Automatic drain system

ABSTRACT

An automatic drain system for removal of condensate from compressed air systems comprises a reservoir having an inlet for entry of condensate and outlet for the periodic discharge of accumulated condensate. The discharge, through a ball valve in the outlet, is controlled by a float structure responsive to the level of accumulated liquid condensate in the reservoir. An air discharge tube is provided for the exiting of air when the float (and liquid level) is at the highest position. The air discharge tube is in fluid communication with an air cylinder outside of the reservoir. The air cylinder is coupled to the ball valve to open the valve and allow liquid condensate to exit in response to air pressure transmitted from the air discharge tube. As the liquid exits the liquid level and float are lowered. When float is at its lower position, the float structure closes across the air discharge tube and the cycle repeats.

INFORMATION

DETAILED DESCRIPTION OF THE INVENTION

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention and the manner in which it may be practiced is further illustrated with reference to the accompanying drawings wherein:

FIG. 1 is a side plan view of the interior of an embodiment of the automatic drain apparatus of this invention when the components are in the closed position.

FIG. 2 is a side plan view of the interior of the embodiment shown in FIG. 1 of the automatic drain apparatus of this invention when the components are in the open position.

FIG. 3 is a side plan view of the interior of an alternate embodiment of the automatic drain apparatus of this invention when the components are in the closed position.

FIG. 4 is a side plan view of the interior of the alternate embodiment shown in FIG. 3 of the automatic drain apparatus of this invention with the components in the open position.

FIG. 5 is a side perspective of the exterior view of the automatic drain apparatus of this invention.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PREFERRED EMBODIMENTS OF THE INVENTION

With particular reference to the drawings, the automatic drain apparatus of the invention includes a reservoir contained within a housing comprising a housing wall positioned between two blocks (FIG. 5) and held tightly in place by bolts . A liquid inlet allows condensate from a compressed air system to enter the reservoir for accumulation there and eventual elimination. Housing wall is preferably made of a transparent or translucent material such as a polyacrylate or a polycarbonate or preferably, a fiberglass composite, so that the user can easily see how much condensate has accumulated at any time. The blocks may be of various suitable materials, such as, aluminum, steel, plastic, or the like. Furthermore, although the preferred shape of the housing wall is cylindrical, as shown, it will be apparent that in place of cylinder there may be employed a housing wall of different cross-sectional shape, such as rectangular. A liquid outlet is located at the lower portion of the reservoir. Both the liquid inlet and the liquid outlet open into the reservoir and are in fluid communication therewith and can be located at any convenient location in the apparatus. In one embodiment the reservoir may have two or more liquid inlets so that the most appropriate inlet location may selected for convenience for a particular installation. The unused inlet(s) may simply remain capped or plugged.

Compressed air is allowed to enter the reservoir through liquid inlet which is in fluid communication with the compressed air system being drained. A vent port is located near the top of the reservoir and is in fluid communication with the compressed air system. As the liquid condensate enters the reservoir through liquid inlet , to gradually fill the reservoir, air can escape through vent port , thus preventing the occurrence of an air lock.

As will be seen from FIGS. 1 and 2, the flow of condensate out of the reservoir is controlled by a float structure comprising a float having a lever arm attached thereto. An air discharge tube , within the reservoir, is in fluid communication with an air cylinder outside of the reservoir (FIG. ). The air cylinder contains a piston with extension rod attached. The piston and extension rod are kept in a closed position by a spring within the cylinder. Extension rod is attached by means of lever to a ball valve that controls the flow through liquid outlet . As the reservoir fills with condensate, the float rises. The lever arm is pivotally attached to a pivot rod near the entrance to air discharge tube .

When float is in its lowest position (FIG. ), seal on the underside of lever arm rests on entrance of air discharge tube , preventing the exiting of air therethrough. Seal may be a resilient material, such as rubber, plastic, or the like. As the float rises, optionally aided by counterbalanced weight , seal is lifted from entrance of air discharge tube (FIG. ). Compressed air from the reservoir then exits through the air discharge tube to air cylinder (FIG. 5) causing extension rod to extend and, in turn, to open ball valve . The air pressure within the reservoir then forces the liquid condensate as well as particulate contaminants through the liquid outlet where it may be passed to a collection site (not shown) for disposal. As the liquid level in the reservoir drops, float is lowered and lever arm pivots downwardly until seal rests on entrance of air discharge tube , stopping the flow of compressed air to air cylinder . At this point the compressed air trapped in air cylinder bleeds off through bleedhole and the spring within the cylinder is allowed to return the extension rod to its normal retracted position, causing ball valve to close.

The liquid condensate then begins to fill the reservoir; float rises and the cycle repeats.

In a preferred embodiment, the closure of air discharge tube may be aided with the use of one or more magnets. For example, a magnet may be attached to the side of entrance opposite pivot rod . Lever arm is made a ferromagnetic material, such as, iron or nickel or, if the lever arm is made of a non-magnetic material, a piece of ferromagnetic material may be attached to the lever arm in alignment with magnet . Alternatively, the attachments may be reversed, that is with the ferromagnetic material attached to the side of entrance and the magnet attached to the underside of lever arm . Furthermore, in place of the ferromagnetic material there may be employed a second magnet with the poles of the magnets appropriately oriented. The use of magnet(s) in this manner affords a more secure closure of air discharge tube while the reservoir is filling. More importantly, the magnet will hold the lever arm and seal in place until float has sufficient buoyant force to overcome the magnetic force. When this occurs, the buoyancy of the float and the leverage exerted by weight that is attached at the other end of lever arm will allow seal to be instantaneously lifted fully from entrance and deliver the full flow of air required to open ball valve via air cylinder and extension rod in sufficient excess of the amount that will be lost through bleedhole .

In a preferred embodiment, as depicted in FIGS. 3 and 4, two lever arms are employed. Float is attached to a first lever arm . Weight is attached to an opposite end of a second lever arm and seal is attached to the underside of the second lever arm at a position in alignment above the entrance of air discharge tube . Both lever arms are pivotally connected to pivot rod at the side of entrance . The second lever arm is flexibly connected by tether to the first lever arm , resulting in a delay in the closing of seal on entrance as the condensate exits and float is lowered. This delay will allow more condensate to be expelled during each cycle. When float is at its lowest position and tether is fully extended second lever arm will pivot downwardly causing seal to close entrance . The closure may be aided by the attractive force between magnet and ferromagnetic material in the manner described hereinabove regarding the embodiment of FIGS. 1 and 2. With entrance closed, liquid condensate, entering through liquid inlet , will begin to fill the reservoir, causing float to rise until it's bouyant force is sufficient to push second lever arm pivotally upward, opening entrance . Air pressure is then transmitted through air discharge tube , to air cylinder causing ball valve to open and the liquid condensate in the reservoir to discharge through liquid outlet . With the lowering of the liquid level in reservoir , the float lowers and the cycle continues.

The apparatus of the invention has been described and illustrated with respect to a preferred embodiment wherein the internal mechanism is contained within a horizontally oriented cylinder. However, if desired, depending on space considerations for installation, the mechanism could be installed in a vertically oriented cylinder.

Although the invention has been described with reference to certain preferred embodiments, it will be appreciated by those skilled in the art that modifications and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

CLAIMS

1. An automatic drain system for removal of condensate and particulate contaminants from compressed air systems which comprises, in combination: a reservoir having a liquid inlet and a liquid outlet; an air discharge tube for discharging air from said reservoir; a first lever arm, having a float attached thereto, said float being responsive to a liquid level in the reservoir and said first lever arm being pivotally connected to a pivot rod; a second lever arm having a weight attached at one end thereof, an opposite end thereof being aligned over said float, said second lever arm being pivotally attached to a pivot rod so that as said liquid level rises and said float is buoyed upwardly, said opposite end is raised and said weight is lowered; a seal attached to said second lever arm in alignment with an entrance of said air discharge tube so that when said weight is lowered, said seal is raised from said entrance permitting air flow therethrough; a tether connecting said first lever arm and said second lever arm so that as said liquid level lowers and said float lowers, said tether is stretched and said opposite end of said second lever arm is pivotally lowered and said seal is lowered onto said entrance, preventing air flow therethrough; an air cylinder in fluid communication with said air discharge tube; a valve for opening and closing said liquid outlet, responsively connected to said air cylinder, said valve being controllably opened and closed in response to pressure from air exiting through said air discharge tube to said air cylinder in response to changes in the liquid level in the reservoir.

2. An automatic drain system according to claim 1 wherein as said float rises in response to a rising liquid level in the reservoir, said second lever arm and attached seal are held in place, with the aid of a magnetic force, preventing air flow through said air discharge tube, until bouyant force on said float is sufficient to overcome the attractive magnetic force.

3. An automatic drain system according to claim 2 wherein said magnetic force is created by a magnet attached to said air discharge tube and a ferromagnetic component integral with said second lever arm.

4. An automatic drain valve for removing condensate from compressed air systems comprising: a reservoir housed in a transparent or translucent housing for accumulating condensate from a compressed air system, said reservoir having a liquid inlet the entry of liquid condensate and a liquid outlet for the discharge of accumulated condensate; an air discharge tube having an entrance within the reservoir; a first lever arm and a second lever arm within said reservoir, each pivotally mounted on a fixed pivot means said first lever arm having a float attached thereto, said float being responsive to a liquid level in the reservoir, said second lever arm having a weight attached to one end thereof, an opposite end of said second lever arm being aligned over said float so that as said liquid level rises, said float is buoyed upwardly raising said opposite end of said second lever arm; a seal means attached to said second lever arm and positioned in alignment with said entrance to said air discharge tube so that as said opposite end of said second arm is in a lowest position, said seal rests upon said entrance, preventing a flow of air therethrough, and when said opposite end is at a highest level, said seal has been lifted from said entrance, allowing the flow of air therethrough; a tether connecting said first lever arm and said second lever arm so that as said liquid level lowers and said float lowers, said tether is stretched and said opposite end of said second lever arm is pivotally lowered and said second seal is lowered onto said entrance, preventing air flow therethrough; a magnet means providing an attractive magnetic force between said float lever arm and said entrance to the air discharge tube holding said seal on said entrance, preventing air flow through said air discharge tube, until a bouyant force on said float is sufficient to overcome said attractive magnetic force; an air cylinder mounted on the outside of said housing and in fluid communication with said air discharge tube; a valve for opening and closing said liquid outlet, said valve being responsively connected to said air cylinder and controllably opened and closed in response to pressure from air exiting through said air discharge tube to said air cylinder in response to changes in the liquid level in the reservoir.

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