JPH0458072A - Syringe pump - Google Patents

Abstract

PURPOSE:To prevent particles in fluid from sinking and/or being aggregated by constituting fluid within a cylinder to be forcively circulated in a syringe pump where fluid goes in/out with a piston advanced/retreated. CONSTITUTION:A pump 10 and a circulating passage 11 are provided. In the second place, during the process of sucking and/or discharging fluid L, or during the time waiting for starting discharge after suction has been over, fluid L is circulated within the inside of a cylinder 1 with the pump 10 operated, so that fluid is thereby in a fluent state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a syringe pump, and more specifically, a syringe pump in which a piston is disposed within a cylinder so as to be relatively movable in a reciprocating manner. The present invention relates to a syringe pump in which a liquid inflow path and a liquid outflow path communicate with each other.

[Conventional technology]

Various types of pumps are known, one of which is a syringe pump. This is as shown in Figure 3.
A piston 2 is disposed in a cylinder cylinder I so as to be able to freely reciprocate, and a liquid inflow path 3 and a liquid outflow path 4 communicate with each other in the cylinder cylinder 1, making it useful as a metering pump.

Further, a suction valve 5 is provided in the inflow path 3, and a discharge valve 6 is provided in the outflow path 4.
A sealing means 7 such as an O-ring is provided between the inner surface of the cylinder cylinder 1 and the outer surface of the piston 2.

In such a syringe pump, when the piston 2 is raised with the suction valve 5 open and the discharge valve 6 closed,
Since the inside of the cylinder tube 1 becomes negative pressure, the liquid to be supplied to the target region flows into the cylinder tube 1. When the predetermined amount of liquid has been suctioned, the suction valve 5 is closed,
When the piston 2 is lowered with the discharge valve 6 open, the liquid in the cylinder tube 1 is discharged and delivered to the target region. Such operations are performed intermittently.

[Problem to be solved by the invention]

However, as mentioned above, with this type of syringe pump, the operation is intermittent, so there is no problem with single-phase liquids, but in systems where small particles are dispersed, the particles may settle and There is a high risk of agglomeration. On the other hand, if the syringe pump is small or has a fast suction/discharge cycle, there is little risk of particle settling or agglomeration, but if the syringe pump is larger or the suction/discharge cycle is slow, particle sedimentation or aggregation may occur. The fear of this is growing.

Therefore, an object of the present invention is to prevent sedimentation and aggregation of particles.

[Means to solve the problem]

The above problem arises in a syringe pump in which a piston is arranged in a cylinder so as to be able to move relatively freely in a reciprocating manner, and liquid flows in and out by moving the piston forward and backward, respectively. This can be solved by providing fluidization.

[Function] In the present invention, since the liquid in the cylinder is forcibly fluidized, sedimentation and aggregation of particles can be reliably prevented.

[Specific structure of the invention]

Hereinafter, the present invention will be explained in more detail by way of examples with reference to the drawings.

In the present invention, a liquid forced fluidization means is provided.

In the example of FIG. 1, a pump 10 and a circulation path 11 are provided,
During the suction/discharge process, or during the waiting time after the end of the suction bow and before the start of discharge, the pump 10 is activated to circulate the internal liquid to cause it to flow.

In the example shown in FIG. 2, a magnetic body 1, such as a piece of steel, is provided inside the cylinder l, a star sea 13 is provided below the bottom surface, and the liquid is made to flow by rotating the magnetic body 12.

In FIG. 3, the syringe pump is turned upside down, and a stirring blade 14 is installed, for example, by penetrating the piston 2, and is rotated to cause the liquid to flow.

Figure 4 shows the stirring blade 14 in a downward syringe pump.
A is provided to fluidize the liquid.

On the other hand, in the past, as shown in Figure 2, suction and discharge were carried out by bringing the piston 2 into direct contact with the liquid. It is also possible to seal gas, for example, air, in the cylinder tube 1 and perform suction and discharge via this air.

Further, as in the example shown in FIG. 4, suction and discharge may be performed by moving the cylinder tube 1 up and down while the piston 2 is not moved but is fixed.

In the present invention, when the size of the pump chamber of the syringe pump is 200 d or more and/or the suction/discharge speed is 0.5 aI/sec or less, the effect of preventing particle sedimentation and agglomeration is remarkable.

In the above example, the inflow passage 3 and the outflow passage 4 were communicated individually into the cylinder cylinder 1, but they are connected to one pipe line through, for example, a three-way valve, and this pipe line is connected to the cylinder cylinder 1. It is also possible to communicate internally.

〔Example〕

Examples will be shown below to clarify the effects of the present invention.

In the syringe pump shown in FIG. 1 with a pump chamber volume of 200 d, the photosensitive material emulsion liquid was sucked in for 120 seconds from the start of suction to the completion of discharge at a rate of 0.5 d/sec. As a result, no sedimentation or aggregation of sedimentary components was observed.

On the other hand, when the liquid was not circulated, slight sedimentation of particles was observed on the bottom surface of the cylinder even during the -th suction and discharge operation.

〔Effect of the invention〕

As described above, according to the present invention, sedimentation and aggregation of particles in a liquid can be prevented.

[Brief explanation of drawings]

1 to 4 are schematic graphs of examples of syringe pumps of the present invention. DESCRIPTION OF SYMBOLS 1...Cylinder tube, 2...Piston, 7...Sealing means, L...Liquid, A...Gas layer (air) Fig. Fig. Fig. Fig.

Claims (1)

[Claims] (1) In a syringe pump in which a piston is disposed within a cylinder so as to be able to move relatively freely in a reciprocating manner, and liquid is caused to flow in and out by retracting and advancing the piston, respectively, forced flow of the liquid within the cylinder is provided. A syringe pump characterized by having a