CA1059874A - Automatically controlled discharge trap - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A plate member containing a restrictive orifice is used in pipe lines carrying vapor under pressure to control the drainage of condensate from the pipe lines with a minimum loss of vapor. A filtering element is located adjacent the plate member in the pipe line to prevent deleterious material from clogging the orifice.

Description

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ACKG~OUND OF THE INVENTION
The present invention relates broadly to fluid handling devices and more particularly to improvements in steam traps as included in the pipe-lines of ship-board steam powered equipment.
Conventional steam traps generally comprisc valving components designed to open in the presence of condensate and to close in the presence of steam. The principal feature of the conventional trap was to minimize the loss of steam in a system while at the same time maintaining the pipe-lines clear of condensate and thereby permit free circulation of steam throughout the system.
Under actual working conditions, conventional steam trap devices ,~
require substantial maintenance to adequately effect the intended operating characteristîcs. In many instances of malfunctioningJ steam traps must be extensively repaired or replaced thereby necessitating a partial or complete shutdown of the steam powered equipment. `
Some well known condensate trap devices employ reservoirs having specially designed conduit outlets open to the atmosphere. In the operation of these types of devices a predetermined quantity of condensate is allowed to collect in a reservoir within the trap. As the operating pressure in the lines of the steam equipment increases, a proportionate amount of th~ col- ;~
lected condensate is discharged from the trap. However, due to the varying pressure conditions within the steam system, largely based on the power demands in any given time period, the conduit outlets are not capable of discharging the condensate at a constant rate. Consequently the condensate, -illustratively water in this instance, may be drawn back into the steam system from the trap, or is never removed from the system into the trap.
This malfunction of the trap forces the retention of harmful moisture in the st0am pipelines and results in the attendant disadvantages of a reduc-tion in the efficiency of the steam po~ered equipment and damage ~o its 3~ working parts~
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SUMM~RY OF T~lE INVENTION
The invention provides for use in a system carr~ing steam under pressure, which system has a drain line for removing condensate and other -~ liquid components from said system, a condensate discharge device comprising a plate having a restrictive orifice therein providing a passage means for the flow of steam and condensate through the plate, the si~e of the orifice being such as to pass all of the condensate reaching the orifice and to ~
minimize the loss of vapor from the line, a first gasket for creating a pres- ;
sure seal at the upstream side of the orifice plate and a second gasket for ;~
creating a pressure seal at the down-stream side of the plate, a strainer carried by the first gasket to extend across the entire flow cross section of the line upstream of said orifice, the openings in the strainer being of a smaller size than the orifice, said gaskets and said plate being positioned such that the latter extends across the entire flow cross section of the ; drain line.
In its preferred embodiments the present invention provides a condensate discharge device which will be automatic in its operation, strong ~ and durable, and not liable to become inoperative at any time during its `~ use. The condensate discharge device is continuous in operation, requires -t 20 no special attention after proper adjustment to operating conditions, and which will continuously remove moisture from a system without becoming over~
pressuri~ed due to being clogged or otherwise fouled in operation. ;~
The objects and advantages of the present invention will become apparent from the following description of a preferred embodiment thereof, the claims, and the drawings in which: -i BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an elevation, in section, showing the orifice plate and the line strainer positioned in accordance with the invention.
Figures 2A and ~B are detail illustrations of the orifice plate of the invention.

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Figure 3 is a detailed illustration of the line strainer of the invention.
Figure 4 is a schematic illustration of a typical installation of a condensate drain orifice in a condensate drain line. `~
DESCRIPTION OF THE PREPERRED EMBODIMENT
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Referring in detail to the drawings, Figure 1 illustrates a con~
densate discharge device embodying the invention and is here-':','"~ ' - :~ ` "
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inaf ~ ~o be descrlbed wlth reference to exemplary use with steam powered equipment designed for shipboard operation.

It is the usual practice when dasigning steam lines to include condensate traps ~o remove liquid, usually water, accumu-lating in the lines. Conventional steam traps open and close automatically depending on the presence of either water or steam ;~ -at the trap location, and hence are subject to mechanical failure resulting in the likelihood of overpressurization of the steam system in the manner as hereinbefore suggested.
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In Figure 1, there is shown an exemplary automatic condensate discharge device 20 which comprises a plate 22 having an orifice 24 of a predetermined diameter centrally located in the plate.
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In practice. the diameter of the orifice 24 is determined by the operating pressure within the particular steam system, since the purpose of the invention is to minimize the loss of steam while `
at the same time effecting optimum condensate discharge. For ex-- ample, at lower pressure, the orifice 24 can be of a larger ;
diameter whereas at higher steam pressures, the diameter would be reduced accordingly. However, once the diameter of the orifice has been established for the particular working steam pressure in a `
system, no further changes in the orifice plate 20 need be made and the system will operate thereafter with a minimum of main-, tenance. Of course, if maintenance is required, or if the pressure of the s~eam system is changed to thereby require a different sized discharge orifice, the unique construction of the discharge device of the invention facilitates the removal and replacement of the plate 20 in a manner to be hereinafter described.
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To pro~ide easy removal of the plate 22 -from a steam line or to permit substitution of a plate ha-ving differently sized ori~
~ice, the plate 22 is located between Elanges 26 and 28 of a steam llne 3~. Gaskets 32 and 34 are shown in Figure 1 to be disposed on opposite faces 36 and 38 of plate 22 and against shoulders 46, 48 of the flanges thereby providing an appropriate seal and pre-venting excessive loss of steam at the jointure illustrated.
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While it is understood that any suitable gasket material may be used to accomplish the sealing effect without departing from the spirit of the invention, the spiral wound gasket assembly as shown in Figures 1 and 3 is preferred. The illustrated gasket assembly is commercially marketed by the Flexitallic Gasket Company rnc. of Camden, New Jersey and Philadelphia, Pennsylvania, under the trademark '~Flexitallic'~.

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15 ~ It should also be ~k~ t~ that the plate 22 may be made from any material suitable for use in a high pressure steam environment. While relatively thick steel is contemplated as the preferred material for the plate 22, it should be recognized that other metals, plastics, or specially developed glass substances '20 having a resistance to the cutting action of the condensate and ~, steam may be employed without departing from the spirit of the in- ;
vention or without other wise affecting the operation of the dis-charge device herein proposed.

Figures 1 and 3 show a strainer screen 52 located within an annular groove 54 of the spiral wound gasket 32. The strainer ,~
32 is locatecl on the pressure side of the plate 22 and comprises a mesh material, preferably of stainless steel, of such size to permit moisture and fine dirt to pass through the opening 24 L~. the plate ~2 but will screen out the larger particles of dirt or scale ' which would clog up the opening in the plate 22.
Referring to Figure 4, the automa~ic condensate discharge device 20 is mounted in a condensate draln line that comprises a conventional drip , leg 60 that is positioned to receive condensate from high pressure line 62.
; The drip leg 60 is in fluid communication with a drain line compris~ng sections 30. The orifice plate 22 and associated gaskets 32 and 34 may be -~
~ , secured between flanges of drain line sections 30. In normal operation, condensate drains into the drip leg and from there to drain line 30. Con- .
densate reaches the level of orifice 24 and condensate and a small quantity of steam pass through orifice 24 in plate 20 into the drain system. In most systems, the condensate is returned to the boiler for reuse as boiler feed . ~, ; . .
1 water. Conventionally the drain line is pitched slightly so that the con- ~
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, ; densate flows by gravity to a collection ar pumping point.
` From the foregoing description it has bee~ shown that this invention provides an improved, maintenance free condensate discharge device that is automatic in operation and which satisfies the previously stated objects and advantages as well as others apparent from this description.
Of course it will be recognized that while the invention has been described with reference to a steam system, it is obvious that the condensate discharge device could be disposed in compressed air systems or in any system wherein the condensate in gas streams must be automatically removed from the system. Moreover, many other modifications, variations and uses of the present invention are possible in the light of the above teachings. It is ;
understood therefore that the invention may be practised otherwise than as -~;
specifically described~

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Claims (4)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. For use in a system carrying steam under pressure, which system has a drain line for removing condensate and other liquid components from said system, a condensate discharge device comprising a plate having a restrictive orifice therein providing a passage means for the flow of steam and condensate through the plate, the size of the orifice being such as to pass all of the condensate reaching the orifice and to minimize the loss of vapor from the fine, a first gasket for creating a pressure seal at the up-stream side of the orifice plate and a second gasket for creating a pressure seal at the down-stream side of the plate, a strainer carried by the first gasket to extend across the entire flow cross section of the line upstream of said orifice, the openings in the strainer being of a smaller size than the orifice, said gaskets and said plate being positioned such that the latter extends across the entire flow cross section of the drain line.

2. Apparatus as in claim 1 wherein the first gasket is a spiral wound gasket.

3. Apparatus as in claim 2 wherein the strainer is a metal mesh screen.

4. Apparatus as in claim 3 wherein the first gasket has an internal peripheral groove, the metal mesh screen being mounted in said internal peripheral groove.