Apparatus and method for removing impurities from water or wastewater

A filter or clarification system for removing impurities from a liquid to be treated, i.e., influent. The system preferably includes a chamber for receiving a liquid to be treated. The chamber has a settling plate assembly including a plurality of inclined liquid passageways through which the liquid to be treated is directed to remove impurities from the liquid to be treated. An efficiency enhancement unit is operably associated with the settling assembly to improve the filtration efficiency of the settling assembly. Preferably, the efficiency enhancement unit includes a vibrator for imparting a vibration force to at least a portion of the settling assembly to improve the filtration efficiency of the settling assembly. Preferably, the vibrator acts to prevent impurities from collecting on one or more settling members in the settling assembly. The settling members can be settling plates or settling tubes. In the preferred form, the vibrator is operated during substantially the entire filtration cycle.

FIELD OF THE INVENTION

The present invention is directed to an apparatus and method for removing impurities from water and/or wastewater. More specifically, the present invention is directed to a filter system that employs a clarifier or filter having a plurality of inclined liquid flow passages through which a liquid to be clarified or filtered is directed to remove impurities from the liquid. The inclined liquid flow passages can be formed by plate settlers or tube settlers. The clarifier or filter of the present invention may be used with one or more flocculators upstream of the clarifier or filter. The clarifier or filter of the present invention may also be used with one or more additional filter systems downstream of the clarifier or filter.

BACKGROUND OF THE INVENTION

Filter or clarification systems have employed a settling assembly to remove impurities from water and/or wastewater for a number of years. In these types of filter systems, tubes or flat plates are commonly used to drastically reduce the footprint of prior clarification systems that merely included an open basin. The tubes or flat plates are commonly mounted at fixed angles to the surface of the liquid to form a plurality of liquid flow channels. The fixed angle of the tubes or plates creates overlapping, horizontally projected surfaces that increases the effective settling surface area compared to an open basin. The increased effective settling surface area is desirable as filtering or clarification capacity is proportional to surface area. The liquid to be filtered is directed through the plurality of liquid flow channels to cause the impurities to settle downwardly at the bottom of a detention basin or sludge collection area. The liquid to be filtered can travel upwardly or downwardly through the plurality of liquid flow channels during the filtration or clarification process.

As the liquid flows upwardly or downwardly through the inclined liquid flow passageways, the impurities settle out of the liquid being filtered. However, over time impurities will build-up on the settling members. The build-up of sludge or other impurities on the settling members is undesirable. For example, the build-up of sludge will reduce the predetermined volume of the fluid flow passageways formed by the settling members which in turn will increase the flow rate of the liquid to be filtered passing through the liquid flow passageways. The increased flow rate will decrease the settling time and, therefore, reduce the efficiency of the clarifier or filter. The build-up of sludge or other impurities must be taken into account when designing the clarifier or filter. For example, the density of the settling members (e.g., settling plates or settling tubes) must be increased to accommodate for the reduction in clarification efficiency. Also, the build-up of sludge on the settling members places restraints on the angle of inclination of the settling members. The lower the angle of inclination of the settling members, the greater the overlap which directly results in a larger effective settling surface area. However, the lower the angle on inclination, the greater the sludge build-up on the settling members. Therefore, prior art designs typically employ an angle of inclination of 55 to 60 degrees. Further, the build-up of sludge on the settling members requires more robust support systems to account for the increased weight on the support system caused by the build-up of sludge on the settling members. This in turn increases the cost and complexity of the clarifier or filter.

EIMCO Water Technologies has developed a plate settler system to address the build-up of sludge on plate settlers. However, this system includes a number of disadvantages not the least of which is that the all of the plates in the plate settler system must be moved from the operational angle of inclination to a vertical position to allow the sludge collected on the inclined plate settlers to descend into the bottom of the basin. The EIMCO design significantly increases the cost and complexity of the clarifier or filter. Also, EIMCO design allows sludge to build-up on the settling plates while the settling plates are oriented in their inclined position. Finally, the EIMCO design will require service interruptions, i.e., to clean the plates, the plates must be moved from their operating position to a vertical position. Notably, even if liquid is allowed to flow through the EIMCO settling plates in the vertical position, the clarification efficiency will be substantially reduced due to the decrease in effective settling area when the settling plates are oriented vertically during cleaning.

Hence, there is a need for a settling system that overcomes the aforementioned disadvantages as well as other disadvantages not articulated above.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the present invention is to provide a novel and unobvious apparatus and method for removing impurities from water and/or wastewater.

Another object of a preferred embodiment of the present invention is to provide a filter system having a settling assembly and a vibrator operably associated with the settling assembly to impart a vibration force to at least a portion of the settling assembly to improve filtration efficiency of the settling assembly.

Still another object of a preferred embodiment of the present invention is to provide a filter system including a settling assembly with a significantly increased effective settling surface area without increasing the number of settling members.

A further object of a preferred embodiment of the present invention is to provide a filter system including a settling assembly where the desired and predetermined volume of the inclined liquid flow channels or passageways is maintained even after prolonged use.

Yet another object of a preferred embodiment of the present invention is to provide a filter system including a settling assembly having a plurality of settling members where sludge is automatically removed from the plurality of settling members without changing the angle on inclination of the plurality of settling members.

Still a further object of a preferred embodiment of the present invention is to provide a filter system including a settling assembly having a plurality of settling members where sludge is automatically removed from the plurality of settling members during a service run, i.e., during filtration or clarification.

Yet still another object of a preferred embodiment of the present invention is to provide a filter system including a settling assembly having a plurality of settling members where the angle of inclination of the settling members is less than those customarily employed in prior systems thereby increasing the effective settling surface area without increasing the number of settling members.

Still yet a further object of a preferred embodiment of the present invention is to provide a simple and cost effective way to prevent the build-up of sludge on settling members of a settling assembly.

Another object of a preferred embodiment of the present invention is to provide an automatic cleaning unit for preventing the build-up of sludge on settling members that can be readily retrofitted to existing clarification or filter systems.

A further object of a preferred embodiment of the present invention is to provide an automatic cleaning unit for preventing the build-up of sludge on settling members that can function intermittently throughout the filtration cycle to prevent sludge from accumulating on the settling members of a settling assembly.

It must be understood that no one embodiment of the present invention need include all of the aforementioned objects of the present invention. Rather, a given embodiment may include one or none of the aforementioned objects. Accordingly, these objects are not to be used to limit the scope of the claims of the present invention.

In summary, one embodiment of the present invention is directed to an apparatus for removing impurities from a liquid to be treated including a chamber for receiving a liquid to be treated. The chamber includes a settling assembly having a plurality of inclined liquid passageways through which the liquid to be treated is directed to cause impurities to settle out of the liquid to be treated. The apparatus further includes at least one vibrator operably associated with the settling assembly to vibrate at least a portion of the settling assembly to improve the filtration efficiency of the settling assembly.

Another embodiment of the present invention is directed to an apparatus for removing impurities from a liquid to be treated including a chamber for receiving a liquid to be treated. The chamber has a plurality of settling members. The plurality of settling members form a plurality of inclined liquid passageways through which the liquid to be treated is directed to cause impurities to settle out of the liquid to be treated. The plurality of settling members each have an angle of inclination between zero degrees and ninety degrees. An automatic cleaning unit is operably associated with at least one of the plurality of settling members to automatically remove impurities on at least a portion of the at least one of the plurality of settling members without changing the angle of inclination of the at least one of the plurality of settling members.

A further embodiment of the present invention is directed to an apparatus for removing impurities from a liquid to be treated including a chamber for receiving a liquid to be treated. The chamber has a plurality of settling members. The plurality of settling members form a plurality of inclined liquid passageways through which the liquid to be treated is directed to cause impurities to settle out of the liquid to be treated. The plurality of settling members have a predetermined orientation during clarification. An automatic cleaning unit is operably associated with at least one of the plurality of settling members to automatically remove impurities on at least a portion of the at least one of the plurality of settling members without changing the predetermined orientation of the at least one of the plurality of settling members.

Still another embodiment of the present invention is directed to a method for removing impurities from a liquid to be treated including the steps of: (a) providing a chamber for receiving a liquid to be treated, the chamber having a plurality of settling members, the plurality of settling members forming a plurality of inclined liquid passageways through which the liquid to be treated is directed to cause impurities to settle out of the liquid to be treated, the plurality of settling members having an angle of inclination between zero degrees and ninety degrees; (b) providing an automatic cleaning unit operably associated with at least one of the plurality of settling members to automatically remove impurities on at least a portion of the at least one of the plurality of settling members without changing the angle of inclination of the at least one of the plurality of settling members; and, (c) automatically removing impurities on at least a portion of the at least one of the plurality of settling members.

The preferred forms of the invention will now be described with reference toFIGS. 1-15. The appended claims are not limited to the preferred forms and no term and/or phrase used herein is to be given a meaning other than its ordinary meaning unless it is expressly stated otherwise.

Referring toFIGS. 1 to 8, a filter system A employing a preferred form of the invention is illustrated in one of many possible configurations. Filter system A includes a tank B, a settling plate assembly C, an automatic cleaning unit D, a primary flocculator E, a secondary flocculator F, an influent (i.e., liquid to be clarified or filtered) connection G, an effluent trough H, an effluent pipe I, a sludge collection area J and a sludge removal system K. The sludge removal system can be the SPYDER® sludge collection system or any other suitable sludge removal system.

The influent to be filtered or clarified enters primary flocculator E at influent connection G. The influent travels downwardly in primary flocculator E where the impurities agglomerate to enhance settling of the impurities when traveling through the settling plate assembly C. Referring toFIG. 3, the influent subsequently enters into secondary flocculator F through opening2. The influent travels upwardly through the secondary flocculator F at which time further agglomeration takes place. The secondary flocculation further enhances settling of the impurities when the influent passes through the settling plate assembly C.

Influent exits secondary flocculator F through an opening (not shown) in wall4. A baffle6is positioned adjacent the opening formed in wall4and directs influent downwardly into equilization chamber7. Wall4extends the width of tank B to separate flocculators E and F from equilization chamber7. The influent equalizes across the width of tank B in equilization chamber7and passes through openings10formed in wall11to allow influent to flow into main chamber8. Wall11extends the width of tank B to separate equilization chamber7from main chamber8. The influent then travels upwardly through the plurality of inclined fluid passageways formed by settling plate assembly C. The influent may enter the inclined fluid passageways through an opening in the bottom that extends substantially the length of the inclined settling plates or through one or more openings formed in the side of the settling plate assembly adjacent the lower portion of the inclined settling plates. The agglomerated floc settles in sludge collection area J where it can be removed from time to time by sludge removal system K. A sludge sensor assembly L may be provided to signal when sludge should be removed from sludge collection area J. Sludge sensor assembly L may include a sludge sensor9and support rod11apassing through effluent trough H. A fluid tight seal is formed around rod11ain effluent trough H to prevent liquid from leaking from effluent trough H. The liquid exiting the settling plate assembly C is collected in effluent trough H and directed through effluent pipe I.

While two mechanical flocculators are shown in the most preferred embodiment, it will be readily appreciated that other flocculation configurations including but not limited to single and multi staged, mechanical or hydraulic types may be used. It should be further noted that while the liquid in the most preferred form travels upwardly through the inclined liquid passageways formed by the settling plate assembly C, it will be readily appreciated that the system could be designed to accommodate downward flow of influent through the inclined liquid passageways.

The settling plate assembly C includes a support frame M for supporting a first settling plate module N and a second settling plate module O on opposite sides of effluent trough H. Preferably, effluent trough H and effluent pipe I are connected to support frame M. It should be noted that any suitable means may be used to secure effluent trough H and effluent pipe I to support frame M. Preferably, a notched or grooved horizontally extending support plate13is secured to each side of the effluent trough H. The support plates13secured on the opposite side walls of effluent trough H could be similar in form to lower support 72 disclosed in U.S. Pat. No. 6,245,243. A notched or grooved horizontally extending support plate15is secured to frame M adjacent sidewalls12and14of tank B. The support plates15could be similar in form to lower support 72 disclosed in U.S. Pat. No. 6,245,243. Therefore, two support plates13and15are located in a spaced manner from each other on each side of the effluent trough H to receive and support a plurality of inclined settling plates therebetween.

Preferably, each support plate13and15includes a plurality of notches or grooves uniformly spaced along the length of the support plates. Each notch or groove is configured to receive an end portion of a rod16attached to a top edge of a corresponding inclined settling plate18. Therefore, a given settling plate18is supported from above the end portions of rod16that extend from the sides of a corresponding settling plate and rest in the aligned notches or grooves formed in the cooperating pair of support plates13and15disposed on one side of effluent trough H. Support frame M includes a pair of spaced lower horizontally extending rails20on each side of effluent trough H to provide lower support for each settling plate18of first settling plate module N and second settling plate module O.

The inclined settling plates18as illustrated inFIGS. 3 and 4have an angle of inclination of (i.e., the angle formed by the settling plate and a horizontal plane) 55 degrees. However, as explained below, the automatic cleaning unit D allows for a much smaller angle of inclination (e.g., 5 degrees) without the customary and significant drawback of accumulation of sludge on the inclined settling plates having such a small angle of inclination.

While two rows or modules of settling plates (one on each side of effluent trough H) are utilized in the most preferred form, the number of rows/modules may be varied as desired. Also, the number of settling plate units and the number of inclined liquid flow passages or channels formed thereby may be varied in the one or more rows/modules of settling plate units. Further, the number and location of effluent troughs may be varied as well. Moreover, other settling members can be used in place of the settling plates. For example, settling tubes may be used instead of settling plates.

Referring toFIGS. 5 to 8, the automatic cleaning unit D includes a support grid22and four vibrators24. Support grid22includes rails26extending across the width of tank B. Each end of rails26include a mounting assembly28for mounting unit D to tank B. The mounting assembly28includes an elastomeric member30and a bracket32. Preferably, the bracket32is welded or otherwise secured to an adjacent portion of tank B. Elastomeric member30prevents vibration forces generated by vibrators24from being transmitted to tank B. It should be noted that similar elastomeric members may be positioned between brackets34on the upper ends of frame M that are secured to adjacent portions of tank B to support the settling assembly C above the bottom of tank B to prevent transmission of vibration forces generated from vibrators24to tank B. Additionally, elastomeric members may be positioned between lower supports36which provide lower support for the settling assembly C and the adjacent portions of tank B to prevent transmission of vibration forces generated from vibrators24to tank B

Support grid22also includes a pair of rails38which are attached to rails26. A vibrator24is attached to rails24directly above the points where rails38are attached to rails26. A plurality of uniformly spaced extension members40are secured to and extend downwardly from rails38. The lower portions of extension members40engage upper portions of inclined settling plates18to transmit vibration forces generated by the vibrators24to each of the inclined settling plates18in modules N and O. The vibration force transmitted to settling plates18through rails24, rails38and extension members40automatically clean the settling plates18by removing any sludge accumulated on inclined settling plates18. In the preferred form, the vibrators can be run intermittently throughout the service run, i.e., the filtration cycle. Further, there is no need to change the orientation of settling plates18to clean settling plates18. The force and frequency of vibrators24may be varied as desired. The preferred range of frequency for vibrators24is 500 Hz to 15000 Hz. The preferred range of force for vibrators24is 50 lbs to 800 lbs.

The alternative embodiments of the present invention will now be described with references toFIGS. 9 through 15. Referring toFIGS. 9 and 14, a filter system P similar to filter system A is illustrated and, therefore, only the differences will be described in detail. Referring toFIGS. 10 and 11, the influent is directed from chamber7into settling assembly C through opening50in cover plate52. Opening50is configured to promote flocculation.

Referring toFIGS. 12 to 14, an alternative form of automatic cleaning unit will now be described. In this embodiment, automatic cleaning units Q are connected directly to frame M above each module R and S. More specifically, each cleaning unit Q includes a support grid54welded or otherwise directly connected to rails13and15of frame M via mounting legs56. Support grid54further includes a longitudinally extending rail58and three transversely extends rails60. Mounting legs56are connected to each end of rails60. Vibrators62are connected to rail58directly above the points at which rails60are connected to rail58. In this embodiment, vibration force generated by vibrators62is transmitted through grid54and frame M to inclined settling plates18connected to frame M to automatically clean settling plates18.

Referring toFIG. 15, a further alternative embodiment is illustrated. A filter system T includes a tank U, an influent connection V, a settling assembly W, a automatic cleaning unit X and an effluent connection Y. Inclined plates70have an angle of inclination of 5 degrees. This small angle of inclination is achievable due to unit X which prevents the build-up of sludge on the settling plates70. Unit X includes a vibrator72, a vertically extending rail74and a plurality of horizontally extending extension members76. Extension members76can either be connected directly to settling plates70or indirectly through side walls78connected to settling plates70. This arrangement transmits the vibration force generated by vibrator72to each of settling plates70to prevent the build-up of sludge on settling plates70. Sidewalls78may have one or more openings80to permit influent to enter the fluid flow passageways formed between adjacent settling plates70. While only one settling plate module is illustrated in this embodiment, it we will be readily appreciated that the number of modules may be varied as desired. While not shown, this embodiment can include one or more flocculators.

While this invention has been described as having a preferred design, it is understood that the preferred design can be further modified or adapted following in general the principles of the invention and including but not limited to such departures from the present invention as come within the known or customary practice in the art to which the invention pertains. The claims are not limited to the preferred embodiment and have been written to preclude such a narrow construction using the principles of claim differentiation.