JPH0721906Y2 - Liquid pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a liquid pump, and more particularly, to shortening the start-up time of a pump for boosting and pumping low-temperature liquefied gas stored in a saturated state. is there.

[Prior Art] Conventionally, in a pump that pumps a liquid having a low boiling point such as liquid oxygen and liquid nitrogen, or a pump that pumps a liquid in a high temperature environment, the liquid in the suction pipe of the pump is vaporized by the heat of external penetration. As a result, a gas removal chamber is connected to the pump to separate the gas in the liquid, and then the liquid is introduced into the pump body.

For example, in the liquid pump described in Japanese Patent Publication No. 59-16105, an outer cylinder having a liquid inlet on the lower side surface and a gas outlet on the upper side, and an appropriate height in the outer cylinder, Further, the gas removal chamber is formed by the inner cylinder, which is arranged between the outer cylinder and the outer cylinder via the ascending passage, and communicates with the suction chamber of the pump body at its lower portion.

According to this gas removal chamber, the bubbles (vaporized gas) in the low temperature liquefied gas (liquid) flowing in from the liquid inlet are separated from each other in the process of ascending in the ascending passage, so that after passing through the ascending passage, from the upper end of the inner cylinder. If the flow velocity of the liquid flowing down into the inner cylinder is controlled to be lower than the ascending speed of the bubbles, the bubbles are not entrained in the flowing liquid and only the liquid is supplied to the suction chamber, so that excellent liquid pressure feeding can be performed.

As described above, according to the liquid pump, the gas separation chamber is provided to enhance the liquid separation capacity, thereby reliably preventing cavitation and improving NPSH (net effective suction lift).

[Problems to be solved by the device]

However, in the above-mentioned pump, for example, when the low-temperature liquefied gas is pressure-fed, it takes a long time to perform pre-cooling at the time of startup. That is, at the time of start-up, it is necessary to cool the pump to approximately the same temperature as the low temperature liquefied gas, but in this pump, the liquid that has flowed down in the inner cylinder contacts the suction chamber and is heated, so that it vaporizes violently and rises. However, the liquid to be continuously flown down to the suction chamber was blown up, so that the cooling could not be performed sufficiently and the precooling time was long.

Then, this invention aims at providing the pump for liquids which can perform the said precooling in a short time, aiming at cavitation prevention and NPSH reduction.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the liquid pump of the present invention has an outer cylinder having a liquid introduction port communicating with a liquid supply pipe for supplying a liquid on the lower side surface and an outer cylinder having a gas discharge port on the upper side. The gas removing chamber has an appropriate height inside the cylinder and is disposed between the outer cylinder and the outer cylinder via an ascending passage, and an inner cylinder communicating with the suction chamber of the pump body at a lower portion thereof. In the liquid pump having the above structure, an auxiliary liquid introduction port communicating with the liquid supply pipe is provided in the lower portion of the suction chamber.

[Action]

By providing the auxiliary liquid inlet in the lower part of the suction chamber as described above, the low temperature liquefied gas can be introduced from the auxiliary liquid inlet into the suction chamber when the pump is started. Can be pre-cooled.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

The liquid pump 1 includes a pump body 6 including a compression chamber 4 having a discharge port 3 having a check valve 2 and a piston 5 reciprocating in the compression chamber 4, and a compression chamber 4 of the pump body 6. The suction chamber 8 communicates with the suction chamber 8 via a suction valve 7, and a gas removal chamber 9 continuously provided on the suction chamber 8.

The gas removing chamber 9 has an outer cylinder 12 having a liquid inlet 10 on the lower side surface and a gas outlet 11 on the upper side, and an appropriate height in the outer cylinder 12, and between the outer cylinder 12 and the outer cylinder 12. An inner cylinder which is arranged through the ascending passage 13 and communicates with the suction chamber 8 at its lower portion.
14 and the liquid inlet 10 communicates with the bottom of the storage tank 16 via the liquid supply pipe 15, and the gas outlet 11 is
It communicates with the upper part of the storage tank 16 via a gas return pipe 17.

Further, an auxiliary liquid introducing port 19 communicating with an introducing pipe 18 branched from the middle of the liquid feeding pipe 15 is provided in the lower portion of the suction chamber 8 through the bottom wall.

In this way, the liquid supply pipe 15 for supplying the liquid to the liquid pump 1
When the liquid pump 1 is started, the liquid can be simultaneously supplied from the upper and lower sides by branching to the middle and connecting to the upper gas removal chamber 9 and the lower part of the suction chamber 8. Even if the liquid flowing down the inner cylinder 14 is obstructed by the vaporization in the inside 8, the suction chamber 8 is cooled in a short time by the liquid from the auxiliary liquid introducing port 19, so that the starting time can be shortened. it can. In addition, the vaporized gas generated at this start is
Since the gas outlet 11 rises through the gas removal chamber 9, it does not stay in each part of the pump, and each part of the pump can be filled with the liquid in a short time.

As described above, since each part of the liquid pump 1 can be rapidly cooled by direct contact with the liquid to significantly reduce the precooling time, that is, the start-up time, the liquid pump 1 is intermittently and automatically operated for a short time. This is an advantage.

It should be noted that the same effects as described above can be obtained when the liquid is pressure-fed in a high temperature environment. The gas removal chamber connected to the upper part of the suction chamber can be of various shapes as long as it can separate and remove the gas in the liquid to be sucked in, and the pump main body is also configured as a liquid. Any structure can be used as long as it can be pressure-fed.

[Effect of device]

As described above, in the liquid pump of the present invention, the gas removal chamber is connected to the upper part of the suction chamber communicating with the pump body through the suction valve, and the liquid removal port is provided in the gas removal chamber. Since the auxiliary liquid inlet that communicates with the liquid supply pipe is also provided in the lower part of the suction chamber, when starting the liquid pump, liquid is simultaneously supplied from above and below to fill each pump part with liquid in a short time, The direct contact with the liquid allows sufficient cooling, and the precooling time, that is, the start-up time can be greatly shortened. This prevents cavitation and
In addition to the effects such as NPSH reduction, precooling loss of liquid is reduced,
It is possible to enable short-term intermittent automatic operation of the pump.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the liquid pump of the present invention. DESCRIPTION OF SYMBOLS 1 ... Liquid pump, 6 ... Pump main body 7 ... Suction valve, 8 ... Suction chamber, 9 ... Gas removal chamber 10 ... Liquid introduction port, 11 ... Gas outlet pipe, 15 ... Liquid delivery pipe, 18 ... Introduction pipe, 19 ... Auxiliary liquid inlet

Claims (1)

[Scope of utility model registration request] 1. An outer cylinder having a liquid introduction port communicating with a liquid supply pipe for liquid supply on a lower side surface and an upper cylinder having a gas outlet, and an appropriate height inside the outer cylinder, Further, in the liquid pump in which a gas removal chamber is formed by the inner cylinder communicating with the suction chamber of the pump main body at a lower portion of the suction passage, the suction passage being provided between the outer cylinder and the outer cylinder. A pump for liquid, characterized in that an auxiliary liquid introducing port communicating with the liquid sending pipe is provided in the lower part of the chamber.