WO2021255700A1

WO2021255700A1 - A thermodynamic steam trap

Info

Publication number: WO2021255700A1
Application number: PCT/IB2021/055393
Authority: WO
Inventors: Prashant RANADE; Mrunmayi BOMADE; Pranil Chavan Patil
Original assignee: Forbes Marshall Private Limited
Priority date: 2020-06-18
Filing date: 2021-06-18
Publication date: 2021-12-23

Abstract

The present disclosure envisages a thermodynamic steam trap (100). The steam trap (100) comprises an inlet (6) and an outlet (8), an air vent passage (2), a thermodynamic disc (4), and an air venting and steam trapping mechanism (1A). The air vent passage (2) is configured to be in fluid communication with the outlet (8) to vent entrapped air from the outlet (8). The mechanism (1A) is operatively disposed in the steam trap (100) in fluid communication with the inlet (6) and the outlet (8). The thermodynamic disc (4) is operatively disposed upstream of the air venting mechanism (1A). The mechanism (1A) configured to allow the flow of entrapped pressurized air through the air vent passage (2) via outlet (8), and further configured to expand and close the air vent passage (2) upon contacting with the hot condensate and prevent leakage of steam to from the outlet (8) to atmosphere.

Description

A THERMODYNAMIC STEAM TRAP

FIELD

The present disclosure relates to the field of devices/ mechanisms for venting air entrapped in steam traps. DEFINITION

As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.

The term “Hot Condensate” refers to as condensate which is at a temperature closer to steam temperature.

BACKGROUND

The background information herein below relates to the present disclosure but is not necessarily prior art.

Typically, a thermodynamic steam trap consists of a moving part i.e., a disc. It has a control chamber and restricted inlet and outlet. The change in the state of steam or water occurs within the control chamber which controls the opening and closing of the disc. On startup, the incoming pressure raises the disc and the cold condensate, and the air gets discharged from the inlet passage, under the disc to the outlet as shown in Figure 1. Hot condensate flowing through the inlet passage into the chamber under the disc, flashes into steam. This flash steam moves at high velocity causing low pressure area under the disc, drawing it towards the seat and closing the thermodynamic steam trap as shown in Figure 2. This high velocity creates a low-pressure area under the disc, drawing it towards its seat and closing the trap. Eventually, the trapped pressure in the upper chamber falls as the flash steam condenses by losing heat to the environment. The disc is raised, as shown in Figure 1 , by the higher condensate pressure and the cycle repeats.

During the startup, sometimes the air gets trapped in the chamber above the disc. In such case, since air cannot condense like flash steam, the pressure in the chamber above the disc continues to close the disc. Even if the condensate is generated in the system, the trap is not able to remove it because of the pressurized air in the chamber above the disc. Thus, it is required to make provision for the automatic removal of the entrapped air so as to enhance the operation of a thermodynamic steam trap.

To overcome the aforementioned drawback, bimetallic elements have also been used in the past for venting trapped air from a thermodynamic steam trap. However, due to its inherent construction, rate at which the trapped air is removed is very low.

Therefore, there is felt a need of a thermodynamic steam trap that alleviates the aforementioned drawbacks of the conventional arrangements.

OBJECTS

Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

An object of the present disclosure is to provide a thermodynamic steam trap.

Another object of the present disclosure is to provide a thermodynamic steam trap having a mechanism that facilitates effective venting of air entrapped therein.

Yet another object of the present disclosure is to provide a thermodynamic steam trap that has increased discharge capacity.

Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY

The present disclosure envisages a thermodynamic steam trap configured to prevent leakage of steam and remove pressurized air entrapped therein. The steam trap comprises an inlet and an outlet, an air vent passage, a thermodynamic disc, and an air venting and steam trapping mechanism. The inlet and the outlet are configured on the steam trap to allow hot condensate to pass therethrough. The air venting and steam trapping mechanism is operatively disposed in the steam trap in fluid communication with the inlet and the outlet. The thermodynamic disc is operatively disposed upstream of the air venting and steam trapping mechanism. The air vent passage is configured to be in fluid communication with the outlet. The air vent passage is configured to vent entrapped air from the mechanism. The thermodynamic disc operatively disposed upstream of the air venting and steam trapping mechanism. The air venting and steam trapping mechanism during startup is configured to allow the air vent passage to remain open for the passage of entrapped pressurized air through the outlet, thereby preventing air locking of the disc. The air venting and steam trapping mechanism is further configured to expand and close the air vent passage upon contacting with the hot condensate or flash steam passing through the trap to prevent leakage of steam to from the outlet to atmosphere.

In an embodiment, the air venting and steam trapping mechanism includes a thermally actuated valve element, and a valve head. The thermally actuated valve element is configured to expand and close the air vent path when surrounding temperature of the thermally actuated valve element rises upon contacting with the hot condensate. The valve head is operatively coupled with the thermally actuated valve element. The valve head is configured to displace upon expansion of the thermally actuated valve element and close the air vent passage to prevent steam to escape via the outlet.

In an embodiment, the thermally actuated valve element includes a temperature sensitive liquid stored therein.

In an embodiment, the temperature sensitive liquid configured to evaporate to allow expansion of the thermally actuated valve element when surrounding temperature rises upon contacting with the hot condensate to close valve head against the valve seat to displace the valve head to close the air vent path.

In an embodiment, the thermally actuated valve element includes a valve head configured to close the flow passage of steam on actuation.

In an embodiment, the temperature sensitive liquid remains in its original state before contacting hot condensate and prevent displacement of the valve head to allow entrapped pressurized air to pass through the outlet.

In an embodiment, the thermally actuated valve element is flexible.

In an embodiment, the valve seat is operatively disposed downstream of the thermally actuated valve element. In an embodiment, the valve seat is operatively disposed upstream of the thermally actuated valve element.

In an embodiment, the air venting and steam trapping mechanism is configured to operate at a temperature which is lower than that of the saturated steam temperature at that given pressure.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

A thermodynamic steam trap of the present disclosure, will now be described with the help of the accompanying drawing, in which:

Figure 1 illustrates a front view of a conventional thermodynamic steam trap in open condition;

Figure 2 illustrates a front view of a conventional thermodynamic steam trap of Figure 1 in close condition;

Figure 3 illustrates a front view of a thermodynamic steam trap with a steam trapping and air venting mechanism, in accordance with an embodiment of the present disclosure; Figure 4A and Figure 4B illustrate an enlarged view of the steam trapping and air venting mechanism of Figure 3 in an open condition;

Figure 5A and Figure 5B illustrate an enlarged view of the steam trapping and air venting mechanism of Figure 3 in a closed condition;

Figure 6 illustrates a front view of a thermodynamic steam trap with a steam trapping and air venting mechanism, in accordance with an alternate embodiment of the present disclosure; and

Figure 7 illustrates an enlarged view of the steam trapping and air venting mechanism of Figure 6.

LIST OF REFERENCE NUMERALS 100 - A thermodynamic steam trap

1A - Steam trapping and air venting mechanism 2 - Air venting passage

4 - Thermodynamic disc 6 - Inlet 8 - Outlet 10 - Valve head

12 - Thermally actuated valve element

DETAILED DESCRIPTION

Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing. Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a”, "an", and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises", "comprising", “including”, and “having” are open ended transitional phrases and therefore specify the presence of stated features, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, operations, elements, components, and/or groups thereof. When an element is referred to as being "mounted on", “engaged to”, "connected to", or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements. Terms such as “inner”, “outer”, "beneath", "below", "lower", "above", "upper", and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.

Figure 1 and 2 shows a conventional thermodynamic steam trap 1 with air venting via the operation of Thermodynamic disc 4. During the startup, sometimes the air gets trapped in the chamber above the disc 4. In such case, since air cannot condense like flash steam, the pressure in the chamber above the disc 4 continues to close the disc. Even if the condensate is generated in the system, the trap 1 is not able to remove it because of the pressurized air in the chamber above the disc 4. Thus, it is required to make provision for the automatic removal of the entrapped air so as to enhance the operation of a thermodynamic steam trap 1.

Therefore, the present disclosure envisages a thermodynamic steam trap for venting entrapped air therein. The thermodynamic steam trap for venting air entrapped therein (herein after referred to as “steam trap 100”) will now be described with reference to Figure 3 through Figure 7.

A typical thermodynamic steam trap 100 comprises an air vent path 2, a thermodynamic disc 4, an inlet 6, and an outlet 8. The present disclosure envisages a thermodynamic steam trap 100 configured to prevent leakage of steam and remove pressurized air entrapped therein. Referring to Figure 3, the steam trap 100 comprises an inlet 6 and an outlet 8, an air vent passage 2, a thermodynamic disc 4, and an air venting and steam trapping mechanism 1A.

The inlet 6 and the outlet 8 are configured on the steam trap 100 to allow hot condensate to pass therethrough. The air venting and steam trapping mechanism 1A is operatively disposed in the trap 100 in fluid communication with the inlet 6 and the outlet 8.

The air vent passage 2 is configured to be in fluid communication with the outlet 8. The air vent passage 2 is configured to vent entrapped air from the mechanism 1A via the outlet 8 to atmosphere.

The thermodynamic disc 4 is operatively disposed upstream of the air venting and steam trapping mechanism 1A. The air venting and steam trapping mechanism 1A is configured to maintain its original shape to allow the air vent passage 2 to remain open for the passage of entrapped pressurized air through the outlet 8, thereby preventing air locking of the disc 4. The air venting and steam trapping mechanism 1A is further configured to expand and close the air vent passage 2 upon contacting with the hot condensate or flash steam passing through the trap 100 to prevent leakage of steam from the outlet 8 to atmosphere.

In an embodiment, the air venting and steam trapping mechanism 1A includes a thermally actuated valve element 12, and a valve head 10. The thermally actuated valve element 12 is configured to expand and close the air vent passage 2 when surrounding temperature of the thermally actuated valve element 12 rises upon contacting with the hot condensate.

The valve head 10 is operatively coupled with the thermally actuated valve element 12. The valve head 10 is configured to displace upon expansion of the thermally actuated valve element 12 when hot condensate flows through the trap 100 and close the air vent passage 2 to prevent steam to escape via the outlet 8. In an embodiment, the thermally actuated valve element 12 is flexible. In an embodiment, the thermally actuated valve element 12 expands upon coming in contact with hot condensate and contracts upon sub-cooling of the condensate, thereby, closing and opening the valve respectively.

In an embodiment, the thermally actuated valve element 12 includes a valve head configured to close the flow passage of steam on actuation.

In an embodiment, the thermally actuated valve element 12 includes a temperature sensitive liquid sealed therein. The temperature sensitive liquid is configured to evaporate to allow the expansion of the thermally actuated valve element 12, upon contacting with the hot condensate to close valve head against the valve seat and to displace the valve head 10 to close the air vent passage 2.

In an embodiment, the temperature sensitive liquid remains in its original state before contacting the hot condensate and prevents displacement of the valve head 10 to allow entrapped pressurized air to pass through the outlet 8 via the air vent passage 2. In an embodiment, one of these thermally actuated valve element 12 carries a valve head which can close the flow passage on actuation. The liquid filled inside the thermally actuated valve element 12 is sensitive to the temperature changes. When the temperature the surrounding the mechanism 1A rises above a set limit the liquid evaporates and closes the valve head against the valve seat. The mechanism 1A operates at a temperature which is at few degrees lower than that of the saturated steam temperature at that given pressure. At normal temperatures mechanism 1A maintains its original shape and the flow passage remains open. In an embodiment, the valve seat is operatively disposed downstream of the thermally actuated valve element 12.

During start up conditions, if the air gets into the chamber above the disc 4, air being at low temperature, the mechanism 1A maintains its original shape thus keeping the flow passage open for the air to pass through it into the outlet. This helps in overcoming the air lock condition in the thermodynamic steam traps. Further, when the sub-cool condensate comes, then also the mechanism 1A maintains its original shape and allows the condensate to flow through the air venting passage 2 by moving the valve head 10 down and allowing the air to escape via the air venting passage 2. This enhances the discharge capacity of the traps. Figure 4A and Figure 4B shows the mechanism 1A in open condition.

Further, when the hot condensate starts flowing out of the trap, it starts flashing which closes the disc 4 and further closing the trap orifice. This flash steam being at high temperature expands the mechanism 1A to allow the valve head 10 to close the air venting passage 2 as well. This ensures no steam leak to the atmosphere. Figure 5A and Figure 5B shows the mechanism 1A in closed condition.

Thus, the mechanism 1A facilitates effective air venting from thermodynamic steam trap 100 which allows enhanced working for the thermodynamic disc 4. Also, the mechanism 1A facilitates increased discharge capacity of the thermodynamic steam traps as compared to normal Thermodynamic disc 4.

Figures 6 and 7 shows an alternate arrangement of the mechanism 1A of the thermodynamic steam trap 100. In this, the valve seat and the thermally actuated valve element 12 are arranged in such a way that the valve seat is placed at the upstream of the thermally actuated valve element 12. The thermodynamic steam trap 100 of Figures 6 and 7 comprises an air vent path 2, a thermodynamic disc 4, an inlet 6, and an outlet 8.

During start up conditions, if the air gets into the chamber above the disc 4, air being at low temperature, thermally actuated valve element 12 maintains its original shape thus keeping the flow passage open for the air to pass through it into the outlet 8.

When the hot condensate starts flowing out of the steam trap 100, it starts flashing which closes the disc 4 closing the trap orifice. This flash steam being at high temperature expands the capsule thus closing the air vent passage 2 as well. In an embodiment, the thermally actuated valve element 12 expands upon coming in contact with hot condensate and contracts upon sub-cooling of the condensate, thereby, closing and opening the valve respectively. This ensures no steam leakage to the atmosphere. In this arrangement, the volume of the control chamber above the disc 4 remains compact as compared to the first arrangement. Since the temperature and pressure is not set and is based on the application where the steam trap 100 is used, the moment hot condensate enters; the thermally actuated valve element 12 will expand.

Thus, the trap 100 of the present disclosure has increased discharge capacity, facilitates effective venting of air entrapped therein, and effectively traps steam as compared to the conventional steam traps. The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

TECHNICAL ADVANCEMENTS

The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a thermodynamic steam trap, that:

• has increased discharge capacity; · facilitates effective venting of air entrapped therein; and

• effectively traps steam.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein. The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A thermodynamic steam trap (100) configured to prevent steam leakage and remove pressurized air entrapped therein, said steam trap (100) comprising: a. an inlet (6) and an outlet (8) configured on said steam trap (100) to allow hot condensate to pass therethrough; b. an air venting and steam trapping mechanism (1A) operatively disposed in said steam trap (100) in fluid communication between said inlet (6) and said outlet (8); c. an air vent passage (2) configured to be in fluid communication with said outlet (8), said air vent passage (2) configured to vent entrapped air from said mechanism (1A); and d. a thermodynamic disc (4) operatively disposed upstream of said air venting and steam trapping mechanism (1A), wherein said mechanism (1A) during startup configured to allow passage of entrapped pressurized air through said air vent passage (2) to said outlet (8), thereby preventing air locking of said disc (4), and said mechanism (1A) further configured to expand and close said air vent passage (2) upon contacting with said hot condensate passing through the trap (100) to prevent leakage of steam from said outlet (8) to atmosphere.

2. The thermodynamic steam trap (100) as claimed in claim 1, wherein said air venting and steam trapping mechanism (1A) includes: a. a thermally actuated valve element (12) configured to expand and close said air vent path when surrounding temperature of said thermally actuated valve element (12) rises upon contacting with the said hot condensate; and b. a valve head (10) operatively coupled with said thermally actuated valve element (12), said valve head (10) configured to displace upon expansion of said thermally actuated valve element (12) and close said air vent passage (2) to prevent steam to escape via said outlet (8).

3. The thermodynamic steam trap (100) as claimed in claim 2, wherein said thermally actuated valve element (12) includes a temperature sensitive liquid stored therein.

4. The thermodynamic steam trap (100) as claimed in claim 3, wherein said temperature sensitive liquid is configured to evaporate to allow expansion of said thermally actuated valve element (12) when surrounding temperature rises upon contacting with the said hot condensate to close valve head against the valve seat to displace said valve head (10) to close the air vent passage (2).

5. The thermodynamic steam trap (100) as claimed in claim 2, wherein said thermally actuated valve element (12) includes a valve head configured to close the flow passage of steam via air vent passage (2) on actuation.

6. The thermodynamic steam trap (100) as claimed in claim 2, wherein said temperature sensitive liquid remains in its original state before contacting hot condensate and prevents displacement of the valve head (10) to allow entrapped pressurized air to pass through said outlet (8) via said air vent passage (2).

7. The thermodynamic steam trap (100) as claimed in claim 2, wherein said thermally actuated valve element (12) is flexible.

8. The thermodynamic steam trap (100) as claimed in claim 2, wherein the valve seat is operatively disposed downstream of the thermally actuated valve element (12).

9. The thermodynamic steam trap (100) as claimed in claim 2, wherein the valve seat is operatively disposed upstream of the thermally actuated valve element (12).

10. The thermodynamic steam trap (100) as claimed in claim 1, wherein said air venting and steam trapping mechanism (1A) is configured to operate at a temperature lower than the saturated steam temperature.