In one of its aspects, the present invention relates to a fluid treatment system. In another of its aspects, the present invention relates to a cleaning apparatus. In yet another of its aspects, the present invention relates to a radiation source module containing the cleaning apparatus. In another of its aspects, the present invention relates to a method of removing fouling materials from an exterior surface of a radiation source assembly. Other aspects of the invention will become apparent to those of skill in the art upon reviewing the present specification.
Fluid treatment systems are known generally in the art.
For example, U.S. Pat. Nos. 4,482,809, 4,872,980 and 5,006,244 [all in the name of Maarschalkerweerd and hereinafter referred to as the Maarschalkerweerd #1 patents] all describe gravity fed fluid treatment systems which employ ultraviolet (UV) radiation.
Such systems include an array of UV lamp frames which include several UV lamps each of which are mounted within sleeves which extend between and are supported by a pair of legs which are attached to a cross-piece. The so-supported sleeves (containing the UV lamps) are immersed into a fluid to be treated which is then irradiated as required. The amount of radiation to which the fluid is exposed is determined by the proximity of the fluid to the lamps, the output wattage of the lamps and the fluid's flow rate past the lamps. Typically, one or more UV sensors may be employed to monitor the UV output of the lamps and the fluid level is typically controlled, to some extent, downstream of the treatment device by means of level gates or the like.
Depending on the quality of the fluid which is being treated, the sleeves surrounding the UV lamps periodically become fouled with foreign materials, inhibiting their ability to transmit UV radiation to the fluid. For a given installation, the occurrence of such fouling may be determined from historical operating data or by measurements from the UV sensors. Once fouling has reached a certain point, the sleeves must be cleaned to remove the fouling materials and optimize system performance.
If the UV lamp modules are employed in an open, channel system (e.g., such as the one described and illustrated in Maarschalkerweerd #1 patents), one or more of the modules may be removed while the system continues to operate, and the removed frames may be immersed in a bath of suitable cleaning solution (e.g., a mild acid) which may be air-agitated to remove fouling materials. This practice was regarded by many in the field as inefficient, labourious and inconvenient.
In many cases, once installed, one of the largest maintenance costs associated with prior art fluid treatment systems is often the cost of cleaning the sleeves about the radiation sources.
U.S. Pat. Nos. 5,418,370, 5,539,210 and RE36,896 [all in the name of Maarschalkerweerd and hereinafter referred to as the Maarschalkerweerd #2 patents] all describe an improved cleaning system, particularly advantageous for use in gravity fed fluid treatment systems which employ UV radiation. Generally, the cleaning system comprises a cleaning carriage engaging a portion of the exterior of a radiation source assembly including a radiation source (e.g., a UV lamp). The cleaning carriage is movable between: (i) a retracted position wherein a first portion of radiation source assembly is exposed to a flow of fluid to be treated, and (ii) an extended position wherein the first portion of the radiation source assembly is completely or partially covered by the cleaning carriage. The cleaning carriage includes a chamber in contact with the first portion of the radiation source assembly. The chamber is supplied with a cleaning solution suitable for removing undesired materials from the first portion of the radiation source assembly.
The cleaning system described in the Maarschalkerweerd #2 patents represented a significant advance in the art, especially when implemented in the radiation source module and fluid treatment system illustrated in these patents.
In recent years, there has been interest in the so-called “transverse-to-flow” fluid treatment systems. In these systems, the radiation source is disposed in the fluid to be treated in a manner such that the longitudinal axis of the radiation source is in a transverse (e.g., orthogonal vertical orientation of the radiation sources) relationship with respect to the direction of fluid flow past the radiation source. See, for example, any one of:
When these fluid treatment systems have been implemented there is a problem of build-up of fouling materials on the exterior surface of the radiation sources. This is particularly a problem in the treatment of municipal waste water where such fouling materials have not been removed upstream of the UV disinfection system. The fouling material often takes the form of elongate debris (e.g., hair, condoms, string, algae and other string-like material) which catches on the exterior surface of the radiation sources and remains there. Failure to adequately remove such fouling material leads to a number of problems, including one or more of the following:
To the knowledge of the present inventors, the above mentioned fluid treatment systems do not teach a cleaning system capable of adequately and reliably removing such fouling material (e.g., elongate debris as discussed above) from the exterior surface of the radiation sources and/or other submerged surfaces in the fluid treatment system during operation of the system (i.e., without the need to cease operation of the system to remove the fouling material).
Accordingly, it would be desirable to have a fluid treatment system capable of removing such fouling material during operation of the system.
It is an object of the present invention to obviate or mitigate at least one of the above-mentioned disadvantages of the prior art.
It is another object of the present invention to provide a novel cleaning apparatus for a radiation source assembly in a fluid treatment system.
It is another object of the present invention to provide a novel fluid treatment system.
Accordingly, in one of its aspects, the present invention provides cleaning apparatus for a radiation source assembly in a fluid treatment system, the cleaning apparatus comprising:
at least one cutting element; and
a motive element configured to cause relative movement between elongate debris in contact with the surface and the at least one cutting element to cause the at least one cutting element to cut the elongate debris.
The invention also relates to a radiation source module and to a fluid treatment system incorporating this cleaning apparatus.
In yet another of its aspects, the present invention relates to a method for removing elongate debris from an exterior surface of at least one radiation source assembly in a fluid treatment system as defined in the immediately preceding paragraph comprising the steps of:
(i) translating the wiping element from the first position toward the second position; and
(ii) causing the at least one cutting element to cut the elongate debris.
In a first embodiment, Steps (i) and (ii) are conducted concurrently. In a second embodiment Steps (i) and (ii) are conducted sequentially.
Preferably, the method comprises the further step of: (iii) translating the wiping element from the second position to the first position.
Thus, the present inventors have discovered a novel cleaning apparatus for use in a fluid treatment system for removing elongate debris from a surface of the fluid treatment system. The “surface of the fluid treatment system” may be any surface on or near which elongate debris is likely to reside. Thus, the “surface” may be comprised in portion of the fluid treatment system such as a sensor, a support element, a drive element, a radiation source assembly and the like. In a preferred embodiment, present cleaning apparatus comprises one or more annular wiping elements making it particularly suitable for use with cylindrical (e.g., rounded) elements and the like.
A preferred embodiment of the present cleaning apparatus further comprises one or both of a wiping element and a cutting surface element. In this preferred embodiment, the at least one cutting element and the cutting surface element are in spaced relation with respect to one another. In one particularly preferred embodiment of the invention, the at least one cutting element is coupled to the wiping element and the cutting surface element is relatively fixed. Alternatively, the cutting surface element may be coupled to the wiping element and the at least one cutting element may be relatively fixed.
Thus, the present cleaning apparatus is particularly advantageous for removing elongate debris from one or more radiation source assemblies disposed in the fluid treatment system. The preferred approach utilized in the present cleaning apparatus is to include at least one cutting element which is moved along the exterior of the radiation source assembly. The cutting element is connected to a wiping element that is translated between a first (e.g., retracted) position and a second (e.g., extended) position. As the wiping element is moved from the first position to the second position, it will tend to push the elongate debris toward a distal portion of the radiation source assembly. During this translation step, it is possible that some of the debris may be cut by the cutting element. As the wiping element approaches to distal portion of the radiation source assembly, it will tend to clamp down on the elongate debris and, as the force of movement is continually applied, the cutting element will cut the elongate debris. Once the elongate debris is cut, it will more readily fall away from the radiation source assembly and this action is facilitated by a flow of fluid past the radiation source assembly.
As mentioned above, in an alternate embodiment, the cutting element may be fixed and the cutting surface element may be coupled to the wiping element that is translated between a first position and a second position. As the wiping element is moved from the first position to the second position, it will tend to push the elongate debris toward a distal portion of the radiation source assembly. As the wiping element approaches the distal portion of the radiation source assembly, the cutting surface element (which may be integral with a portion of the wiping element) will tend to clamp down on the elongate debris and, as the force of movement is continually applied, the (relatively fixed) cutting element will cut the elongate debris. Once the elongate debris is cut, it will more readily fall away from the radiation source assembly and this action is facilitated by a flow of fluid past the radiation source assembly
Thus, the present cleaning apparatus allows for removing problematic debris such as elongate debris during regular operation of the fluid treatment system and without the need to shut down the system for servicing to remove the elongate debris. The present cleaning apparatus may or may not be incorporated in a radiation source module that contains one or more radiation source assemblies. In other words, it is possible to directly implement the present cleaning apparatus in a fluid treatment system.
The present cleaning apparatus is particularly well suited for implementation in a fluid treatment system wherein the radiation source assemblies are disposed transverse to the direction of fluid flow through the fluid treatment system.
Embodiments of the present invention will be described with reference to the accompanying drawings, wherein like reference numerals denote like parts, and in which:
In one of its aspects, the present invention relates to a cleaning apparatus. Preferred embodiments of the cleaning apparatus may include any one or a combination of any two or more of any of the following features:
The cleaning apparatus may be incorporated in a radiation source module that may include any one, or a combination of any two or more, of the following features:
The radiation source module may be incorporated in a fluid treatment system that may include any one or a combination of any two or more of any of the following features:
With reference to
Disposed between baffle plates 30 is a radiation source module 100. Radiation source module 100 comprises a series of radiation source assemblies 110. The distal portions of radiation source assemblies are coupled to a footer 132 that spans a distance between pair of sidewalls 20 of open channel 15. Footer 132 includes a series of apertures for receiving the distal ends of radiation source assemblies 110. The proximal portions of radiation source assemblies 110 are connected to and supported by a module header 120. Additional details on the construction and components in module header 120 may be found in co-pending U.S. provisional patent application Ser. No. 61/202,797 [Traubenberg et al.], filed on Apr. 24, 2009.
Each radiation source assembly 110 may comprise a radiation source (not shown for clarity) disposed in a radiation transparent protective sleeve as described above. Preferably, the radiation source is an ultraviolet (UV) radiation source.
A cleaning apparatus 150 comprises a series of wiping elements 155 engaged to the exterior of each radiation source assembly 110—preferably each wiping element 155 also functions as a cleaning element. Cleaning apparatus 150 is connected to a drive element (not shown) which is configured to move cleaning apparatus 150 from a first position (
A pair of support elements 125 (only one is shown for clarity) serve to interconnect modular header 120 with footer 132. This allows for radiation source module 100 to be considered as a unit or repeating element that may be placed in open channel 15 such that the bottom of footer 132 of radiation source module 100 rests on floor 25 of open channel 15.
With particular reference to
As can be seen, each distal portion 158 of wiping element 155 comprises a pair of cutting elements 160. Cutting elements 160 are elongate and oriented to be at an angle to the direction of fluid flow past radiation source assemblies 110—this will be discussed further below.
As shown in
When is it desired to remove elongate debris 50 from the exterior surfaces of radiation source assemblies 110, the drive element to which cleaning apparatus 150 is connected is actuated to translate cleaning apparatus 150 toward the distal ends of radiation source assemblies 110—see particularly
With reference to
The above-mentioned suspension effect created between proximal portion 156 of wiping element 155 and carriage 152 obviates or mitigates a disproportionate force being applied by cleaning apparatus 150 to support elements 165. This accounts for the event where there are different amounts of elongate debris 50 attached different radiation source assemblies 110. This also compensates for slight misalignment of the various elements due to normal manufacturing tolerances. Thus, jamming of cleaning apparatus 150 and consequential risk of breaking radiation source assemblies 110 is minimized or avoided. This is particularly important when there is a single drive element being used to move a relatively large number of wiping elements 155, more particularly when those large number of wiping elements 155 are spaced apart over a relatively large area.
With reference to
With reference to
The positioning of cutting element 160 in this manner results in asymmetric cutting of elongate debris. By “asymmetic cutting” is meant that cutting action applied to a piece of elongate debris generally results in two pieces of different length and weight. This result, coupled with the fact that the cut takes place away from the most upstream point of the radiation source assembly, allows the fluid flowing past the radiation source assembly to facilitate release of the elongate debris from the radiation source assembly. A further advantage of positioning cutting element 160 in this manner is that it is also for a provision of a gap between cutting element 160 and radiation source assembly 110 to allow wiping element 155 to operate in the same vicinity (re. radiation source arc length and position) as cutting element 160.
With reference to
With reference to
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While this invention has been described with reference to illustrative embodiments and examples, the description is not intended to be construed in a limiting sense. Thus, various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments.
All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.
The present application claims the benefit under 35 U.S.C. §119(e) of provisional patent application Ser. No. 61/272,858, filed Nov. 12, 2009, the contents of which are hereby incorporated by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA10/01792 | 11/10/2010 | WO | 00 | 9/6/2012 |
Number | Date | Country | |
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61272858 | Nov 2009 | US |