WO2016085384A1

WO2016085384A1 - Liquid treatment apparatus comprising a bottom plug

Info

Publication number: WO2016085384A1
Application number: PCT/SE2015/051221
Authority: WO
Inventors: Henrik FERNSTRÖM; Johan Bergqvist
Original assignee: Wallenius Water Ab
Priority date: 2014-11-27
Filing date: 2015-11-16
Publication date: 2016-06-02

Abstract

A liquid treatment apparatus, configured for light treatment of a liquid flowing through at least one essentially vertically arranged treatment chamber having an upper end and a lower end, the treatment chamber is defined as a first elongated circumferential hollow cavity between an inner wall of a housing and an outer wall of a translucent sleeve arranged to protect and include a lamp. The apparatus comprises at least one bottom plug (50) configured to be in a closed state where the plug (50) prevents liquid in said treatment chamber to flow out, and in an open state where liquid may flow out from said chamber via at least one outlet opening (52) in said plug, without having to remove said plug from the lower end. The plug (50) is provided with a centring member (54) configured to cooperate with a mating part (56) of a lower end of said sleeve to centre the sleeve within the housing with regard to a longitudinal symmetry axis (A) of the housing to assure that said hollow cavity having a predetermined distance between an outer sleeve surface and an inner surface of housing is defined when the bottom plug (50) is in its closed state and in its open state.

Description

LIQUID TREATMENT APPARATUS COMPRISING A BOTTOM PLUG

Technical field

The present invention relates to a liquid treatment apparatus according to the preamble of the independent claim. In particular the invention relates to a bottom plug for a treatment chamber in a liquid treatment apparatus using UV-light.

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 US-5124131 and US-5626768 relate to UV-radiation treatment systems and methods were a liquid is moved along a UV-radiation source. Furthermore, PL- 156927 comprises a device for disinfecting water with ultraviolet rays with a number of columns including a quartz tube installed in each of the columns.

For maintenance purposes of a UV-light treatment apparatus it is necessary to be able to drain a treatment chamber of the liquid therein. This must be able to be performed in a safe way, avoiding any spillage of the liquid.

Furthermore, the treatment chamber is defined as the hollow cavity between the inner surface of a housing and the outer surface of a sleeve enclosing a UV-lamp. The position of the sleeve within the housing is important in order to achieve improved liquid treatment. The object of the present invention is to achieve an improved liquid treatment apparatus provided with features that is practical to use and that achieves improved liquid treatment.

Summary of the invention

The above-mentioned objects are achieved by the present invention according to the independent claim.

Preferred embodiments are set forth in the dependent claims. The present invention relates to a liquid treatment apparatus, configured for light treatment of a liquid flowing through at least one essentially vertically arranged treatment chamber having an upper end and a lower end. The treatment chamber is defined as a first elongated circumferential hollow cavity between an inner wall of a housing and an outer wall of a translucent sleeve arranged to protect and include a UV-lamp. The apparatus comprises at least one bottom plug to be arranged at a lower end of the treatment chamber and being configured to be in a closed state where the plug prevents liquid in the treatment chamber to flow out, and in an open state where liquid may flow out from said chamber via at least one outlet opening in said plug, without having to remove said plug from the lower end.

The plug is provided with a centring member configured to cooperate with a mating part of a lower end of said sleeve to centre said sleeve within the housing with regard to a longitudinal symmetry axis A of the housing to assure that the hollow cavity having a predetermined distance between an outer sleeve surface and an inner surface of the housing is defined when the bottom plug is in its closed state and in its open state.

When unscrewing the bottom plug liquid within the treatment chamber will flow out; by a tunnel-arrangement within the plug only one outlet opening is available, thereby minimizing liquid spillage.

The solution provides for centring of the sleeve within the outer housing to assure that the hollow cavity has a predetermined distance between the outer sleeve surface and the inner surface of housing.

Furthermore, in one embodiment the outer diameter of the bottom plug is equal or larger than the inner diameter of the housing, which is advantageous when performing maintenance of the treatment chamber, i.e. of the inner of the housing, in that the inner of the housing is easily accessible when the bottom plug is removed from the housing.

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 shows a cross-sectional view along the longitudinal symmetry axis of two treatment chambers according to one embodiment of the present invention.

Figure 7 shows a cross-sectional view along the longitudinal symmetry axis of an upper part of two treatment chambers according to one embodiment of the present invention. Figure 8 shows a cross-sectional view along the longitudinal symmetry axis of a lower part of the treatment chamber according to one embodiment of the present invention. Figure 9 is a cross-sectional view of the bottom plug according to one embodiment of the present invention.

Figure 10 is a view from below of the bottom plug according to one embodiment of the present invention.

Figure 11 is a side view of the bottom plug according to one embodiment of the present invention.

Figure 12 is a cross-sectional view of the bottom plug according to one embodiment of the present invention.

Figure 13 is a view from above of the bottom plug according to one embodiment of the present invention.

Figure 14 is a cross-sectional view of a detail of the centring member according to the present invention.

Figure 15 is a perspective view of the bottom plug according to one embodiment according to the present invention. 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 a translucent sleeve 18 arranged to protect and include a lamp 20.

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 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 figures 6-15 various embodiments of the present invention will now be described in detail, and specifically figures 9-15 illustrates various views of the bottom plug according to one embodiment.

It should be noted that in the cross-sectional views shown in figures 6-8 only parts and details relevant for the present invention are designated. Furthermore, figures 6-8 are not drawn in the same scale.

Figure 6 is a cross-sectional view of two treatment chambers connected in series. The liquid is received from the pumping device via inlet 40 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 42 and then continues downwards through the second treatment chamber and is returned to the tank via an outlet 44. A typical length of a treatment chamber is in the range of 150-200 cm. The apparatus comprises at least one bottom plug 50 configured to be in a closed state where the plug 50 prevents liquid 4 in the treatment chamber 6 to flow out, and in an open state where liquid may flow out from the chamber 6 via at least one outlet opening 52 in said plug, without having to remove the plug from the lower end 10 of the treatment chamber. Thus, each treatment chamber 6 is provided with a bottom plug 50, which makes it possible to drain the chamber from liquid. This may be necessary for maintenances, e.g. for removing damages sleeves or lamps, but also in order to avoid liquid in the treatment chamber when the apparatus is turned off. The plug is preferably provided with a threaded connection 62 configured to be screwed into a mating thread 64 at a lower end of the housing 14.

Furthermore, the plug 50 is provided with a centring member 54, including a guiding arrangement 66, configured to cooperate with a mating part 56 of a lower end of the sleeve 18 to centre the sleeve within the housing 14 with regard to a longitudinal symmetry axis A of the housing. This illustrated in figure 8. Thereby it is assured that the hollow cavity having a predetermined distance between an outer sleeve surface and an inner surface of housing is defined when the bottom plug 50 is in its closed state and in its open state. The predetermined distance is e.g. related to a flow rate of said liquid and is, preferably, in the range of 2-10 mm.

The plug 50 is preferably provided with a tunnel-arrangement 58 connecting the treatment chamber 6 with the at least one outlet opening 52 when the bottom plug 50 is in its open state. More precisely the tunnel-arrangement 58 is configured to lead liquid from inlet openings 60 to the at least one outlet opening 52 when the bottom plug is in its open state. As seen from figures 9, 11 and 15 the inlet openings 60 are located at an outer

circumferential surface parallel to the axis A, and being preferably evenly distributed along the surface. In the illustrated exemplary plug the number of inlet openings is four. The tunnel arrangement comprises tunnels, in the example four tunnels connecting the inlet openings to the outlet opening.

In the closed state the bottom plug is screwed firmly to the housing to provide a liquid- proof sealing. A sealing member is provided at the interface between the bottom plug and the lower part of the housing. When the bottom plug is unscrewed such that the sealing function seizes as the sealing member is moved from contacting the lower part of the housing liquid may flow out from the treatment chamber into the inlet openings 60, via the tunnel-arrangement and out through the outlet opening 52 where it may be collected in a vessel (not shown). It should be noted that in the open state the bottom plug is still attached to the housing via the threaded connection, and that liquid is prevented from escaping through the threaded connection.

The sealing member is preferably a circular sealing ring 51 made from an elastic rubber material, and is arranged in a circular depression 53 (see figures 9, 12 and 13). The bottom plug 50 has a circular extension in a plane perpendicular to the longitudinal symmetry axis A of the housing 14 when the plug is in its open and closed states. The at least one outlet opening 52 is centrally arranged at the circular extension. The centring member 54 is provided with a guiding arrangement 66 having an extension in the longitudinal symmetry axis (A) of the housing 14 and arranged along the perimeter of a circle having a diameter slightly larger than an outer diameter of the sleeve 18.

The guiding arrangement 66 comprises in the illustrated example four flat guiding parts having upper ends 67 being shaped such that the cooperation with the lower end of the sleeve is facilitated. In figure 14 is illustrated one such upper end, which is bevelled at the inner side.

According to one embodiment, and with references to figures 8, 11 and 13 an outer diameter OD of the bottom plug is defined in a plane perpendicular to the axis A. As mentioned above the plug is preferably provided with a threaded connection 62 configured to be screwed into a mating thread 64 at a lower end of the housing 14 and the outer diameter OD is the diameter of the plug of the circumferential part of the plug where the threaded connection is provided.

The housing has an inner diameter ID (see figures 7 and 8) along its major part. The outer diameter OD of the bottom plug is related to the inner diameter ID of the housing such that OD is essentially the same or larger than ID. The reason is that the inner of the housing may then be easily accessed when the bottom plug is completely removed from the housing, e.g. in order to perform maintenance, and to remove e.g. broken lamps and/or sleeves, in that essentially no residual spaces exist at the bottom of the housing which is difficult to access. The outer diameter OD of the bottom plug is, according to one embodiment in the range of 60-65 mm.

According to another embodiment, the sleeve 18 is provided with an essentially horizontal front end surface 68 (see figure 8), and the plug 50 is provided with a central inner surface 70 (see figures 8, 9 and 12). The front end surface and said central inner surface are configured to be arranged along the longitudinal symmetry axis A of the housing 14 such that, when the bottom plug is in its closed state, a distance D is defined between the surfaces along the longitudinal axis A that is related to a longitudinal extension L of a sealing arrangement 72 (see figure 7) configured to be arranged in connection with an upper end of the sleeve. The distance D is less than the longitudinal extension L of the sealing arrangement 72. The reason is to prevent, in the unlikely situation that the sleeve come loose and moves downward, liquid from escaping from the treatment chamber at the upper part of the sleeve. By allowing the sleeve only to move downward the distance D, being smaller than L, the sealing arrangement still has a sealing function when the sleeve eventually will rest at the central inner surface 70 of the bottom plug 50.

A further function of the bottom plug is that it, in its open state, prevents the sleeve from falling out when said bottom plug is in its open state.

The bottom plug 50 is further provided with a tool gripping part 74 for cooperation with e.g. a wrench for screwing on and unscrewing the plug.

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.

Claims

1. A liquid treatment apparatus (2), configured for light treatment of a liquid (4) flowing through at least one essentially vertically arranged treatment chamber (6) having an upper end (8) and a lower end (10), 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 a translucent sleeve (18) arranged to protect and include a lamp (20), c h a r a c t e r i z e d i n that the apparatus comprises at least one bottom plug (50) provided with a threaded connection (62) configured to be screwed into a mating thread (64) at a lower end of said housing (14), and configured to be in a closed state where the bottom plug (50) is screwed firmly to the housing to prevent liquid (4) in said treatment chamber (6) to flow out, and in an open state where the bottom plug (50) is unscrewed such that liquid may flow out from said chamber (6) via at least one outlet opening (52) in said plug, without having to remove said plug from the lower end (10), wherein the plug (50) is provided with a centring member (54) configured to cooperate with a mating part (56) of a lower end of said sleeve (18) to centre said sleeve within said housing (14) with regard to a longitudinal symmetry axis (A) of said housing to assure that said hollow cavity having a predetermined distance between an outer sleeve surface and an inner surface of housing is defined when said bottom plug (50) is in its closed state and in its open state.

2. The liquid treatment apparatus (2), according to claim 1, wherein said plug (50) is provided with a tunnel-arrangement (58) connecting the treatment chamber (6) with said at least one outlet opening (52) when said bottom plug (50) is in its open state.

3. The liquid treatment apparatus (2), according to claim 2, wherein said tunnel-arrangement (58) is configured to lead liquid from inlet openings (60) to said at least one outlet opening (52) when the bottom plug is in its open state.

4. The liquid treatment apparatus (2), according to any of claims 1-3, wherein said bottom plug (50) has a circular extension in a plane perpendicular to said longitudinal symmetry axis (A) of said housing (14) when the plug is in its open and closed states, and that said at least one outlet opening (52) is centrally arranged at said circular extension.

5. The liquid treatment apparatus(2), according to any of claims 1-4, wherein said centring member is provided with a guiding arrangement (66) having an extension in the longitudinal symmetry axis (A) of the housing (14) and arranged along the perimeter of a circle having a diameter slightly larger than an outer diameter of said sleeve (18).

6. The liquid treatment apparatus (2), according to any of claims 1-5, wherein said predetermined distance is related to a flow rate of said liquid.

7. The liquid treatment apparatus (2), according to any of claims 1-6, wherein said predetermined distance is in the range of 2-10 mm.

8. The liquid treatment apparatus (2), according to any of claims 1-7, wherein said bottom plug (50) has an outer diameter OD which is related to an inner diameter ID of the housing (14) such that OD is essentially the same or larger than ID.

9. The liquid treatment apparatus (2), according to any of claims 1-8, wherein said sleeve (18) is provided with an essentially horizontal front end surface (68), and that said plug (50) is provided with a central inner surface (70), wherein said front end surface and said central inner surface are configured to be arranged along the longitudinal symmetry axis (A) of said housing (14) such that, when the bottom plug is in its closed state, a distance D is defined between said surfaces along said longitudinal axis that is related to a longitudinal extension L of a sealing arrangement (72) configured to be arranged in connection with an upper end of said sleeve, and wherein said distance is less than said longitudinal extension of said sealing arrangement (72).

10. The liquid treatment apparatus (2), according to any of claims 1-9, wherein said lamp (20) is a UV-lamp of a fluorescent tube type, and in particular a low pressure UV-lamp.