NL2004137C2 - FAN HOUSE FOR A FAN FOR SUPPLYING A FUEL / OXIDATOR MIXTURE TO A BURNER, INSERT, AND FEEDING DEVICE THEREFOR. - Google Patents

Description

Fan housing for a fan for supplying a fuel / oxidant mixture to a burner, insert and feeding device therefor. The present invention relates to a fan housing for a fan for supplying a fuel / oxidant mixture to a burner.

The invention further relates to an insert for such a fan housing.

The present invention also relates to a supply device for such a fan housing.

The present invention also relates to a heat appliance comprising such a fan housing.

The present invention also relates to a hot water appliance comprising such a fan housing.

The present invention also relates to a combi boiler comprising such a fan housing.

The invention also relates to a method for supplying a fluid fuel with an oxidizing fluid to a fan.

In burners such as those used in the prior art, there is sound development, which sound development is largely determined by the so-called thermo-acoustic behavior. The thermo-acoustic behavior is influenced inter alia by the burner itself, but also by elements upstream and to a lesser extent downstream from the burner. One of the elements that influences thermo-acoustic behavior 30 is a fan that forces the fuel / air mixture through the burner.

2

The object of the present invention is to provide a heat appliance with an improved thermo-acoustic behavior compared to the prior art.

To this end, the present invention provides a fan housing for a fan for supplying a fuel / oxidizer mixture to a burner comprising: a supply opening; a fluid supply space terminating at the supply opening; a first supply means for supplying a fluid fuel; a second supply means for supplying an oxidizing fluid; wherein the fluid supply space comprises mixing means for mixing the fluid fuel with the oxidizing fluid; and wherein the supply opening is at an angle with respect to the supply direction of the fluid in the fluid supply space.

In a preferred embodiment, the fuel comprises natural gas and the oxidizing fluid comprises air. In an alternative embodiments, the fuel comprises methane, propane, and / or butane.

Measurements from applicant have shown that when the fuel / oxidant mixture undergoes a substantial reversal of the flow direction before the mixture passes through the fan vane space, the thermo-acoustic behavior of the burner is positively influenced in that the noise production is decreasing.

By providing this fan housing, by using the fan housing in a heat appliance, a heat appliance is provided with an improved thermo-acoustic behavior with respect to heat appliances of the prior art.

In a preferred embodiment, a fan housing is provided, wherein the mixing means comprise a venturi. The venturi creates an underpressure near the venturi 3 and downstream of the venturi, as a result of which the oxidizing fluid is drawn in from the second supply means and mixes with the fuel. An additional advantage is that the venturi and the fan housing are now integrated, whereby a more compact assembly is obtained. In the prior art heaters, on the other hand, the fan housing and the venturi are designed as separate components.

In a further preferred embodiment, the present invention provides a fan housing, wherein the supply opening is arranged transversely with respect to the supply direction of the fluid in the fluid supply space. Measurements by the applicant have shown that the transverse positioning of the supply opening has a particularly favorable effect on the thermo-acoustic behavior of the burner.

In yet another advantageous embodiment, a fan housing is provided, wherein the second supply means is arranged in the first supply means and is located in the flow direction of the first supply means, and which second supply means opens into the first supply means, and wherein the first supply means opens near the mouth of the second feed means comprises a narrowing.

The narrowing near the mouth of the second supply means forms the venturi. Because the venturi on the second supply means, which in turn is arranged in the first supply means, and this assembly is integrally formed with a fan housing, a particularly compact construction is obtained. As a result, not only is a heat device obtained which exhibits a more favorable thermo-acoustic behavior than the prior art, but is moreover more compact.

In a very advantageous embodiment the invention provides a fan housing, wherein at or near the mouth of the second feed means an obstruction extends downstream of a portion of the circumferential wall of the second feed means in a downstream direction to some distance from the mouth in order to close the at the mouth of the second supply means to prevent a fluid flow transverse to the main flow direction in the first supply means.

Measurements by the applicant have again shown that the provision of this obstruction has a positive effect on the thermo-acoustic behavior of a heating device 10 comprising such a fan housing. In particular when a downstream movement with respect to the fan, for example in the discharge of flue gases, occurs, the obstruction makes a positive contribution to the thermo-acoustic behavior. Namely, when such a stagnation occurs, a circulating underpressure is created at the supply opening of the fan housing. The obstruction obstructs the circulating fluid flow and causes a local pressure increase at the mouth of the second supply means, whereby the gas supply stops. The result is a more favorable thermo-acoustic behavior than is the case in the prior art.

The positive effect of the obstruction on the thermo-acoustic behavior is independent of the fact that the supply opening of the fan housing is at an angle with respect to the supply direction of the fluid in the fluid supply space. Both the obstruction and the angle each have a favorable effect on the thermo-acoustic behavior and can be implemented independently of each other.

In a preferred embodiment the invention provides a fan housing, wherein the extending obstruction is an extension of the wall of the second supply means. In this way the obstruction can be formed in a simple manner.

In an advantageous embodiment, the present invention provides a fan housing, wherein the second supply means and the mixing means are formed from an insert piece that can be placed in the fluid supply space. By designing the second supply means and the mixing means as an insert, a compact assembly is obtained relative to the state of the art, and on the other hand the possibility is obtained in a simple manner of adapting the fan housing to the capacity provided for the heat appliance. by only varying the insert and manufacturing the rest of the fan housing in a single embodiment for different types of heaters of different capacities.

The present invention also provides such an insert.

In an alternative embodiment the invention provides a supply device for supplying fluid to a fan housing, comprising a closing piece for closing off a supply side of a fan housing; a fluid supply space for supplying a fluid, the fluid supply space opening onto the fan side of the closing piece by means of a supply opening; a first supply means for supplying a fluid fuel; a second supply means for supplying an oxidizing fluid; wherein the fluid supply space comprises mixing means for mixing the fluid fuel with the oxidizing fluid; and wherein the supply opening is at an angle with respect to the supply direction of the fluid in the fluid supply space.

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As an alternative to a ventilation housing in which the mixture of the fluid fuel and the oxidizing fluid are introduced into the fan housing at an angle, the present invention provides an embodiment in which only a supply device is provided which can be arranged on the supply side of a ventilation housing . In a specific embodiment the supply device is designed as a cover of the ventilation housing.

In an embodiment, the present invention further provides a heat device comprising such a fan housing or a fan housing comprising such a supply device.

The invention furthermore provides in a further embodiment a hot water appliance comprising such a fan housing or a fan housing comprising such a supply device.

In a further embodiment the present invention also provides a combi boiler for heating tap water and central heating water, the combi boiler comprising such a fan housing or a fan housing comprising such a supply device.

According to another aspect of the invention, a method is provided for supplying a fluid fuel with an oxidizing fluid to a fan, comprising the steps of: guiding the fluid fuel through a venturi; providing the oxidizing fluid in or near the venturi, whereby the oxidizing fluid is sucked in by the Venturi effect and mixes with the fluid fuel; supplying the mixture of the fuel and the oxidizing fluid at an angle to a fan, which fan blows the mixture into a burner space.

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Further embodiments and advantages of the present invention are discussed below with reference to the figures, in which:

Figure 1A shows a partially cut-away view of a fan housing with a feed device according to the present invention mounted thereon;

Figure 1B shows an exploded view of the fan housing of Figure 1B;

Figure 1C shows the rear side with respect to Figures 1A and 1B of the fan housing of Figures 1A and 1B;

Figure 2 shows a frontal view of a feeding device according to the present invention;

Figure 3 shows an axonometric view of the feeding device of Figure 2; and

Figure 4 shows a second axonometric view of the feeding device of Figure 2.

A fan housing 10 (Figure 1) is provided with a supply device 20 according to the present invention. The supply device 20 is designed as a cover which is arranged on the supply side of the fan housing 10.

The fan housing 10 comprises a main body 30 and a discharge line 42 for guiding a gas / air mixture to the burner.

The natural gas is supplied via a supply line 28 in which the insert 50 is placed which comprises a venturi 54. The venturi 54 causes an underpressure downstream of the venturi in the natural gas supply line 28. As a result of this underpressure, air is drawn in from the air supply line 52, as a result of which a mixing of the natural gas and the air occurs in the fluid supply space 26, a part of the outer wall 24 of which in Figure IA is cut away. A supply opening 22 8 is recessed in the lid 20, through which the natural gas / air mixture flows into the fan housing 10. By rotating the fan, an underpressure is created at the level of the supply opening 22, which underpressure causes the natural gas / air flow 5 from the fluid supply space into the fan housing 10. As soon as the natural gas / air mixture flows into the fan housing 10 via the supply opening 22, the gas flow is considerably deflected by the arrangement of the supply opening 22 transversely of the main flow direction in the fluid supply space 26. At the discharge line 42 an excess pressure is created whereby the natural gas / air mixture flows into the burner via the discharge line 42.

Figure 2 shows a similar fan housing cover as in figure 1. The wall 24 of the fluid supply space is omitted in this figure for clarification of the underlying components. The insert 50 is provided on a part of the circumference of the mouth of the air supply line 52 with an extension 56 of the wall of the air supply line 52. Because the air supply line 52 does not extend completely at the height of the extension 56, mixing of natural gas and air at this height possible. However, a transverse flow of the natural gas / air mixture is prevented here by the extension 56. This appears to have a favorable effect on the thermo-acoustic behavior of the burner.

Figure 3 again shows the fan housing cover 20 of Figure 2, but now from a different angle, with a portion of the cover 20 and of the fluid supply space 26 being cut away.

Figure 4 again shows the fan housing cover 20 of Figure 2, but now from yet another angle, wherein the same part of the cover 20 and of the fluid supply space 26 is cut away as in Figure 3.

The shown and described embodiments are only included to illustrate the principle of the invention and to show or describe some advantageous embodiments. The invention is not limited to the embodiments shown and described. It is clear to the person skilled in the art that many modifications are possible within the invention to the embodiments shown. Thus, it is without doubt possible to combine the different embodiments shown or described and thus again to obtain embodiments according to the invention. The protection required is therefore not determined by the embodiments shown and described, but by the following claims.

Claims (14)

A fan housing 10 for a fan for supplying a fuel / oxidizer mixture to a burner 5 comprising: a supply opening 22; a fluid supply space 26 which opens at the supply opening 22; a first supply means 28 for supplying a fluid fuel; a second supply means 52 for supplying an oxidizing fluid; wherein the fluid supply space comprises mixing means 54 for mixing the fluid fuel with the oxidizing fluid; and wherein the supply opening 22 is at an angle with respect to the supply direction of the fluid in the fluid supply space 26. 2. Fan housing 10 according to claim 2, wherein the mixing means comprise a venturi 54. 3. Fan housing 10 according to claim 1 or 2, wherein the supply opening 22 is arranged transversely with respect to the supply direction of the fluid in the fluid supply space 26. 4. Fan housing 10 according to claim 2 or 3, wherein the second supply means 52 is arranged in the first supply means 28 and is located in the flow direction of the first supply means 28, and which second supply means 52 debouches in the first supply means 28, and wherein the first supply means 28 near the mouth of the second supply means 52 comprises a restriction. 5. Fan housing 10 according to claim 4, wherein at or near the mouth of the second feed means 52 over an area of the circumferential wall of the second feed means 52 an obstruction 56 extends downstream to some distance from the mouth in order to close the at the mouth of the second supply means 52 to prevent a fluid flow transverse to the main flow direction in the first supply means 28. 6. Fan housing 10 according to claim 5, wherein the extending obstruction 56 is an extension of the wall of the second supply means 52. 7. Fan housing 10 as claimed in any of the claims 1-6, wherein the second supply means 52 and the mixing means 54 are formed from an insert 50 which can be placed in the fluid supply space 26. The insert 50 as defined in claim 7. 9. Supply device 20 for supplying fluid to a fan housing 30, comprising a closing piece 20 for closing off a supply side of a fan housing 30; a fluid supply space 26 for supplying a fluid, wherein the fluid supply space 26 debouches on the fan side of the closing piece 22 by means of a supply opening 22; a first supply means 28 for supplying a fluid fuel; a second supply means 52 for supplying an oxidizing fluid; wherein the fluid supply space 26 comprises mixing means 54 for mixing the fluid fuel with the oxidizing fluid; and wherein the supply opening 22 is at an angle with respect to the supply direction of the fluid in the fluid supply space 26. 10. Supply device 20 as claimed in claim 9 for use in a ventilation housing 10 as claimed in any of the claims 1-7. 11. Heat device comprising a fan housing 10 according to claims 1-7 or a fan housing 10 including a supply device 20 according to claim 9 or 10. 12. Hot water appliance comprising a fan housing 10 according to claims 1-7 or a fan housing 10 comprising a supply device 20 according to claim 9 or 10. 13. Combination boiler for heating tap water and central heating water, the combi boiler comprising a fan housing 10 according to claims 1-7 or a fan housing 10 comprising a supply device 20 according to claim 9 or 10. 14. Method for supplying a fluid-shaped fuel with an oxidizing fluid to a fan, comprising the steps of: guiding the fluid-shaped fuel through a venturi 54; providing the oxidizing fluid in or near the venturi 54, whereby the oxidizing fluid is sucked in by the Venturi effect and mixes with the fluid fuel; supplying the mixture of the fuel and the oxidizing fluid at an angle to a fan, which fan blows the mixture into a burner space.