WO2010090606A1

WO2010090606A1 - Self-cleaning electromagnetic valve of a condensate drain

Info

Publication number: WO2010090606A1
Application number: PCT/SI2010/000002
Authority: WO
Inventors: Jure Robic; Gojmir Furlan; Mitja Rihtarsic
Original assignee: Omega Air d o o
Current assignee: Omega Air d o o
Priority date: 2009-02-04
Filing date: 2010-02-01
Publication date: 2010-08-12
Anticipated expiration: 2011-08-04
Also published as: SI22980A

Abstract

The subject of the present invention is a self-cleaning electromagnetic valve arranged on a device for an automatic condensate drain from a compressed air system or another tube system or gas storage system, where condensate is produced. The valve is an electromagnetic valve and operates by a longitudinal stroke of the plunger, i.e. it opens and closes the flow by a stroke up and down and is characterised in that the condensate enters above the plunger (34), i.e. the condensate enters at one side of the plunger (34) and exits at another side of the plunger (34), and the plunger (34) is provided with means for the flow of condensate at its upper front and optionally along the lateral surface area. The plunger may have a shape of a cylinder or a truncated cone and may be provided with at least one means for condensate drain on the top, said means being in the shape of a radial or curved groove, and with at least one means for condensate drain on the lateral surface area in the form of a longitudinal groove or a groove in the form of a helix.

Description

SELF-CLEANING ELECTROMAGNETIC VALVE OF A CONDENSATE DRAIN

The subject of the present invention is a self-cleaning electromagnetic valve arranged on a device for an automatic condensate drain from a compressed air system or another tube system or gas storage system, where condensate is produced. In said systems humidity in the form of condensate is reduced from gas, and especially from air in compressed air systems. Condensate rinses dirt, especially oil, grease and rust off tube walls. This dirt causes defects in the operation of known valves. Modern condensate drains are electronic and automated, i.e. they are provided with sensors, adequate electronics and controllers that electrically control a valve. The term "condensate" used herein refers to a segregate of a fluid mixed with dirt and gas bubbles.

Two most common variants of valves are shown in Figures 1 and 2. Figure 1 shows a direct-acting electromagnetic valve. A plunger 1 is controlled by a return spring 2 and a coil 3 of the electromagnet. As electronics determines adequate conditions for condensate drain, current flows through said coil 3 and the electromagnet displaces said plunger from a drain outlet 5 thus opening it for the condensate to drain. Direction of condensate flow is indicated with arrows. It is evident from Figure 1 that said plunger 1 is present in a pressure section of a valve, i.e. in direct contact with condensate. As dirt is present in the condensate, it collects on the walls of the plunger and the housing, in which said plunger moves. In time a layer of dirt deposited on the walls of the plunger and the housing prevent the plunger from moving and the operation of the valve is herewith prevented. A valve of this type may also have a plunger with longitudinal grooves, which are filled with condensate that partially, yet not sufficiently, rinses dirt off the walls of the plunger and the housing.

A known valve disclosed in Figure 2 is an electromagnetic membrane servo valve. The drain outlet 5 is covered by a membrane 6 with a spring 7. Said membrane 6 is provided with a small hole 8 for pressure equalisation. The plunger 1 only opens a linking passageway. When the conditions for the discharge of condensate are met, the electric magnet with a coil 3 attracts the plunger and releases negative pressure in the compartment above said membrane 6, which opens the drain outlet 5. This valve has three disadvantages: it is provided with a membrane having a limited life span, dirt clogs the hole 8 and dirt blocks the movement of the plunger 1.

The patent application DE 10 2008 023 290 A1 shows a solution with a membrane provided with a pneumatic servo system. Disadvantages of this solution are a limited life span of the membrane, a possibility of pressure passageways getting clogged and the fact that the presented valve does not allow for electric regulation.

The patent application EP 1 961 457 A2 shows a mechanical valve, in which a moving plunger has sealing rings. However, these sealing rings are subject to mechanical wear. The valve does not allow for electric regulation.

The patent US 3,516,430 discloses a mechanical valve with a membrane. The valve does not allow for electric regulation.

Disadvantages of known valves are unreliable operation due to a deposition of dirt, limited life span of the membrane and/or lack of possibility of electric regulation of the valve.

The task of the invention is a construction of such valve that would provide for electric regulation and also have a long life span, whose operation will not be hindered by dirt and that would be simple in its construction.

The task of the invention is solved by a self-cleaning valve of a condensate drain as claimed in an independent claim.

The invention will be described by way of an embodiment and drawings, representing in Figure 1: a known direct-acting electromagnetic valve,

Figure 2: known electromagnetic membrane servo valve,

Figure 3: embodiment of a drain condensate with a valve of the invention,

Figure 4.1 : cross-section C-C of the valve plunger of the invention,

Figure 4.2: top view of the valve plunger of the invention,

Figure 4.3: bottom view of the valve plunger of the invention,

Figure 4.4: elevation of the valve plunger of the invention,

Figure 4.5: cross-section D-D of the valve plunger of the invention,

Figure 5: view on the cross-section of the valve housing,

Figure 6: embodiment of the plunger provided with two helical grooves,

Figure 7: embodiment of the plunger provided with several helical grooves,

Figure 8: first embodiment of a conical plunger,

Figure 9: second embodiment of a conical plunger.

The valve of the invention is an electromagnetic valve having a movable plunger. When the electromagnet is not excited, the plunger closes a condensate drain and when the electromagnet is excited, the plunger moves away from the drain outlet and condensate may drain. Condensate under the pressure of the system, from which condensate is drained, enters the condensate drain provided with a valve of the invention in compliance with Figure 3 from the top side in direction of arrows and is collected in a collector 31. From the bottom of said collector 31 a duct 32 leads condensate from the top to an inlet 35 of a valve housing 33. The condensate enters said housing 35 in direction of arrows and flows over a plunger 34 up to an outlet 36. The plunger 34 in this embodiment is shaped like a tall cylinder with an upper and lower front, i.e. a base surface and a lateral surface area. A ratio between the cylinder diameter and its height ranges from 1:1 to 1 :7. Said plunger 34 is movably arranged within said housing 33 to freely move up and down and rotate. Condensate can reach said outlet 36 because said plunger 34 is provided with flow-through means, which are in this embodiment at least one radial groove 37 on the upper front of said plunger 34 and at least one longitudinal groove 38 on the lateral surface area of said plunger 34. Said groove 37 or several grooves have such diameter to allow for such flow of the condensate as is the flow capacity between said plunger 34 and said outlet 36. The groove 38 of the embodiment or several grooves have such diameter that - together with the clearance between said plunger 34 and said valve housing 33, where the plunger

34 moves - they allow for such flow of the condensate as allowed by a gap between said plunger 34 and said outlet 36. Figures 4.1 to 4.5 disclose details of said plunger 34 with grooves 37 and 38. This embodiment has grooves 37 and 38 of a rectangular cross-section, yet the cross-section of grooves may be of a different shape. Said plunger 34 is provided with an indentation, into which a gasket 39 is inserted. Said gasket 39 in this embodiment is movable in the height of said plunger 34 and a spring 40 presses thereon. Said spring 40 in this embodiment is used only to press against said gasket 39. As said plunger 34 travels downwards, i.e. as the magnet with a coil 14 is released, said plunger provided with said gasket 39 heavily hits said outlet 36 due to overpressure and condensate movement. Said spring 40 absorbs the hit. Other embodiments of use or non-use of said spring are possible and they will be described in the continuation. As the valve of the invention and of the embodiment is closed, said plunger 34 provided with said gasket 39 rests on said outlet 36. When the conditions for condensate drain are met, the magnet with said coil 41 attracts said plunger 34 upwards herewith opening said outlet 36 and allowing the condensate to drain. Condensate flowing past said plunger 34 rinses dirt off the walls of said housing 33 and said plunger 34 and thus allows an undisturbed operation of the valve.

In the present embodiment said spring 40 is arranged between said gasket 39 and the upper edge of said plunger 34. Other embodiments are possible, in which a spring may be absent or be arranged between a gasket and a valve housing or between a plunger and a valve housing.

The terms "up", "upper", "upwards", "on the top" denote direction, from which condensate flows. The term "lower" means at the condensate drain side.

The plunger of the embodiment is provided with means for condensate drain down the lateral surface area. However, the scope of invention also allows for another embodiment, where clearance, i.e. a gap between the plunger and the valve housing, in which the plunger moves is such to allow the condensate to flow through said gap and therefore the means for the condensate flow along the plunger are optional.

The valve of the invention may also be coupled directly to the system with a condensate drain, i.e. without a collector and the valve housing is directly coupled to the system.

The construction of the valve of the invention consists either of a collector coupled to a valve housing or the valve is directly coupled to the system so that the condensate enters the system at the one side of the plunger and exits at the opposite side. The plunger is provided with means for condensate flow at one front and optionally along the lateral surface area, and with a gasket at another front.

The described embodiment has a plunger in the shape of a cylinder provided with at least one front radial means or one means arranged longitudinally on the lateral surface area for condensate drain. Other shapes of means for condensate drains and other shapes of plungers fall under the scope of the invention as well.

The entire drain means in Figure 6 is formed as a curved groove and the lateral surface area of the cylinder has the means for condensate drain formed as a groove in the form of a helix. The entire drain means in Figure 7 consists of several curved drains, so they form a turbine, and the lateral surface of the cylinder has the means for condensate drain formed as several grooves in the form of a helix. The scope of the invention covers embodiments with one or several radial front grooves and optionally with one or several helical grooves on the lateral surface area and of course also those having one or several curved front grooves and optionally one or several longitudinal grooves on the lateral surface area. An advantage of curved or helical grooves is that the plunger rotates under the influence of reaction force of running condensate and thus contributes to a better rinsing of dirt off the walls of valve housing and off the plunger itself.

The scope of the invention also covers a possibility that only part of the condensate be delivered above the plunger to rinse dirt off the lateral surface area of the plunger. The remaining portion of the condensate is delivered under the plunger directly towards the drain under the plunger.

Of course, all described shapes of the means for condensate drains different than cylindrical, for instance plungers of a conical shape, are also possible. Figures 8 and 9 show conical plungers, i.e. plungers having the form of a truncated cone, where the angle between the radius of the base plate and the longitudinal axis of the lateral surface area ranges from 0 to 30°. The ratio between the arithmetical mean of the diameters of the lower and upper surface of the truncated cone, i.e. between the upper and lower front part is in the range from 1:1 to 1 :7. As the electromagnet first attracts and then releases the plunger, a condensate flow is created at the walls of the plunger and the valve housing, which flow rinses dirt and thus contributes to an undisturbed operation of the valve.

The self-cleaning electromagnetic valves of a condensate drain on a device for an automated condensate drain from a system with compressed air or another tube or storage system of gas in which condensate is drained, wherein the valve is of an electromagnetic type and functions with the longitudinal stroke of the plunger is characterised in that condensate is led from the collector above the valve housing, so that condensate enters above the plunger, which means that the condensate enters the plunger at one side and exits at the opposite side of the plunger and the plunger is provided with a means for the flow of the condensate at one of its front parts and along the lateral surface area. The plunger may have a shape of a cylinder or a truncated cone. The plunger may be provided with at least one means for condensate drain on the front, where the condensate enters the valve, in the shape of a radial or curved groove and at least one means for condensate drain on the lateral surface area in the form of a longitudinal groove or a groove in the form of a helix.

Claims

1. A self-cleaning electromagnetic valves of a condensate drain on a device for an automated condensate drain from a system with compressed air or another tube system or storage system of gas, where condensate is produced, wherein the valve is of an electromagnetic type and functions with the longitudinal stroke of the plunger, characterised in that condensate enters above the plunger, which means that the condensate enters the plunger at one side and exits at the opposite side of the plunger and the plunger is provided with a means for the flow of the condensate at one of its front parts and along the lateral surface area.

2. Valve as claimed in Claim 1, characterised in that the plunger is in the shape of a cylinder or truncated cone.

3. Valve as claimed in Claims 1 and 2, characterised in that the plunger is provided with at least one means for condensate drain in the form of a radial or curved groove on the front, where the condensate enters the valve.

4. Valve as claimed in Claims 1 and 2, characterised in that the plunger is optionally provided with at least one means for condensate drain in the shape of a longitudinal groove or a groove shaped like a helix on the lateral surface area.