GB2339423A - Water softening - Google Patents

Description

2339423 Water Softening The invention relates to water softening systems,

and particularly to water softening systems using electrical water softening devices.

Limescale causes fin-fing in many household appliances, such as kettles and showerheads. Scale also appears for example in baths, basins and toilets. Shampoos and detergents do not lather as they should and instead produce scum. These are the visual symptoms, but there are many hidden ones. Particular damage is caused to pipes and water heaters by internal limescale encrustation, which often results in a substantial waste of energy. For example, just 3mm of scale can cause up to 25% loss in heating efficiency. Eventually it is necessary to replace items such as pipes and hot water cylinders. However, at the same time, the minerals present in hard water are essential to humans and animals. Studies have shown that high levels of calcium in drinking water can reduce the incidence of heart attacks, compared to the incidence of heart attacks in areas having softer drinking water.

It is known to use electrical and magnetic devices to soften water. One particular known arrangement uses aerials (ie. conducting wires) wrapped around a water pipe and supplied by an alternating electrical supply provided by an electronic watersoftening unit. Such electronic water softening units are controlled by pre-programmed micro- - chips to provide the aerials with electrical signals having a combination of different frequencies and amplitudes. The electromagnetic radiation given off by such aerials interacts with the dissolved salts present in hard water, causing the formation of sub- microscopic clusters.

These clusters act as nucleation seeds for the precipitation of calcium carbonate when the water is heated. Precipitation, in the form of larger crystals, occurs on these seeds in the body of the water and not as a hard deposit of limescale on the inside of the pipes.

Since the presence of nucleation seeds encourages the precipitation of calcium carbonate in the form of crystals in suspension. Limescale encrustation in hot water 2 cylinders, on heating elements and other surfaces in contact with the water is substantially reduced. The crystals will either settle as a soft sludgy deposit, or be carried away with the flowing water. New appliances such as, showers, hot water cylinders and combi-boilers will remain clear. If the appliance is already encrusted, existing deposits will become soft and will either break off or be washed away in the flowing water.

To users, the treated water which contains less dissolved free calcium appears to behave much like chemically softened water. There is reduced encrustation, better lathering and less scum formation in the hot water. At the same time, but unlike chemically softened water where all the minerals are removed, the cold water from the tap can be safely used for drinking. There is no need for a separate "hard water tap" and no health risks whatsoever.

A typical test for hard water is to measure the amount of lather created by soap. The poor lathering of soap associated with hard water is caused by the reaction of the soap's soluble compounds with dissolved free calcium. However, the clusters created by an electronic waterconditioning unit convert more of the dissolved free calcium in the water into crystals in suspension than would otherwise occur. The resulting water, with less dissolved free calcium now behaves as if it were chemically softened. Soap will create more lather despite the fact that the total amount of calcium, dissolved and suspended, remains the same.

Unlike ion exchange softened water, where all the minerals are removed and replaced 25 by sodium, the treated water is safe to drink. There is no need for a separate drinking source, no health risks and no salt effluent.

However, such electronic water-conditioning units do not always operate effectively, and a certain variation has been found in their ability to soften water in practice. It is an object of the invention to provide a method of softening water and a water softening system which improve on the prior art.

3 According to the invention there is provided a method of softening water, comprising the steps of increasing the iron concentration of the water, and then softening the water using an electrical water softening device.

The applicant has discovered that such water softening devices do not operate effectively when the concentration of iron is too low.

The method preferably includes raising the iron concentration of the water to at least about 70ppb (parts per billion) (or 70 micrograms per litre).

If the water forms part of a water supply, the method may further include the step of measuring the rate of flow of the water.

The method preferably includes controlling the rate at which the iron concentration is increased in accordance with the measured rate of flow of the water.

The invention also provides a water softening system for carrying out the above method, the system comprising an electrical water softening device attached to a water supply at a first location, and dosing means attached to said water supply at a second location upstream of said first location for increasing the concentration of iron in the water reaching said water softening device.

If the water softening system is used to soften water in a given house or building, said first and second locations may both lie within said house or building.

The dosing means may be a dosing pump or an electrolytic device.

The water softening device may be an electronic water softening unit provided with at least one aerial for producing electromagnetic radiation within the water supply.

Said water supply may be provided in a pipe, in which case the water softening device and dosing means may be connected or attached to said pipe.

4 The dosing means may be adapted to add a soluble iron salt, such as ferric chloride or ferric sulphate, to said water supply.

The water softening system may further comprise flow rate detection means for measuring the rate of flow of water in said water supply.

The dosing means may be adapted to add iron to said water supply in quantities which vary according to the measured rate of flow.

The invention will now be more particularly described, by way of example only, with reference to the single accompanying Figure, which shows a water softening system in accordance with the invention.

The water softening system 2 shown in the Figure comprises an electronic water softening unit 4 (for example Water King WKI available from the applicant, Lifescience Products Ltd) attached to a water pipe 8. The pipe 8 directs water from a water supply 10 to a water user 12.

The electronic water softening unit 4 is provided with two aerials 14, each of which is coiled around the pipe 8. The aerials 14 are fed by an alternating electrical supply (not shown separately) provided by said electronic water softening unit 4, in order to radiate electromagnetic radiation into the water within the pipe 8, and thus soften the water in known fashion. As an alternative to the electronic water softening unit 4, a magnetic 25 water softening unit can be used.

The dosing pump 6 is located down stream of said electronic water softening unit 4, and feeds one or more soluble iron salts (such as ferric chloride, or ferric sulphate) into the water within the pipe 8.

An electrolytic device (shown schematically as 18) may be provided as an alternative to the dosing pump 6, and may use a sacrificial anode (not shown to increase the iron concentration of the water.

The system 2 also comprises a flow rate detector 16 which measures the rate of flow of the water. This detector feeds signals to the dosing pump 6 so that the rate at which the water is dosed is increased if the flow rate increases.

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Claims (9)

CLAIMS:

1. A method of softening water, comprising the steps of increasing the iron concentration of the water, and then softening the water using an electrical or magnetic 5 water softening device.

2. A method of softening water as claimed in claim 1, which includes raising the iron concentration of the water to at least about 70ppb.

3. A method of softening the water as claimed in any preceding claim, which further includes the step of measuring the rate of flow of the water.

4. A method of softening water as claimed in claim 3, which further includes controlling the rate at which the iron concentration is increased in accordance with the measured rate of flow of the water.

5. A water softening system for carrying out the method any preceding claim, the system comprising an electrical or magnetic water softening device attached to a water supply at a first location, and dosing means attached to said water supply at a second location upstream of said first location for increasing the concentration of iron in the water reaching said water softening device.

6. A water softening system as claimed in claim 5, wherein said first and second locations both lie within the same house or building.

7. A water softening system as claimed in claim 5 or 6, wherein the dosing means is a dosing pump.

8. A water softening system as claimed in claim 5 or 6, wherein the dosing means is an electrolytic device.

7. A water softening system as claimed in claim 5 or 6, wherein the dosing means is a dosing Z' pump-

8. A water softening system as claimed in claim 5 or 6, wherein the dosing means ZP 3 0 is an electrolytic device.

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9. A water softening system as claimed in any one of claims 5 to 8, wherein the water softening device is an electronic water softening unit provided with at least one aerial for producing electromagnetic radiation within the water supply.

10. A water softening system as claimed in any one of claims 5 to 9, wherein said water supply is provided in a pipe, and the water softening device and dosing means are connected or attached to said pipe.

11. A water softening system as claimed in any one of claims 5 to 10, wherein the 10 dosing means is adapted to add a soluble iron salt, such as ferric chloride or ferric sulphate, to said water supply.

12. A water softening system as claimed in any one of claims 5 to 11, which further comprises flow rate detection means for measuring the rate of flow of water in said 15 water supply.

13. A water softening system as claimed in 12, wherein the dosing means is adapted to add iron to said water supply in quantities which vary according to the measured rate of flow.

13 Amendments to the claims have been filed as follows i. A method of softening water, comprising the steps of the iron concentration of the water, and then softening the water using an electrical or magnetic water softening device.

2. A method of softening water as claimed in claim 1, which includes raising the iron concentration of the water to at least about 70ppb.

3. A method of softening the water as claimed in any preceding claim, which further includes the step of measuring the rate of flow of the water.

4. A method of softening water as claimed in claim 3, which further includes controlling the rate at which the iron concentration is increased in accordance with the measured rate of flow of the water, 5. A water softening system for carrying out the method of any preceding claim, the system comprising an electrical or magnetic water softening device attached to a water supply at a first location, and dosing means attached to said water supply at a second location upstream of said first location for increasing the concentration of iron in the water reaching said water softening device.

6. A water softening system as claimed in claim 5, wherein said first and second locations both lie within the same house or building.