Field of the invention

The present invention relates to a water treatment system that can be easily built and maintained and that can be deployed in developing countries.

Background of the invention

Obtaining clean water in developing countries may be a difficult task. Getting water clean enough such that people can drink it is often an even greater challenge. Nowadays, many people in developing countries still have to rely on water directly taken from a river or a well which they then consume without any further filtering and/or treatment.

Sometimes such water can be filtered, treated and cleaned before it is used by end- consumers. After such treatment, filtering and cleaning it can be pumped into a bucket or container for further transport.

US2008/0217244 shows a water treatment system including a flow path for water to be cleaned via a settling tank 1 which has an output to deliver cleaned water to a filtration unit 2. This document shows a bypass of the settling tank 1 for received water to the filtration unit 2 as controlled by a valve in the bypass itself. However, that valve is not explained any further in the specification. It is not operated in dependence on how dirty water received from a water source is.

Summary of the invention

Developing an easy and cost-effective system that can be used at many sites to provide treated / purified water to local people in developing countries is not straight forward. The object of the present invention is to provide such a system, especially a system that can cope with dirty water as received from a water source.

Brief description of the drawings

The invention will be explained in detail with reference to some drawings that are only intended to show embodiments of the invention and not to limit the scope. The scope of the invention is defined in the annexed claims and by its technical equivalents. I.e., a person skilled in the art will understand that features, components, elements, etc. explicitly used to explain the invention can be substituted by technical equivalents unless otherwise stated. Moreover, separate features of different embodiments can be combined, even if not explicitly shown in the drawings or explained in the specification, unless such combination is physically impossible.

The drawings show:

Figure 1 provides a schematic overview of a water treatment system.

Figure 2 shows a portion of the water treatment system where treated water can be supplied to customers. Detailed description of embodiments

The system according to the invention is arranged to provide purified or filtered water, preferably to a potable level. This water is, here, also referred to as "treated" water.

The system 1 of figure 1 may comprise the following elements / components.

A water pipeline 7 is provided that is long enough to reach a natural water source 3 in the ground. Such a natural water source 3 may be located at rather deep levels, e.g. as deep as 600 meters or even more, which is not easily accessible to ordinary people. While one end of the water pipeline 7 is located deep enough in the ground to allow pumping up of water through the water pipeline 7, the other end of the water pipeline 7 is connected to a water pump 5. The water pump 5 may be a hydraulic pump.

A water pipeline 9 has one end connected to the same water pump 5 and another end connected to a valve 13 in a distribution center 11. A power generator 10 is arranged within the distribution center 11. The power generator 10 is connected to the valve 13 to provide the valve 13 with power, e.g. electrical power, in order to operate the valve 13. Alternatively, the valve 13 may be manually operated. The power generator 10 may also be connected to the water pump 5 to supply power, e.g. electrical power, to the water pump 5 such that it can pump up water from the water source 3. Of course, alternatively, the water pump 5 can have its own separate power generator (not shown in figure 1) for that purpose. The power generator 10 is driven by a suitable engine (not shown in figure 1) fueled with a suitable fuel like petrol, gas, diesel, LPG, LNG, solar energy, wind energy, etc.

The power generator 10 and engine may be connected via a suitable cable 59 to a processor 53. This processor 53 may be located anywhere in the system. A water level sensor 63 may be provided and arranged to detect the water level in water source 3. The water level sensor 63 may be connected to the processor 53 via a suitable cable 57 to transmit its water level measurements to the processor 53.

The valve 13 is also connected to a water pipeline 17 which, at its other end, is connected to a water reservoir 19 with sedimentation facilities. The water reservoir 19 is also connected to an end of a water pipeline 23 and an end of a water pipeline 25. The water pipeline 23 has another end connected to a water reservoir 21. Also the water pipeline 25 has another end connected to the water reservoir 21. Also this water reservoir 21 has sedimentation facilities.

The water reservoir 19 is, preferably, provided with a water level gauge 48, and the water reservoir 21, preferably, with a water level gauge 46. Both water levels 46, 48 are connected to processor 53. The connections to the water level gauges 46, 48 are not explicitly shown. The processor 53 is shown to have a several open connections 55 which are, in reality, connected to several units in the water treatment system which are controlled by the processor 53, among which are the water level gauges 46, 48 (see also hereinafter).

The water reservoir 19 may have a capacity of between 50 and 2,500 m ³ . The water reservoir 21 may have a smaller volume, e.g., a maximum of 1,500 m ³ .

A sludge output unit 20 is provided between the water reservoir 19 and a sludge tank 40. Moreover, a sludge output unit 22 is provided between the water reservoir 21 and the sludge tank 40.

The water reservoir 19 and/or water reservoir 21 may be connected by one or more suitable water pipelines to a water tower (not shown). In such a case there will also be a pump arranged to pump the water into the water tower as controlled by processor 53.

A water pipeline 15 is provided having one end connected to the valve 13 in the distribution center 11 and having a second end connected to a filtration unit 27. Also the water reservoir 21 is connected to the filtration unit 27 by a water pipeline 31. A water pipeline 29 has a first end connected to the filtration unit 27 and a second end connected to a treated water reservoir 37.

The treated water reservoir 37 is, preferably, located below the ground since that helps to keep treated water as contained in the treated water reservoir 37 within a desired temperature range of, 0-25°C, e.g., 10-20°C.

The treated water reservoir 37 is provided with a water level gauge 65 which is connected to processor 53 via one of the connections 55. At least one water pipeline 33 is provided between the water reservoir 21 and the treated water reservoir 37. Instead of one water pipeline 33 there may be provided one or more further water pipelines 35 between the water reservoir 21 and the treated water reservoir 37. A sludge output unit 39 is provided having one end connected to the treated water reservoir 37 and another end connected to the sludge tank 40.

All water pipelines are shown in the drawings as having the form of a cylindrical pipe. However, any other suitable form may be used instead. They may also be formed from several sub-units. Therefore, also the term "water connection" may be used instead.

At least one water tank station 41 is connected to the treated water reservoir 37 via one or more treated water output units 45, where customers can buy treated water. Preferably such water tank stations 41 are provided with a card reader unit 43 arranged to read at least one of a debit card and credit card from a customer. Alternatively, or in addition, the card reader 43 can be arranged to read an electronic purse on a chip card and to debit an amount of money from such an electronic purse in accordance with an amount of treated water supplied by the water tank station 41 to the customer.

In addition to or instead of supplying treated water to the water tank stations 41, treated water may be directly delivered to homes 51 via suitable water pipelines 49 connected to the treated water reservoir 37.

The water tank station 41 may have the form as shown in figure 2. Figure 2 shows the water tank station 41 as having several pillars including one or more of the card reader units 43, as well as water outputs 47. The water outputs 47 are shown as water pipelines having an end at a predetermined height above the ground, e.g. as high that a lorry with a tank can drive under the end such that water can be delivered into the tank of the lorry. Of course, alternatively or in addition to that, such water pipelines 47 may end at a much lower height such that customers can easily fill hand carried water tanks, a bucket or the like. Such water pipelines 47 may be provided with a handle at their end that can be manually operated to open / close the water pipelines 47.

Also, such water supplying units like the water pipelines 47 can be replaced or be provided in addition to flexible water hoses with a handle to open / close the water hose.

The card readers 43 are connected via one or more suitable telecom networks in any known way to bank processors who are arranged to perform desired financial transactions.

The water tank stations 41 and homes 51 may be located as far as 15 km away from the treated water reservoir 37. Preferably, all water pipelines have a valve at at least one of their ends, which are connected to one of the connections 55 of the processor 53 such that they can be controlled by processor 53. Also, the water reservoirs 19, 21 and the treated water reservoir 37 are provided with suitable water pumps connected to the processor 53 via these connections 55, such that the processor can control inflow and outflow of water to them via the respective water pipelines explained above.

The water treatment system as shown in figures 1 and 2 may either operate automatically or manual where the manual operation forms an override. Automatic Operation

In the automatic operation , the water pump 5 pumps up water from the water source 3 and supplies this water to the distribution center 11 as controlled by processor 53, e.g., in dependence on the water level measurements received from the water level meter 63 arranged to detect whether or not there is any water in the water source 3. If there is no water, the processor will control the water pump 5 to be switched off.

Manual override

The water pump 5 pumps up water from the water source 3 and supplies this water to the distribution center 11. Operation of the water pump 5 may be manually controlled by an operator who operates a button arranged to switch on/off the power generator 13.

When the treated water reservoir 37 is not yet full, as sensed via water level gauge 65, the valve 13 is preferably switched by processor 53 in a position such that water flowing into the distribution center 11 from the water pump 5 is flowing through the water pipeline 15 to the filtration unit 27. The filtration unit 27 is arranged to filter the received water to a predetermined filtered level, preferably such that it is potable by human beings. This water is called "treated water" or "purified water". The treated water is output from the filtration unit 27 through the water pipeline 29 to the treated water reservoir 37 for storage. The filtration process as used by the filtration unit 27 may be any suitable known filtration process to purify water, preferably to a potable level. However, a preferred method may be sand filtration, finer bags filtration and/ or using a twin filter. Geographical, physical and economic considerations determine which method is the most suitable one.

From the treated water reservoir 37, the water is output to at least one of the water tank stations 41 and homes 51. The longer the treated water is stored in the treated water reservoir 37, the more residual, non-filtered sediments will deposit on the bottom of the treated water reservoir 37. These residual sediments will be collected, e.g., by suitable scrapers and output to the sludge tank 40 via sludge output unit 39. This later process may be controlled by processor 53.

When the treated water reservoir 37 is full, as sensed via water level gauge 65, or when water received from the water source 3 is very dirty, or at other moments as for instance determined by an operator, the valve 13 is operated to switch in a position to let water received from the water pump 5 flow towards water reservoir 19 via water pipeline 17. The term "or" is to be understood here, as meaning that the valve can be operated to switch in that position either when the treated water reservoir is full or when the received water is very dirty, or in both situations. Moreover, the term "very dirty" means that the purity of the water as received from the water source 3 is below a predetermined purity level. The higher the purity level, the cleaner the water is. Such a purity level can be measured by a purity level sensor 67 arranged upstream from the valve 13, so in water pipeline 7 or 9, i.e. either upstream or downstream from water pump 5. Such a purity level sensor 67 will be connected to the processor 53 which is arranged to control the valve 13 accordingly in dependence on the output signal of the purity level sensor 67 and as compared to the predetermined purity level. In this way, very dirty water is led first to water reservoir 19 (or smaller water reservoir 21) to undergo the additional cleaning step of sedimentation.

The water reservoir 19 is a huge storage for received water. Water can stay there for a long time, such that a sedimentation process takes place and sediment will be formed on the bottom. This sediment will be collected, e.g., by suitable scrapers and output to the sludge tank 40 via sludge output unit 20.

However, before filling the water reservoir 19, the system may be arranged to first fill the second, smaller water reservoir 21, and only fill the water reservoir 19 after the water reservoir 21 is completely filled. Water may be flowing from water reservoir 19 to water reservoir 21 via water pipeline 25 whereas water pipeline 23 may be arranged such that water can flow in both directions between water reservoir 19 and water reservoir 21, as controlled by processor 53. Back and forth flow of water between water reservoirs 19 and 21 is provided because of safety reasons and/or contamination reasons. I.e., the quantity and capacity of back and forth water flow between water reservoirs 19, 21 is regulated to obtain a smooth flow of settling particles under reservoirs 19 and 21 to be removed to sludge tank 40. Moreover, in this way an efficient and effective water flow can be ensured while either reservoir 19 or 21 is out of service and should, for instance, be empty for cleaning purposes.

If treated water reservoir 37 is not full enough anymore and can receive new water, as e.g. sensed by water level gauge 65 in the treated water reservoir 37, a suitable valve (not shown) in water reservoir 21 may be opened as controlled by processor 53 to let water flow from water reservoir 21 to filtration unit 27 via water pipeline 31.

The one or more water pipelines 33, 35 may be arranged to let unfiltered water flow in either direction between water reservoir 21 and treated water reservoir 37. This back and forth option is because of the same reasons as between water reservoirs 19, 21.

Treated water in the reservoir 37 may flow back through at least one of the water pipelines 33 and 35 to reservoir 21 for re-filtration in a situation when the treated water is still too contaminated or in any other desired situation.

As an alternative, water reservoir 19 is not provided and water pipeline 17 is directly connected to water reservoir 21.

The above explained process may be manually controlled. However, it envisaged that it is controlled by processor 53, programmed with a suitable computer program containing instructions and data arranged to let the processor 53 perform the desired functions.

The processor 53 is preferably arranged to receive a water level measurement value from at least one of the water gauges 46, 48 and control flow of water between the water reservoir 21 and the further water reservoir 19 based on the water level measurement value. This may e.g. be done such that the water level in water reservoir 21 is kept at a desired level while still allowing water to circulate in the system and keep it fresher in this way. Moreover, if both water reservoir 21 and water reservoir 19 are entirely full, the processor 53 may shut down water pump 5.

The processor 53 may also be arranged to receive a treated water level measurement value from the water gauge 65 and control flow of water between water reservoir 21 and the treated water reservoir 19 based on the treated water level measurement value. The processor 53 may be physically located in e.g. the distribution center 11 or the filtration unit 27. A distributed processor system may be used instead.

It is to be understood that the invention is limited by the annexed claims and its technical equivalents only. In this document and in its claims, the verb "to comprise" and its conjugations are used in their non-limiting sense to mean that items following the word are included, without excluding items not specifically mentioned. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".