JPH04358800A - Liquid feeding pump - Google Patents

Abstract

PURPOSE:To eliminate sliding parts to prolong the service life of a pump by providing an inlet and outlet port for gas in a liquid container in which a liquid inlet and a liquid outlet each provided with a check valve are provided, and making introduction and exhausting of the gas alternately to feed liquid into the container and exhaust the liquid from it, respectively. CONSTITUTION:An inlet and outlet port 6 for gas is provided in a liquid container 3 in which a liquid inlet 1 and a liquid outlet 2 each provided with a check valve are provided. In the inlet and outlet port 6, a three-way valve 9 for switching over between a flow line 7 for forcibly feeding gas to the container 3 and a flow line 8 for discharging the gas fed forcibly is provided. Then a part or all of the liquid which is contained in the container to approximately the same level as the level of liquid to be fed 10 is forced out from an outlet nozzle 11 by feeding a gas forcibly to the container 3. Then the three- way valve 9 is switched over to connect the interior of the container to the atmosphere, and the liquid is introduced into the container 3 by hydrostatic pressure, while a part of the gas in the container is exhausted. By making the above-mentioned forced feeding and exhausting of the gas to the container 3 repeatedly, liquid can be fed successively.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to liquid pumps, and is useful in fields where long life, chemical resistance, and steam sterilization are required.

0002

2. Description of the Related Art Conventionally, peristaltic pumps have been used as liquid pumps, particularly in systems that require chemical resistance and steam sterilization. However, peristaltic pumps generally pump liquid by crushing the rubber tube, which not only does not have sufficient chemical resistance, but also shortens the tube's lifespan.
It is short, about 0 to 30 days, and cannot be used for a long time. In addition, as a dispenser or a syringe pump, as shown in FIG. 1, a liquid container 3 having a liquid inlet 1 and a liquid outlet 2 equipped with a check valve is equipped with a liquid inlet/outlet 4 and a syringe 5, and the syringe is connected as shown in the arrow. Devices that send liquid by moving the syringe up and down are generally used, but they cannot guarantee the sterility of the liquid and require a drive unit to move the syringe up and down, making the device bulky.

0003

DISCLOSURE OF THE INVENTION The present invention is a liquid pump having a gas inlet and an outlet in a liquid container having a liquid inlet and a liquid outlet each having a check valve. Specifically, gas is sent to a liquid container having a liquid inlet and a liquid outlet equipped with a check valve, the liquid in the container is sent from the liquid outlet, and then part or all of the sent gas is extracted from the container. The present invention proposes a pump that pumps liquid by drawing it into a container from a liquid inlet. Here, if the gas is removed too much, the liquid will also be removed, so it is preferable to provide a mechanism for blocking the liquid at the gas inlet/outlet to prevent the liquid from flowing out. In addition, in order to use this in a system that requires sterility, such as culture, it is recommended to provide a sterile filter at the gas inlet and outlet.If the liquid container is equipped with a sterile filter and is sterilized using an autoclave, etc., it will be sterile. can be kept.

0004

Embodiment 1 FIG. 2 shows a schematic diagram of Embodiment 1 of the present invention. A liquid container 3 equipped with a liquid inlet 1 and a liquid outlet 2 each having a check valve has a gas inlet/outlet 6, and the gas inlet/outlet includes a channel 7 for pumping gas into the container and a channel for removing the pumped gas. It is equipped with a three-way valve 9 for switching 8. Part or all of the liquid contained in the container is pushed out from the outlet nozzle 11 by force-feeding gas into the container 3 until the liquid level is almost the same as the liquid surface 10 to be sent, and then the three-way valve 9 is switched to transfer outside air to the inside of the container. When the outside air is passed through the container 3, the liquid is introduced into the container 3 by hydrostatic pressure, and a part of the gas inside the container is discharged. In this way, the liquid can be fed by repeating pressure feeding and evacuation of gas into the container 3.

Embodiment 2 FIG. 3 shows a schematic diagram of Embodiment 2 of the present invention. In Example 1, the gas in the container 3 was discharged by naturally raising the liquid level using hydrostatic pressure, but since it takes time to introduce the liquid into the container 3, there is a limit to the liquid feeding rate. If the gas is forcibly discharged, the liquid can be introduced more quickly, so the liquid feeding speed can be increased. However, at this time, if the amount of gas discharged is too high, the liquid may also be drawn out, so it is desirable to block the liquid at the gas inlet and outlet. In this embodiment, a float-type stop valve 12 is provided, so that when an excessive amount of liquid is drawn in due to exhaust gas, the float blocks the gas inlet/outlet and prevents the liquid from coming out. Other ways to prevent liquid from entering the gas inlet/outlet are to install a liquid level sensor in the container 3 to prevent the liquid from reaching above a certain level, or to install a dropper at the gas inlet/outlet 6 instead of the three-way valve 9. There is a method of attaching a bag-shaped rubber bag with one end closed like a rubber part, and then crushing or loosening this rubber bag. In this case, liquid feeding can be automated by using an automatic pinch valve that crushes the rubber tube.

[0006]

Embodiment 3 FIG. 4 shows an embodiment of a liquid pump that can be used in systems that require sterility, such as culture. A sterile filter 13 is provided at the gas inlet/outlet 6. A rubber nozzle 14 is provided at the liquid inlet. The bottle 15 contains the liquid to be sent, and is equipped with a vent filter 16 and a liquid extraction pipe 17, and the liquid extraction pipe 17 is connected to the nozzle 14 by a silicone rubber tube 18. By attaching a silicone rubber tube or the like to the liquid outlet nozzle 11 and autoclaving, the liquid can be delivered aseptically.

[0007]

[Effects of the Invention] The pump according to the present invention has a simple structure, and materials such as stainless steel, glass, and plastic can be freely selected for the wetted parts, so that it can easily be used in cases where chemical resistance is required. Even if the liquid is slurry, it can be sent. There are no driving parts and there are almost no parts that are easily broken, so it has a long life. The discharge pressure can be freely selected depending on the gas pressure. Furthermore, aseptic liquid delivery is possible. The flow rate also has various advantages, such as being able to be adjusted by the gas pressure and the period of gas supply and discharge. Furthermore, by keeping the amount of air fed and the amount of air exhausted to the liquid container 3 constant, it can also be used as a dispensing device that feeds a fixed amount of liquid every cycle of air feeding and exhausting. By supplying an excessive amount of air, it is possible to push the liquid with gas, or to sandwich gas between two liquids. It is also possible to drive multiple pumps with a common air supply and exhaust source. Further, although pulsation occurs in this pump, pulsation can be eliminated or reduced by operating a plurality of pumps with different phases.

[Brief explanation of drawings]

FIG. 1 shows a schematic diagram of a conventionally used dispenser or syringe pump.

FIG. 2 shows an embodiment of the present invention.

FIG. 3 shows an embodiment of the present invention.

FIG. 4 shows an embodiment of the present invention.

[Explanation of symbols]

1 Liquid inlet with check valve 2 Liquid outlet with check valve 3. Liquid container 6 Gas inlet/outlet 12 Liquid blocking valve 13. Sterile filter

Claims (3)

[Claims] 1. A liquid feeding pump characterized in that a liquid container has a liquid inlet and a liquid outlet, each having a check valve, and a gas inlet and outlet. 2. The liquid pump according to claim 1, further comprising a mechanism for preventing liquid from entering the gas inlet and outlet. 3. The liquid pump according to claim 1 or 2, further comprising a sterile filter at the gas inlet and outlet.