GB2139290A - Water purification device - Google Patents

Abstract

A device is provided for raising water of an aquarium from the aquarium to a second site 18 above the level of water in the aquarium. The device comprises a pipe 22 arrangeable to extend from the aquarium water to the second site 18 and means, for example a tube 24, to introduce gas into the pipe at an introduction point below the water level so that the rising gas will tend to carry water up the pipe, the dimensions of the pipe at the introduction point being such that there is a sufficient body of water available at the introduction point to be carried up the pipe to a level higher than the water level in the aquarium. <IMAGE>

Description

SPECIFICATION Water purification device The invention relates to water purification devices, in particular to water purification devices for use with domestic size tanks.

For fish to be able to live in an aquarium the water must be substantially free from waste products and it must also contain dissolved oxygen. If either of these conditions is not met, the health of the fish will suffer. In nature, the water is kept in a good condition by continuous bacterial action and by the cycle of rainfail. Bacterial action breaks down waste products into water-soluble gases and the process of rainfall, i.e. evaporation and condensation of water, discharges these gases and recharges the water with oxygen. The bacteria required for the breaking down of waste products are aerobic. They are present naturally in an aquarium, but one way of improving the bacteria is to have good filtration under a bed of gravel, thus providing the bacteria with oxygen which is dissolved in the water.However, the bacteria cannot work efficientiy since they are continuously under water. The fish and the bacteria are competing for the limited amount of oxygen dissolved in the water.

One method of increasing the bacterial activity is to pump water from the tank to an exterior site open to the atmosphere where aerobic bacteria can work in their preferred environment. However, this has necessitated a relatively expensive water pump which is often too costly for the amateur aquarist and this method is generally reserved for use in large public aquaria. Most aquarists already have an air pump for use with a conventional filter, but these pumps can only lift a small amount of water through a short distance, because of the limited amount of water which can be trapped by the air and pushed through a tube.

It is an object of the invention to provide a device for purifying water which works efficiently, eliminates the need for a water pump, and can be used in domestic size aquarium tanks.

According to one aspect, the invention provides a device for raising water of an aquarium from the aquarium to a second site above the level of water in the aquarium, comprising a pipe arrangeable to extend from the aquarium water to the second site, means to introduce gas into the pipe at an introduction point below the water level so that the rising gas will tend to carry water up the pipe, the dimensions of the pipe at the introduction point being such that there is a sufficient body of water available at the introduction point to be carried up the pipe to a level higher than the water level in the aquarium.

Preferably, the pipe is wider than the rest of the pipe at the introduction point.

The gas may be introduced by a tube passing through the pipe. A gas porous body may be attached to the tube at the introduction point to finely distribute the gas through the water.

According to a second aspect, the invention provides a device for purifying water in an aquarium tank, in which water is passed over material arranged to promote the growth of aerobic bacteria outside the aquarium tank, the material comprising pieces of expended silicate material.

According to another aspect, the invention provides a device for purifying water of an aquarium tank outside the aquarium tank, in which the water to be purified is spread substantially evenly over a purifying medium.

The water to be purified may be spread by means of a tray with perforations therein, the tray being situated above the medium.

The tray may be provided with at least one recessed portion, the perforations being in the or each recessed portion.

Preferably, the water to be purified runs only in the or each recessed portion.

The or each recessed portion may comprise a groove.

Preferably, the recessed portion comprises a main reservoir portion to receive the water to be purified and a plurality of distributing grooves leading from the reservoir portion.

At least part of the device may be transparent to encourage light and algal action.

At least part of the device may be coloured, for example green, so as to deter the growth of algae.

According to a further aspect, the invention provides a device for purifying the water of an aquarium tank outside the tank comprising a chamber containing means to promote the growth of aerobic purifying bacteria, means for delivering water from the tank to the top of the chamber, means to distribute the delivered water over the promotion means in the chamber, means to deliver the water from the base of the chamber back to the tank, the device being such that the rate of entry of water into the chamber is related to the rate at which water leaves the chamber in such a way as to ensure that the promotion means do not become immersed in water. The base of the chamber may contain water collecting means so that any water gathering in the base of the chamber gathers in the collecting means and does not cover the promotion means.The collecting means may comprise one or more grooves in the base of the chamber. The invention includes a device according to the invention in combination with an aquarium.

By wag of example, a specific embodiment of the invention will now be described, with reference to the accompanging drawings, in which: Figure 1 is a perspective view of a water purification device for an aquarium, according to the invention; Figure 2 is a detail cross-section looking in the direction of arrows Il-Il in Figure 1; Figure 3 is a plan view of water purification material and a container for the material, used in the embodiment; Figure 4 is a plan view of a water distribution device used in the embodiment; and Figure 5 is a plan view of the base of the container shown in Figure 3.

Referring firstly to Figure 1, there is illustrated a water purification device for a domestic aquarium tank. The device, in use, rests on opposite walls of the tank by means of a substantially pianar tray 10, comprising a transparent plastics moulding and provided with grooved ribs 1 2 for strength which are produced during moulding. Seated in the grooves of two of the ribs 1 2 are steel strips 14 which lie along the grooves underneath the tray and these provide additional support for the device.

A rectangular hole 16 is provided in the tray to allow the base of a container 18, which will be described later, to be open to the underneath of the tray 10. The container 1 8 is prevented from falling through the hole 16 by means of a shoulder, on which the container 18 is seated, provided around the whole periphery of the hole 16. This shoulder is not visible in Figure 1. The container is provided with a perforated transparent plastics lid 20 which will also be described later.

A transparent plastics tube 22 of about 3/4 inch in diameter projects into the container 1 8 through a hole 23 (see Figure 5) in the base of the container. The top of tube 22 is visible in Figure 1 underneath the lid 20 inside the container 1 8. A second, thinner, flexible piastics tube Z4 is positioned within tube 22 and this passes out of the top of tube 22 and out of the container 1 8 through the lid 20 via a reinforced hole 26. The tube 24 is connected to one end of an elbow 28 of substantially rigid plastics tubing, the other end of the elbow 28 being connected to a further piece 30 of thin tubing, which is in turn attached to an air pump (not shown), as will be explained.

The lower end of tube 22 is covered with a filter 32 in the form of cylindrical sponge material, and this lower end is shown in more detail, in cross-section, in Figure 2. The tube fits into a cylindrical cavity 33 in the sponge.

As can be seen from Figure 2, the diameter of tube 22 increases at its lower end to provide a wider portion 34. Positioned inside the wider portion is a substantially cylindrical piece of air-porous stone 36. A short piece of tubing 38 is glued into position in a hole 40 provided in the stone 36 and this tubing 38 is, in use, forced sealingly into the lower end of tube 24. A plastics collar 42 is positioned around the joint of pipes 24 and 38, and is provided with two resilient plastics arms 44 which press against the inner walls of tube 22 and centralise the stone 36 in the wider portion 34. As can be seen, the tube 22 extends downwards further than the stone 36.

This is because a circular cut is provided round the periphery of the base of cavity 33, but material 46 remains since it is not cut at its base.

Referring now to Figures 1, 3 and 5, the container 18 comprises an open box with a substantially rectangular base 48 and outwardly-sloping walls 50. A shoulder 51 extends around the periphery of the box parallel to the base 48. However, the top of the container is not parallel to the base because of a raised backwall portion 52 and two wedgeshaped side walls 54. Referring to Figure 5, the base 48 of container 1 8 is provided with a plurality of transverse ribs 56. These protrude downwardly from the base and are dished in cross-section. One end of each rib 56 is provided with two small holes 58.

Adjacent ribs are provided with holes at opposite ends, as illustrated in Figure 5. The hole 23 allows the passage of tube Z2 into the container and the tube 22 is a sealing fit in hole 23.

Turning now to Figure 3, with the tube 22 in position, stones 60 are placed in container 1 8 to a depth of about one inch. These stones are of expanded silicate rock and there is a large number of very small air pockets in each stone. The reason for the air pockets will become apparent during the description of the operation of the device.

With the stones 60 in place in the container, a water distribution tray 62 shown in Figure 4 is fitted over the stones. The tray 62 comprises a generally flat rectangular transparent plastics moulding 64. A lip 66 is provided around the periphery of the tray 62.

Shaped in the tray 62 at one corner is a rectangular portion 68 at a lower level than the main level of the moulding 64. Portion 68 is provided with a hole 69 which allows tube 22 to pass sealingly therethrough when the tray 62 is fitted in position. At a slightly higher level than portion 68, but lower than the main level of the moulding 64 is a further shaped portion 70. This mainly comprises six narrow finger-like concave channels 72. Each channel has a plurality of downwardly projecting outlet spouts 74 in its base. The walls of the outlet spouts are frusto-conical in crosssection. Also provided in the main level of the moulding 64 are larger outlet spouts 76.

These too are frusto-conical. In use, the tray 62 rests on shoulder 51 of the container 18 with tube 22 seated sealingly through hole 69.

Turning now to Figure 1, the perforated, transparent, plastics lid 20 sits on top of container 18,seated on the uppermost periphery of the container. The lid is provided with three raised ribs 82, each of which is provided with three spouts 83, similar to the spouts 74 of tray 62 in Figure 4, but extend ing upwardly. As mentioned previously, the lid is also provided with a reinforced hole 26 to allow tube 24 to pass therethrough.

The purification device is assembled by placing tube 22 in position in the hole 23 in container 1 8. The stones 60 are then placed in the container and tray 62 is placed in position on shoulder 51. The lid 20 may then be placed on top of the container and the tube 24 can be fed through tube 22 and hole 26 and then connected to elbow 28. The cylindrical sponge filter 32 is then pushed on to the end of tube 22 and the assembled components are then supported by tray 10 which sits astride an aquarium.

In use, the purification device is arranged so that the sponge filter 32 and part of the tube 22 above the filter 32 are under the water of the aquarium tank. Tube 30 is con nected to a conventional air pump and thus air is forced down the tube 24. Since the tube 24 is connected to the stone 36 and the stone 36 is air-porous, bubbles of air force their way out of the stone 36 and up the pipe 22. The level of water in the tank will only be a few inches below the upper end of pipe 22 and the force of the air moving up the pipe 22 is sufficient to raise the water in the tube 22, up to the top of the tube 22 where the water spills out into the shaped rectangular portion 68 of the tray 62. Because the diameter of the lower portion 34 of tube 22 is increased more water can be drawn up from the aquarium through the filter 32 and pushed up tube 22, as compared with a constant diameter pipe.When the rectangular portion 68 is full, further water spilling over from the tube 22 will now cause water to flow into the slightly higher portion 70 and along the channels 72. The water then falls through outlets 74 on to the stones 60 in the container 1 8 below. The outlets 74 and fingers 72 are arranged so that there will be an even distribution of water over the stones below.

Should the level of water rise above the level of portion 70, the water will not flow uncontrollably over the sides of tray 62. The water will be restricted from flowing over the edge of the tray 62 by means of lip 66 and will eventually flow away on to the stones through the larger spouts 76.

The stones 60 in the container 18 are always exposed to the air, even when temporarily covered in water, because of the numerous air pockets in the porous rock. Aerobic bacteria form naturally on the stones and these bacteria thrive on waste products in the water, products such as fish faeces and urine.

Thus, these unwanted products, which would otherwise remain in the water and harm the fish, are removed by the bacteria and converted into water-soluble gases. As the water is selashed on to the tray 62 and on to the stones 60 umwanted gases such as nitrogen and carbon dioxide which are already dissolved in water are driven off, and the passage of the water through the air and through the stones with numerous air pockets increases the amount of oxygen dissolved in the water. The removal of unwanted gases is important because water can only dissolve a certain amount of gas and if the concentration of unwanted gases is high, the concentration of oxygen will be low, and the fish rely on oxygen dissolved in water to be able to breathe.Thus, after passage over the stones 60, waste products are removed and the water is then clean and oxygenated although the water-soluble gases from the conversion of waste matter are also dissolved in the water.

The water then collects in the dished ribs 56 in the base of the container 1 8 and falls back into the aquarium through the holes 58. The arrangement of the holes on adjacent ribs provides an even distribution of water falling back into the aquarium. The splashing of the water from the container into the water in the aquarium simulates a natural rain shower and further increases the amount of oxygen dissolved in the water and removes the watersoluble gases which originated from the conversion of the waste products.

Since the flow of water through the tray 62 is only slow, the water has time to escape through the holes 58 and hence the stones 60 are never submerged in water, so the stones are open to atmosphere and can work in their favoured environment. The slow movement of water over the stones also gives the bacteria more time to treat the waste products.

The lid 20 is provided as a condensation device. If tropical fish are kept, the water must be warm and so water in the tray 62 would tend to evaporate more quickly. This is undesirable because a significant proportion of the water which had been raised for treatment would simply evaporate were it not for the lid 20, and the concentration of waste products in the water which remained would increase. As can be seen in Figure 1, the lid 20 is angled so that water which has condensed on the lid will be able to flow back into the tray 62.

The invention is not restricted to the details of the foregoing embodiment.

For example, the spongle filter 32 and container 1 8 can be coloured, for example green, to deter the growth of algae. More than one device may be used, depending on the size of aquarium.

Claims (16)

1. A device for raising water of an aquarium from the aquarium to a second site above the level of water in the aquarium, comprising a pipe arrangeable to extend from the aquar ium water to the second site, means to introduce gas into the pipe at an introduction point below the water level so that the rising gas will tend to carry water up the pipe, the dimensions of the pipe at the introduction point being such that there is a sufficient body of water available at the introduction point to be carried up the pipe to a level higher than the water level in the aquarium.

2. A device as claimed in claim 1, in which the pipe is wider then the rest of the pipe at the introduction point.

3. A device as claimed in claim 1 or claim 2, in which the gas is introduced by a tube passing through the pipe.

4. A device as claimed in claim 3, in which a gas porous body is attached to the tube at the introduction point to finely distribute the gas through the water.

5. A device for purifying water in an aquarium tank, comprising a device for passing the water over material arranged to promote the growth of aerobic bacteria outside the aquarium tank, the material comprising pieces of expanded silicate material.

6. A device for purifying water of an aquarium tank outside the aquarium tank, the device comprising means arranged to spread the water to be purified evenly over a purifying medium.

7. A device as claimed in claim 6, in which the spreading means comprises a tray with perforations therein, the tray being situated above the medium.

8. A device as claimed in claim 7, in which the tray is provided with at least one recessed portion, the perforations being in the or each recessed portion.

9. A device as claimed in claim 8, in which the water to be purified runs only in the or each recessed portion.

10. A device as claimed in claim 8 or claim 9, in which the or each recessed portion comprises a groove.

11. A device as claimed in claim 8 or claim 9, in which the recessed portion comprises a main reservoir portion to receive the water to be purified and a plurality of distribution grooves leading from the reservoir portion.

1 2. A device as claimed in any one of claims 6 to 11, in which at least part of the device is transparent to admit light and encourage algal action.

1 3. A device as claimed in any one of claims 6 to 1 2, in which at least part of the device is coloured, for example green, to deter the growth of algae.

14. A device for purifying the water of an aquarium tank outside the tank comprising a chamber containing means to promote the growth of aerobic purifying bacteria, means for delivering water from the tank ts the top of the chamber, means to distribute the delivered water over the promotion means in the chamber, means to deliver the water from the base of the chamber back to the tank, the device being such that the rate of entry of water into the chamber is related to the rate at which water leaves the chamber in such a way as to ensure that the promotion means do not become immersed in water.

1 5. A device as claimed in claim 14, in which the base of the chamber contains water collecting means so that any water gathering in the base of the chamber gathers in the collecting means and does not cover the promotion means.

16. A device as claimed in claim 1 5, in which the collecting means comprise one or more grooves in the base of the chamber.

1 7. A device constructed and arranged substantially as herein described, with reference to the accompanying drawings.

1 8. An aquarium when fitted with a device as claimed in any one of the preceding claims.