Technical field

The present invention relates to a liquid treatment apparatus according to the preamble of the independent claim. In particular the invention is directed to a liquid treatment apparatus using UV-light that is easy to install and to use.

Background

There are many applications where UV light sources are used for treating liquids. The applicant of the present application, Wallenius Water AB in Sweden, has developed and is selling water treatment equipment having a water purifier comprising an elongated tubular treatment chamber with an inlet and an outlet. In the center of the treatment chamber a light generally tubular quartz glass is arranged and inside the quartz glass a UV source, such as a lamp capable of generating wavelengths in the UV region. Low pressure UV lamps offer great efficiency and find particular application e.g. in the disinfection of water. Examples of different types of low pressure lamps include e.g. ozone-free mercury low pressure lamps, mercury ozone-generating low pressure lamps, and U-shaped lamps which supply high power in a compact design. The inner surface of the treatment chamber of the water treatment equipment may be covered with catalytic material, such as titanium dioxide, which catalysts promotes and increases the amount of treatment material. The treatment equipment also comprises a pumping device which pumps liquid from the tank into the treatment chambers. One type of treatment reactor developed by the applicant comprises a treatment chamber having oppositely arranged in- and outlets, where the UV light sources are arranged in elongated quartz glass tubes. These tubes are arranged perpendicular to the flow of liquid to be treated through the treatment chamber. Similar arrangements are also described by others within the field as exemplified by the following. US-5625194 relates to an apparatus for continuous cleaning of tubular lamp wells for UV- light producing lamps.

US-7425272 relates to a system for cleaning protective sleeves in UV decontamination systems. The disclosed system for cleaning the outer surface of a quartz sleeve is based on the recognition that providing a honing material with a predetermined abrasiveness through the annulus at high velocity works to remove aggregated particles from the outer surface. In US-7425272 the linear velocity of a slurry material passing through the annulus during a cleaning process is about 1 m/s, and in one particular example it is stated that the velocity is at least 0.5 m/s.

Also EP-2481711, CN-2021156942U, US-5124131 and US-5626768 relate to UV- radiation treatment systems and methods were a liquid is moved along a UV-radiation source.

Normally, UV-lamps intended to be mounted in UV-radiation treatment systems are transported separately due to that they are fragile. Therefore, they need to be mounted within the translucent sleeve before the apparatus can be used. This may be result in damaged lamps, both during transportation and also when mounting the lamp.

An object of the present invention is to achieve a liquid treatment apparatus that may be transported having the lamps already in place, and that the apparatus therefore is easier to install and to use in comparison to the presently used systems. Summary of the invention

The above-mentioned object is achieved by the present invention according to the independent claim.

Preferred embodiments are set forth in the dependent claims.

This solution is related to the requirement that the liquid treatment apparatus should possible to transport having the UV-lamp(s) already mounted and therefore provided with means securing that the lamps not will be damaged during transportation. This is achieved by firmly clamping the lamp within the sleeve, at least in the axial direction, but also, preferably in a radial direction.

Thereby, the apparatus is easy to install without lengthy procedures in that the lamps are already mounted.

Furthermore, the solution is related to this specific application, e.g. the importance of centration of the lamp in order to achieve an even light intensity at the sleeve.

The liquid treatment apparatus is provided with means enabling the UV-lamps to be already mounted in the treatment chamber when the apparatus is delivered to the user, and assuring a safe transportation without damaging the lamps.

More specifically, the UV-lamp is clamped within the sleeve by a connection arrangement provided with a force generating member, which is preferably elastic, configured to generate a force to the UV-lamp socket arranged in connection to a sleeve opening at one end of the treatment chamber. The force is directed essentially in the longitudinal direction of the sleeve.

In one embodiment, at least one elastic radial supporting member is provided configured to support the lamp in relation to the sleeve and damp movements of the lamp in relation to the sleeve in essentially radial directions with regard to a symmetry axis A of the sleeve.

The connection arrangement is configured to clamp the UV-lamp within the sleeve. In one embodiment the connection arrangement, by means of the elastic radial supporting members, is configured to centre the UV-lamp within the sleeve in conjunction with a front end support member provided at a front end of the UV-lamp to support and damp the UV-lamp against an inner surface of the sleeve in both radial and axial directions.

Short description of the appended drawings

Figure 1 is a schematic illustration of a liquid treatment apparatus according to the present invention further illustrating how the liquid flows from the tank through the apparatus and back to the tank after the treatment. Figure 2 is a schematic illustration of a liquid flow through a pumping device and treatment chamber/treatment equipment of the liquid treatment apparatus according to the present invention.

Figure 3 is a cross-sectional view of a treatment chamber according to an embodiment of the present invention,

Figure 4 is a front view of a liquid treatment apparatus according to an embodiment of the present invention.

Figure 5 is a perspective view of a liquid treatment apparatus of an embodiment according to the present invention.

Figure 6 is a cross-sectional view schematically illustrating a treatment chamber according to the present invention.

Figure 7 is a cross-sectional view schematically illustrating a treatment chamber according to an embodiment of the present invention.

Figure 8 is a cross-sectional view of two treatment chambers according to the present invention.

Figure 9 is a cross-sectional view of the upper part of the two treatment chambers illustrated in figure 8.

Figure 10 is a cross-sectional view of the lower part of one treatment chamber illustrated in figure 8.

Detailed description

The present invention will now be described with references to the appended figures. Throughout the figures the same, or equivalent, items will have the same reference signs. Generally, the present invention relates to a liquid treatment apparatus 2 intended for treating a liquid 4, e.g. cutting liquid, with UV-light. The apparatus will now be described with references to figures 1-5.

The apparatus is configured for light treatment of a liquid 4 flowing through at least one, preferably vertically arranged, treatment chamber 6 having an upper, or first, end 8 and a lower, or second, end 10. More specifically, the treatment equipment 9 is arranged to perform UV-light treatment of the liquid 4. The treatment chamber 6 is defined as a first elongated circumferential hollow cavity 13 between an inner wall 12 of a housing 14 and an outer wall 16 of an elongated translucent sleeve 18 arranged to protect and include a lamp 20, and that the sleeve is provided with a sleeve opening 24 and a closed an opposite the opening 24. Preferably, the lamp 20 is a UV-lamp of a fluorescent tube type.

Preferably, the lamp 20 is also a low pressure lamp. The lamp has preferably an elongated shape in the form of a tube and having an essentially circular cross-section. The distance d between the inner wall 12 and the outer wall 16 is chosen, among other things, in dependence of different parameters of the liquid (e.g. the opacity) and is normally in the range of 2-10 mm. An exemplary length of the elongated treatment chamber is in the range of 150-200 cm.

The liquid treatment apparatus also comprises a pumping device 3 configured to pump the liquid to be treated from a tank 25 via a tube, e.g. a flexible tube, into the at least one treatment chamber 6. The pumping device 3 has an inlet connection 22 (see figures 4 and 5) through which the liquid 4 is sucked from a tank 25 with liquid 4 to be treated and further to the treatment chamber 6. The pumping device 3 can also be arranged downstream of the treatment chamber 6. The liquid 4 flows, at a flow rate velocity, through the treatment chamber(s) 6 where it is subjected to UV-radiation. The treated liquid 4 is then returned to the tank 25 via another tube. Preferably, the pumping device 3 is configured to flow said liquid 4 through the hollow cavity 13 at a velocity such that the velocity of the fluid 4 in relation to the outer surface of the sleeve 16 prevents fouling and/or scaling from aggregating on the outer surface of the sleeve 16. A recirculation assembly 42 is configured to recirculate the fluid through the hollow cavity 13.

Figure 4 is a front view, and figure 5 is a perspective view of a liquid treatment apparatus 2 according to one embodiment of the present invention. The apparatus includes a mounting socket 38 on which the pumping device 3, an optional air trap vessel 5 and treatment equipment 9 are mounted. The treatment equipment 9 including treatment chambers 6, e.g. two or four, is mounted within a protective enclosure. A control panel 29 is provided at the front side of the enclosure, and also a safety disconnector 27. Inlet and outlet connectors 22, 35 are arranged for connection to tubes to the tank with the liquid to be treated. Electrical connectors are provided for electrical supply of the UV-lamps. The apparatus is controlled by a control unit 7, e.g. a dedicated processing device or a computer, via control instructions applied via the control panel 29.

With references to in particular figures 6-10 the present invention, and various embodiments, will now be described in detail.

Thus, the liquid treatment apparatus comprises a connection arrangement 23 (see figure 6) configured to be arranged in connection to the sleeve opening 24 at the first end 8 of the treatment chamber 6.

The connection arrangement 23 is provided with a force generating member 26 configured, when the connection arrangement 23 is in a closed state, to generate a force to a lamp socket 28 to clamp the lamp 20 within the sleeve 18. The connection arrangement 23 provides a sealing function when it is in the closed state, and is attached to the housing and sleeve via an attachment member 42, e.g. a threaded connection.

The force generating member 26 is e.g. a helix-shaped spring, which is illustrated in figures 6, 7 and 9, but may also be embodied by any elastic member configured to generate the clamping force, e.g. made from a rubber material.

The force is directed essentially in the longitudinal direction of the sleeve 18, which is downward in the illustrated embodiments. The apparatus further comprises a front end support member 30 provided at a front end 32 of the lamp 20 to support the lamp against an inner surface 34 of the closed end of the sleeve 18 in an axial direction when the connection arrangement 23 is in its closed state. The front end support member 30 comprises an elastic force damping member made e.g. from a rubber material. In one embodiment illustrated in figure 10 the front end support member is ring-shaped.

When designing the force generating member many aspects must be taken into account, the force is e.g. chosen taking transportation issues into account and also structural strength issues of the UV-lamp. In one embodiment the force generating member 26 is configured to generate a predetermined force which is related to the weight of the lamp, and is preferably in the range of 5-50 N, such as 10 N.

The clamping function is required to secure that the UV-lamp is firmly held in its position which is important in particular during transportation of the entire liquid treatment apparatus. The connection arrangement 23 also comprises, among other things, electrical connections to the lamp, e.g. in the shape of connections pins.

With references to figure 7 one further embodiment will now be described. In this embodiment at least one elastic radial support member 36, 40 is provided configured to support the lamp 20 against said sleeve 18 in a radial direction with regard to a

longitudinal symmetry axis A of the sleeve 18. The elastic radial support member(s) further improves protection of the lamp during transportation in that the lamp is held in position when the liquid treatment apparatus is subjected to movements, e.g. during transportation, by damping movements in the radial direction. The elastic radial support member(s) is/are preferably made from a rubber material

In one further embodiment the at least one elastic radial support member 36, 40 is also configured to centre and damp the lamp 20 with regard to a longitudinal symmetry axis A of the sleeve 18.

This may be achieved by providing the front end support member 30 with an elastic radial support member being an elastic centring arrangement 36 to centre and damp the lamp 20 with regard to a longitudinal symmetry axis A of the sleeve 18. The lamp 20 will then be arranged with regard to the sleeve 18 such that a second elongated circumferential hollow cavity 39 is defined.

Furthermore, the connection arrangement 23 comprises an elastic radial support member being a lamp socket centring member 40 that in combination with the centring

arrangement 36 provides an essentially constant predetermined distance d between an inner wall surface of the sleeve and an outer wall surface of the lamp along the major part of the lamp, to provide for a uniform light intensity through the sleeve. The distance d is preferably in the range of 2-15 mm. The thus obtained uniform light intensity is advantageous in that fouling and/or scaling at the outer surface of the sleeve will be more evenly distributed and may therefore be easier to remove.

The outer diameter of lamp is typically 19-25 mm, and inner diameter of the sleeve is typically 28-50 mm. It should be noted that in the cross-sectional views shown in figures 8-10 only parts and details relevant for the present invention are designated.

Figure 8 is a cross-sectional view of two treatment chambers connected in series. The liquid is received from the pumping device via inlet 45 and passes upwards through the first treatment chamber, to the left in the figure, where it is subjected to UV-radiation from the UV-lamp. The liquid enters the second treatment chamber via a horizontal connection tube 46 and then continues downwards through the second treatment and is return to the tank via an outlet 47.

Figure 9 is a cross-sectional view of the upper part of the two treatment chambers illustrated in figure 8. In particular the connection arrangement 23 is shown more in detail. The helix-shaped spring 26 applies a force directed downwards to the lamp 20 via a lamp socket 27, where also electrical connections to the lamp are provided. A sealing arrangement 72 is arranged at the upper part of the sleeve between the sleeve 18 and the housing 14. The elastic radial support member, here embodied by the lamp socket centring member 40, is preferably arranged at an outer surface of the lamp socket 27 facing the inner surface of the sleeve, and is e.g. ring-shaped and made from a rubber material. The lamp socket 27 is preferably an integrated part of the lamp 20.

By removing the connection arrangement 23, e.g. by unscrewing attachment member 42, the lamp is accessible and may be replaced if required. Thus, the apparatus is then in its open stated.

In figure 10 a cross-sectional view of the lower part of one treatment chamber is shown. A ring-shaped front end support member 30 is provided to support the front end 32 of the lamp 20 against the inner surface 34 of the sleeve 18 in an axial direction when the connection arrangement 23 is in its closed state.

The embodiment illustrated in figure 10 also illustrates the elastic radial support member, here embodied as the centring arrangement 36 to centre the lamp 20, inside the sleeve, with regard to a longitudinal symmetry axis A of the sleeve 18. The centring arrangement is here realized by a circular rubber ring. The present invention is not limited to the above-described preferred embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the invention, which is defined by the appending claims.