Fan

Abstract

A portable fan includes a casing having an air inlet, and an air outlet having an interior passage for receiving an air flow, and a mouth for emitting the air flow, the interior passage extending about an opening through which air is drawn by the air flow emitted from the mouth. The fan includes an impeller and a motor for rotating the impeller to generate an air flow between the air inlet and an air outlet which has a static pressure of at least 150 Pa downstream from the impeller. A filter unit is detachably connected to the casing. A filter of the filter unit is located upstream of the air inlet to remove airborne particulates from the air flow before it enters the casing.

Description

REFERENCE TO RELATED APPLICATIONS[0001]This application claims the priority of United Kingdom Application No. 1004813.0 filed Mar. 23, 2010, the entire contents of which are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to a portable fan. Particularly, but not exclusively, the present invention relates to a floor or table-top fan, such as a desk, tower or pedestal fan.BACKGROUND OF THE INVENTION[0003]A conventional domestic fan typically includes a set of blades or vanes mounted for rotation about an axis, and drive apparatus for rotating the set of blades to generate an air flow. The movement and circulation of the air flow creates a ‘wind chill’ or breeze and, as a result, the user experiences a cooling effect as heat is dissipated through convection and evaporation. The blades are generally located within a cage which allows an air flow to pass through the housing while preventing users from coming into contact with the rotating blades...

AI Technical Summary

Benefits of technology

[0008]The filter unit is preferably in the form of a disposable filter unit which can be replaced when, for example, the fan is assigned to a different patient, when the fan is moved with the patient from an isolation ward to a general ward, or when the filter has reached the end of a prescribed usage period. This can significantly reduce the costs associated with the use of the fan, as the frequency with which the fan may need to be taken off site for cleaning can be significantly reduced. The fan is arranged to generate an air flow with a static pressure of at least 150 Pa, preferably in the range from 250 to 1.5 kPa, so that the air flow is not choked when the filter unit is attached to the casing.

[0010]The filter preferably comprises a high energy particle arrester (HEPA) filter. The filter may also comprise one or more of a foam, carbon, paper, or fabric filter. The filter preferably has a surface area in the range from 0.5 to 1.5 m2 which is exposed to the air flow generated by the fan. To minimize the volume of the filter, the filter is preferably pleated to form a filter which is substantially annular in shape for surrounding the air inlet of the casing. In this case, the filter unit may comprise two annular discs between which the filter is located. These discs can be easily wiped clean during use of the filter unit. Each disc may comprise a raised rim extending towards the other disc for retaining the filter between the discs. The filter may be readily adhered to the discs during the construction of the filter unit. The discs may together be considered to form at least part of a filter unit to which the filter is adhered during construction of the filter unit.

[0011]The filter unit preferably comprises at least one seal for engaging an outer surface of the fan. This can enable the filter unit to form one or more air-tight seals with the fan to ensure that the air flow generated by the fan passes through the filter and not around the filter. Preferably, the filter unit is attachable to the casing so that the filter is located over the air inlet of the fan. In a preferred embodiment the filter unit is in the form of a sleeve which is locatable about an outer surface of a casing. Forming the filter unit in the form of a sleeve can enable the filter unit to be easily pushed or pulled over the casing of the fan as required. The filter unit may comprise a first seal for engaging the casing of the fan, and a second seal for engaging the air outlet of the fan so that an air flow is drawn through the filter unit between the seals and through the filter. The casing may be in the form of a base, which may be free-standing on a floor, desk, table or other surface.

[0012]The filter unit may comprise an outer cover comprising a plurality of apertures through which air enters the filter unit. This outer cover can provide a first, relatively coarse filter of the filter unit to prevent airborne objects such as insects or large particles of dust from coming into contact with the filter, and can prevent the filter from being contacted by a user, particularly during the attachment of the filter unit to the fan, and so prevent damage to the filter. The outer cover is preferably transparent to allow a user to see the amount of dust or debris which has been captured by the filter.

[0015]The casing may have a first connector, and the air outlet may have a second connector. The filter unit may include a third connector, which is substantially the same as the second connector, for co-operating with the first connector to removably connect the filter unit to the casing, and a fourth connector, which is substantially the same as the first connector, for co-operating with the second connector to removably connect the air outlet to the filter unit. This can allow the air outlet to be connected either directly to the casing, or for the filter unit to be connected between the casing and the air outlet. The type of connection made between the filter unit and the casing, and between the air outlet and the filter unit, is the same as the type of connection which is made between the air outlet and the casing in the absence of the filter unit. This facilitates the connection of the filter unit to the casing and the air outlet, as the technique for connecting the air outlet to the casing is the same as that for connecting the filter unit to the base, and for connecting the air outlet to the filter unit.

Problems solved by technology

The cleaning of bladed fans can be time consuming for the employee, as the cage housing the blades of the fan needs to be disassembled before the blades of the fan can be cleaned.

This disassembly usually requires the use of a screw driver, which cannot be carried by a nurse on a hospital ward.

Often, it can be more convenient for the hospital to engage a specialist cleaning company to clean the fan off site, although this can be very expensive.

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