 10 and then flows into the vacuum-pumping port 410 through the gap 510, thereby increasing the contact area between the gas and the evaporation coil 10.

The interior of the cold trap 40 is evacuated through the evacuation port 410, and the gas in the cold trap 40 flows toward the evacuation port 410. The gas comprises water vapor that sublimes from the material and contacts the expansion coil 10 as the gas flows toward the evacuation port 410. Because of the lower temperature of expansion coil 10, water vapor condenses on the surfaces in contact with expansion coil 1030. The evaporator coil 10 has a gap 420 with the side wall of the cold trap 40, and the vacuum port 410 is in communication with the gap 420, and gas can flow in the gap 420 to cause condensation of water vapor on the surface of the evaporator coil 10 facing the side wall of the cold trap 40. The baffle 50 at least partially shields the evacuation port 410, and the baffle 50 is provided with a notch 510, wherein the notch 510 is in communication with the evacuation port 410. So that the gas entering the vacuum port 410 bypasses the baffle 50, enters the gap 510 and flows into the vacuum port 410. Because the baffle 50 is arranged in the gap 420 between the evaporating coil 10 and the side wall of the cold trap 40, the gas also flows around the evaporating coil 10 in the process of flowing around the baffle 50, so that the contact area between the gas and the evaporating coil 10 is increased, more water vapor is condensed on the evaporating coil 10, and the water capturing capacity of the cold trap 40 is improved. Meanwhile, only a small amount of water vapor enters the vacuumizing device through the vacuumizing port 410, so that the burden of the vacuumizing device is reduced, and the service life of the vacuumizing device is prolonged.

Optionally, the sidewall of the cold trap 40 is further provided with an air inlet, which is higher than the vacuum pumping port 410. The baffle 50 comprises a first baffle. The first baffle is disposed above the vacuum-pumping port 410, is lower than the air inlet, and extends along the direction from the inner sidewall of the cold trap 40 to the evaporation coil 10, and the first baffle abuts against the inner sidewall of the cold trap 40.

With this alternative embodiment, the gas inlet is higher than the vacuum port 410 and the gas moves from the top down. The first baffle is disposed above the vacuum port 410 and below the gas inlet. That is, the first baffle is disposed on the movement path of the gas flowing from the gas inlet to the vacuum-pumping port 410, and prevents the gas from flowing directly from the gas inlet to the vacuum-pumping port 410, so that the gas moves around the first baffle, that is, around the evaporation coil 10, the contact area between the gas and the evaporation coil 10 is increased, the evaporation coil 10 captures more water vapor, and the water-capturing capacity of the cold trap 40 is improved. The first baffle extends in the direction from the inner side wall of the cold trap 40 to the evaporating coil 10, so that the area of the first baffle for obstructing the flow of gas is larger, and more gas can flow around the evaporating coil 10. The first baffle is abutted against the inner side wall of the cold trap 40, so that gas can be prevented from flowing into the vacuumizing port 410 from a gap between the first baffle and the inner side wall of the cold trap 40, more gas is in contact with the evaporation coil 10, and the water capturing capacity of the cold trap 40 is improved.

In some alternative embodiments, the baffle 50 further comprises a second baffle. The upper end of the second baffle is connected to the baffle 50 of the cold trap 40, the lower end of the second baffle extends to the lower part of the vacuuming port 410, and the second baffle at least partially shields the vacuuming port 410.

With this alternative embodiment, at least a portion of the gas enters the cold trap 40, flows downward, and then into the evacuation port 410 due to the sinking action of the cold air. The gas contacts the evaporating coil 10 during the downward flow and the evaporating coil 10 captures the water vapor. The upper end of the second baffle is connected with the baffle 50 of the cold trap 40, and the lower end of the second baffle extends to the lower part of the vacuumizing port 410, so that gas is blocked from directly entering the vacuumizing port 410 from the front side of the vacuumizing port 410, the gas moves around the second baffle, namely around the evaporation coil 10, the contact area between the gas and the evaporation coil 10 is increased, the evaporation coil 10 captures more water vapor, and the water capturing capacity of the cold trap 40 is improved.

After the gas enters the cold trap 40, most of the gas enters the evacuation port 410 from the upper and front sides of the evacuation port 410. The upper end of the second baffle is connected to the baffle 50 of the cold trap 40, and can block the gas entering the evacuation port 410 from the upper side and the front side of the evacuation port 410, so that the gas moves around the evaporation coil 10, thereby improving the water trapping capacity of the cold trap 40.

In some alternative embodiments, the baffle 50 further comprises a third baffle. The third baffle is disposed below the vacuum-pumping port 410, is located between the second baffle and the sidewall of the cold trap 40, and abuts against the sidewall of the cold trap 40.

With this alternative embodiment, the gas flows downward after entering the cold trap 40 due to the sinking of the cold air, and a portion of the gas flows into the evacuation port 410 from below the evacuation port 410. The third baffle is arranged below the vacuumizing port 410, and blocks the gas from flowing to the vacuumizing port 410, so that the gas moves around the third baffle, namely around the evaporation coil 10, the contact area between the gas and the evaporation coil 10 is increased, the evaporation coil 10 captures more water vapor, and the water capturing capacity of the cold trap 40 is improved.

The above description and the drawings sufficiently illustrate embodiments of the disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The embodiments of the present disclosure are not limited to the structures that have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (10)

1. A refrigeration system for a lyophilizer comprising:

an evaporator coil (10);

a compressor (20) in communication with the evaporator coil (10);

the air return pipe (30), one end of air return pipe (30) with the gas outlet of evaporating coil (10) is linked together, the other end of air return pipe (30) with the air inlet of compressor (20) is linked together, the highest point of air return pipe (30) is higher than the air inlet of compressor (20).

2. Refrigeration system for a freeze dryer according to claim 1, characterized in that said air return duct (30) comprises:

one end of the first air return pipe (31) is communicated with an air outlet of the evaporation coil (10);

one end of the second air return pipe (32) is communicated with the other end of the first air return pipe (31), and the other end of the second air return pipe (32) is communicated with an air inlet of the compressor (20);

wherein, a bend (33) is formed at the communication position of the one end of the second air return pipe (32) and the other end of the first air return pipe (31), and the highest point of the air return pipe (30) comprises the highest point of the bend (33).

3. The refrigeration system for a lyophilizer of claim 2,

the included angle range of the straight line of the first air return pipe (31) and the straight line of the air outlet of the evaporation coil pipe (10) is 0-70 degrees.

4. The refrigeration system for a lyophilizer of claim 2,

the second return pipe (32) has a greater gradient than the first return pipe (31).

5. The refrigeration system for a lyophilizer of claim 4,

the second gas return pipe (32) extends at least partially vertically downward in the refrigerant flow direction.

6. The refrigeration system for a lyophilizer of claim 2,

the first return pipe (31) extends upward in the refrigerant flow direction.

7. The refrigeration system for a lyophilizer of claim 2,

the communication position of one end of the second air return pipe (32) and the other end of the first air return pipe (31) is arc-shaped.

8. The refrigeration system for a lyophilizer of claim 1,

the highest point of the air return pipe (30) is lower than the liquid inlet of the evaporation coil pipe (10).

9. The refrigeration system for a lyophilizer according to any one of claims 1 to 8,

the liquid inlet of the evaporation coil (10) is higher than the gas outlet of the evaporation coil (10).

10. A lyophilizer, characterized in that it comprises:

a cold trap (40);

refrigeration system for a freeze dryer according to any of claims 1 to 9, the evaporation coil (10) being located inside the cold trap (40) or wound outside the cold trap (40).

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