CN110651126A

CN110651126A - Compact expansion tank

Info

Publication number: CN110651126A
Application number: CN201880033309.7A
Authority: CN
Inventors: R·贝内托洛; A·巴尔多
Original assignee: Zilmett Co Ltd
Current assignee: Zilmett Co Ltd
Priority date: 2017-05-22
Filing date: 2018-04-24
Publication date: 2020-01-03
Anticipated expiration: 2038-04-24
Also published as: WO2018215852A1; IT201700055381A1; CN110651126B

Abstract

The invention is an expansion tank (1) comprising: a row of pipes (100) consisting of pipes (10); a waterside flange (2) in which holes and channels are provided to connect to the interior of each of the pipes (10) and to the hydraulic system in which pressure and volume changes need to be compensated; -a gas-side flange (3) wherein holes and channels are obtained to connect a pressure relief valve (331) with the interior of each of said ducts (10), and wherein there is at least one float (4) inside each of said ducts (10), said float (4) tightly dividing the interior of said duct (10) into an upper compartment (V1) or a gas-side compartment, and a lower compartment (V2) or a water-side compartment.

Description

Compact expansion tank

Technical Field

This patent relates to expansion tanks, and more particularly it relates to a new expansion tank that is compact and free of diaphragms.

Background

The expansion tank is a hydraulic component commonly present in domestic heating boilers, heating systems and water supply systems, in which the function of the expansion tank is to compensate for volume changes due to temperature changes of the fluid used in the circuit, thus avoiding dangerous pressure increases in the circuit itself, which could otherwise be absorbed by the pipes and other components of the system.

Expansion tanks are also commonly present in pumping systems and lifting systems, in which the function of the expansion tank is to accumulate the fluid in the circuit and to return said fluid to the circuit itself.

The expansion tank also serves to protect the system from sudden pressure changes due to transient flow interruptions that can result in the generation and propagation of water hammer.

An expansion tank is known which comprises two semi-rigid hat-shaped half-shells, generally made of metal material, which are opposite and joined to each other so as to form a closed casing with a substantially circular cross-section.

Inside the tank there is a diaphragm dividing the internal space into two compartments, respectively for containing a compressible gas, which compensates for the increase in volume of the fluid contained in the system, and an incompressible fluid, which undergoes a volume change.

The half-shells for containing the system fluids are provided with connection ducts communicating with the respective internal compartment and for connecting the compartment itself to the hydraulic circuit.

Instead, the other half-shell is provided with a valve seat carrying a preload valve adapted to regulate the gas pressure. The valve is adapted to open in case of overpressure of the compartment containing the compensation gas.

The half-shells constituting the known types of expansion tanks are generally made of metallic material, typically stainless steel.

The interior of the expansion vessel, more particularly the interior of the compartment into which the liquid flows, is subject to corrosive action by the water or other fluid circulating therein.

In order to overcome this drawback, expansion tanks have been developed provided with an opposing cover inserted and applied inside the second half-shell, made of thermoplastic material, i.e. a material capable of resisting the corrosive action of the fluid.

The counter covers are made in the following way: which is adhered to the inner surface of said second half-shell and is provided with an opening identical and aligned with the opening provided in the connection duct connecting the second half-shell to the system.

The counter-cover is normally tightly constrained to the half-shell, for example by a metal ring, at the level of the connecting duct and inside the half-shell.

Similarly, a corrosion-resistant connecting duct is known, which consists of a duct, which is threaded on the inside at least on its section facing the inside of the second half-shell, and an internal sealing flange made of thermoplastic material, which is mounted inside the counter-cover and is adapted to be screwed into the duct to protect the duct itself.

More specifically, the internal sealing flange in turn comprises an externally threaded tubular section adapted to be screwed onto the internal thread of the pipe to be connected to the system, and a flat ring orthogonal to the axis of the threaded tubular section and adapted to adhere to the internal counter-cover of the second half-shell.

The tightening of said internal flange, and the use of suitable gaskets, prevent the leakage of the liquid and air circulating in the system between the second half-shell and the internal counter-cover or between the internal flange and the pipes for connection to the system.

The expansion tank manufactured as described above is difficult to construct and assemble, and furthermore, stress and long-term use may affect the tightness of the connection between the components over time.

Another drawback with known types of expansion tanks is that they have considerable overall dimensions, both due to their size (depending on the type of system in which they are installed) and to their substantially circular shape (or anyway their shape with a circular cross section).

In practice, these expansion tanks must be installed in specially prepared spaces (for example in the boiler or another part of the system).

In order to overcome the above drawbacks, a new expansion tank has been designed and constructed, which is compact and free of membranes.

Disclosure of Invention

The main object of the present invention is to provide an expansion tank which is more compact than the known types of expansion tanks with half-shells, in particular because the shape of the new expansion tank is substantially parallelepiped and can be adapted according to the space available for its installation.

Another object of the invention is to simplify the procedures required for the production and assembly of the new expansion vessel. In fact, the new expansion vessel has no diaphragm at all, and it consists of parts that do not require the application of any counter-covers.

In addition to the above, the new expansion vessel solves all the problems related to the assembly of hydraulic connection pipes described above.

These and other direct and complementary objects are achieved by a new expansion vessel whose main components comprise:

a row of tubes consisting of two or more tubes open at both ends, arranged side by side and parallel to each other;

a lower flange, hereinafter called waterside flange, which in turn comprises a substantially flat plate, wherein one or outer side comprises at least one hole for connection with a hydraulic system in which pressure and volume changes need to be compensated, while the opposite inner side facing the row of pipes comprises a plurality of holes connected to each of the lower open ends of each of the pipes, and wherein one or more channels obtained in the plate put the connection hole in communication with all of the holes provided in the inner side, so that water can flow through the connection hole, the channels and the holes between the hydraulic system and the interior of each of the pipes;

an upper flange, or gas-side flange, which in turn comprises a substantially flat plate, wherein one or outer side comprises holes for mounting pressure relief valves, while the opposite inner side facing the row of ducts comprises a plurality of holes connected to each of the upper open ends of the ducts, and wherein one or more channels obtained in the plate place the holes formed in the outer side in communication with each of the holes formed in the inner side, so that the pressure relief valves are in communication with the interior of each of the ducts,

and wherein inside each of said ducts there is at least one float, in turn comprising a body whose cross-section has a shape matching that of the duct, so as to divide the inside of the duct tightly into two compartments: an upper or gas side compartment; and a lower or waterside compartment, and wherein the body has a specific gravity lower than that of the liquid circulating in the connected system and is movable between the two ends of the pipe due to the effect of the pushing action exerted by the liquid itself.

When the volume of liquid present in the hydraulic system increases, the liquid flows into the expansion tank through said water-side flange and, due to the pushing action exerted by the liquid, the float body of each pipe moves upwards towards said gas-side flange, reducing the volume of the gas compartment, the pressure inside said gas compartment increasing.

The pressure increase is limited by the pressure relief valve, which is set according to the normal operating pressure value of the system and opens when an overpressure is caused by a fault.

When the volume of liquid present in the hydraulic system decreases, liquid flows out of the expansion tank through the water side flange, so that the float of each of the pipes moves downwards towards the water side flange, so that the pressure in the gas side compartment decreases.

When the expansion vessel is completely emptied, that is to say when all the liquid flows out of each of the pipes, the float moves downwards until it reaches the water-side flange. The bottom surface of the float is shaped to tightly close an aperture provided in a suitable valve or protrusion so that no air can flow into the hydraulic system when the expansion vessel is fully emptied.

The number and arrangement of the pipes making up the line of pipes of the new expansion tank determine the shape and overall dimensions of the tank itself. Thus, depending on the type of boiler or hydraulic system, it is possible to design and assemble an expansion vessel that can be integrated in the available space.

Drawings

In the following description, the characteristics of the new expansion vessel will be highlighted in greater detail with reference to the attached drawings by way of non-limiting example.

Fig. 1 shows a vertical section of the new expansion vessel (1).

Fig. 2 shows a detailed cross-sectional view of the waterside flange (2).

Fig. 3 shows a detailed cross-sectional view of the gas-side flange (3).

Fig. 4 shows a section of the central part of the new expansion vessel (1), in which the floats (4) housed in each pipe (10) and dividing the interior of each of said pipes (10) tightly into two compartments (V1, V2) can be seen.

Fig. 5 shows a three-dimensional view of a possible embodiment of the new expansion vessel (1).

Detailed Description

The novel expansion tank (1) comprises a line bank (100) of pipes (10), said line bank (100) consisting of two or more pipes (10) arranged side by side and in parallel to each other.

Each of the ducts (10) comprises a side wall (11), for example cylindrical or substantially prismatic, the side wall (11) having an open lower end (12) and an upper end (13).

The row of ducts (100) may for example be constituted by one or more aligned rows of ducts (10) as shown in figures 1 and 5, or by a plurality of ducts arranged in any way.

The line (100) of pipes is therefore substantially parallelepiped-shaped or consists of components having a parallelepiped shape.

The expansion vessel (1) comprises a lower or waterside flange (2) shown in detail in the sectional view shown in fig. 2.

The water-side flange (2) in turn comprises a substantially flat plate (21), wherein one or outer side (22) comprises at least one hole (23) for connection with a hydraulic system in which pressure and volume changes need to be compensated.

Said connection hole (23) is made, for example, of a cylindrical element (231), which cylindrical element (231) protrudes from said outer lateral face (22) and is preferably screwed on an outer lateral face (232), or in any case configured so that it is suitable for connection with a pipe of the hydraulic system to which it is connected.

The inner opposite side (24) of the plate (21) facing the row (100) of ducts comprises a plurality of seats or projections (241), said seats or projections (241) being suitable for being tightly connected to the open lower end (12) of each of the ducts (10). Tightness is ensured, for example, by an O-ring (243) interposed between said protrusion (241) and the inner wall of said duct (10).

Each of said seats or projections (241) comprises at least one hole (242).

Furthermore, the plate (21) is provided with one or more channels (25), the channels (25) communicating the connection hole (23) with the hole (242) formed in the protrusion (241).

In this way, liquid can flow through the connection holes (23), through the channels (25) and the holes (242) to the interior of all the ducts (10).

More specifically, according to the invention, said connection holes (23) can communicate directly with one of said ducts (10), for example the interior of the central duct (10') of said row (100), and also with said channel (25) through one or more holes (242') formed in said projections (241') inserted in said central duct (10').

The new expansion vessel (1) also comprises an upper or gas side flange (3) shown in detail in the sectional view of fig. 3.

The gas-side flange (3) in turn comprises a substantially flat plate (31), wherein an outer side (32) comprises a hole (33) for mounting a pressure relief valve (331), while an opposite inner side (34) facing the duct row (100) comprises a plurality of seats or protrusions (341) tightly connected to the upper open end (13) of the duct (10).

Tightness is ensured, for example, by an O-ring (343) interposed between said protrusion (341) and the inner wall of said pipe (10).

The seat or protrusion (341) includes one or more apertures (342).

The plate (31) of the gas-side flange (3) is also provided with one or more channels (35), said channels (35) communicating the valves (331) mounted in the holes (33) of the outer lateral surface (32) with the interior of each of the ducts (10).

Inside each of said ducts (10) there is at least one float (4), this float (4) in turn comprising a body whose cross-section has a shape matching that of the duct (10), so as to divide the inside of said duct (10) tightly into two compartments: an upper or gas side compartment (V1); and a lower or waterside compartment (V2).

The specific gravity of the float (4) is lower than that of the liquid circulating in the connected system, and the float (4) is movable between the two ends (12, 13) of the pipe (10) as a result of the pushing action exerted by the liquid.

The bottom surface of the float (4) is shaped so as to tightly close the hole (242) formed in the seat or protrusion (241) of the water-side flange (2).

For example, the lower surface (41) of each of the floats (4) and/or the upper surface (244) of the protrusion (241) is equipped with a sealing gasket.

According to the invention, in order to ensure correct assembly of the new expansion valve, it is possible, but not necessary, to use a tie rod (6) mounted between the water-side flange (2) and the gas-side flange (3), as schematically represented in fig. 5.

The tie rod (6) is for example inserted and bolted into a correspondingly formed hole (61) in the flange (2, 3).

According to the invention, for installing the new expansion tank, brackets (5) in any way limited to the tank (1), for example the water side flanges (2), can be used, wherein each of the brackets (5) comprises a first flat portion (51), for example facing the water side flanges (2), and an angled portion (52) orthogonal to the first flat portion (51) and suitable for being fixed to a structure, for example a wall meeting boiler.

The new expansion vessel (1) can be made entirely of plastic material particularly suitable for withstanding the working pressures and any contact with corrosive substances.

These are illustrative overviews sufficient for a person skilled in the art to practice the invention and, therefore, in practical applications, modifications may be developed which do not affect the essence of the innovative concepts described herein.

Accordingly, with reference to the description provided above and the attached drawings, the following claims are expressed.

Claims

1. Expansion tank (1), characterized in that said expansion tank (1) comprises:

-a row (100) of ducts (10), said row (100) of ducts being composed of two or more ducts (10) open at both ends (1, 13), arranged side by side and parallel to each other;

a lower or water-side flange (2), which in turn comprises a substantially flat plate (21), wherein an outer side (22) comprises at least one hole (23) for connection with a hydraulic system in which pressure and volume variations need to be compensated, while an opposite inner side (24), i.e. the side facing the row (100) of ducts (10), comprises a plurality of holes (242) in tight connection with the lower open end (12) of each of the ducts (10), and wherein one or more channels (25) obtained in the plate (21) put the connection hole (23) in communication with the holes (242) provided in the inner side (24), so that water can flow between the hydraulic system and the inside of each of the ducts (10) through the water-side flange (2);

an upper or gas-side flange (3), which in turn comprises a substantially flat plate (31), wherein an outer side (32) comprises a hole (33) for mounting a pressure relief valve (331), while an opposite inner side (34), i.e. the side facing the row (100) of ducts (10), comprises a plurality of holes (342) tightly connected with the upper open end (13) of the duct (12), and wherein one or more channels (35) obtained in the plate (31) put the pressure relief valve (331) in communication with the holes (342) provided in the inner side (34) and therefore with the interior of each of the ducts (10),

and wherein inside each of said pipes (10) there is at least one float (4), the shape of said float (4) corresponding to the internal cross section of the pipe, so as to divide the inside of the pipe (10) tightly into an upper compartment (V1), or a gas-side and a lower compartment (V2), or a water-side compartment, and wherein the specific gravity of said float (4) is lower than that of the liquid circulating in the system in which the pressure and volume variations need to be compensated, and said float (4) is movable along the pipe (10) due to the effect of the pushing action exerted by the liquid itself.

2. An expansion tank (1) according to claim 1, characterized in that each of said pipes (10) has a cylindrical or prismatic cross section.

3. An expansion tank (1) according to claim 1, characterized in that the conduits (10) are arranged in one or more rows, such that the rows (100) of conduits are substantially parallelepiped-shaped or consist of parallelepiped-shaped components.

4. An expansion tank (1) according to claim 1, characterized in that said connection hole (23) of said water side flange (2) is obtained in a cylindrical element (231) projecting from said outer lateral face (22) and shaped so that it can be connected to a conduit of the hydraulic system.

5. An expansion tank (1) according to claim 1, characterized in that said connection aperture (23) communicates directly with one central duct (10') of said ducts (10) of said row (100) of ducts and also communicates with said channel (25) obtained in said water-side flange (2) through said one or more holes (242') communicating with said central duct (10 ').

6. An expansion tank (1) according to claim 1, characterized in that the lower side of each of the floats (4) is shaped to tightly close the hole (242) provided in the inner side (24) of the waterside flange (2).

7. An expansion tank (1) according to any of the preceding claims, characterized in that the pipe (10), the flanges (2, 3) and the float are made of plastic material.

8. An expansion tank (1) according to any of the preceding claims, characterized in that it comprises an assembly tie rod (6) mounted between the water-side flange (2) and the gas-side flange (3).

9. An expansion tank (1) according to the preceding claim, characterized in that said tie rod (6) is inserted and bolted into holes (61) formed correspondingly in said flanges (2, 3).

10. An expansion tank (1) according to any of the preceding claims, characterized in that it comprises at least one bracket (5) connected to the expansion tank (1) in any way so as to constrain the expansion tank (1) to a supporting structure.