CN2156350Y - Gas low-pressure cutting off valve - Google Patents

Abstract

An annular permanent magnet (1) is fixed in an air inlet whose shape is like the shape of a three-way part. A piston (2) is made of iron, and the size of the piston is equal to the size of the annular permanent magnet. The rod of the piston can move freely within a guide rod (3), and the end of the rod of the piston can not deviate from the guide rod (3). When the guide rod (3) is drawn, the guide rod drives the piston (2) away from the annular permanent magnet, and a valve is opened. When gas is stopped by accident, or low pression appears, because the force exerted by the annular permanent magnet on the piston is larger than the self weight of the piston and the gas pressure exerted on the piston, the piston can be attracted, and the valve is closed, so as to realize automatic closure of the low pression.

Description

Gas low-pressure cutting off valve

The utility model relates to a kind of gas safety valve.

During the coal gas air feed since contingency or use the gas peak cause sometimes and stop the supple of gas or steam or hypotony (50mmH ₂Below the O, promptly can not normal combustion), to making flame extinction, at this moment, should in time close, prevent but suddenly gas cause gas poisoning; Should in time close in addition, avoid managing internal pressure and cross to be low to moderate air is entered, cause because of emptying process not and cause pipe explosion.

For addressing this problem, common way is that user oneself notes, discovery is stopped the supple of gas or steam or the hypotony user oneself in time closes.So just, can avoid accident to take place.But can not notice immediately for the accident user that stops the supple of gas or steam, so just be difficult in time close.

In case the purpose of this utility model is will provide a kind of to stop the supple of gas or steam or device that hypotony just can in time be closed, and whole process is finished automatically.

The purpose of this utility model is to realize like this; As valve port, use piston with ring magnet as spool.When supply gas pressure just often, the gravity of piston and suffered gas pressure sum be greater than the suffered magnetic force of piston, thereby annular permanent magnnet can not drink up piston, valve remains unimpeded.But when accident is stopped the supple of gas or steam or during hypotony, at this moment the suffered gas pressure of piston is reduced to and makes piston gravity and suffered gas pressure sum less than the suffered magnetic force of piston, thereby annular permanent magnnet drinks up piston, and is close to it.When piston was close to annular permanent magnnet, because magnet magnetic induction intensity is chosen as 5000 Gausses, the magnetic force that piston is produced was much larger than coal gas maximum pressure (250mmH ₂O) pressure that piston is produced.Thereby, recover just often even work as gas pressure, also still can not open, must manually just can open.Prevent gas poisoning like this, avoided air to enter pipeline.

The utility model is because adopt permanent magnet as the power source of closing automatically, thereby need not electricity consumption or gas as the power source of closing, thus simple in structure, reliable and stable, be swift in motion.

Concrete structure of the present utility model is provided by following embodiment and accompanying drawing thereof.

Make the parts (7) of a shape with aluminium or casting in bronze as three links, in suction port, fix an annular permanent magnnet (1), with iron do one with the sizable piston of ring magnet (2), and the bar of this piston can unrestricted motion in guide rod (3), the bar end does not break away from guide rod (3).For making piston rod not break away from guide rod (3), guide rod is made A, B two-part, and inner aperture is different, and the A hole is little, and the B hole is big, and both are connected by screw thread.Piston-rod end has screw thread and joins nut.During installation, earlier piston rod is inserted in the A hole, then piston-rod end is screwed on nut, at last again with A, two ones of B screw on.Like this, piston rod just can unrestricted motion in guide rod, and does not take off anti-guide rod.Guide rod (3) is unlikely along guide rod gas and is leaked by closing element (5), (6) sealing.

When pulling guide rod (3), guide rod will drive piston (2) and leave annular permanent magnnet, thus valve open, and gas enters.Piston (2) is more away from annular permanent magnnet (1), and institute is magnetic field force induced just more little.Guide rod (3) is because spring (4) effect, and making sets back again after the guide rod pulling puts, and will stop piston will continue outside motion because of magnetic force less than gas pressure like this.Like this, piston will be close to guide rod front end transfixion, thereby air-flow passes through valve continually.Stop the supple of gas or steam or pressure when being lower than magnetic force when coal gas, piston (2) will be close to the annular permanent magnnet direction, and, magnetic field force induced big more the closer to institute, be close to annular permanent magnnet (1) valve closing at last.Because the magnetic force that the magnet of selecting produces, can make piston be close to magnet and to the attraction force of piston general maximum pressure greater than coal gas.Like this, when coming gas again,,, have only outside pulling guide rod to drive piston so valve still is in closed condition because gas pressure is lower than magnetic force, could be with valve open.Thereby realization low pressure is ended, and high pressure still is in cut-off state.

Claims (1)

1, a kind of coal gas low-pressure shutoff valve, it is characterized in that: make parts (7) as three links with aluminium or casting in bronze, in suction port, fix an annular permanent magnnet (1), with iron do one with the sizable piston of annular permanent magnnet (2), and the bar of piston can be free movable in guide rod (3), and bar is not held and do not broken away from guide rod.

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