Water purification device

Abstract

A water purification device includes an expandable water collecting device having a variable volume, wherein at least part of the surface of the water collecting device includes a filter area, the filter area being permeable to water and allowing water to enter the water collecting device when the filter area is submerged in water. The device further includes a mechanically driven expansion means for exerting a force for increasing the volume of the water collecting device and thereby drawing water through the filter area into the water collecting device. In use, the water collecting device is submerged and the expansion means is released, drawing water into the water collecting device through the filter membrane.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates to the field of water purification devices, and in particular to a low-cost, small scale purification device as described in the preamble of claim 1.[0003]2. Description of Related Art[0004]Access to clean water is an essential human necessity. In developing countries, in emergency situations, and simply for outdoor activities, there is a need for simple, lightweight, and cheap water purification devices. Numerous filtering devices, e.g. using ceramic filters, multiple water collecting devices with intervening filters etc. are known.[0005]U.S. Pat. No. 4,879,030 describes a water purification and emergency nutrition package. The package comprises a compartment having a semipermeable membrane which allows it to desalinate water, and a compartment comprising a mixture of water-soluble nutrients such as fructose. Once a minimum amount of water has entered the package, osmotic pressure caused by the wa...

AI Technical Summary

Benefits of technology

[0009]For use, the water collecting device is first compressed, that is, brought into a reduced volume or, ideally, a minimum volume configuration. This is done e.g. by flattening the water collecting device, counteracting the force of the expansion means. While flattening the water collecting device, a clean water outlet should be opened, allowing air trapped in the water collecting device to escape. For practical reasons, the water collecting device will preferably also be delivered and stored in a reduced volume configuration. The water collecting device is then submerged in water that requires filtering before consumption, i.e. in a well or a river or the like. The water collecting device may also be left to rest on the water, with the filter area being at least partially submerged, i.e. in contact with the water. The expansion means is then released, allowing the water collecting device to expand, whereby water enters the water collecting device through the filter membrane. When a predetermined amount of filtered water has accumulated inside the water collecting device, the water collecting device is removed from the water, and the filtered water is drained from the water collecting device through an outlet. The water collecting device is extremely simple to use.

[0015]In a preferred embodiment of the invention, a substantial part of the entire surface of the water collecting device is made of a material serving as the filter. In other preferred embodiments, at least a quarter or at least half the surface area of the water collecting device is made of said filtering material. The filter is permeable to water but impermeable to a group of water contaminants, reducing the concentration of contaminants in the filtered water. The filter may be a simple mechanical filter, inhibiting passage of particles exceeding a predetermined size, but may also be chemically treated or coated or comprise multiple layers implementing different water treatment functions and mechanical functions. The filter pore size is preferably smaller than one micrometer, and in particular smaller than 0.5 or 0.1 micrometers or less, for filtering out bacteria and preferably also viruses. The filter, and the water collecting device as a whole, are preferably made of a biodegradable material. Preferably, the filter material is treated to make it hydrophilic. As a result, the minimum pressure, at which the water flow through the filter is triggered, is decreased.

[0017]In further embodiments of the invention, the layer or layers may be treated by welding them along welding lines or in a plurality of welding points. This serves to reinforce, join, and / or to stiffen the layers.

[0020]In the reduced volume state, the water collecting device is well suited for efficient storage and transport. Thus, the water collecting device will preferably be produced to be stored in a reduced volume state, e.g. pre-folded, with the faces of the water collecting device being folded inwards or outwards.

Problems solved by technology

Applicability of the device is limited in that it can be used only once, in that it does not provide water alone, but rather a mixture of water and sugars, i.e. nourishment, and in that it is focused on the desalination of sea water.

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