EP4253865A1 - Blower for a heating device, heating device and use of metal foam - Google Patents

Abstract

What is proposed is a fan (2) for a heater (1) comprising a housing (6) that consists at least partially of metal foam. The housing (6) can comprise a first housing part (14) and a second housing part (15). According to an advantageous embodiment, the metal foam can be an aluminum foam.

Description

The invention relates to a fan for a heater, a heater and a use of metal foam.

Modern heaters that generate heat energy by burning a fuel, for example natural gas or hydrogen, usually have a conveying device that can convey a mixture of combustion air and fuel in a combustion chamber of the heater. The conveyor device is often designed as a fan that is driven by an electric motor.

The fan must be designed to provide gas flow for the entire modulation range of the heater. For this purpose, the fans are usually designed to be small in order to be able to promote defined low volume flows for small performance ranges. For high performance ranges and large volume flows required, this small blower must be operated at high speed, which can result in significant noise emissions.

For the reasons mentioned, fans are often responsible for a significant proportion of the heater's noise emissions. There are efforts to reduce the noise emissions of the fans or the driving electric motors in order to increase comfort for the user. For this purpose, housings for the motors and/or an elastic, vibration-damping suspension/mounting of the fans or electric motors can be used, but this causes additional costs and makes assembly more difficult.

The DE 690 06 547 T2 shows a housing for a blower. comprising a porous layer which may be made of a thermoplastic resin. The porous layer can improve the sound-absorbing properties of the housing. However, a thermoplastic can only be used to a very limited extent for the housing of a heater due to high temperature loads.

Proceeding from this, it is the object of the invention to propose a fan for a heater and a use of metal foam that at least partially overcome the problems described in the prior art. In particular, low-noise operation of the heater should be made possible throughout the entire modulation range.

In addition, the invention should at least not significantly increase the complexity of a heater and only require minor structural changes to a heater and enable simple integration into an existing production process.

These tasks are solved by the features of the independent patent claims. Further advantageous embodiments of the solution proposed here are specified in the independent patent claims. It should be noted that the features listed in the dependent patent claims can be combined with one another in any technologically sensible manner and define further embodiments of the invention. In addition, the features specified in the patent claims are specified and explained in more detail in the description, with further preferred embodiments of the invention being presented.

A fan for a heater, comprising a housing that is at least partially made of metal foam, contributes to this.

The heater is in particular a gas heater which is designed to burn a gaseous fuel, such as natural gas or in particular hydrogen, while supplying ambient air in order to provide heat, for example for a heating circuit or a hot water supply. The heater can generally have at least one burner and a conveyor device that conveys a mixture of fuel (gas) and combustion air through a mixture channel of the heater to the burner. The combustion products can then be led through an exhaust duct of the heater to an exhaust system.

The blower can be a blower suitable for providing a combustion air flow or a volume flow of a mixture of fuel gas and combustion air, for example radial or axial fans. In particular, the fan can be a centrifugal fan.

Centrifugal fans usually have a radial impeller and can suck in a fluid (air) from a direction parallel to the drive axis and blow it out in a radial direction. For this purpose, radial fans often have a housing in which the radial impeller is mounted and on which a drive device (electric motor) can be arranged to drive the radial impeller. The housing is generally designed in several parts, in particular in two parts, whereby the two housing parts can be assembled in the axial direction. In order to cover the entire modulation range of a heater and to be able to provide defined low volume flows, a small housing for the fan can be selected. To provide high volume flows (in high performance ranges of the heater), the fan must be operated at a high speed in order to promote sufficient volume flow.

With centrifugal fans, a significant proportion of noise emissions can arise in the housing, especially at high speeds. According to an idea of this invention Improved noise insulation of the housing can be achieved in which the housing consists at least partially of a metal foam. A metal foam can absorb vibrations very well and thus limit noise emissions.

The metal foam is in particular a two-phase material, having at least one area which can be filled with a gas (with bubbles) or another solid (usually with a significantly lower density), which is (on both sides) of (solid and / or closed ) metallic walls are separated. Metal foams can be produced, for example, by adding blowing agents that release a gas, such as hydrogen, and thus enable foam formation. Other known methods use gas injection or use gases dissolved in the melt, which are released as a result of a reduction in the ambient pressure when the melt solidifies, to produce metal foams.

According to an advantageous embodiment, the housing of the blower or at least part of the housing can be manufactured in an injection molding process. A component can advantageously be made from a metal foam that has a closed surface. Foam formation can be achieved, for example, by adding a blowing agent. In particular, foam formation can be achieved by adding polymer granules, whereby the polymer granules do not decompose due to the short injection molding process time and remain in the material as a filler and/or can be removed by thermal treatment. In particular, a housing is proposed that consists entirely of parts that are manufactured using an injection molding process, because this ensures that the housing is gas-tight.

According to an advantageous embodiment, the metal foam can be an aluminum foam, which can combine the advantages of low weight with very good noise insulation.

According to an advantageous embodiment, the housing can consist largely entirely of metal foam or be formed (exclusively) with it. Mechanically stressed areas, such as bearing mounts or fastening areas of the housing parts to one another or to the drive device, can also advantageously be reinforced by a solid design. It is possible to introduce or provide reinforcing elements, such as ribs, in stressed areas.

According to an advantageous embodiment, the housing can also only have metal foam in certain areas. For example, a housing part, on which the drive device can be arranged, for example, could be made solid and another housing part, which can essentially house a radial impeller, could be formed as or with metal foam. An additive manufacturing process involving a 3D printing process could be used for this purpose.

According to a further aspect, a heater is proposed, comprising a fan according to one of the preceding claims. The heater can in particular be a condensing boiler.

According to a further aspect, the use of metal foam for producing a housing of a fan for a heater is also proposed. The individual features of the metal foam and/or the housing can be used to determine the design of the metal foam used and/or its integration into the housing.

Here, a fan for a heater, a heater and a use of metal foam are specified, which at least partially solve the problems described with reference to the prior art. In particular, the fan for a heater, the heater and the use of metal foam at least contribute to reducing the noise emissions of a heater, especially in high performance ranges.

In addition, the invention can be easily implemented since only a different material has to be used to produce a housing for a fan for a heater.

Fig. 1:

ein hier vorgeschlagenes Gebläse und

Fig. 2:

ein hier vorgeschlagenes Heizgerät.

The invention and the technical environment are explained in more detail below using the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments given. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description. In particular, it should be noted that the figures and in particular the proportions shown are only schematic. Show it:

Fig. 1:

a blower suggested here and

Fig. 2:

a heater suggested here.

Fig. 1 shows an example and schematically of a blower 2 proposed here. This can include a housing 6 comprising a first housing part 14 and a second housing part 15, which can be put together in an axial direction 22. Inside the housing 6, a radial impeller 18 can be rotatably mounted and axially connected to an electric motor 17. The blower 1 can suck in a gas stream via an inlet 11 in an inlet direction 21, which can largely correspond to the axial direction 22, and eject it via an outlet 23 in an outlet direction 20.

A blower 2 proposed here can have a first housing part 14 and/or a second housing part 15 at least partially consisting of metal foam, in particular aluminum foam. The first housing part 14 and the second housing part 15 can be connected via a flange connection and fastening screws

Fig. 2 shows an example and schematic of a heater 1 proposed here. This can suck in combustion air 4 through a fan 2 via a supply and add a gas, for example hydrogen, to the sucked-in volume flow of combustion air via a gas valve 5. The combustion mixture of gas and combustion air can now be fed via a mixture channel 16 to a burner 3 arranged in a combustion chamber 8. The combustion products can be fed from the combustion chamber 8 to an exhaust system 10 via an exhaust pipe 9. A UV sensor 13 for flame monitoring can be arranged outside the combustion chamber 8, protected from the high temperatures in the combustion chamber 8.

As a precaution, it should be noted that the number words used here ("first", "second",...) primarily serve (only) to distinguish between several similar objects, sizes or processes, i.e. in particular no dependency and/or order of these objects, sizes or prescribe processes to each other. If a dependency and/or sequence is required, this is explicitly stated here or it will be obvious to the person skilled in the art when studying the specifically described embodiment. To the extent that a component can occur multiple times ("at least one"), the description of one of these components can apply equally to all or part of the majority of these components, but this is not mandatory.

Reference symbol list

1

heater

2

fan

3

burner

4

Supply of combustion air

5

Gas valve

6

Housing

7

Control and control device

8th

combustion chamber

9

exhaust pipe

10

Exhaust system

11

inlet

13

UV sensor

14

first housing part

15

second housing part

16

Mixture channel

17

Electric motor

18

Radial impeller

19

Direction of rotation

20

Exhaust direction

21

Inlet direction

22

axial direction

Claims (10)

Fan (2) for a heater (1), comprising a housing (6) which consists at least partially of metal foam. Blower (2) according to claim 1, wherein the housing 6) comprises at least a first housing part (14) and a second housing part (15). Blower (2) according to one of the preceding claims, wherein the housing (6) consists entirely of metal foam. Blower (2) according to one of the preceding claims, wherein the metal foam is aluminum foam. Blower (2) according to one of the preceding claims, wherein at least one housing part (14) was made from metal foam using an injection molding process. Blower (2) according to one of the preceding claims, wherein the at least one housing part (14) has a closed, gas-tight surface. Heater (1), comprising a fan (2) according to one of the preceding claims. Heater (1) according to claim 7, wherein the heater (1) is a condensing heater. Heater according to claim 8 or 7, wherein the heater (1) is set up to burn a fuel gas. Use of metal foam to produce a housing (6) of a fan (2) for a heater (1).

Images