JPS63106378A - Nonslidable pump for transferring liquid under pressure - Google Patents

Abstract

PURPOSE:To permit the operation free from leak of liquid by installing a working bellows and a press transfer bellows in series through an intermediate cut-off wall inside a liquid storage tank and allowing the bellows to alternately extend and contract to absorb and discharge the liquid by the working fluid. CONSTITUTION:When the pressure of the working oil in a working fluid chamber 15 is increased, a working bellows 6 is extended through an intermediate cut-off wall 7, and a bellows 9 for press transfer contracts. The head 130 of a valve mechanism 13 is attached onto a valve seat part 70 by the lowering of the cut-off wall 7 due to the subsequent increase of the fluid pressure, and the inside of a tank 1 and a press-transfer chamber 11 are separated. At the same time, the liquid A enclosed in the press transfer chamber 11 is sent under pressure through a liquid feeding passage 10 and a check valve 12 by the reduction of the capacity of the press transfer chamber 11. When the pressurization for the fluid chamber 15 is released, the both bellows 6 and 9 are restored by the own restoration force, and the liquid A in the tank 1 is inhaled into the press transfer chamber 11 from an introducing hole 8 by the opening of the valve mechanism 13, and is set in waiting for the next process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pump for pumping liquids, and particularly to a pump for pumping liquefied gases such as liquefied natural gas without sliding.

[Conventional technology and its problems]

The use of liquefied gases such as liquefied natural gas (LNG) and liquid hydrogen (L Hs) as fuel for various combustion engines including automobile engines is being considered. An important issue is the development of a pump, a means of pumping the substances from storage containers or tanks to combustion means.

This pump sucks in liquefied gas from the tank and pumps it in liquid form to an external injection valve, etc., and its function is the same as a pump for pumping gasoline, diesel oil, etc.
However, as is well known, liquefied natural gas has a boiling point of -161°C.
Liquid hydrogen is a cryogenic liquid with a boiling point of -253°C, extremely low viscosity, and small molecular diameter. This made it difficult to design a stable and durable pump of this type.

For example, Hydraulic and Pneumatic Vol.16, &5, No.21-2
On page 5, a plunger type liquid hydrogen pump using a cylinder and a piston is proposed. However, in this structure, whether the piston is reciprocated or the cylinder is reciprocated, a sliding portion occurs. However, due to the liquid properties mentioned above, lubricants cannot be used.
It is easy to cause malfunctions such as seizure, and to avoid this, use a non-lubricated sliding surface made of a combination of Teflon, Amber, etc., set an appropriate clearance, and deal with dimensional changes due to temperature. As a result, it requires extremely high precision and a complex configuration, and even then, it is difficult to completely prevent malfunctions and liquid leaks due to sliding, and the pump is likely to become inoperable in a short period of time. There is a problem.

[Means for solving problems]

The present invention was developed through research to solve the above-mentioned problems, and its purpose is to eliminate any sliding parts and therefore prevent malfunctions and leaks caused by these parts.
The object of the present invention is to provide a pump of this type that can stably and reliably pump liquefied gas and has a relatively simple structure.

To achieve this objective, the invention adopts a special structure using two bellows, namely an actuating bellows and a pumping bellows connected in series through an intermediate blocking wall in the receiving chamber of the liquid to be pumped. In addition, a liquid introduction hole is formed in the lower part of the intermediate blocking wall to communicate with the liquid delivery path via the inside of the bellows for pressure feeding. This is characterized by a valve mechanism that separates the inside of the bellows from the liquid storage chamber in conjunction with the contraction operation of the bellows.

The pump of the present invention is suitable for the general pumping of liquids whose sliding parts are difficult to design, such as liquefied natural gas and liquid hydrogen, and can also be applied to the pumping of hazardous liquids where leakage is not allowed.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 4 show an embodiment of the non-sliding pump for pumping liquid according to the present invention. In FIG. It is filled with the desired liquid, such as natural gas. 2 is tank 1
The pumping section, 3, preferably located near the bottom, is a sliding pump according to the invention.

1 and 2 show the details of the non-sliding pump 3, 4 is a surrounding wall that constitutes the pumping section 2, a cylindrical fixing g15 is installed in a part of this surrounding wall 4, and this An operating bellows 6 is integrally connected to the fixed wall 5 at one end.

The other end of the operating bellows 6 is connected to an intermediate blocking wall 7 that intersects with the bellows axis, and the opening of the operating bellows 6 is completely closed by this intermediate blocking wall 7. This intermediate blocking wall 7 is made thick and rigid to have a predetermined mechanical strength, and a valve seat portion 70 enlarged in a trumpet shape is provided on the lower side, and a valve seat portion 70 is provided with a valve seat portion 70 extending through the wall thickness. Several liquid introduction holes 8 are formed 6 Further, one end of a pressure-feeding bellows 9 is connected to the lower end of the valve seat portion 70 in series with the first actuating bellows 6 . The other end is fixed so as to surround the entrance of a liquid delivery passage 10 formed in the surrounding wall 4, and a pressure delivery chamber 11 communicating with the liquid introduction hole 8 and the liquid delivery passage 10 is formed in the pressure delivery bellows.

A check valve 12 that opens when the pressure in the pressure chamber 11 reaches a certain level is disposed on the exit side of the liquid delivery path 10, and the liquid from this check valve 12 is led to a pressure transfer system such as a pressure accumulation chamber (not shown). ing.

A valve mechanism 13 is disposed in the pressure-feeding chamber 11 to separate the pressure-feeding chamber from the inside of the tank in conjunction with the contraction operation of the pressure-feeding bellows 9. This valve mechanism 13 is not particularly limited, but the one shown in the figure includes a head 130 that approaches and separates from the valve seat portion 70, and a shaft portion 131 that extends from the head 130 in the axial direction.
The liquid delivery path 10 has a structure including a stopper 132 that approaches and separates from the seat portion 14 formed on the artificial back, and a spring 133 that urges the head 130 toward the valve seat portion. A liquid passage hole 134 communicating with the pumping chamber 11 is bored in the shaft portion 131 .

The stopper 132 is configured such that the head 130 is separated from the valve seat 70 when the bellows 9 for pressure feeding is expanded, and the spring 133 is configured such that the head 130 is separated from the valve seat portion 70 when the bellows 9 for pressure feeding starts to expand from the contracted state. The spring constant is so weak that the head 130 separates from the valve seat portion 70 when a slight difference occurs between the pressure inside and the pressure in the pressure feeding chamber.

In addition, a pressure stroke element acts on the actuating bellows 6. In the illustrated example, the inside of the actuating bellows 6 is configured as a working fluid chamber 15, and this working fluid chamber 15 is inserted through the surrounding wall 4. By connecting to a fluid supply/control system outside the tank and pressurizing fluid into the working fluid chamber 15, the actuating bellows 6 is extended to a required stroke via the intermediate blocking wall 7, thereby contracting the pressure-feeding bellows 9. .

It is designed to obtain a compression/pumping stroke. Of course, instead of this, the intermediate blocking wall 7 may be directly reciprocated by mechanical means such as a crank.

In the case of the hydraulically actuated type shown, a spring may be used to assist the return of the actuating bellows 6 from the extended state to the retracted state, for example by extending the intermediate blocking wall 7 in the radial direction. This can be easily achieved by interposing a spring between this and the lower fixed wall.

The operating bellows 6, the pressure-feeding bellows 9, and the intermediate blocking wall 7 are integrally formed of a material that can withstand low temperatures, or are integrated by welding, bonding, or the like. At least the actuating bellows 6 preferably has an inner and outer double wall 17 with a hollow portion 18 in the middle in the thickness direction, as shown in FIGS. 3(a) and 3(b).
It has a heat insulating structure consisting of a and 17b.

[Effect of the embodiment]

The operation and function of the non-sliding pump of the above embodiment will be explained.

In the set state and in the state where no external force is applied, the actuating bellows 6 is contracted and the pumping bellows 9 is in an expanded state, as shown in FIG. At this time, the valve mechanism 13 is in an open state with the head 130 separated from the valve seat part 70, so the liquid A in the tank flows from the liquid introduction hole 8 into the pressure feeding chamber 11 of the pressure feeding bellows 9, and the valve mechanism 13 The liquid delivery path 10 is
is satisfied, and at this time the check valve 12 is closed.

Next, when the pressure of the hydraulic oil or other desired fluid in the working fluid chamber 15 is increased, the pressing force applied to the intermediate blocking wall 7 causes the working bellows 6 to extend 5, while the pumping bellows 9 begins to contract. If the pressure of the working fluid is further increased, intermediate cutoff can be achieved! Due to the lowering of t7, the head 130 of the valve mechanism 13 is attached to the spring 13 on the valve seat portion 70 as shown in FIG.
3, so that the inside of the tank and the pumping chamber 1 are in close contact with each other.
At the same time, the liquid A' confined in the pressure-feeding chamber 11 is forced into the liquid delivery path 10 due to the volume reduction of the pressure-feeding chamber 11, and the degree of pressure rise due to this reaches the opening set pressure of the check valve 12. Then.

Pumping begins.

When the pressure in the pressure-feeding chamber 11 begins to decrease due to this pressure-feeding, if the pressurization of the working fluid chamber 15 is simultaneously released, the operating bellows 6 and the pressure-feeding bellows 9 will be in the state shown in FIG. 1 by their own restoring force. When the pressure-feeding bellows 9 is extended, the valve mechanism 1
Since the head 130 of No. 3 is separated from the valve seat part 70, the liquid introduction hole 8 again communicates with the pressure-feeding chamber 11 in the pressure-feeding bellows, and suction of the liquid A in the tank is started. The liquid in the tank 1 is sucked into the pressure-feeding bellows 9, and is successively pumped through the liquid-feeding path 10.

In the present invention, this suction and pressure feeding are achieved by the expansion and contraction of two bellows 6.9 for actuation and pressure feeding, which are arranged in series and separated in the axial direction by an intermediate blocking wall 7. There is no sliding part, which was essential, so there is no need to consider sliding clearance or lubrication between the two members.

Even with liquids with low viscosity, malfunctions due to seizure or abrasion will not occur, and since bellows are connected in series, appropriate liquid tightness can be maintained, and there are no gaps due to the formation of sliding parts. Therefore, leaks associated with drive transmission can be prevented without the need to take measures to prevent leaks such as oil seals.

Therefore, the durability of the pumping action is improved, and low-temperature liquids with extremely low viscosity and small molecular diameter can be stably and reliably pumped.

In addition, when the valve mechanism 13 as shown in the figure is used, the generation of internal negative pressure in the pressure feeding chamber 11 is reduced by setting the side area and lower area of the valve seat of the head 130, and the spring constant, thereby preventing boiling and vaporization of the liquid. It can be prevented.

〔Effect of the invention〕

According to the present invention described above, the operating bellows 6 and the pressure-feeding bellows 9 are provided in series with the intermediate blocking wall 7 interposed in the storage chamber for the liquid to be pumped.

A stroke element is made to act on the operating bellows 6, and a pressure-feeding bellows 9 is provided at the lower part of the intermediate blocking wall 7.
A liquid introduction hole 8 is formed which communicates with the liquid delivery path 10 through the inside, and a valve mechanism 1 is provided in the pressure-feeding bellows 9 to separate the inside of the bellows and the liquid storage chamber in conjunction with the contraction operation of the bellows.
Because I placed 3.

There are no sliding parts that can cause seizures, and there are no leaks.
Therefore, it is possible to reliably and stably pump liquids with small viscosity and molecular diameter, such as liquefied gases, and can also form a self-lubricating surface and set precise tolerances.

Since no measures such as applying a seal to prevent leakage are required, the mechanism is relatively simple and excellent effects such as good durability can be obtained.

[Brief Description of the Drawings] Fig. 1 is a cross-sectional view showing an example of a non-sliding pump for pumping liquid according to the present invention in a set state, Fig. 2 is a cross-sectional view showing the pumping stroke thereof, and Fig. 3 ( a) and (b) are partial sectional views of the bellows in the present invention, and FIG. 4 is an explanatory view showing an example of application of the pump of the present invention. 1...Liquid storage chamber (tank), 6...Bellows for operation. 7... Intermediate blocking wall, 8... Liquid introduction hole, 9 River pressure feeding bellows, 10... Liquid sending path, 13... Valve mechanism patent applicant Diesel Kiki Co., Ltd. Agent Patent attorney Black 1) YasuhiroFigure 1Figure 2

Claims (1)

[Claims] An operating bellows and a pressure-feeding bellows are provided in series in a storage chamber for the liquid to be pumped through an intermediate blocking wall, so that a stroke element acts on the operating bellows, and a pressure-feeding bellow is provided at the bottom of the intermediate blocking wall. A liquid introduction hole communicating with the liquid delivery path is formed through the inside of the bellows, and a valve mechanism is arranged inside the bellows for separating the inside of the bellows and the liquid storage chamber in conjunction with the contraction operation of the bellows. A non-sliding pump for pumping liquids.