WO2017042827A1 - Single chamber air release valve - shape optimization for anti surge protection - Google Patents

Abstract

Kinetic Air release Valve will be having mainly three functions, (1) to escape the air during filling of water (2) to allow air to enter into the pipe system during draining of water from the system, (3) to release the air getting trapped during normal operation of the piping system. But during the surge phenomenon, the water entering velocity is high and conventional kinetic valves will not react to this situation, resulting in sudden increase in transient pressure. This increase in transient pressure is high than the normal design pressure of the pipes and valves in the system and thereby damaging them. Utilizing the Bernoulli's principle, the shape of the body and shape of the floats are designed in this invention. This will result in allowing the air escaping into atmosphere, in a controlled way, during the occurrence of surge phenomenon. Hence resulting in limiting the transient pressure and protecting the pipes and valves in the system.

Description

SINGLE CHAMBER AIR RELEASE VALVE - SHAPE OPTIMIZATION FOR ANTI SURGE PROTECTION

FIELD OF THE INVENTION:-

The present invention is directed to Air Release Valve (ARV), particularly the shape of the body of the Air release valve and the shape of the floats inside the ARV. The body shape in conjunction with the float shapes, designed in such a way that it ensures the achievement of specified function of the air release valve at one of the condition during the operation of the valve at the field. The invention is based on the fluid flow principles, so that the required movement of the fluid float is achieved to have a controlled air outflow when the approaching air velocity in the pipe exceeds the critical speed.

RELATED PRIOR ART:-

Though there are non-kinetic valves also there, which does only air release function during normal operation, considering the technology behind this concept, the functions are compared with kinetic air release valves only. The traditional air release valve ( or vacuum valve or kinetic air release valve) will be having three types of functioning, depending upon the condition of water in the pipeline.

First at startup, the pipeline filled with air which must be exhausted during filling of water. As the pipeline is getting filled with water, much of the air would be removed by Air release valves, since the floats are in open condition. But irrespective of the water entering velocity, the floats will always open to exhaust air and only when water lifts the floats, the float will come in close position.

l Second, when water is getting drained out from the system, air has to enter into the pipeline, to avoid creation of negative pressure in the pipeline. This is very much essential for drinking water line, as the negative pressure increases the chances of foreign fluids entering the pipeline system which will be dangerous.

Thirdly, during the normal operation, estimated 2% of air will be entered in the pipeline system, this is to be removed from the system periodically.

All the kinetic air release valves will be performing the above three functions, but they will not take into account the water entering velocity during the filling of water. Also the shape of the body and floats will not be designed considering air flow characteristics. Normally the body of the ARV will be cylindrical only in the prior arts. This shape will not aid in easy achievement of function required when water entering velocity exceeds critical value.

Disadvantages :-

Water Hammer Condition

An air valve discharging air at high differential pressures, and velocities on closure will induce high, damaging transient pressures. This is due to water flow entering the valve suddenly being arrested by the float sealing. The effect of this phenomenon of pipeline dynamics is equivalent to the rapid closure of an isolating valve. The magnitude of the transient pressures induced often exceed the transient pressures of the valves and pipeline and thereby damaging the pipeline / valves. Water Spillage

This will occur when the floats fail to react with high velocity water entering the valve chamber. This results in the water covering the float effectively holding the float down , and exiting through the large opening. The amount of water spilled in this manner is substantial and results in flooded valve chambers. This will end up in high cost of repairing the damage than the cost of the valve. Also the cost of actual water being spilt is a loss. Again, this phenomenon is also very similar to sudden closing of isolation valve and creates high magnitude of transient pressure.

Seal Failure

When the transient pressure is high, this will also damage the seal placed between the air release valve and the pipe system. And water will start leaking / spilling, till it is repaired causing huge amount of loss of water and also reducing the pressure in the piping system.

In short kinetic air valves, which are not taking into account the water entering velocity and thereby devising a method to control the transient pressure, will result in huge damage of the pipes and valves. The increase in transient pressure, results during surge in the water line, and the system is expected to fail during this extreme condition.

Summary of the invention

The present invention is to provide solution to the surging phenomenon in the pipe line system. This present invention applies to all the sizes and ranges of ARV's When the water entering velocity is exceeding, the critical velocity, the air preceding the water also will attain high velocity. The body and the floats of the ARV are shaped in such a way that, they will be forming an orifice with convergent and divergent kind of profile. When the air with high velocity passes through this orifice kind of arrangement, this will result in increased pressure in the divergent zone, based on Bernoulli's principle.

The increase in the pressure will help to lift and close the top most float, even before the water reaches the valve chamber. And thereby sealing the float with large orifice. There is an opening designed in this top float and now air has to escape through this relatively small opening only. This controls the air escaping and result in no increase in transient pressure. By this way, the new shape of the body and shape of the floats of ARV, help to limit the transient pressure, during surging operation and thereby protecting the valves and pipeline system to a greater extent

So this present invention provides a solution of anti-surge protection mainly governed by the shape of the body and the shape of the floats.

Detailed Description of the Invention :-

As shown in Fig 1 , the single chamber air valve includes the Body (01), the Top Flange (02) which is fixed to the Body (01) through fasteners(12) and O- Ring (11) placed between the Body and Top flange. The Anti surge Float (03), Top Float (04) Bottom Float (05) and Baffle Plate (10) are placed into the Body (01) chamber. Seal (08) and Retainer plate (07) are installed into the Bottom Float (05) and the Capillary Nozzle (06) is fixed with Top float (04) The vent Cover (09) is screwed with Top flange by using Fasteners (12). The Anti surge Float (03), Top Float (04) and Bottom Float (05) are self-actuated by flow medium. When the pipe system filling with medium during pump on stage the air will be released through the large orifice ( the top flange having a larger orifice equal to the valve flow bore) and while in services the dropped air will be released by Capillary Nozzle (06) fixed in the top float (04) and while drain the pipeline the air valve allows air in the pipeline system. When the air velocity increases above the supersonic speed the Anti surge float (03) will work independently and close the large orifice and release /allow the air into pipe line system through controlled anti surge orifice.

Brief Description of the Accompanying Drawings :-

Fig 1 :- The Sectional View of Air valve in this invention

Fig 2 :- Exploded Perspective view of Air valve in this invention

Fig 3 :- Assembled Perspective view of Air valve in this invention

Fig 4 :- The Internal view of Air valve, which body, floats and other parts having this invention

Claims

CLAIMS :-

We claim

1 ) A single chamber Air release valve wherein the Single Chamber Air valve includes the top body (01), the Top flange (02) which is fixed to the body (01) through fasteners (12) and O-Ring (11) placed between the Body and the Top flange.

2) A single chamber air release valve as claimed in Claim 1 , wherein the Anti Surge float (03), Top float (04) Bottom Float (05) and the Baffle Plate (10) are placed into the Body (10) chamber.

3) A single chamber air release valve as claimed in Claims 1 and 2, wherein the seal (08) and Retainer Plate (07) are installed into the Bottom Float (05) and the Capillary nozzle (06) is fixed with Top float (04)

4) A single chamber Air release valve as claimed in claims 1 , 2 and 3 wherein the Vent Cover (09) is screwed with top flange by using Fasteners (12)

5) A single Chamber Air release valve as claimed in claims 1 , 2, 3 and 4 wherein the Anti surge float (03) top float (04) and bottom float (05) are self-actuated by flow medium.

6) A single Chamber Air release valve as claimed in claims 1 , 2, 3,4 and 5 wherein the pipe system filling the medium during pump on stage the air will be released through the large orifice ( The top flange having a larger orifice equal to the valve flow bore) and while in service the dropped air will be released by capillary nozzle (06) fixed in the top float (04) and while drain the pipe line the air valve allows air in the pipeline system.

7) A single Chamber Air release valve as claimed in claims 1 , 2, 3,4, 5 and 6 wherein the air velocity increases above the supersonic speed the anti-surge float (03) will work independently and close the large orifice and release / allow the air into pipeline system through controlled anti surge orifice.

8) A single chamber air release valve substantially as herein above with reference to the accompanying drawings.