WO2012052553A1

WO2012052553A1 - Anticondensate thermostatic valve device for thermal systems

Info

Publication number: WO2012052553A1
Application number: PCT/EP2011/068463
Authority: WO
Inventors: Marco Caleffi
Original assignee: Caleffi S.P.A.
Priority date: 2010-10-22
Filing date: 2011-10-21
Publication date: 2012-04-26
Also published as: EP2630395A1; ITMI20100321U1

Abstract

The anticondensate thermostatic valve device (10) for thermal systems comprises a valve body (11) having a first inlet port (12) for a first thermal fluid extending on a longitudinal axis of the valve body (11), a second inlet (13) for a second thermal fluid and a third (14) outlet port for a mixed thermal fluid, the second and third ports transversally extending to the longitudinal axis on opposite sides of the valve body (11). The inlet and outlet ports (11, 2, 13) open towards a central chamber (15) where a flow control member (16), disposed between a thermostatic actuator (17) and a biasing spring (18) is axially movable between the first and the second inlet ports (11, 12). The flow control member (16) has a disc-shaped element (16') on a side for closing the first inlet port (12) and an axially spaced apart annular element (16") on an opposite side for closing the second inlet port (13), said disc shaped element (16') and said annular element (16") being connected by 1 radial spokes (16'"). The assembly comprising the biasing spring (18), the flow control member (16) and the thermostatic actuator (17) is suitable for being axially inserted and removed through a single opening of the valve body (11), opposite to the first inlet port (12).

Description

ANTICONDENSATE THERMOSTATIC VALVE DEVICE FOR THERMAL SYSTEMS

BACKGROUND OF THE INVENTION

The present invention relates to a thermostatic valve device for controlling the temperature of a fluid in thermal systems, particularly adapted for being used as anticondensate valve device in heating systems comprising an auxiliary boiler operated by solid fuel such as coal, firewood and processing waste, as biomasses in general; the invention also relates to a pumping unit comprising the thermostatic valve device.

STATE OF THE ART In a conventional heating system, comprising an auxiliary solid fuel boiler, the thermal fluid that is fed to the auxiliary boiler from a return line of the heating system should have a minimal prefixed temperature, in order to prevent condensation phenomena of the flue gases in the exchange circuit of said auxiliary boiler.

For this purpose, the thermal systems of this type comprise a so-called "anticondensate" valve, that allows the heated thermal fluid exiting the auxiliary boiler to be recirculated to an inlet port of the same boiler, and/or a fraction of the thermal fluid heated by the boiler to be mixed with a fraction of a thermal fluid coming fluid from a conventional heating system, in order to enable a prefixed temperature of the thermal fluid fed the auxiliary boiler, required for preventing said condensing phenomena, to be quickly achieved and/or maintained. A valve device of this type is known for exam ple from E P-A-1967935, disclosing a valve body having a first inlet port for the recirculation of a thermal fluid, a second inlet port for the thermal fluid from the heating system, and an outlet port for the mixed fluid to be fed to the auxiliary boiler, which inlet and outlet ports open towards a central mixing chamber, where a reciprocating valve piston member is arranged for controlling and shuttering the flows of thermal fluid entering the valve device.

The first inlet port extends along a longitudinal axis of the valve body, whereas the second inlet port and the outlet port of the fluid are transversally arranged on opposite sides of the valve body, adjacent to the first inlet port; the piston member for controlling the fluid flows is provided with a first and a second disc-shaped members for closing the first inlet port, respectively the second inlet port, and is operatively disposed between a thermostatic actuator and a counteracting biasing spring, in order to be axially moved between a first closure position for the first inlet port, and a second closure position for the second inlet port, and wherein the second disc member tightly closes an annular seat peripherally formed in respect to a passage hole for the fluid, provided in an intermediate partition wall configured to separate the second inlet port from the first inlet port and the outlet port.

In order to assemble the valve components, the valve body has an opening for the insertion and removal of the thermostatic actuator at a side of the valve body opposite to the first inlet port, which opening is closed by a screwable plug; on the contrary, the control piston and the biasing spring may be assembled and removed from the valve body through the first inlet port.

In a valve of this type, the sensitive bulb of the thermostatic actuator is arranged between the two disc-shaped members of the control piston; therefore, the sensitive bulb of the actuator is only partially lapped by the thermal fluid returning from the thermal system, since a fraction of the fluid directly flows towards the outlet port. That implies a lower sensitivity of the thermostatic actuator in respect to temperature variations of the fluid coming from the heating system, with consequent lower precision in controlling the temperature of the fluid to be fed to the auxiliary boiler.

Furthermore, automatic assembling of the valve components is complicated, since the valve components have to be assembled from two different sides of the valve body, with consequent manipulation and handling problems during assembling.

OBJECTS OF THE INVENTION A main object of the present invention is to provide a thermostatic valve device for controlling the temperature of a fluid for thermal systems, which is constructively simple and provides a reliable and accurate operation in regulating the temperature of the thermal fluid outcoming from said valve device.

Another object of the present invention is to provide a thermostatic control valve device of the above mentioned type that is suitable for being easy and rapidly assembled by automatic operations, to be used separately or in combination with a pumping device.

SUMMARY OF THE INVENTION

All said above can be achieved by a thermostatic valve device for controlling the temperature of a fluid for thermal systems, according to claim 1 .

More properly, according to the invention a thermostatic valve device has been provided, comprising:

a valve body having a longitudinal axis;

a first inlet port axially aligned to the valve body;

a second in let and a third outlet port angularly spaced apart and transversally extending to the longitudinal axis of the valve body;

said inlet and outlet ports opening into a mixing chamber; and a fluid flow control member axially movable in the fluid mixing chamber, arranged between a thermostatic actuator and a biasing spring;

said flow control member comprising a first closure element configured and arranged to close, shuttering and throttling the first inlet port, and a second closure element axially spaced apart from said first closure element configured for closing and shuttering the second inlet port;

an internal partition wall being provided for separating said inlet and outlet ports, the partition wall comprising a fluid passage hole and a sealing seat for the first closure member;

in which the valve body comprises an auxiliary opening at a side opposite to the first inlet port,

characterised in that:

the control member comprises a first disc-shaped closure element connected by spokes to a second annularly-shaped closure element having an axially extending cylindrical wall tightly sliding against the sealing seat of the passage hole in the partition wall; and

in that the valve body, on said side opposite to the first inlet port, is provided with an auxiliary opening configured for assembling into and removing from the mixing chamber, the thermostatic actuator or an assembly comprising the flow control member, the thermostatic actuator, and the biasing spring.

BRIEF DESCRIPTION OF DRAWINGS These and further characteristics of the invention, will be more clear from the following description with reference to the enclosed drawings, wherein:

Fig. 1 is a longitudinal cross-sectional view of the thermostatic valve device for controlling the temperature of a fluid in thermal systems, in which the flow control member is shown in an open condition of the first inlet port and in a closed condition of the second inlet port;

Fig. 2 is a longitudinal cross-sectional view of the valve device of Fig. 1 , in which the flow control member partially opens the first and second inlet ports;

Fig. 3 is a longitudinal cross-sectional view, wherein the thermostatic actuator is lapped by the thermal fluid from the first inlet port, at a still higher temperature, causing the second inlet port to further open in respect to Fig. 2;

Fig. 4 is a longitudinal cross-sectional view of the valve device of Fig. 3, wherein an increase of the thermal fluid temperature at the second inlet port causes the first inlet port to be closed;

Fig. 5 is a cross section of a pumping unit comprising the valve device according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the general characteristics of the thermostatic valve device according to the present invention will be disclosed by means of some embodiments.

In the figures 1 to 4 the thermostatic valve device for controlling the temperature of a fluid in thermal systems is shown, which thermostatic valve device is particularly suitable for being used as an anticondensate valve in heating systems comprising an auxiliary solid fuel boiler.

The control valve device, overall indicated by the reference number 10, comprises a valve body 1 1 , extending along a longitudinal axis from a first inlet port 12, arranged along said longitudinal axis, for a first thermal fluid, consisting for example of recirculating water coming from an auxiliary boiler, not shown, and a second inlet port 13 for a second thermal fluid, consisting for example of water coming from a heating system. The inlet ports 12, 13 communicate with an outlet port 14 for a mixed fluid through a mixing chamber 15, where a reciprocating flow control member 16 is arranged for controlling the flow of the thermal fluids that are fed to the inlet ports 12, 13, to be mixed and fed at the outlet port 14.

The second inlet port 13 and the outlet port 14 are transversely arranged in respect to the longitudinal axis at respective sides of the valve body 1 1 , and in respect to the first inlet port 12; preferably, the second inlet port 13 and the outlet port 14 are axially aligned at opposite sides of the valve body 1 1 , or are angularly spaced apart and orthogonal oriented in respect to the longitudinal axis of the valve body 1 1 . The control member 16 for adjusting the fluid flows by shuttering or throttling the inlet ports is reciprocable and axially movable within the mixing chamber 15, and is disposed between a thermostatic actuator 17 and a counteracting biasing spring 18, in order to be moved between a first closure position of the first inlet port 12 shown in figure 4, and a second closure position of the second inlet port 13 shown in figure 1 .

According to the present invention, the valve body 1 1 at a side opposite to the first inlet port 12, has an auxiliary opening or through hole 19 provided with a removable plug 20; said opening 19 is configured and dimensioned for enabling the assembly comprising the control member 16, the biasing spring 18 and the thermostatic actuator 17 to be assembled into and removed from the mixing chamber 15 of the valve body 1 1 .

Internally to the valve body 1 1 , a partition wall 21 is provided to separate the second inlet port 1 3 from the first inlet port 12 and the outlet port 14; the partition wall 21 has a passage hole 22 for the fluid that has the same diameter and is coaxially arranged to the auxiliary opening 19.

The control member 16 comprises a disc shaped closure element 16', for closing and shuttering the first inlet port 12, and an annular element 16" for closing and shuttering, or throttling, the second inlet port 13; as shown, the annular closing element 16" comprises an axially extending cylindrical wall for closing the second inlet port 13, coaxially sliding against a sealing ring 23, within a circular seat along the rim of the passage hole 22 in the partition wall 21 . In order to close the second inlet port 13, the cylindrical wall of the annular closing element 16" has a bevelled edge 24 conformed to come into contact with an annular sealing seat or shoulder surface 25 at the end of the plug 20 facing the mixing chamber 1 5 of the valve body 1 1 , at the closure of the second inlet port 13.

The closure disc-shaped element 16' and the closure annular element 16" of the control member 16 are mutually connected by radial spokes 16"', so as to result axially spaced apart in order to define a fluid passage between the disc member 16' and said annular element 16".

The control member 16 and the thermostatic actuator 1 7 are operatively connected to each other by the sensitive bulb 1 7' of the actuator, that is inserted between spokes 16"' that radially extend from an internal surface of the cylindrical wall of the annular element 16" up to the bulb 17', defining thus an axial fluid passage through said control member 16.

On the basis of this conformation of the flow control member 16 and the arrangement of the actuator 17, the whole flow of fluid entering the second inlet port 13 laps the sensitive bulb 17', ensuring a high detecting precision for the temperature of the thermal fluid from the thermal system and thus a stable and reliable operation of the valve device.

Preferably, the sealing surface 25 for the front edge 24 of the annular element 16" is provided by the internal end rim of the plug 20, in particular in the form of an annular shoulder surface on a side of the plug 20 facing the mixing chamber 15; however, in order to define said sealing surface 25, the possibility is not excluded, for example, of providing an additional annular element conformed with said sealing surface fitted into the opening 19.

On an internal side, the plug 20 further provides a guide wall 20', into which a rear portion of the body of the actuator 17 in sealingly and slidably manner extends, from which protrudes a sliding stem 17" of said actuator in order to operatively contact the plug 20.

Conversely, the biasing spring 18 extends at an opposite side of the control member 16 in respect to the actuator 17, and is arranged within a tubular portion 12' of the valve body 1 1 that defines the first inlet port 12, between an internal annular shoulder 26 and the disc-shaped element 16' of the control member 16.

The operation modes of the valve device 10 are now explained with reference to the figures.

In particular, a first operative condition of the valve device 10 according to the invention is shown in Fig. 1 , which corresponds for example to a start up step of an auxiliary boiler of a heating system, wherein the second inlet port 13 is in closed condition, since the temperature of the recirculating fluid coming from the first inlet port 12 results lower than a threshold value, for example 55°C, for the thermostatic actuator 17.

In Fig. 2, the fluid entering through the first inlet port 12 has achieved or exceeded the threshold temperature, causing the thermostatic actuator 17 to expand, with consequent partial opening of the second inlet port 13.

In Fig. 3, the temperature of the fluid, coming from the second inlet port 13, and lapping the bulb 17', has increased, for example to a value of 62°-63°C, causing the control member 16 to further open the second inlet port 13, shuttering and partially closing the first inlet port 12. In Fig. 4, the temperature of the water coming from the second inlet port 13 has further increased, for example to 65°C, causing the first inlet port 12 to be closed by the disc-shaped element 16' that, having the same internal diameter of the inlet port 12, has tightly penetrated into the tubular portion 12' of the valve body 1 1 ; in these temperature conditions, hot fluid recirculating from the auxiliary boiler is no longer required to be fed.

In the case, not shown, that the temperature of the fluid coming from the second inlet port 13 still increases, reaching for example 90°C, the stem 17" of the thermostatic actuator 1 7 extends up to reach an extra-stroke condition, wherein the closure disc-shaped element 16' is caused to further penetrate the tubular portion 12' of the valve body 1 1 .

Figure 5 shows, by way of example, an application of the valve device 10 to a pum ping unit for recircu lating a therm al flu id in a heating system comprising an auxiliary boiler; in figure 5, the same reference numbers of the previous figures were used, in order to indicate similar or equivalent parts.

As shown in figure 5, in this case the valve device 1 0 is structurally and functionally integrated within the body 1 1 ' of a pumping unit 30, whose impeller 31 is disposed between the outlet side for the fluid from the mixing chamber 15, and the outlet port 14.

Also in this case, as in the previous case, the assembly consisting of the biasing spring 18, the thermostatic actuator 17 and the member 1 6 for controlling the fluid flows, is suitable for being assembled into the mixing chamber and removed from a single opening of the valve body, that in this case is coincident with inlet of the body 1 1 ' of the pumping unit 30. The solution of figure 5 differs from the previous solution in that, in order to assemble and axially remove through the inlet port 12 the assembly consisting of the spring 18, the thermostatic actuator 17 and the member 16 for controlling the flows, a sleeve 32 has to be firstly removed, equivalent to the tubular portion 1 2' of the valve body 1 1 of the previous exam ple; furthermore, in substitution of the plug 20 of figure 1 , the stem of the thermostatic actuator 17 now abuts against a cup element 20' inside the valve body 1 1 ', around which cup element 20' the fluid, fed at the inlet port 1 3, flows towards the m ixing chamber 1 5 as in the previous case; the peripheral rim 25 of the cup element 20' defines the sealing seat for the annular closure element 16". All was said and shown with reference to the enclosed drawings, was merely given by way of illustrative example of the general characteristics of the valve device, a preferred embodiment of said valve device, as well as a possible application of said valve device to a pump group; therefore, other modifications and variations may be made to the thermostatic control valve device, without thereby departing from the scope of the accompanying claims.

Claims

1 . A thermostatic valve device ( 1 0) suitable for control ling the temperature of a fluid in a thermal system, comprising:

a valve body (1 1 ) having a longitudinal axis;

a first inlet port (12) axially aligned to the valve body (1 1 );

a second inlet (13) and a third outlet port (14) angularly spaced apart and transversally extending to the longitudinal axis of the valve body (1 1 ); said inlet and outlet ports (12, 13, 14) opening into a mixing chamber (15);

a fluid flow control member (16) axially movable in the fluid mixing chamber, arranged between a thermostatic actuator (17) and a biasing spring (18);

said flow control member (16) comprising a first closure element (16') configured and arranged to close, shuttering and throttling the first inlet port (12), and a second closure element (16") axially spaced apart from said first closure element (16') configured for closing and shuttering the second inlet port (13);

an internal partition wall (21 ) for separating said inlet and outlet ports (12, 13, 14), the partition wall (21 ) being provided with a fluid passage hole (22) and a sealing seat for the first closure member (12), between the inlet and the outlet ports (12, 13, 14); and

in which the valve body (1 1 ) comprises an auxiliary opening (19) at a side opposite to the first inlet port (12),

characterised in that:

the control member (16) comprises a first disc-shaped closure element (16') for the first inlet port (1 3) connected by spokes (16"') to a second annularly-shaped closure element (16") for the second inlet port (13), having an axially extending cylindrical wall tightly sliding against the sealing seat of the passage hole (22) in the partition wall (21 ); and

in that the valve body (1 1 ), on said side opposite to the first inlet port (12) is provided with an auxiliary opening (19) configured for assembling into and removing from the mixing chamber of the valve body (1 1 ) the thermostatic actuator (17) or an assembly comprising the flow control member (16), the thermostatic actuator (17), and the biasing spring (18).

2. The thermostatic valve device according to claim 1 , characterised in that the auxiliary opening (19) is closed by a removable plug member (20) conformed, at an end facing the m ixing chamber (1 5), with an annular surface (25) providing a sealing seat for the second closure element (16").

3. The thermostatic valve device according to claim 1 , characterised in that, the second inlet port (1 3) and the outlet port (14) are angularly spaced apart on respective sides of the valve body (1 1 ) and orthogonally arranged to the longitudinal axis of the valve body (1 1 ) and the first inlet port (12).

4. The thermostatic valve device according to claim 1 , characterised in that the closure disc-shaped element (16') is tightly sliding along a tubular extension of the first inlet port (12).

5. The thermostatic valve device according to claim 1 , characterised in that, said radial spokes (16"') of the control member (16) are conformed to seat a sensitive bulb (17') of the thermostatic actuator (17).

6. The thermostatic valve device according to claim 2, characterised in that, said plug (20) comprises, an internal annular wall (20') for slidably housing a rear portion and an axially sliding stem (17") of the thermostatic actuator (17).

7. A pump unit (30) for circulation of a thermal fluid into an auxiliary boiler of a heating system, characterised by comprising a control valve device (10) according to claim 1 .

8. The pump unit (30) according to claim 7, characterised in that the biasing spring (1 8), the thermostatic actuator (1 7) and the fluid control member (16) of the valve device (10) are axially assemblable and removable through an inlet port (1 1 ") of the pumping unit (30).

9. The pump unit (30) according to claim 7, characterised in that the mixing chamber (15) of the valve device (10) is in fluid communication with an impeller (31 ) of the same pumping unit (30).