Direct diffuse vapor separator—steam trap system

A device for separating liquid from gas including: a fluid inlet configured to receive a fluid that includes a liquid and a gas; a gas outlet; a deflector positioned between the fluid inlet and the gas outlet, the deflector obstructing a path from the fluid inlet to the gas outlet; and a liquid channel adjacent to a liquid outlet; wherein the deflector is configured to deflect the liquid to the liquid channel; wherein the liquid deflected to the liquid channel exits the device through the liquid outlet; and wherein the gas flows around the deflector and exits the device through the gas outlet.

FIELD OF THE INVENTION

The invention generally relates to fluid flow control devices. More particularly, the invention relates to a direct diffuse vapor separator for separating liquid from gas in a fluid stream.

BACKGROUND

In many systems, it is advantageous to separate liquid matter from gaseous matter in a process steam. A device that separates liquid from gas or vapor has many practical applications. For example, a device for the removal of water particulate from natural gas transporting pipe line systems is needed in order to protect valves, pumps and similar equipment. In the production of specialty gases, such as helium, it is desirable to remove condensates from the gas production line. Furthermore, in steam supply systems, the efficiency may improve if water or other liquid is removed. Another application of such device is for the compressed air systems where water and oil need to be separated from the air.

In order to facilitate clear and concrete discussions of the device, a practical example of a vapor separator for steam systems, i.e., a stream trap is disclosed in greater detail. A steam trap is a valve device that discharges condensate and air from the line or piece of equipment without discharging the steam.

The three important functions of steam traps are:To discharge condensate as soon as it is formed.Not to allow steam to escape.To be capable of discharging air and other incondensable gases.

There are three basic types of steam trap as classified by the international Standard ISO 6704:1982:1. Thermostatic (operated by changes in fluid temperature)—The temperature of saturated steam is determined by its pressure. In the steam space, steam gives up its enthalpy of evaporation (heat), producing condensate at steam temperature. As a result of any further heat loss, the temperature of the condensate will fall. A thermostatic trap will pass condensate when this lower temperature is sensed. As steam reaches the trap, the temperature increases and the trap closes.2. Mechanical (operated by changes in fluid density)—This range of steam traps operates by sensing the difference in density between steam and condensate. These steam traps include “ball float traps” and “inverted bucket traps.” In the “ball float trap,” the ball rises in the presence of condensate, opening a valve which passes the denser condensate. With the “inverted bucket trap,” the inverted bucket floats when steam reaches the trap and rises to shut the valve. Both are essentially “mechanical” in their method of operation.3. Thermodynamic (operated by changes in fluid dynamics)—Thermodynamic steam traps rely partly on the formation of flash steam from condensate. This group includes “thermodynamic,” “disc,” “impulse” and “labyrinth” steam traps.

However many conventional steam traps include moving mechanical parts, which may have a limited life span and may be expensive and complex to manufacture in order to provide a reliable and functional steam trap. Other conventional steam traps have complex linkages and levers that are prone to sticking, clogging, and/or binding (e.g., when bent by forces of a water hammer). These conventional steam traps are generally installed off-line from the steam transportation line, requiring addition plumbing installation and taking up addition space.

Many of these same problems are also present in other systems, such as natural gas transporting pipe line systems, compressed air systems, specialty gas production systems, etc., as mentioned above.

Therefore, there is a need for a new low-cost, in-line diffuse vapor separation device that is simple in its design to provide reliable and consistent removal of condensate with minimal vapor loss, and without the need for additional plumbing.

SUMMARY

One embodiment of the present invention provides a device for separating liquid from gas including: a fluid inlet configured to receive a fluid that includes a liquid and a gas; a gas outlet; a deflector positioned between the fluid inlet and the gas outlet, the deflector obstructing a path from the fluid inlet to the gas outlet; and a liquid channel adjacent to a liquid outlet; wherein the deflector is configured to deflect the liquid to the liquid channel; wherein the liquid deflected to the liquid channel exits the device through the liquid outlet; and wherein the gas flows around the deflector and exits the device through the gas outlet.

One embodiment of the present invention provides a steam system including a steam trap connected in-line to a steam pipe carrying a fluid that includes a liquid and steam, wherein the steam trap includes: a fluid inlet configured to receive the fluid; a steam outlet; a deflector positioned between the fluid inlet and the steam outlet, the deflector obstructing a path from the fluid inlet to the steam outlet; and a liquid channel adjacent to a liquid outlet; wherein the deflector is configured to deflect the liquid to the liquid channel; wherein the liquid deflected to the liquid channel exits the device through the liquid outlet; and wherein steam flows around the deflector and exits the device through the steam outlet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure describes the best mode or modes of practicing the invention as presently contemplated. This description is not intended to be understood in a limiting sense, but provides an example of the invention presented solely for illustrative purposes by reference to the accompanying drawings to advise one of ordinary skill in the art of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts.

An example embodiment of the present invention provides an in-line steam trap that ensures that a steam system will operate more efficiently by virtually eliminating condensate in the steam line. The unique, compact design of the steam trap according to an embodiment can be mounted either vertically or horizontally, and is installed directly into the steam line, eliminating the need for additional plumbing. Adding the steam trap according to an embodiment to a steam mixing unit set up reduces condensate in the steam line, reduces rust caused by condensate, and significantly reduces maintenance costs.

FIG. 1shows a vapor separator100in accordance with an embodiment. As can be seen fromFIG. 1, the vapor separator is compact in size and can be installed in-line to the process steam line. In a preferred embodiment, an arrow indicating the flow direction of the fluid is provided on the outside surface of the vapor separator so as to provide a visual guide for installation or maintenance.

In one embodiment, the vapor separator includes a top part and a bottom part.FIG. 2shows the top part210and the bottom part220. In one embodiment, the top part and the bottom part have matching pipe thread and can be joined by threading the top part to the bottom part. Note that, in addition to threading, other methods of joining the top and bottom parts, such as soldering, glue, etc., are contemplated.

FIG. 3Ashows the side view of the top part of the vapor separator, andFIG. 3Bshows the cross-sectional view of the top part of the vapor separator. The top part has a fluid inlet310. The fluid inlet may be threaded so that it can be connected to a threaded end of a steam delivery pipe. As can be seen inFIG. 3B, the inner diameter of the side wall320is smaller than the inner diameter of the side wall340, the tapered side wall330gradually increases in diameter from that of the side wall320to that of the side wall340. A liquid outlet350passes through the sidewall340. The inner surface end360in the top part may be threaded or sized to match a corresponding coupling end in the bottom part.

FIG. 4Ashows the side view of the bottom part of the vapor separator, andFIG. 4Bshows the cross-sectional view of the bottom part of the vapor separator. In one embodiment, the deflector410is cone-shaped. Note that in order to facilitate a smooth and streamlined flow of the fluid, as shown inFIGS. 4A and 4B, the outside edge of the base of the cone may be rounded and the surface of the cone rim makes an angle (e.g., 30 degrees) the horizontal. In general, the deflector can be any geometric shape with its diameter having a first value at one end and gradually increases to a second value at the other end. In some embodiments, the deflector may be a paraboloid, frustum, pyramid, etc. The deflector410is fixed to and supported above the gas outlet460by one or more support columns420, such that the deflector410blocks a direct path to the gas outlet460, but leaves a gap430for the gas to enter the gas outlet460. The side wall440of the bottom part has an outer diameter smaller than the inner diameter of the side wall340of the top part. When the wall450of the bottom part engages with the inner surface end360of the top part, a liquid channel is formed between the side wall440of the bottom part and the side wall340of the top part. Liquid deflected by the deflector is collected in the liquid channel. In one embodiment, the fluid inlet, the gas outlet, and the liquid channel are each rotationally symmetrical about a rotational axis, and wherein the deflector is conical and centered about the rotational axis. In one embodiment, the deflector has the shape of a right circular cone, and preferably the half-angle470of the cone is about 25 degrees.

FIG. 5illustrates the operation of the vapor separator in accordance with an embodiment. A fluid510enters the vapor separator via the fluid inlet. In this non-limiting example, the fluid510includes at least a liquid520and a gas530. The liquid520is deflected by the deflector540to the liquid channel560, and the deflected liquid520exits the vapor separator through the liquid outlet570, The gas530flows around the deflector and enters the gas outlet via the gap550. Note that when the liquid520accumulates in the channel560, the liquid520blocks the liquid outlet570and thus the gas530cannot escape through the liquid outlet570.

As shown inFIG. 6, the gas may be prevented from escaping through the liquid outlet620by installing a valve610. In one embodiment, the valve is a thermo-electric valve. When gas is present, the temperature is high and the valve is closed, and thus the gas cannot escape. When liquid is present, the temperature is low and the valve is open, and thus the liquid can exit. As can be seen fromFIG. 6, the vapor separator is installed in-line to the process line. In contrast, conventional steam traps are generally installed off-line from the steam transportation line, requiring addition plumbing installation and taking up addition space.

FIG. 7shows a thermo-electric valve according to an embodiment. The valve730is supported by the off-open spring740. The guide750guides the valve730to seal the entrance when the valve is pushed to the closed position by the thermo-electric element720. When high temperature is sensed (e.g., by a thermocouple), the thermo-electric element720expands and pushes the valve730down to the close position. When low temperature is sensed, the thermo-electric element720contracts, and the spring740pushes the valve730up to the open position. Also shown inFIG. 7is an access cover710to allow for servicing the parts in the thermo-electric valve.

Note that embodiments of the present invention are described and illustrated in some non-limiting applications of steam systems. However, it is contemplated that the present invention may be generally applied to other fluid systems, in which the fluid includes at least a gas and a liquid.