FIELD OF THE INVENTION

The present invention relates to a liquid level regulating system, particularly a dual-valve liquid level regulating system for filling a liquid tank.

BACKGROUND OF THE INVENTION

A liquid level regulating system regulates the fluid level in a liquid tank for controlling the flow rate with which the pump delivers liquid to the tank, maintaining the threshold liquid level in the tank.

Conventionally, the liquid level regulating system involves using sensors and probes to detect the liquid level in the tank. In the event a sensor and a probe detect that the liquid level has dropped below the threshold level, the valve in the liquid tank will be opened for filling and closed again after the desired liquid level is reached. Consequently, frequent opening and closing of the valve and the frequent use of the pump cause the diaphragm seal to wear off quickly results in the pump and valve failure.

Besides, some of the liquid level regulating systems are operated by electricity as well as electronically via internet of things to monitor the liquid level and control the filling process in real time. Apparently, the electrically or electronically operated liquid level regulating systems lack sustainability and are not cost-effective.

US20100236644A1 discloses a valve assembly for controlling fluid flow. The valve assembly includes a first electro-statically actuated valve placed between a first chamber and a second chamber, and a second electro-statically actuated valve placed between the second chamber and a third chamber. The first chamber is connected to an inlet and the third chamber is connected to an outlet. Both the first electro-statically actuated valve and the second electrostatically actuated valve may allow or block fluid communication between the chambers responsive to their respective electrical signal. However, the valve assembly involves using electricity to control the fluid flow which then incurs high operating expenses.

CN100552153C discloses a water-saving double-float valve flushing device composed of an upper and lower valve mechanisms. The first valve mechanism on the upper layer and the second valve mechanism on the lower layer are provided with mutually engaging joints, so that the first valve mechanism on the upper layer and the second valve mechanism on the lower layer are engaged with each other to form a valve flushing device combo. However, the double float valve flushing device has a limited range of water level control and thus the valves open and close frequently resulting in wear off of the diaphragm seal.

FR2719922 discloses a liquid level control device for household appliances. The liquid level control device comprises a solenoid valve configured on the water inlet pipe of the device, wherein a venturi is inserted on the water inlet pipe to accelerate the flow of the liquid. However, the solenoid valve is an electrically controlled valve. Hence, the solenoid may not work correctly due to lack of power, incorrect voltage and burnt coil.

The valves and devices of aforesaid prior arts appear to have several disadvantages including cost, environmental sustainability and durability. Accordingly, there is a need to provide a non-electric dual-valve liquid level regulating system that is environmentally friendly, cost-effective and durable for use in filling a liquid tank in domestic and industrial applications.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. It is an objective of the present invention to provide a cost-effective dual-valve liquid level regulating system for filling a liquid tank automatically in domestic and industrial applications.

It is also an objective of the present invention to provide a non-electric dual-valve liquid level regulating system to achieve environmental sustainability, in which the dual-valve liquid level regulating system of the present invention is fully mechanically operated.

It is further an objective of the present invention to provide a low maintenance and durable dual-valve liquid level regulating system by reducing the valve opening and closing frequency thus extending the lifespan of the diaphragm seal and the pump.

Accordingly, these objectives may be achieved by following the teachings of the present invention. The present invention provides a dual-valve liquid level regulating system for a liquid tank comprising an upper valve, wherein the upper valve comprises an inlet flood chamber, an outlet chamber, an egress control chamber and a float chamber, characterized by a lower valve connected to the upper valve vertically via a connector, the lower valve comprises an inlet flood chamber and a float chamber, a venturi jet disposed in the outlet chamber of the upper valve, and a tube connecting the connector and the venturi jet, wherein liquid in the upper valve, the connector and the lower valve drain when liquid level of the liquid tank drops below the lower valve and causes both the upper and lower valves open to fill the liquid tank, wherein the lower valve closes when liquid of the liquid tank reaches the lower valve and causes liquid in the connector flows to the venturi jet when there is a pressure differential so as to remain the upper valve opens as the liquid level rises above the lower valve until an isobaric pressure is achieved, wherein liquid stops flowing into the liquid tank when liquid level reaches the upper valve and causes the upper valve to close. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may have been referred by embodiments, some of which are illustrated in the appended drawings. However, it is to be noted that the appended drawing illustrates only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

The features, benefits, and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

Figure 1 shows a diagram of a dual-valve liquid level regulating system (100) in accordance to first embodiment of the present invention;

Figure 2 shows a diagram of a dual-valve liquid level regulating system (100) in accordance to second embodiment of the present invention;

Figure 3 shows a diagram of a dual-valve liquid level regulating system (100) in accordance to third embodiment of the present invention;

Figure 4 shows a diagram of a dual-valve liquid level regulating system (100) in accordance to fourth embodiment of the present invention;

Figure 5 shows a diagram of a venturi jet (400) in accordance to an embodiment of the present invention;

Figure 6 shows a top view of a means for air purging (500) in accordance to an embodiment of the present invention;

Figure 7 shows a schematic diagram of a dual-valve liquid level regulating system (100) in accordance to the first embodiment of the present invention, when liquid level of the liquid tank drops below the threshold level of the lower valve (300);

Figure 8 shows a schematic diagram of a dual-valve liquid level regulating system (100) with liquid flow direction in accordance to the first embodiment of the present invention, when there is a pressure differential within the system (100) in the presence of the venturi jet (400); and

Figure 9 shows a schematic diagram of a dual-valve liquid level regulating system (100) in accordance to the first embodiment of the present invention, when an isobaric pressure is achieved within the system (100).

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described, and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely to provide a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the composition, element or group of elements and vice versa.

The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only, and are not intended to limit the scope of the claims. In addition, several materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary, and are not intended to limit the scope of the invention.

Referring to Figures 1 to 6, the invention will now be described in more detail.

The present invention provides a mechanically operated dual-valve liquid level regulating system (100) to fill a liquid tank automatically without using electricity. The liquid includes but is not limited to volatile and non-volatile low viscosity liquid.

In accordance with an embodiment of the present invention, the dualvalve liquid level regulating system (100) comprises an upper valve (200) and a lower valve (300). The upper valve (200) comprises an inlet flood chamber (202), an outlet chamber (204), an egress control chamber (206) and a float chamber (208). The lower valve (300) comprises an inlet flood chamber (302) and a float chamber (304), wherein the lower valve (300) is connected to the upper valve (200) vertically via a connector (102), as shown in Figures 1 to 4. More preferably, the connector (102) is disposed of between the float chamber (208) of the upper valve (200) and the inlet flood chamber (302) of the lower valve (300), wherein the length of the connector (102) is adjustable to suit desired threshold level below the lower valve (200). When liquid level of the liquid tank drops below the threshold level of the lower valve (300), the liquid in the upper valve (200), the connector (102) and the lower valve (300) drain and consequently trigger opening of both the upper valve (200) and the lower valve (300) to fill the liquid tank.

In accordance with an embodiment of the present invention, a venturi jet (400) is disposed in the outlet chamber (204) of the upper valve (200). In the first embodiment as shown in Figure 1 , the outlet chamber (204) of the upper valve (200) is further connected with an outlet extension (2040), wherein the venturi jet (400) is disposed in the outlet extension (2040) as part of the outlet chamber (204). Alternatively, the venturi jet (400) is disposed of in the outlet chamber (204) of the upper valve (200), as shown in Figures 2 to 4. The venturi jet (400) is provided to induce a pressure difference within the system (100) so as when the liquid level of the liquid tank rises above the lower valve (300), the lower valve (300) is closed and flooded with the liquid creating high pressure. As the pressure difference takes place, the liquid will flow from high pressure to low pressure, that is the liquid flows from the connector (102) to the venturi jet (400) to maintain the opening of the upper valve (200) and enable continuous filing of the liquid into the liquid tank. In accordance with an embodiment of the present invention, a tube (104) is provided for connecting the connector (102) and the venturi jet (400), wherein the tube (104) is an external tube which is disposed outside the upper valve (200), as shown in Figures 1 and 2. Alternatively, the tube (104) is integrated within the upper valve (200), as shown in Figures 3 and 4. The liquid in the connector (102) flows to the venturi jet (400) via the tube (104) when there is a pressure differential so as to remain the upper valve (200) opens for filling until an isobaric pressure is achieved, that is when the negative pressure inside the connector (102) is overwhelmed by the liquid ingress flooding the float chamber (208). The filling of the liquid tank stops when the liquid level of the liquid tank reaches the upper valve (200) and causes the upper valve (200) to close.

In accordance with an embodiment of the present invention, the venturi jet (400) comprises three reducers (402, 404, 406) connected in series, wherein the second reducer (404) is in inverted position having a mouth (408) extended downwardly connecting the tube (104). As shown in Figure 5, the venturi jet (400) further comprises a jet tube (410) placed within the first reducer (402) and the second reducer (404), wherein the jet tube (410) is fixed in the first reducer (402) and the second reducer (404) via a gauge clip (412), a sealing clip (414) and a self-locking sleeve (416) to maintain the structural integrity of the venturi jet (400).

In accordance with an embodiment of the present invention, the tube (104) further provided with a pressure regulator (106) for regulating the pressure in the tube (104).

In accordance with an embodiment of the present invention, the liquid level regulating system (100) further comprises a downpipe (108) connected to the outlet chamber (204) for smooth drainage by minimizing noise, splashing and turbulence during filling.

In accordance with an embodiment of the present invention, the downpipe (108) is provided with an atmospheric vent (110) to control the pressure in the downpipe (108) despite the change in liquid level of the liquid tank, as well as preventing pressure impaction in the venturi jet (400). More particularly, the atmospheric vent (110) allows air to flow in during filling and flow out during drawdown for normalizing the pressure in the downpipe (108) to ambient pressure.

In accordance with an embodiment of the present invention, the float chamber (208) of the upper valve (200) and the float chamber (304) of the lower valve (300) respectively comprises a pair of means for air purging (500) having four openings (502, 504, 506, 508) arranged concentrically, as shown in Figure 6. The four openings (502, 504, 506, 508) act as atmospheric vent for air purging and ingress openings for the flowing of liquid. More particularly, the four openings comprise a high-level opening (502) and three low-level openings (504, 506, 508), wherein the high-level opening (502) is positioned above the three low-level openings (504, 506, 508) and act as an atmospheric vent for enhancing air purging in the float chambers (208, 304) during filling and drawdown, whereas the three low-level openings (504, 506, 508) act as ingress openings for flowing of liquid into the float chambers (208, 304) during filling and also act as atmospheric vents for enhancing air purging in the float chambers (208, 304) during drawdown.

Hereinafter, an example of the present invention will be provided for a more detailed explanation using the schematic diagrams as shown in Figures 7 to 9. The advantages of the present invention may be more readily understood and put into practical effect from these examples. However, it is also to be understood that the following examples do not limit the scope of the present invention in any way.

Example

The lower valve (300) position in the liquid tank determines the desired threshold level of the liquid tank to initiate a liquid filling. Assuming the lower valve (300) is placed about 20% of the height of the liquid tank as the desired threshold level. As shown in Figure 7, when liquid level in the liquid tank drops below threshold level of the lower valve (300) or that is below 20% of the height of the liquid tank, the holding liquid in the upper valve (200), connector (102) and lower valve (300) are drained from the lower valve (200) in tandem and thus triggering the upper valve (200) and the lower valve (300) open for filling the liquid tank. As shown in Figure 8, when liquid rises to the highest level at the float chamber (304) of the lower valve (300), the float rises actuates closure of a diaphragm seal (306) in the float chamber (304) and thus causing the lower valve (300) close, while the upper valve (200) remains open to continue filling. For this purpose, the connector (102) has to be free of liquid for preventing the closure of the upper valve (200). Therefore, the venturi jet (400) is introduced to induce a pressure difference within the system (100) to expel liquid from the connector (102).

As aforementioned, the venturi jet (400) can be disposed of in the outlet chamber (204) of the upper valve (200) and the connector (102) is connected to the venturi jet (400) via a tube (104), more particularly connecting to the mouth (408) of the second reducer (404) of the venturi jet (400). When liquid flows from the outlet chamber (204) to the venturi jet (400), the first reducer (402) and third reducer (406) of the venturi jet (400) receive liquid at low-speed flow and high pressure. Meanwhile, the constricted section of the first reducer (402) and the second reducer (404) receives liquid at high-speed flow and low pressure. Accordingly, liquid diffused by the venturi jet (400) creates negative pressure behind the venturi jet (400). As a result, low suction pressure is induced in the tube (104) to suck the liquid from the connector (102) to the venturi jet (400) and thus causes the connector (102) free of water. Hence, the upper valve (200) is prevented from closure and the filling continues. Additionally, the flowing of liquid from the connector (102) to the venturi jet (400) is also facilitated by the high pressure in the lower valve (300), that is when liquid floods the lower valve (300).

When liquid level of the liquid tank rises to the top of the float chamber (208) of the upper valve (200), the low-level openings (504, 506, 508) in the float chamber (208) of the upper valve (208) allows rising liquid to rush into the inlet flood chamber (202) via an opening (2060) in the egress control chamber (206) and thus floods the inlet flood chamber (202). The flooding of the upper valve (200) causes the pressure in the upper valve (200) and the suction pressure induced by the venturi tube (400) to reach an isobaric pressure which then results in the closing of the upper valve (200) and completing the filling process as shown in Figure 9. In short, the addition of lower valve (300) enables the holding of liquid in the connector (102) and thus preventing the upper valve (200) opens during drawdown even as the liquid of the liquid tank drops below the threshold level of the upper valve (200). Accordingly, low frequency of opening and closing the upper valve (200) and infrequent use of the pump is conducive to extending the lifespan of the diaphragm seals and the pump. Moreover, the mechanically operated dual valve liquid level regulating system (100) of the present invention is a reliable closed-loop system that refills liquid automatically without the need of sensors, probes, electricity and electrical devices. Therefore, it provides a relatively low cost, low maintenance, environmentally friendly solution for both domestic and industrial applications compared to the other conventional liquid level regulating systems.

Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but provides the broadest scope consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claim.

Description of the reference numerals used in the accompanying drawings according to the present invention: