WO2013110516A1

WO2013110516A1 - Blade wheel with intumescent coating

Info

Publication number: WO2013110516A1
Application number: PCT/EP2013/050547
Authority: WO
Inventors: Christian Hammel
Original assignee: Ebm-Papst Mulfingen Gmbh & Co. Kg
Priority date: 2012-01-25
Filing date: 2013-01-14
Publication date: 2013-08-01
Also published as: DE102012100628A1

Abstract

The invention relates to a blade wheel (7) for an axial ventilator or a radial or diagonal fan, comprising multiple blades (8) and a supporting part (9, 10) on which the blades (8) are arranged. The supporting part (9, 10) and/or the blades (8) consist of plastic. The supporting part (9, 10) and/or the blades (8) are completely or partly covered with an intumescent coating (6) which acts as a fire protection coating. The invention further relates to a housing (12) with a housing wall (15, 17, 19, 20) for receiving a blade wheel (7) according to the invention, said housing wall (15, 17, 19, 20) being completely covered, i.e. over the entire surface, or partly covered with an intumescent coating (6) as a fire protection coating.

Description

"Paddle wheel with intumescent coating"

The present invention relates to a paddle wheel for axial fans or Radialbzw. Diagonal fan, comprising a plurality of blades and a support member on which the blades are arranged, wherein the support member and / or the blades of

Plastic, as well as a fan or blower housing for receiving such a paddle wheel.

For high fire protection requirements with high strength requirements usually paddle wheels made of metal are used.

Depending on the application, plastic impellers are subject to different fire protection requirements, such as: B. according to the provision UL94 "Tests for

Flammability of Plastic Materials for Parts in Devices and Applications

Underwriters Laboratories (UL), which is a method of assessment and

Classification of the flammability of plastics describes and was the same content in the standards IEC / DIN EN 60695-1 1-10 and -20 adopted. According to these standards, tests are carried out on specimens with prescribed 50-Watt or 500-Watt flame under specified experimental conditions

Dimension performed. The burning time and in the so-called V-tests also the falling off of burning parts are evaluated. In particular, the plastic paddle wheels must meet the requirements of V-0 and V5A according to UL94. Where: a) V-2: extinction of a vertically clamped sample within 30 seconds after exposure to a 50 watt flame; b) V-1: like V-2, however, no burning dripping of plastic melt is allowed, and c) V-0: as V-1, but with extinguishment of the flame within 10 seconds. The plastic paddle wheels, which must therefore meet the classification V-2 are additionally tested with the 500-watt flame, the corresponding classifications have the following meaning: d) 5VB: extinguishing a vertically clamped sample after five flashes for five seconds, where no dripping is allowed; e) 5VA: as 5VB with an additional test on a horizontally clamped plate and neither dripping nor the formation of burn holes with a diameter> 1 mm are allowed.

Plastics such. As polypropylene or polyamide with a glass fiber content and with an addition of a flame retardant have mechanically worse

Properties as plastics containing only glass fiber components. For this reason, plastic impellers in which the plastic material contains a flame retardant such that these plastic wheels meet the requirement of UL94 (V-0; V5A) do not reach the same operating speed as

Plastic paddle wheels in which the plastic material contains no flame retardant.

The present invention is based on the object, starting from

Paddle wheels made of plastic, to design them in such a way that they meet the highest fire protection requirements and in particular the criteria of

Classifications V-0 and V5A meet UL94, but this

Plastic paddle wheels to reach the same operating speed, as

Plastic paddle wheels of the same material if the plastic material does not contain a flame retardant.

According to the invention this is achieved in that the carrier part and / or the blades of the impeller completely or partially with a

Fire protection coating acting intumescent coating are provided. The requirements of UL94 (V-0; V5A) can thus be met. Because the material of the the respective base body of the carrier part and / or blades, on each of which the coating is located, can remain free of flame retardant additives, thereby the strength of these components and thus the achievable maximum speed is not diminished.

In this case, the intumescent coating preferably consists of a polymer binder matrix in which an intumescent flame retardant is incorporated. As the polymer material of the binder matrix, polypropylene or polyamide is suitably used.

The intumescent coating can be applied as a lacquer or as a coating by dipping, spraying or the like.

The operating principle of such an intumescent coating is that foaming initially takes place under the action of heat, ie. H. An insulating layer is formed as a heat brake, so that a foamed ash layer is formed, which hinders the supply of oxygen and thus the flame propagation. Furthermore, there is an endothermic effect by hydrates, by

Steam release cause a cooling. In addition, a arises

Expansion pressure, which can seal any gaps. Thus, an intumescent coating is formed by the intumescent coating in case of fire.

Advantageously, the composition of an inventive

Intumescent Coating Polyalcohols which act as charcoal donors in the formation of the heat barrier insulating layer,

Ammonium polyphosphate to achieve an endothermic effect and as

Acid dispensers and / or melamine resins as blowing agents.

In particular, suitable organic flame-proofing agents are organic triphosphates

(Organophosphate). As a flame retardant is suitable, for example

in particular also DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide). This is a halogen-free flame retardant, which can be used in particular with epoxy resins.

Furthermore, the invention relates to a housing having a housing wall for receiving a paddle wheel according to the invention, wherein the

Housing completely or partially with the invention

Intumescent coating is provided as a fire-resistant coating.

Advantageous embodiments of the invention are contained in the subclaims and will be described with reference to the accompanying drawings

Embodiments explained in more detail. Show it:

Fig. 1 is a view of a paddle wheel according to the invention for a

Axial fan,

Fig. 2 is a view of a paddle wheel according to the invention for a Radialbzw. Diagonal fan,

Fig. 3 is an axial section through an inventive housing for

Recording a paddle wheel for a radial blower according to FIG. 2,

4 is a detail view in section according to IV-IV in Fig. 1, Fig. 2 and Fig. 3.

In FIGS. 1 to 4, the same parts or functionally identical parts are identified by the same reference numerals. If certain described and / or removable from the drawings features of the paddle wheel or its components are described only in connection with an embodiment, but these are also essential according to the invention regardless of this embodiment as a single feature or in combination with other features of the embodiment and are claimed as belonging to the invention. Fig. 1 shows a view of a paddle wheel 1 according to the invention for an axial fan. This impeller 1 consists of a support member 2, which is cup-shaped in the illustrated embodiment, and consists of a cross-section - apart from optionally present reinforcing ribs, etc. - substantially circular peripheral wall 3 and an end-side bottom part 4. This support member 2 forms the rotor an electrical

External rotor motor. On the outer circumference of the peripheral wall 3 blades 5 are circumferentially arranged, preferably at equal intervals. The support member 2 may also consist only of an annular part formed by the peripheral wall, which is pressed onto the rotor of an external rotor motor.

The support member 2 and the blades 5 are preferably made of plastic material, such as a glass fiber reinforced polyamide or a

glass fiber reinforced polypropylene, formed and are preferably

manufactured in one piece in an injection molding process. On its surface, the paddle wheel 1 is provided over its entire surface or partially with an intumescent coating 6 according to the invention as a fire protection coating according to UL94 (V-0, V5A).

This intumescent coating 6 preferably comprises a polymer binder matrix and an intumescent flame retardant incorporated in this matrix, it also being possible for fillers to be included.

It is also within the scope of the invention, when the carrier part 2 and the

Blades 5 are not integral, but are designed as separate components and are connected to each other, for example via screw or the like.

The glass fiber content in the plastic material used for the production of the carrier part 2 and the blades 5 is preferably at most 50% by mass. In FIG. 4 it can be seen that the intumescent coating 6 according to the invention can be applied to the blades 5 on both sides. The basic body made of plastic of the blade is therein with the reference symbol G

designated. In the carrier part 2, the intumescent coating 6 is preferably present on both sides on the carrier part 2.

The intumescent coating 6 preferably has a layer thickness d of 50 pm to 500 pm, so that the following applies: 50 pm <d <500 pm. The inventive

Intumescent coating 6 can be applied, for example, as a lacquer, or else the intumescent coating 6 can be applied in particular in a spraying or dipping process. As a flame retardant in particular a phosphoric acid ester is used, wherein, for example, ammonium polyphosphate can be used. Furthermore, it is possible according to the invention to use as halogen-free flame retardant, for example, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, for which the name DOPO is also customary. It is advantageous if a binder as a

multifunctional epoxy resin is used.

The mode of action of such a flame retardant according to the invention is based on three different processes, namely: First, a

formed inflammable carbon layer, which is a protective layer and thus reduces the amount of combustible material. A second effect is caused by the so-called intumescence, whereby in the reaction below

Heat-released gases forming a voluminous protective layer is formed. The third effect is based on the release of radicals, especially phosphorus oxide radicals (POs), which are generated by heat and inhibit the free radical combustion process.

The binders for the binder matrix used according to the invention include, for example, polyurethanes, silicone rubbers, silicone resins, phenolic resins, Melamine resins, epoxy resins, polyvinyl acetate, urea-aldehyde resins and / or also z. B. polypropylene.

Inorganic fillers that may be included within the intumescent coating include, for example, silica, silicon carbide, titanium dioxide, sodium borate, zinc borate, and / or sodium phosphate.

FIG. 2 shows an illustration of a blade wheel 7 according to the invention for a radial fan. This paddle wheel consists of the blades 8, which are arranged between a cover plate 9 and a bottom plate 10, wherein the bottom plate 10 and the cover plate 9 each form the carrier part.

According to the invention, both the blades 8 and the bottom disk 10 and the cover disk 9 are preferably provided over their entire surface with an intumescent coating 6 according to the invention, as already described with reference to FIGS. 1 and 4. Here, the blades 8 and the bottom plate 10 and the cover plate 9 made of a plastic material, such as

Polyamide or polypropylene, which is preferably glass fiber reinforced. The blades 8, the bottom plate 10 and the cover plate 9 may be made in one piece or assembled from several parts and manufactured by injection molding. The application of the intumescent coating 6 also takes place in this embodiment as described for FIG. 1.

In Fig. 3 by way of example, an electric motor driven radial fan 1 1 is shown with a paddle wheel 7 similar to the embodiment shown in Fig. 2. Such a radial fan 1 1 consists essentially of a fan housing 12, the paddle wheel 7, consisting of the blades 8, the bottom plate 10 and the cover plate 9 and an electric motor 13. The fan housing 12 is composed of a peripheral wall 15, one in the plane arranged perpendicular to a motor shaft 16, front end wall 17 having an inlet opening 18, a mounted between the impeller 7 and the electric motor 13, rear end wall 19 and one at the rear end wall 19th attached, the motor 13 enclosing cap 20. The motor 13 is designed as an external rotor motor, wherein a stator 21 of a rotor 22nd

is enclosed, which drives the impeller 7 via a motor shaft 16.

The blower housing 12 is made of a plastic material, such as a glass fiber reinforced polyamide or polypropylene. On its surface, the blower housing 12 is wholly or partly with an inventive

Intumescent coating 6 provided. As far as the composition and application of the intumescent coating 6 is concerned, it can be fully applied to the

Remarks to Fig. 1 be referenced.

If polypropylene is used as the production material according to the invention, a pretreatment is expedient in order to activate the surface to be coated. This activation can z. B. by Flourieren or a so-called plasma activation

The invention is not limited to the illustrated and described embodiments, but also includes all the same in the context of the invention embodiments. Furthermore, the invention has hitherto not been limited to the feature combinations defined in claims 1 and 14, but may also be defined by any other combination of particular features of all the individual features disclosed overall. This means that in principle virtually every individual feature of the independent claims can be omitted or replaced by at least one individual feature disclosed elsewhere in the application. In this respect, the claims are to be understood merely as a first formulation attempt for an invention.

Claims

claims

1. paddle wheel (1, 7) for an axial fan or a radial or

Diagonal fan (1 1) comprising a plurality of blades (5, 8) and a support member (2, 9, 10) on which the blades (5, 8) are arranged, wherein the support member (2, 9, 10) and / or the blades (5, 8) are made of plastic,

characterized in that the carrier part (2, 9, 10) and / or the

Buckets (5, 8) completely or partially with a

Fire protection coating acting intumescent coating (6) are provided.

2. paddle wheel (1, 7) according to claim 1,

characterized in that the intumescent coating (6) comprises a binder matrix and an incorporated intumescent flame retardant and in particular further fillers.

3. paddle wheel (1, 7) according to claim 1 or 2,

characterized in that the carrier part (2, 9, 10) and / or the

Blades (5, 8) are injection-molded parts, and the carrier part (2, 9, 10) and the blades (5, 8) each formed from separate parts or integrally connected to each other.

4. paddle wheel (1, 7) according to one of claims 1 to 3,

characterized in that the carrier part (2, 9, 10) and / or the

Blades (5, 8) made of polypropylene or polyamide, wherein when using polypropylene, a pretreatment of the surface by flourification or plasma activation is present.

5. paddle wheel (1, 7) according to one of claims 1 to 4,

characterized in that the plastic material for the blades (5, 8) and / or for the carrier part (2, 9, 10) has a glass fiber content <50%

(Percent by weight).

6. paddle wheel (1, 7) according to one of claims 1 to 5,

characterized in that the intumescent coating (6) has a layer thickness (d), for which applies: 50 μιη <d <500 pm.

7. paddle wheel (1, 7) according to one of claims 1 to 6,

characterized in that the intumescent coating (6) consists of a lacquer.

8. paddle wheel (1, 7) according to one of claims 1 to 6,

characterized in that the intumescent coating (6) is applied by dipping, by a spraying method or in powdery form.

9. paddle wheel (1, 7) according to one of claims 1 to 8,

characterized in that the binder matrix of the intumescent coating (6) is formed from a polymer of polypropylene, polyurethane, silicone rubber, silicone resin, phenolic resin, melamine resin, epoxy resin, polyvinyl acetate.

10. paddle wheel (1, 7) according to one of claims 1 to 9,

characterized in that the flame retardant a

Phosphoric acid ester or 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

1 1. Blade wheel (1, 7) according to one of claims 1 to 10,

characterized in that the intumescent coating (6)

Polyalcohols, ammonium polyphosphate and / or melamine resins.

12. paddle wheel (1, 7) according to one of claims 1 to 1 1,

characterized in that it, both the support part (2, 9, 10), and the blades (5, 8), meets the fire protection classes V-0 and V5A according to UL94.

13. paddle wheel (1, 7) according to any one of claims 1 to 12,

characterized in that the carrier part (2, 9, 10) via a

Electric motor, in particular an external rotor motor is driven.

14. housing (12) having a housing wall (15, 17, 19, 20) for receiving

a paddle wheel (1, 7), in particular according to one of claims 1 to 13, characterized in that the housing wall (15, 17, 19, 20) completely, d. H. all over, or partially with an intumescent coating (6) as a fire-resistant coating according to the characteristics of

characterizing part of one or more of claims 2, 6 to 12 is formed.