JPS5925095A - Pumping plant - Google Patents

Abstract

PURPOSE:To make a carrier fluid carrying no pulstion flow and excellent in quantitative characteristics feedable as well as to cause air bubbles to be hardly produced there, besides ease of maintenance, by driving two plungers, whose sectional area is in the ratio 2:1 each, for reciprocating motion, while coupling all ranges from a discharge port of one side pump head to a suction port of the other side pump head. CONSTITUTION:From the point that suction of 12a and discharge of 12b are all over, a connecting rod 10 gets moving to the left at a fixed speed (-v) while a carrier fluid stored in a first pump head is discharged from piping 13 at a fixed flow rate 2g0 but at this time, simultaneously a plunger 11b is as well pulled back to the left side at the fixed speed (-v) so that half of the fluid in the total carrier fluid fed out of the piping 13 is stored inside a cylinder in a second pump head 12b at a fixed flow rate g0 and the rest half of the carrier fluid is fed to a separation column 7 at the fixed flow rate g0 by way of piping 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for quantitatively feeding a liquid at high pressure, which is used in high-speed liquid pneumatic magnetography and the like.

In high performance liquid chromatography, pump devices for feeding carrier liquid to separation columns include (1)
Conditions such as constant flow performance, especially the ability to feed the carrier liquid to the separation column in a non-pulsating flow, (2) the ability to withstand high pressure, and (8) the ability to accurately and freely set the flow rate, are required. ing. Among these conditions, satisfying the constant flow condition (1) in particular not only contributes to improving measurement accuracy and reducing noise, but is also extremely important to prevent deterioration of the separation column. Various pumps have been proposed to meet this condition. As a means to ensure a constant flow rate of liquid using a conventional reciprocating plunger type pump, prepare multiple pump heads and connect the piping on the discharge side from these as shown in Figure 1 (two pump heads are prepared). connected to seven connectors in parallel like /as/b of
There is a method of forming the ejection pattern shown in FIG. 1 by synchronously driving the plunger 'Ihs'lb of asJb with opposite phases. However, with this method, if gas is generated in each pump head, this gas expands and contracts in response to the reciprocating motion of the plunger, so not only does the constant flow rate of liquid flow disappear, but the liquid is not pumped at all. In many cases, the maintenance required a great deal of effort from the user. In addition, as another method, as shown in Figure 3, 7
Seven pump heads ja having the same cylinder internal volume are prepared on the suction side of the pump heads tb, and the piping 6 is connected in series, so that the suction of pump heads j-b and the pump head j
By synchronizing the discharge of a, the pump head, t
Even if suction of sb is performed very rapidly, the carrier liquid necessary for this is forcibly supplied from the pump head 5a, so no depressurization occurs in the cylinder of the pump head sb, and the generation of bubbles is prevented. Furthermore, even if a small amount of gas enters, it can be forced out, making maintenance of the device quite easy. However, as shown in FIG. 9, the liquid feeding pattern using the pump of this method has the drawback that the liquid is not fed to the separation column side during suction by the pump head Sb, and the constant flow rate is impaired. Also, pump head! Since the suction operation b is performed by a sudden movement of the connecting rod 7, there are also drawbacks such as leakage between the plunger 20 and the plunger seal 79 and severe wear of the plunger seal /q. .

The present invention eliminates the drawbacks of the conventional devices described above, and provides a pump device that has a constant flow rate, is less likely to generate bubbles, has a simple structure, and is easy to maintain.

That is, the pump of the present invention is a pump device for feeding a liquid, and includes a number of plungers having a cross-sectional area of 2 pairs/a, and a means for reciprocating the number of plungers. This is a pump device in which the discharge port of one pump head is connected to the suction port of the other pump head. and - By attaching the two plungers coaxially to both ends of seven connecting rods that are reciprocated in the axial direction, it is possible to synchronously reciprocate on the same axis, and each pump It is possible to always perform the ejection and suction in the head synchronously. Further, the plunger is driven by a cam,
By forming the shape of the cam so that the amount of axial displacement of the plunger increases linearly when the cam is rotated at a constant speed, the discharge speed and suction speed at each pump head are always constant. It is possible to keep it.

Next, one embodiment of the present invention will be described using the drawings.

FIG. 5 is a schematic diagram showing an embodiment of liquid climadography with a pump according to the invention.

When the connecting rod IO is driven to the right at a constant speed (?), the plunger of cross-sectional area XAO //
& is drawn, the carrier liquid is sucked from the carrier liquid reservoir 9 into the first pump head/2a at a constant flow rate of 2h (=koA.?), and at the same time, the cross-sectional area of the second pump head/, 2b is Plunger //b is pressed, and the carrier liquid stored in the cylinder reaches a constant flow rate f! -o (=AO?) and is discharged toward the separation column 7 through the piping IS. This /: inhalation of 1a, /2b
From the moment when the discharge of is completed, the connecting rod lθ
begins to move to the left at a constant speed (-?), and the carrier liquid stored in the first pump head flows through the pipe/h at a constant flow rate.
3, but at the same time plunger //b is also pulled back to the left at a constant speed (-V),
Half of the carrier liquid sent from piping 13 is stored in the cylinder of the second pump head/2b at a constant flow rate, and the remaining half of the carrier liquid is passed through piping 15 at a constant flow rate to the separation column. The liquid is sent to 7. The above liquid feeding patterns are shown with the flow rate on the vertical axis and the drive time on the horizontal axis in Figures 6(A), (B), and (0), and Figure 6(A).
shows the relationship between the discharge/suction amount and time in the first pump head 7.2a, and FIG. 6(B) shows the relationship between the discharge/suction amount and time in the first pump head/Jb. , Fig. 4(C) shows the relationship between the flow rate and time when the liquid is actually sent to the separation column 7.The carrier liquid, which is always at a constant flow rate, is sent to the separation column 6-Q in a non-pulsating flow. It will be done. The reciprocating movement of the connecting rod is driven by a cam/7 rotated at a constant speed by a constant speed rotation motor/g. This cam shape is the seventh
As shown in Figures (A) and (B), between the distance R from the center to the circumference and the rotation angle θ, R-a + b w (0≦
θ≦Ir), R= a + b! (T≦θ≦a)
It is designed to have a certain relationship. For this reason, the spring: l
The cam follower/6, which is pressed onto the circumferential surface of the cam/7 by the repulsive force of O, follows the constant rotational movement of the cam/7 at a constant speed (?) (-mutual・d-!-)π dt Therefore, the connecting rod IO to which this cam follower /6 is fixed is also driven reciprocally at a constant speed (→).In addition, as another driving method, if the center O is length l of any string passing through
But, l-R0R'=(a0b4)+(a00)=koa+b
Since it is always constant, as shown in Figure 5,
Two cams 7 oror 23 on connecting rod IO
a, 2. ? b in the axial direction l + rl + r2 (r
l and r2 are the radii of the outer circumferential circles of the portions of the cam 7 lowers 22a and 22b that are in contact with the cams. It is also possible to reciprocate at a constant speed.

Furthermore, since the rotation speed of the constant speed rotation motor/l can be freely changed, the flow rate of the carrier liquid can also be easily set. Additionally, since the pump heads /2a and /2b are connected in series, even if bubbles occur in one pump head, the bubbles will be removed with the help of suction or discharge from the other pump head. It can be easily removed from the pump head, and there is no sudden suction action, so there is less air bubbles, and the plunger //a, //b
Leakage between the plunger seal λ/as-2/b and wear of the plunger seals 2/a and Su/b are also reduced.

As described above, according to the present invention, there is provided a pump device that is free from pulsating flow, is capable of feeding a carrier liquid quantitatively, is less likely to generate bubbles, and is easy to maintain.

[Brief explanation of drawings]

Figures 1 and 3 are schematic diagrams of four examples of conventional pump devices applied to liquid chromatography; Figure 2 shows the discharge pattern of the pump device in Figure 1; FIG. FIG. S is a schematic diagram showing an embodiment of liquid chromatography equipped with the pump device of the present invention, and FIG. 6 shows the discharge pattern of this pump.
A schematic diagram of the shape of the cam used is shown in FIG. The second figure is a schematic diagram showing a driving method when seven cams are used without using a spring. /a: Piping /b: Piping Connector 3a: Pump head 3b: Pump head Hiroa Niblunger jerk b Niblunger Sa: Pump head 5b: Pump head 6
: Piping 7 separation columns g = Detector 9 : Carrier reservoir /θ : Connecting rod //a: Cross-sectional area, 2AO blanker //b:
Plunger in cross-sectional area /2a: First pump head isb: First pump head 13: Piping /4'a: Check valve l da b: Check valve /ri; Piping /A :Cam 7 oror /7:Cam/g:Constant speed rotation motor
/9: Plunger seal 20 - Plunger J/a: Plunger seal 21b for plunger //a: 2 plunger seals for plunger //b: Spring Patent applicant Asahi Kasei Industries Co., Ltd. Agent Patent Attorney Toru Hoshino - IO = Figure 1 Figure 2 Time Figure 3

Claims (3)

[Claims] (1) A pump device for feeding a liquid, comprising two plungers having a cross-sectional area of ≦//, and a means for reciprocating the ≦ plungers. ,
A pump device that connects the discharge port of one pump head to the suction port of the other pump head. (2) By coaxially attaching the two plungers to both ends of the seven connecting points that are reciprocated in the axial direction, it is possible to synchronously reciprocate on the same axis. A pump device according to claim 1. (3) A patent in which the plunger is driven by a cam, and the cam is shaped such that when the cam is rotated at a constant speed, the amount of axial displacement of the plunger increases linearly. A pump device according to claim 1.