GB2270846A - Water processing unit - Google Patents

Abstract

A water processing unit particularly for use with a dentist's drill, has first and second treatment units (20, 21) connected in series to treat pressurised mains water supplied to the drill, which is driven by pressurised air, such air being alternatively utilised to actuate a pump (25) to draw disinfectant to the drill instead of said treated water for periodic flushing. The first treatment unit (20) contains a filter (34) for removing toxins in the water supply, the filter being received in a ceramic filter element (33) for preventing passage of solid material. The second treatment unit (21) includes an ion exchange resin body (42) which disinfects the water to kill any viruses and/or bacteria. <IMAGE>

Description

WATER PROCESSING UNIT This invention relates to a water processing unit through which water under pressure can be supplied to for example, a dental drill.

The purpose of the water is to provide for cooling of the drill and the tooth being drilled and also to provide for the flushing from the working zone of debris which has been removed from the tooth. It is essential that the water which is supplied to the drill or indeed to a mouth washing jet, should be free from suspended matter in order to avoid blockage, and also sterile in order to avoid infection of the patient. In this respect it is known to supply such equipment from a sterile water source. This known technique does not however overcome the problem that the water in the various flow passages within the drill may become contaminated by the blood or other fluids of a patient.

It is the object of the present invention to provide a water processing unit for the purpose specified, in a simple and convenient form.

According to the invention a water processing unit comprises treatment means, the treatment means comprising filtration means and means for introducing a disinfectant into the water, in use, the treatment means receiving water from a pressurised source, in use, which is passed through said filtration means whereby solid material is filtered from the water prior to its supply to said means for introducing a disinfectant into the water.

An example of a water processing unit in accordance with the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a fluid circuit diagram of the processing unit, and Figures 2 and 3 are sectional views of first and second treatment units which are shown in outline in Figure 1.

Referring to Figure 1 of the drawings the water processing unit includes outlets 10, 11 for connection to the air inlet and water inlet of a dental unit incorporating one or more drills. The processing unit also includes inlets 12, 13 for connection to a source of air under pressure and a source of water under pressure respectively. The air provides the motive power for driving the drill and the water provides for cooling of one or more drills and the tooth being drilled, together with the flushing away of debris removed by the drill.

Upstream of the outlets 10, 11 are non-return valves 14, 15 respectively which act to prevent air or water being forced back into the processing unit from the outlets and downstream of the inlets 12, 13 are non-return valves 16, 17 respectively which act to prevent air or water being forced from the processing unit into the air and water supplies respectively. Considering now the water circuit, there is provided downstream of the non-return valve 17, a pressure regulator 18 the outlet of which is connected to an ON/OFF valve 19. The outlet of the valve 19 is connected to the inlet of a first treatment unit 20 and the outlet of the first treatment unit is connected to the inlet of a second treatment unit 21, so that the units 20 and 21 are connected in series. The outlet of unit 21 is connected to a point upstream of the nonreturn valve 15 by way of a non-return valve 22.

Associated with the air circuit and located downstream of the non-return valve 16 is a pressure regulator 23 the outlet of which is connected to the inlet of a selector valve 24. One outlet of the selector valve is connected to of the non-return valve 14, so that the selector valve is upstream thereof, while the other outlet of the selector valve is connected to the air inlet of a venturi pump 25, the outlet of which is connected through a non-return valve 26 to a passage 27 which is connected to the upstream side of the non-return valve 15. The other inlet of the venturi pump is connected to a storage vessel 28 from which disinfecting and/or chemical stabilising (neutralising) solution can be drawn when the valve 24 is set to permit air to flow through the venturi pump.

The first treatment unit 20 is shown in greater detail in Figure 2 and it comprises an upper mounting 29 in which is formed an inlet 30 and a central outlet 31.

Secured to the mounting is a detachable housing 32 and also secured to the mounting and extending within the housing is a filter element 33 which conveniently is formed from ceramic material. The inlet 30 communicates with the space defined between the filter element and the housing 32. Although ceramic material is the preferred material for the element 33, other materials may be used which will permit flow of water, but which will retain solid contaminant smaller than 1 micron. Within the filter element is located an activated carbon filter 34 through which passes all the water which flows to the outlet 31. The activated carbon filter acts to remove any toxins in the water and whilst activated carbon is the preferred material, any other material may be used which is capable of removing the toxins.

The second treatment unit 21 is shown in greater detail in Figure 3 and this also comprises an upper mounting 35 and a detachable housing 36. The mounting defines a central flow opening 37 and a further opening 38. Figure 1 shows the outlet from the treatment unit 20 connected to the opening 37 but this is optional since the water flow through the second treatment unit can take place in either direction. Indeed flow in the opposite direction is more preferable. The mounting 35 carries a central tube 39 within which defines a space 40.

The treatment unit 21 includes an ion exchange resin body 42 which is of annular form and is located between a pair of spaced apertured end plates 41. The resin is bounded on its external peripheral surface by means of an annular member 43 which is provided with seals to form a seal with the housing 36. The water which enters the unit must therefore flow through the ion exchange resin body 42. Although as shown the ion exchange resin body is mounted outside the tube 39 it may be located in the space 40 or additional resin may be located in the space 40 depending upon the water consumption. As shown, carbon 34 is provided in space 40, in this embodiment.

In use, the valve 24 is set so that air is delivered by way of the non-return valve 14 to the outlet 10 and the valve 19 is set in the open position so that water is delivered to the outlet 11. The water as it passes through the first treatment unit is filtered by the action of the filter element 33 and the retained debris collects in the base of the housing 32. In addition the activated carbon filter removes toxins which may be present in the water. As the filtered water passes through the second treatment unit and in particular through the ion exchange resin body, a disinfectant, in this example, iodine, is dissolved in the water from the ion exchange resin. Passage of the water through this second treatment unit kills any bacteria which may have passed through the first treatment together with any viruses, such as AIDS, which are present.Flow in the direction from the opening 38 to opening 37 is preferred to produce the proper concentration of disolved iodine, so that there is proper functioning of the disinfectant.

In the use of the drill it is possible for fluids from the patient to enter into the various passages within the drill. However, since the water which is supplied to the drill contains iodine any dangerous viruses which may be contained within the fluids will be killed and the possible spread of infection minimised.

It is desirable to be able to flush the pipes through which water is supplied to the drill and the various passages within the drill, periodically to disinfect the piping/tubing or manifold blocks of the units, and/or replace the water by a chemically inert liquid. Such a liquid would be held in the storage vessel 28 and when flushing is required the valve 19 is moved to the closed position and the valve 24 moved to its alternative position in which air is supplied through the venturi pump 25. The pump acts to draw the liquid from the vessel and this flows into the passage 27 by way of the non-return valve 26. From the passage 27 the liquid flows past the non-return valve 15 to the outlet 11 and into the various passages of the drill.During the flushing operation the non-return valve 22 is closed so that there is no flow of the liquid towards the treatment units and furthermore, when water is being supplied to the drill the non-return valve 26 is closed to ensure that no water flows to the venturi pump.

It will be understood that the various pipes and valves are constructed from materials compatible with the fluids which they convey. This also applies to the mountings and housings of the treatment units. The housings of the treatment units are readily separable from the mountings to admit of changing the filters and the ion exchange resin body 42.

A suitable ion exchange resin can be obtained from Cataract Systems BV of Amsterdam Holland. The valves 19 and 24 may be operated manually or they can be controlled by a suitable timing device which will ensure that the flushing process takes place for an adequate length of time to achieve its purpose.

Claims (20)

1. A water processing unit comprising treatment means, the treatment means comprising filtration means and means for introducing a disinfectant into the water, in use, the treatment means receiving water from a pressurised source, in use, which is passed through said filtration means whereby solid material is filtered from the water prior to its supply to said means for introducing a disinfectant into the water.

2. A water processing unit as claimed in Claim 1, in which the treatment means comprises first and second treatment units connected in series, the first treatment unit receiving water, in use, from said pressurised source, and containing said filtration means, and the second treatment unit containing said means for introducing a disinfectant into the water.

3. A unit as claimed in Claim 2, wherein the filtration means is a filter element in a flow path of the water from an inlet to an outlet of the first treatment unit.

4. A unit as claimed in Claim 3, wherein within the filter element is a filter for removing toxins from the water flowing through the first treatment unit, in use.

5. A unit as claimed in Claim 4, wherein the filter is in the form of activated carbon.

6. A unit as claimed in any one of Claims 2 to 5, wherein the means for introducing a disinfectant into the water is disposed in a flow path of the water from an inlet to an outlet of the second treatment unit.

7. A unit as claimed in Claim 6, wherein the,means for introducing a disinfectant is ion exchange resin.

8. A unit as claimed in Claim 7, wherein the ion exchange resin is in a body of annular form sealingly disposed between a housing of the second treatment unit and a central flow tube.

9. A unit as claimed in Claim 7, wherein the ion exchange resin is received in a central flow tube of a housing of said second treatment unit.

10. A unit as claimed in Claim 9, wherein the ion exchange resin is also received around the central flow tube, being in the form of an annular body sealingly engaged with the housing.

11. A unit as claimed in any one of the preceding claims, wherein a line for supplying pressurised water through said treatment means to an outlet for connection to the water inlet of an appliance contains valve means for stopping said supply.

12. A unit as claimed in Claim 11, wherein a timing device is associated with said valve means.

13. A unit as claimed in Claim 11 or Claim 12, including a first line normally for supplying air from a pressurised source to an outlet for connection to the air inlet of said appliance.

14. A unit as claimed in Claim 13, comprising a selector valve having one outlet for supplying said air to said outlet connection along said first line, and another outlet for supplying said air along a second line to a pump.

15. A unit as claimed in Claim 14, wherein said pump has an inlet connected to a storage vessel containing disinfectant and/or chemical stabilising solution, said selector valve being operable, when said valve means is actuated to stop said water supply, to direct pressurised air along said second line instead of said first line, whereupon said solution is drawn into said second line for delivery to an outlet for connection to said water inlet of said appliance.

16. A unit as claimed in Claim 15, wherein a first valve is provided downstream of said treatment means to prevent said solution entering said treatment means when said selector valve is operated, in use, to deliver said solution and said valve means is actuated to stop said supply of pressurised water.

17. A unit as claimed in any one of Claims 14 to 16, wherein a second valve is provided downstream of said pump to prevent said supply of pressurised water from said second treatment unit flowing to the pump when said selector valve is operated, in use, to direct said pressurised air along said first line.

18. A unit as claimed in any one of Claims 2 to 10, wherein each treatment unit comprises a mounting and a housing releasably engaged therewith.

19. A unit as claimed in any one of Claims 11 to 17, wherein said appliance is a dental drill.

20. A water processing unit substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.