CN117180802A - Vacuum degasser for liquid chromatography - Google Patents
Vacuum degasser for liquid chromatography Download PDFInfo
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- CN117180802A CN117180802A CN202311075644.2A CN202311075644A CN117180802A CN 117180802 A CN117180802 A CN 117180802A CN 202311075644 A CN202311075644 A CN 202311075644A CN 117180802 A CN117180802 A CN 117180802A
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- air pressure
- vacuum
- vacuum box
- pressure threshold
- degasser
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- 238000004811 liquid chromatography Methods 0.000 title claims abstract description 12
- 239000002904 solvent Substances 0.000 claims description 19
- 239000002985 plastic film Substances 0.000 claims description 7
- 229920006255 plastic film Polymers 0.000 claims description 7
- 239000012466 permeate Substances 0.000 claims description 3
- 230000000630 rising effect Effects 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 6
- 230000002159 abnormal effect Effects 0.000 abstract description 4
- 230000007704 transition Effects 0.000 abstract description 3
- 238000004458 analytical method Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 22
- 238000010586 diagram Methods 0.000 description 3
- 238000004587 chromatography analysis Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000004128 high performance liquid chromatography Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Landscapes
- Degasification And Air Bubble Elimination (AREA)
Abstract
The invention provides a vacuum degasser for liquid chromatography analysis, which fully considers different conditions possibly met by field equipment, or normal or abnormal conditions, utilizes three sets of different operation modes according to local conditions in the operation process of the degasser and switches the operation modes at proper time, thereby effectively ensuring the normal operation of the degasser. The transition from the first normal operation mode to the second normal operation mode and then to the fault mode represents the process of the vacuum degasser from stable operation to gradually unstable operation, and correspondingly, the operation mode also sequentially transits from fine operation to rough operation, which is very suitable for the actual operation of the vacuum degasser.
Description
Technical Field
The invention relates to the field of liquid chromatography, in particular to a vacuum degasser for liquid chromatography.
Background
In the process of high performance liquid chromatography, the gas dissolved in the mobile phase solvent often escapes in the form of bubbles when mixed, which seriously affects the separation efficiency of the chromatographic column, thereby seriously negatively affecting the stability and sensitivity of the chromatographic analysis. For this purpose, it is highly necessary to use a vacuum degasser to eliminate in advance the gas (mainly air) contained or dissolved in the mobile phase before the chromatographic analysis.
In reality, however, the conditions of the mobile phase solvent flowing through the vacuum degasser tend to vary from one to another. Specifically, the concentration of the gas contained in each solvent varies greatly, thereby also causing a significant variation in the vacuum level in the vacuum box during operation of the deaerator. In the face of such differences, vacuum deaerators that are operated in only a single mode in the prior art tend to be unchecked.
Disclosure of Invention
The present invention provides a vacuum degasser for liquid chromatography, which can effectively solve the defects in the prior art.
Specifically, the present invention provides a vacuum degasser for liquid chromatography, in which a transport pipe extends from a container and into a vacuum box, the transport pipe extends a certain distance in the vacuum box and then passes out of the vacuum box and is connected to a suction pump, the vacuum box is also attached with a sensor, the sensor is connected to the vacuum pump via a control circuit, the vacuum pump extends into the vacuum box, the gas carrying period of the vacuum degasser comprises a first normal operation mode, a second normal operation mode, a fault mode, in which first normal operation mode: firstly, starting a suction pump, so that the solvent in the container is sucked into a conveying pipe from the container under the suction of the suction pump and passes through a vacuum box in the conveying pipe, wherein the conveying pipe is made of a tubular plastic film, when the solvent is pumped through the conveying pipe, the dissolved gas in the solvent penetrates through the tubular plastic film and enters the vacuum box, thereby, a sensor senses the rising of the gas pressure in the vacuum box and then transmits a sensing signal to a control circuit, the vacuum pump is triggered to vacuumize the vacuum box, the gas pressure in the vacuum box is caused to rapidly drop, once the sensor senses that the gas pressure in the vacuum box drops to a first gas pressure threshold P1, the vacuum pump is immediately turned off, the solvent flowing in the conveying pipe still continues to release dissolved gas, the rising of the gas pressure in the vacuum box is caused to be higher than the first gas pressure threshold P1, and once the sensor senses that the gas pressure in the vacuum box is higher than the first gas pressure threshold by a differential gas pressure delta P, the vacuum pump is started again to reduce the gas pressure in the vacuum box to the first gas pressure threshold P1, and then the vacuum pump is turned off again, and so on until the gas pressure in the vacuum box always fluctuates between P1 and delta P1; once the sensor senses that the air pressure is always above the first air pressure threshold for a first predetermined time in the first normal mode, the first normal operation mode is switched to a second normal operation mode in which: the vacuum pump is started for a specific time period at intervals of a preset time, a second air pressure threshold value P2 and P2> P1 are set, the air pressure in the vacuum box is maintained between the first air pressure threshold value and the second air pressure threshold value, and once the air pressure in the vacuum box exceeds the second air pressure threshold value, the vacuum pump is switched to a fault mode, and in the fault mode: and once the air pressure in the vacuum box exceeds the second air pressure threshold value, immediately starting to continuously operate the vacuum pump, and if the air pressure in the vacuum box still cannot be reduced to be lower than the second air pressure threshold value after the vacuum pump is continuously operated for a second preset time, judging that the vacuum degasser is out of order, and stopping the operation of the vacuum pump at the moment.
Preferably, the first pressure threshold p1=115 Torr and the second pressure threshold p2=190 Torr.
Preferably, in the second normal operation mode, the vacuum pump is operated for 30 seconds every 2 minutes.
Preferably, the first predetermined time and the second predetermined time are each 8 minutes.
The vacuum degasser provided by the invention fully considers different conditions possibly met by field equipment, or normal or abnormal conditions, and three sets of different operation modes are utilized according to local conditions in the operation process of the degasser and are mutually switched at proper time, so that the normal operation of the degasser is effectively ensured.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following discussion will discuss the embodiments or the drawings required in the description of the prior art, and it is obvious that the technical solutions described in connection with the drawings are only some embodiments of the present invention, and that other embodiments and drawings thereof can be obtained according to the embodiments shown in the drawings without inventive effort for a person skilled in the art.
In summary, the present invention provides a vacuum degasser that can flexibly switch between modes during degassing according to in-situ conditions, thereby being adaptable to
FIG. 1 shows a schematic block diagram of a vacuum degasser for liquid chromatography according to the invention;
fig. 2 shows a schematic diagram of the operation of the vacuum degasser for liquid chromatography according to the invention.
Detailed Description
The following description of the embodiments of the present invention will be made in detail with reference to the accompanying drawings, wherein it is apparent that the embodiments described are only some, but not all embodiments of the present invention. All other embodiments, which can be made by a person of ordinary skill in the art without the need for inventive faculty, are within the scope of the invention, based on the embodiments described in the present invention.
The vacuum degasser according to the invention provides a plurality of operating modes, which can be switched appropriately according to different field conditions, thereby accommodating various changes in the vacuum box. How the multiple sets of operation modes are effectively switched in the present invention will be described in detail below.
Fig. 1 shows a schematic configuration diagram of a vacuum degasser for liquid chromatography according to the present invention.
As shown in fig. 1, the vacuum degasser is provided with a vacuum box 100, and a transfer pipe 101 extends from a container 102 and penetrates the vacuum box 100, and the transfer pipe 101 extends a certain distance in the vacuum box 100 and then penetrates the vacuum box 100 and is connected to a suction pump 106. Meanwhile, the vacuum box 100 is also attached with a sensor 103, and the sensor 103 is connected to a vacuum pump 105 via a control circuit 104. The vacuum pump 105 extends into the vacuum box 100.
In operation, suction pump 106 is activated, whereby solvent in container 102 is sucked from container 102 into duct 101 under suction of suction pump 102 and through vacuum box 100 in duct 101 until it is sucked out.
It should be noted that the transfer tube 101 here is made of a tubular plastic film, and when the solvent is pumped through the transfer tube 101, the dissolved gas in the solvent will permeate through the tubular plastic film into the vacuum box 100, thereby changing the vacuum level within the vacuum box 100.
The change in vacuum level within vacuum box 100 may be sensed by sensor 103 attached to vacuum box 100 to form a sensing signal. The sensing signal is then transmitted to the control circuit 104, and the control circuit 104 converts the sensing signal into an electrical control signal to thereby activate the vacuum pump 105 to perform a vacuum pumping operation on the vacuum box 100.
The specific structure of the vacuum degasser for liquid chromatography according to the present invention has been described in detail hereinabove. Hereinafter, how the vacuum degasser can adapt to complex and variable field conditions by adopting different working modes will be described based on the specific structure.
First, a first normal operation mode is described. The first normal operation mode has been started from the start of the vacuum degasser. The vacuum degasser is started and solvent is pumped through the transfer pipe 101 and the dissolved gas in the solvent permeates through the tubular plastic film into the vacuum box 100, whereby in a first normal operation mode, the sensor 103 senses an increase in the air pressure of the vacuum box 100 and transmits a sensing signal to the control circuit 104, thereby triggering the vacuum pump 105 to evacuate the vacuum box 100, resulting in a rapid decrease in the air pressure within the vacuum box 100, as shown in fig. 2 for the first stage of the first normal operation mode.
Of course, in the first normal operating mode, the vacuum pump 105 may not be continuously evacuated, and once the sensor 103 senses that the air pressure within the vacuum box 100 has fallen to the first air pressure threshold P1 (shown as 115Torr in FIG. 2), the vacuum pump 105 is turned off. Thereby, the first phase of the first normal operation mode as shown in fig. 2 ends.
Of course, with the vacuum pump 105 turned off, the second phase of the first normal operation mode begins. The solvent flowing in the delivery tube 101 will continue to release dissolved gases, which in turn will cause the air pressure within the vacuum box 100 to rise above the first air pressure threshold P1. And as soon as the sensor 103 senses that the air pressure in the vacuum box 100 is higher than the first air pressure threshold value by the differential air pressure value deltap, the vacuum pump 105 can be started again to reduce the air pressure in the vacuum box 100 to the first air pressure threshold value P1. Subsequently, the vacuum pump 105 is turned off again. With this circulation, the air pressure in the vacuum chamber 100 always fluctuates between P1 and P1+ΔP.
As best shown in fig. 2, the air pressure within the vacuum box 100 is constantly exhibiting saw tooth like fluctuations during the second phase of the first normal operation mode.
And as the solvent continues to flow through the delivery tube 101 and the flow rate continues to rise, the solvent will accelerate the release of a large amount of dissolved gas. Thus, it is difficult to maintain the air pressure around the first air pressure threshold value in the first normal mode.
Once the sensor 103 senses that the air pressure is always above the first air pressure threshold for a first predetermined time (shown as 8 minutes in fig. 2) in the first normal mode, the vacuum degasser switches from the first normal operation mode to the second normal operation mode.
As mentioned above, the starting and shutting down of the vacuum pump 105 in the first normal operation mode is based on the inductive feedback of the sensor 103 to the air pressure. In contrast, the second normal operating mode is a fixed timing mode. In the second normal operation mode, the vacuum pump 105 is activated for a certain period of time at predetermined intervals (e.g., every 2 minutes the vacuum pump 105 is operated for 30 seconds).
Further, a second pressure threshold value P2, P2> P1 is set (for example, P2 is shown as 190Torr in fig. 2). Unlike the first normal operating mode, which is intended to always maintain the air pressure near the first air pressure threshold, the second normal operating mode is relatively "rough" in that it is only necessary to maintain the air pressure between the first air pressure threshold and the second air pressure threshold (between 115Torr and 190Torr in the illustration of FIG. 2).
The above-described switching of the first and second normal operation modes is sufficient to meet the requirements of normal operation of the vacuum degasser. However, with "normal" there is always the possibility of "abnormal". In the event that further operation of the vacuum degasser encounters a severe fault (e.g., a blow-by), the air pressure within the vacuum box 100 will increase dramatically, quickly exceeding the second air pressure threshold, thereby requiring a failure mode to be initiated.
In the fault mode, once the air pressure within vacuum box 100 exceeds the second air pressure threshold, continuous operation of vacuum pump 105 is immediately initiated. If the vacuum pump 105 is continuously operated for a second predetermined time (8 minutes as shown in FIG. 2) and the air pressure within the vacuum box 100 still fails to drop back below a second air pressure threshold (e.g., 190 Torr), then it may be determined that the vacuum degasser is malfunctioning, at which time the vacuum pump 105 is shut down.
The construction and operation of the vacuum degasser according to the invention have been described so far. The vacuum degasser provided by the invention fully considers different conditions possibly met by field equipment, or normal or abnormal conditions, and three sets of different operation modes are utilized according to local conditions in the operation process of the degasser and are mutually switched at proper time, so that the normal operation of the degasser is effectively ensured.
As described above, the transition from the first normal operation mode to the second normal operation mode and then to the failure mode characterizes the process from stable to gradually unstable operation of the vacuum degasser, and correspondingly, the operation mode sequentially transitions from fine to rough gradually, which is very suitable for the actual operation of the vacuum degasser.
The foregoing description of the exemplary embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any modifications, equivalents, and variations which fall within the spirit and scope of the invention are intended to be included in the scope of the invention.
Claims (4)
1. A vacuum degasser for liquid chromatography, in which a transport pipe extends from a container and into a vacuum box, the transport pipe extending a certain distance in the vacuum box and out of the vacuum box and being connected to a suction pump, the vacuum box being further attached with a sensor connected to the vacuum pump via a control circuit, the vacuum pump extending into the vacuum box, characterized in that:
the air-carrying period of the vacuum degasser comprises a first normal operation mode, a second normal operation mode and a fault mode,
in a first normal operation mode:
the suction pump is first activated, whereby the solvent in the container is sucked from the container into the transport pipe under suction of the suction pump and through the vacuum box in the transport pipe,
the conveying pipe is made of tubular plastic film, when solvent is pumped through the conveying pipe, the dissolved gas in the solvent permeates through the tubular plastic film and enters the vacuum box, so that the sensor senses the rising of the air pressure in the vacuum box, and then sends the sensing signal to the control circuit to trigger the vacuum pump to vacuumize the vacuum box, and the air pressure in the vacuum box is quickly reduced,
once the sensor senses that the air pressure in the vacuum box is reduced to a first air pressure threshold value P1, the vacuum pump is immediately turned off, the solvent flowing in the conveying pipe still continuously releases dissolved air, the air pressure in the vacuum box is increased to be higher than the first air pressure threshold value P1, the vacuum pump is started again to reduce the air pressure in the vacuum box to the first air pressure threshold value P1 as long as the sensor senses that the air pressure in the vacuum box is higher than the first air pressure threshold value by a differential air pressure value delta P, then the vacuum pump is turned off again, and the air pressure in the vacuum box always fluctuates between P1 and P1+delta P;
once the sensor senses that the air pressure is always above the first air pressure threshold for a first predetermined time in the first normal mode, the first normal operation mode is switched to the second normal operation mode,
in the second normal operation mode:
the vacuum pump is activated for a certain period of time at predetermined intervals,
setting a second air pressure threshold value P2, wherein P2> P1, maintaining the air pressure in the vacuum box between the first air pressure threshold value and the second air pressure threshold value, switching to a fault mode once the air pressure in the vacuum box exceeds the second air pressure threshold value,
in failure mode:
once the air pressure in the vacuum box exceeds the second air pressure threshold value, the continuous operation of the vacuum pump is started immediately,
if the vacuum pump is continuously operated for a second preset time, the air pressure in the vacuum box still cannot be reduced to be lower than a second air pressure threshold value, the vacuum degasser is judged to be in failure, and the vacuum pump stops operating at the moment.
2. The vacuum degasser of claim 1, wherein said first pressure threshold p1=115 Torr and said second pressure threshold p2=190 Torr.
3. A vacuum degasser according to claim 2, characterized in that in the second normal operation mode the vacuum pump is run for 30 seconds every 2 minutes.
4. A vacuum degasser according to claim 3, wherein the first predetermined time and the second predetermined time are each 8 minutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311075644.2A CN117180802A (en) | 2023-08-24 | 2023-08-24 | Vacuum degasser for liquid chromatography |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311075644.2A CN117180802A (en) | 2023-08-24 | 2023-08-24 | Vacuum degasser for liquid chromatography |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117180802A true CN117180802A (en) | 2023-12-08 |
Family
ID=88984187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311075644.2A Pending CN117180802A (en) | 2023-08-24 | 2023-08-24 | Vacuum degasser for liquid chromatography |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117180802A (en) |
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2023
- 2023-08-24 CN CN202311075644.2A patent/CN117180802A/en active Pending
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