US-12618483-B2 - Drain valve

US12618483B2US 12618483 B2US12618483 B2US 12618483B2US-12618483-B2

Abstract

A drain valve for a pressurised fluid chamber comprises a collection chamber for collecting pressurised fluid from the pressurised fluid chamber; a vent chamber for venting the pressurised fluid from the collection chamber; a master valve between the collection chamber and the vent chamber; and a slave valve between the pressurised fluid chamber and the collection chamber. The master valve is configured to open the slave valve when the master valve is closed, and to close the slave valve when the master valve is open. The master valve is configured to open the slave valve to allow pressurised fluid from the pressurised fluid chamber to enter the collection chamber, and configured to close the slave valve to allow pressurised fluid from the collection chamber to enter the vent chamber. The master valve and the slave valve cannot be shut at the same time.

Inventors

Abel Justin Lord

Assignees

GARDNER DENVER LTD

Dates

Publication Date: 20260505
Application Date: 20220804
Priority Date: 20210805

Claims (18)

1 . A drain valve for a pressurised fluid chamber, comprising: a collection chamber for collecting pressurised fluid from the pressurised fluid chamber; a vent chamber for venting the pressurised fluid from the collection chamber; a master valve between the collection chamber and the vent chamber; and a slave valve between the pressurised fluid chamber and the collection chamber; wherein the master valve opens the slave valve when the master valve is closed, and closes the slave valve when the master valve is open; wherein the master valve directly contacts the slave valve to open the slave valve to allow the pressurised fluid from the pressurised fluid chamber to enter the collection chamber, and closes the slave valve to allow the pressurised fluid from the collection chamber to enter the vent chamber; and wherein the master valve and the slave valve cannot be shut simultaneously.
2 . The drain valve according to claim 1 , further comprising a valve seat, including a master valve seat and a slave valve seat.
3 . The drain valve according to claim 2 , further comprising a spring, a force of the spring urging the slave valve against the slave valve seat.
4 . The drain valve according to claim 3 , wherein the slave valve further comprises a spring retaining plate that includes through holes.
5 . The drain valve according to claim 2 , wherein the slave valve comprises a material to seal against the slave valve seat, and the material is softer than a material of the master valve.
6 . The drain valve according to claim 2 , wherein the master valve moves at least partly within the valve seat.
7 . The drain valve according to claim 2 , wherein the master valve, the slave valve, and the valve seat are all co-axially arranged.
8 . The drain valve according to claim 1 , wherein the pressurised fluid chamber comprises a filter.
9 . The drain valve according to claim 2 , wherein the collection chamber is further away from the master valve seat than one or more passages which extend from the collection chamber to the master valve seat.
10 . The drain valve of claim 2 , wherein the valve seat is integrated into a base of a filtration assembly, or remotely mounted and piped from a filtration assembly.
11 . A method for draining a pressurised fluid chamber, comprising: providing a drain valve with a collection chamber for collecting pressurised fluid from the pressurised fluid chamber, a vent chamber for venting the pressurised fluid from the collection chamber, a master valve between the collection chamber and the vent chamber, and a slave valve between the pressurised fluid chamber and the collection chamber, wherein the master valve directly contacts the slave valve to open the slave valve when the master valve is closed, and closes the slave valve when the master valve is open, wherein the master valve opens the slave valve to allow the pressurised fluid from the pressurised fluid chamber to enter the collection chamber, and closes the slave valve to allow the pressurised fluid from the collection chamber to enter the vent chamber, and wherein the master valve and the slave valve cannot be shut simultaneously; and switching between a first mode and a second mode in any order, wherein, in the first mode, the master valve is closed and the slave valve is open to collect the pressurised fluid in the collection chamber, and wherein, in the second mode, the slave valve is closed and the master valve is open to vent the pressurised fluid from the collection chamber to the vent chamber.
12 . The method of claim 11 , wherein a time duration of the first mode is forty times, or more, than a time duration of the second mode.
13 . The method of claim 11 , wherein the switching is only achieved by operating the master valve.
14 . The method of claim 13 , wherein the master valve is operated by a pilot fluid from a compressor for the pressurised fluid chamber, or a solenoid mechanism.
15 . The method of claim 14 , wherein only a pneumatic signal from the compressor for the pressurised fluid chamber is used for the switching between the first mode and the second mode.
16 . The drain valve according to claim 2 , further comprising a housing in which the collection chamber, the vent chamber, the master valve, the slave valve, and the valve seat are all disposed.
17 . The drain valve according to claim 1 , wherein the master valve and the slave valve are centered on and move along a common axis.
18 . The drain valve according to claim 17 , wherein the slave valve is positioned above the master valve on the common axis.

Description

TECHNICAL FIELD The present disclosure relates to a drain valve and a method for draining. More particularly, the present disclosure relates to a drain valve for a pressurised chamber and method for draining a pressurised chamber when filtering gases at high pressures. BACKGROUND Drain valves are used for draining a fluid from a container. In filtration applications where a filter element or cartridge is held in a chamber of a pressurised housing, the element will be ideally sized in order to maintain maximum filtration efficiency. A major factor considered in this sizing is the velocity of the gas stream though the filtration media. If the chamber requires periodic draining of the separated fluid by opening a tapping in the bowl to a much lower pressure, such as atmospheric, the pressure in the chamber quickly reduces whilst the mass flow rate stays the same and therefore the velocity through the filtration element will increase beyond desirable limits. This may cause physical failure of the element, in extreme cases bursting of the element, or may cause the separated fluid which has been collected in the filtration media to return to the previously filtered gas stream. To prevent this undesirable operation, the filtration element tends to be sized larger than is required during the normal operation, the non-drain period. This means that the element spends much of it's time operating with the gas velocity below the optimal to give maximum efficiency. A problem is thus to allow the chamber to be drained without a significant loss of pressure so that the filtration element can be correctly sized for optimal efficiency. A chamber containing filtration media, or mechanical separation devices, is required to be periodically drained to remove the separated fluid is subjected to a fatigue cycle during this periodic draining. A fatigue cycle is also experienced when the machine or process the filtration chamber is part of stops or is interrupted. In compressor applications, typically the chambers which house breathing air filtration are manufactured from aluminium so as to keep their weight low and to avoid the corrosion seen with ferrous materials due to moisture in the air. Aluminium is less resistant to fatigue, and does not display a true endurance limit, therefore aluminium parts have to be replaced after a certain period of time or number of cycles. The current state of the art practise of draining of chambers of high pressure compressors is by periodically venting the chambers of the separators. However, this results in the compressor not delivering compressed gas from the outlet during such periodic venting, the drain period, as the gas is venting out of the chambers of the separators. The way of solving this is to employ a delivery buffer vessel to ensure continuous gas flow during the drain period. If a compressor is to support any sort of downstream continuous process that requires a steady and continuous flow of gas, then a delivery buffer vessel is to be used. It is desirable to have a compressor that does not require the use of a downstream buffer vessel. It is also desirable to have a valve that reduces any reduction of flow rate in the gas to be delivered by the compressor. A valve that allows the chamber to be drained without a significant loss of pressure and that on shut down of the system maintained pressure in the housing for an extended period, not drain as normal, would extend the life of parts of a separation device by reducing the number of fatigue cycles. A problem is to provide a valve that fulfils all the requirements above, such as draining without a significant loss of pressure, reducing fatigue cycles, maximize efficiency, and maintaining pressure on shut down. Other ways of draining a filter housing is to use a float valve, or a high pressure solenoid valve. However, these two options are not reliable at high pressure and can therefore not be used. The use of ball valves or a shuttle valve are also not options, because they are too large and expensive. Ball valves and shuttle valves have also reliability issues. It is therefore desirable to provide a drain valve and a method for draining that do not have the inherent drawbacks and properties of ball valves, shuttle valves, float valves, or high pressure solenoid valves. SUMMARY OF THE INVENTION It is an object of the present invention to provide a drain valve for a pressurised fluid chamber and a method for draining a pressurised chamber with such a drain valve. This object can be achieved by the features as defined by the independent claims. Further enhancements are characterised by the dependent claims. According to one embodiment, a drain valve for a pressurised fluid chamber is disclosed. The drain valve comprises a collection chamber for collecting pressurised fluid from the pressurised fluid chamber; a vent chamber for venting the pressurised fluid from the collection chamber; a master valve between the collection chamber and