The present invention refers to a laundry dryer having a fire protection system.
A laundry dryer, in particular a condenser-type laundry dryer, is generally provided with a heat exchanger where moisture is removed from a drying air flow leaving a laundry treating chamber and it is further provided with heating elements, such as an electric resistance for heating up said drying air. It is also known that drying air passed through laundry is enriched of fluff material that needs to be filtered so as to limit its deposition on operational devices encountered by the drying air flow after having exited a laundry treatment chamber and before being reintroduced into said chamber.
Generally, user accessible air filtering means are provided just in the first portion of a drying air circuit having its air inlet opening placed in the laundry treating chamber. Such arrangement is disclosed in
It has been found that fluff contacting an active electric resistance as heating unit may be burnt almost instantaneously thereby causing not only production of incandescent fragments but also of flames having a temperature that may fuse at least partially the air conduit inner surface and its gaskets which, normally, are both made of polymeric material. This problem arises particularly on bent portions of the drying air conduit that are normally formed in a region adjacent to electric resistance. An arrangement provided for preventing an object exiting the laundry treating chamber in counter-flow relative to the drying flow from reaching the heating elements is disclosed in
The aim of the present invention is therefore to solve the noted drawbacks and thus providing a laundry dryer in which the risk of fusion or fire damages to the inner surface of a drying circuit are avoided.
An object of the present invention is to provide a laundry dryer having an improved fire protection system that does not cause further losses in drying air flow.
A further object of the invention is to provide a laundry dryer having an improved fire protection system that may be inspected and promptly removed from laundry dryer structure.
Another object of the invention is to provide a laundry dryer wherein the fire protection system provided therein is suitable to collect any possible incandescent fluff that me be ignited, even when drying air is flowing through the drying air conduit.
Still another object of the present invention is to provide a laundry dryer wherein the fire protection system provided therein cannot be ignited.
Advantages, objects, and features of the invention will be set forth in part in the description and drawings which follow and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be reached and attained as particularly pointed out in the appended claims.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate possible embodiments of the invention and together with the description serve to explain the principles of the invention. Like reference numbers represents like features throughout the accompanying drawings, wherein
With reference to the attached Figures, a laundry dryer according to the invention comprises a drying air circuit 1 in which drying air is circulated so as to be passed through a laundry treating chamber 2 formed by a rotating drum 3. Drying air is moved along the drying air circuit 1 by means of a fan (not shown) and it is introduced into laundry treating chamber 2 from a rear bulkhead 4 having a perforated wall 5 and being arranged on a supporting wall 17, which, preferably, is the rear wall of the cabinet of the laundry dryer. Drying air exits laundry treating chamber 2 from a front passage 6 provided in proximity of a main opening 7 that allows laundry to be loaded within chamber 2. Air exiting the laundry treating chamber 2 passes through a drying air moisture condensing unit 8 consisting, for example, in a air-air heat exchanger accommodated in a seat 11 formed in a basement 12, that is preferably made of polymeric material. Such unit 8 removes moisture from drying air through a condensation process. Downstream of condensing unit 8 a drying air heating device 9, for example one or more electric resistance, heats up drying air exiting condensing unit 8 before reintroducing air within laundry treating chamber 2.
Drying air circuit 1 comprises a conduit portion 10 placed upstream said drying air heating device 9 relative to the drying air flow illustrated by arrows "A" in
Conduit portion 10 is provided with a fire protection system 15 having a shield region 16 that is suitable for preventing particles, such as fluff material removed from laundry by drying air, that may be ignited by the high temperature existing around the heating device 9 from reaching/contacting/touching the conduit portion 10 itself causing fusion thereof and/or a possible source of fire. Considering the drying air flow direction shown in
Fire protection system 15 is inserted in a seat 18 formed on the upper portion 13 of basement 12 and extends downwards into the lower portion 14 of said basement 12. A manifold 19 associates drying air heating means 9 with the upper portion 13 of basement 12 in correspondence of seat 18. Preferably, the manifold 19 comprises a rear cabinet cover 21 and the back side 22 of the supporting wall 17 so as to form a conduit for conveying drying air from the basement 12 to the heating device 9. Preferably, sealing means are provided between the rear cabinet cover 21 and back side 22 of the supporting wall 17 for preventing drying air leakages. Preferably, the rear cabinet cover 21 and the supporting wall 17 rest on the basement 12 and particularly on a section of the seat 18 of the upper portion 13 of basement 12. A gasket 32 is arranged/pinched between the seat 18 on one side and the rear cabinet cover 21 and the supporting wall 17 on the other side for making the manifold 19 air-tight. In order to prevent ignited particles to reach the gasket and to avoid such particles to escape shield region 16, the fire protection system 15 comprises a coupling surface 20 that interposes between manifold 19 and the upper portion 13 of basement 12 by resting on seat 18. As it can be seen in
The air permeable wall 25 is made by forming a plurality of apertures 28A, 28B, 28C, 28D on wall 25. A solid wall 27 is provided opposite to the air permeable wall 25 and spaced apart from the latter. Drying air passing through the air permeable wall 25 hits on solid wall 27 and goes up to the heating device 9. Air permeable wall 25 slopes downwardly towards the solid wall 27 such that ignited particles descending from the heating device 9 and being pushed by the drying air flow passing through the air permeable wall 25, may be collected within the bottom wall 30 of basket-like body 23.
A couple of eyelets 29A, 29B are provided on the air permeable wall 25 side for joining body 23 to back side 22 of supporting wall 17 by means of threaded fastening device, rivets or the like. In this way, basket-like body 23 is kept stable under the effect of the drying air flow.
Alternatively the body 23 can be snap fitted to the seat 18.
In order to avoid any risk of fire, the fire protection system 15 is made by a fireproof material. Fluff that may be ignited by the heating device 9 and falling towards the basket-like body 23 of fire protection system 15 does not cause fusion of the bottom wall 30 thereof.
It should be noted that drying air circuit 1 has an opening 31 formed on the upper portion 13 of basement 12 in correspondence of seat 11 for drying air moisture condensing unit 8. Such opening 31 serves to let a drying air portion to exit circuit 1 and flowing inside the machine cabinet for ventilating the interior space thereof. In this way condensation of vapor onto electronic components like a user interface may be avoided.
As it can be inferred from the description above, a laundry dryer has been provided with a fire protection system that is capable to collect any possible incandescent fluff that me be ignited by contacting an active electric resistance heating up drying air. Said fire protection system avoid ignited fluff from dispersing along the drying air circuit thereby preventing any possible risk of conduit damages and fire promotion. Advantageously, the fire preventing system is efficient even when drying air is flowing within the drying air conduit, i.e. when incandescent fluff may be agitated randomly in any direction by the action of drying air flow. According to the invention a fire protection system is designed so as not to cause further losses in drying air flow and is made in a fireproof material. The same fire protection system may be promptly removed by laundry dryer structure for inspection
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.