Method and apparatus for cleaning filter media

Abstract

Systems and processes for cleaning a medium in a container include directing a cleaning liquid into the container. The fluidization pump draws the cleaning liquid from the container and returns a portion of the cleaning liquid to the fluidization nozzle, which is directed downwardly into the container. The fluidizing nozzle discharges the cleaning liquid in the form of a jet that comes into contact with the medium, moving the medium upward in the container and fluidizing the medium. The medium is continuously fluidized and agitated for a period of time. In this process, contaminants associated with the medium are separated and become contained in the cleaning liquid. During this process, a majority of the medium is confined within the vessel.

Description

Technical Field

[0001] The present invention relates to filters, such as nutshell filters, for filtering wastewater. Background Art

[0002] Media filters, such as nutshell filters, are used to remove contaminants from fluids. They have many applications. For example, in the oil and gas industry, nutshell filters are used to remove oil, suspended solids, and other contaminants from produced water. Nutshells, such as walnut and pecan shells, remove oil by causing it to agglomerate between media particles. Over time, nutshell media becomes clogged or partially clogged with suspended solids, crude oil coatings, and other contaminants. This reduces the efficiency of the nutshell filter, and the nutshell media must be cleaned from time to time.

[0003] Many nutshell filters utilize an internal or external scrubber containing a scrubber screen to clean the nutshell media. The nutshell media is transferred from a container forming part of the nutshell filter to an external scrubber including a cleaning screen as described above. During the cleaning process, the nutshell media passes through the scrubber and returns to the container. In practice, the nutshell media circulates back and forth between the container and the scrubber continuously for a period of time.

[0004] Nutshell filters that rely on internal or external scrubbers have many disadvantages and drawbacks. During startup, the scrubber screens often become fouled with media fines. This requires cleaning multiple times a week or month. After startup, the scrubber screens still require periodic cleaning.

[0005] Although the scrubber screens are located outside the filter container, removal and cleaning are difficult and time consuming. Prior to cleaning, the scrubber screens must be isolated or locked out from the filter container. Scrubber screens are typically large and heavy and are located at heights that often require a mobile crane to facilitate removal. Furthermore, cleaning these screens is a repetitive and non-trivial maintenance task for operators.

[0006] Additionally, in some filter designs, the pump and motor that circulates the media during cleaning are mounted on the top of the vessel in order to self-drain the media that accumulates during the cleaning cycle. This requires maintenance personnel to perform maintenance on the pump and motor on the top of the vessel. If the pump or motor needs to be replaced, then this may also require a crane. In addition, due to the pump mounting structure and the need to adjust the RPM, many top-mounted pumps are belt-driven. Some operators require horizontal direct-coupled ANSI or API pumps, which complicates the design and is costly. In addition, filters with top-mounted pumps and motors require upper platforms and ladders to access the pumps and motors. The size of these platforms has increased over time to meet regulatory requirements. Finally, these high-profile vessels that employ top platforms and top-mounted motors and pumps significantly increase the overall cost of the filter.

[0007] In nutshell filter applications, there may be several nutshell filters in operation on site. The overall design of these filters requires each filter to have a dedicated pump for pumping the media through the scrubber. However, only the pump employed for cleaning is used periodically. Therefore, a significant amount of cost can be eliminated by providing a media filter design where a single pump for media cleaning can service multiple filters. Summary of the invention

[0008] The present invention entails a media filter design that eliminates internal or external media scrubbers and includes a system and process for cleaning the media within the vessel of the filter.

[0009] In one embodiment, the cleaning medium needs to guide the cleaning liquid into the container. A fluidizing pump extracts the cleaning liquid from the container and returns at least a portion of the cleaning liquid to the fluidizing nozzle, which is guided downward into the container. The fluidizing nozzle discharges the cleaning liquid downward in the form of a jet, and the jet contacts the medium in the container, causing the medium to move upward through the container and fluidize in the container. The medium is continuously fluidized and agitated in the container within a selected period of time. In this process, pollutants associated with the medium are separated from it and become contained in the cleaning liquid. During this cleaning process, most of the medium is confined in the container so that the cleaning process is carried out in the container, and no medium leaves the container and enters the scrubber outside the container or passes through the washing filter screen inside the container. During the medium cleaning stage, a portion of the cleaning liquid bypasses the fluidizing nozzle and is discharged.

[0010] During the cleaning phase, small amounts of media can escape the container and be entrained in the cleaning liquid that bypasses the fluidizing nozzles. Before discharge, the cleaning liquid passes through a media collector that collects the media entrained in the cleaning liquid. After the media cleaning phase is completed, the cleaning liquid is directed from the container through the media collector, where the cleaning liquid collects the media, using a fluidizing pump, and thereafter the cleaning liquid and the collected media are returned to the container via the fluidizing nozzles.

[0011] Another aspect of the present invention requires a media filter design in which the fluidizing pump for cleaning the media is configured within the overall filter design so that it can be used to fluidize media in multiple containers, thereby eliminating the need for all filters to have a media fluidizing pump.

[0012] The above discussion relates specifically to cleaning media. Prior to cleaning the media, the media filter is used to filter liquids, such as produced water, for example. It has been found that the media during start-up can be quite buoyant. To address this problem, it is preferred to hydrate the media for a selected period of time prior to commencing the service phase. This will reduce the buoyancy of the media during the filtration phase, increase the efficiency of the media, and prevent the media from leaving the container in large quantities.

[0013] Other objects and advantages of the present invention will become apparent from a study of the following description and accompanying drawings which illustrate the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a media filter of the present invention illustrating a piping network and flow control devices incorporated for controlling the flow of liquid through the media filter during filtration, media cleaning, and media recovery.

[0015] Figure 2 is similar to Figure 1 Schematic diagram of FIG. 1 , but with thick dashed lines showing the flow of liquid during the filtration phase.

[0016] Figure 3 is similar to Figure 1 , but showing the flow of liquid through the system during the media cleaning phase in bold dashed lines.

[0017] Figure 4 is similar to Figure 3 , but showing the flow of liquid during the media recovery phase with thick dashed lines.

[0018] Figure 5A and Figure 5B A media collector in the form of a hydrocyclone is shown for collecting media during the media cleaning phase.

[0019] Fig. 6A and Figure 6B is a schematic diagram of a dual screen assembly capable of serving as a media collector during a media cleaning phase.

[0020] Fig. 7A and Figure 7B is a schematic diagram of a modified Y-type strainer that can be used as a media collector during the media cleaning phase.

[0021] Figure 8 is a schematic diagram showing how a single fluidizing pump associated with a media filter may be utilized to fluidize media in one or more other containers. DETAILED DESCRIPTION

[0022] Media filters are known. For example, see the media filters described in US5,635,080 ('080 patent) and US8,828,237 ('237 patent), the disclosures of which are expressly incorporated herein by reference. Various types of media can be used in media filters. One type of media is nut shells, such as walnuts or walnut shells. Other types of media are also used in various filtering applications. As discussed in the '080 and '237 patents, a media filter includes a container containing media. The influent or liquid to be treated is directed into the upper portion of the container. From there, the influent passes downward through the media. In this process, contaminants, such as suspended solids and oils, are captured, agglomerated or adsorbed onto the media. This produces a filtrate at the bottom of the container. The filtrate is discharged from the bottom of the container. Over time, the media will be blocked or partially blocked by suspended solids and other contaminants removed from the influent during filtration. When this happens, the efficiency of the media filter is reduced, and the media must be cleaned as discussed above. The following discussion focuses on an effective cleaning process for cleaning the media. First, it is an object of the present invention to perform a cleaning operation while substantially all or most of the media remains in the container. This eliminates the need for an external scrubber used by some media filters. In addition, the inventors realized through testing that it is difficult to keep all of the media in the container during fluidization and cleaning. That is, although the overall design is intended to confine the media within the container during cleaning, it is likely that a small amount of media will escape the container. Therefore, one of the features of the media filter design described herein relates to a system and process for collecting the escaping media outside the container and returning the media to the container. This is one of the advantages of the media filter of the present invention. Current media filter designs are subject to media loss, and the operator or customer needs to add media from time to time. This does not happen with the media filter described here because all media that escapes the container (except for normal media wear) is captured and returned to the container.

[0023] Go to the attached picture, Figure 11 is a schematic diagram of a media filter, generally represented by the number 10, and its basic components together with a piping network. The media filter 10 includes a container 12 designed to hold a media 14. An inlet line 16 extends into the upper portion of the container 12 and is used to introduce an influent (liquid to be filtered) into the container 14. A feed pump 15, usually provided by the end user, pumps the influent into the inlet line 16. Once in the container 12, the influent passes downward through the media 14 toward the bottom of the container. In the process, contaminants, such as suspended solids and oils, are captured or adsorbed onto the media 14. This produces a filtrate, which is directed to a distributor disposed in the bottom of the container. The filtrate is discharged from the container 12 into a filtrate discharge line 18.

[0024] Before discussing the media cleaning system and process, it should be noted that the media filter 10 includes a means for draining gas and oil from the upper portion of the vessel 12. The oil and gas should be drained from the vessel prior to cleaning the media and periodically during service. Figure 1 As shown, a discharge line 20 enables the discharge of gas and oil collected in the upper part of the container 12. The oil and gas are finally directed to a discharge point.

[0025] The media filter 10 includes a backwash feed line 22. Line 22 directs feed water (during media cleaning) into the lower portion of the container 12. As will be discussed later, during the media cleaning process, a cleaning solution is continuously supplied to the container 12. The term "cleaning solution" as used herein in a broad sense includes any liquid stream used to clean the media (including backwash and recirculation streams) or to recycle the media from the media collector described later. In the illustrated embodiment of the accompanying drawings, the source of the cleaning solution is a processed liquid stream. However, the source of the cleaning solution can be a dedicated cleaning solution source or any other liquid stream suitable for the media filter.

[0026] The media filter 10 includes a fluidizing pump 26. The fluidizing pump 26 can be located at various locations relative to the container 12. In particular, the design of the media filter 10 does not require the fluidizing pump 26 to be located at the top of the container 12 or any particular place for that matter. It can be conveniently located in a variety of places, and as described later, a single fluidizing pump 26 can be used by multiple media filters 10 without requiring each media filter to include its own dedicated fluidizing pump.

[0027] The media filter 10 includes a fluidizing nozzle 28 disposed internally within the vessel 12. It should be noted that in the drawings, the fluidizing nozzle 28 is located at an intermediate height within the vessel 12 and is directed downwardly toward the media 14 below.

[0028] The media filter 10 also includes a media collector 30 disposed outside of the container 12. The media collector 30 is designed to intercept and collect media entrained in the cleaning fluid during the media cleaning stage. As discussed later, the media collector 30 is designed to allow the cleaning fluid to pass through it and at the same time cause the media entrained in the cleaning fluid to be directed to a collection area 30A in the media collector. In addition, the media collector 30 is designed so that after the media is cleaned, a liquid flow, such as a cleaning fluid, can be directed through the media collector 30 and through the collection area to recover the collected media and return it to the container 12.

[0029] The media filter 10 includes a network of pipes or conduits integrated with the container 12, the fluidizing pump 26, the fluidizing nozzle 28, and the media collector 30. The pipe network includes pipes, valves, and various other flow control elements for controlling and directing the flow of the influent or cleaning fluid through the media filter system. Figure 1 .

[0030] From the piping network, line 34 is connected to the top of vessel 12 and extends from there to the low pressure side of fluidizing pump 26. Line 36 extends from the high pressure side of fluidizing pump 26 to flow diverter FD. During the media cleaning phase, flow diverter FD diverts the flow of cleaning liquid through line 36 so that a portion of the flow in line 36 is directed into line 40 leading to fluidizing nozzle 28 and another portion is directed into line 42 leading to media collector 30. Line 42 continues through media collector 30 to a discharge point referred to as "wastewater discharge" in the drawings.

[0031] During the cleaning of the medium, the cleaning liquid is pumped into the pipeline 22 and enters the container 12 through the post-wash inlet. When the cleaning liquid is supplied to the container 12, the fluidizing pump 26 generates suction at the top of the container, which causes the fluid in the container to move upward through the outlet in the top of the container into the pipeline 34. The cleaning liquid in the pipeline 34 travels through the fluidizing pump 26 and enters the pipeline 36. From the pipeline 36, the cleaning liquid (via the diverter FD) is split (split), wherein the first part of the cleaning liquid is directed to the fluidizing nozzle 28 via the pipeline 40, and the second part of the cleaning liquid is directed to the pipeline 42 at the same time. The above-mentioned diverter is usually a T-shaped pipe (pipe tee) incorporated into the pipeline. In normal operation, the flow in the pipeline 42 is equal to the flow in the pipeline 22, because the valve 80 is 100% open overall. Valve 96 is a modulation control valve for controlling the flow in the pipelines 22 and 42. In any case, the cleaning liquid flowing through the pipeline 40 is discharged downward by the fluidizing nozzle 28. The discharge of the cleaning liquid is in the form of a high pressure jet directed downwardly toward the media below. This causes the media to move upwardly into the upper portion of the vessel 12, which effectively fluidizes the media. This is a continuous process in which the fluidization agitates the media and separates suspended solids and other contaminants from the media so that the contaminants are now contained in the cleaning liquid. As the media is cleaned in the vessel 12 by this fluidization process, a smaller stream of cleaning liquid in line 42 passes through the media collector 30 and is discharged from the system.

[0032] As can be seen in the drawings, the piping network includes many valves that control the flow of liquids during certain operating stages. During media cleaning, valves 80, 82, 84 and 96 are opened. The remaining valves, namely valves 86, 88, 90, 92 and 94 are closed. This enables the cleaning liquid to be pumped from the container 12 through the fluidizing pump 26 and to the fluidizing nozzle 28 and the media collector 30.

[0033] During the medium recovery period, valve 94 is opened and the remaining valves are closed. Figure 4 As can be seen in FIG. 1 , the post-wash flow is pumped from the vessel 12 through the line 34 and the fluidizing pump 26 into the line 43. Because the valve 94 is open, the cleaning liquid can pass through the media collection chamber 30A of the media collector 30. As the cleaning liquid passes through the media collection chamber 30A, the media collection chamber picks up the media, and the cleaning liquid and the collected media enter the line 45, which returns the cleaning liquid and the collected media to the vessel 12 via the fluidizing nozzle 28. This portion of the process is relatively short, as only the relatively small amount of media collected in the chamber 30A needs to be returned to the vessel 12.

[0034] The media collector 30 can take various forms. Three examples of media collectors are shown in Figures 5A-7B Shown in. Figure 5A and Figure 5BThere is schematically shown a hydrocyclone generally indicated by the numeral 100. The hydrocyclone 100 comprises an upper section 102 and a lower section 30A forming a media collection chamber. Figure 5A 1 shows the flow of cleaning liquid through the hydrocyclone during the media cleaning phase. This simply involves directing the cleaning liquid containing some media into the upper section 102 which substantially separates the media from the cleaning liquid. The separated media falls into the lower section or media collection chamber 30A and the cleaning liquid exits the upper section 102 and is collected in the lower section 102. Figure 5A It is called "wastewater". Figure 5B The hydrocyclone is shown when the media in the media collection chamber 30A is being recovered. Here, the cleaning fluid from the fluidizing pump 26 is again directed through the lower section or media collection chamber 30A where it picks up the collected media and returns it to the container 12.

[0035] Fig. 6A and Figure 6B A dual screen assembly 110 is shown which may be used as a media collector in the system described above. The dual screen assembly 110 includes two aligned screens 112 and 114. During media cleaning, a cleaning fluid carrying some of the media is directed into screen 112 and the media is collected therein as the cleaning fluid flows through this screen. Once the media is separated from the cleaning fluid, the cleaning fluid continues through a second screen 114 and exits the second screen as "waste water". See Fig. 6A Once the media cleaning phase is complete, the flow of cleaning fluid through the dual screen assembly 110 is generally reversed. To recover the media collected in the screen 112, the cleaning fluid from the fluidizing pump is first directed through the second screen 114 and then through the first screen 112 where it captures the collected media and directs it out the side outlet and back to the container 12. It should be appreciated that the dual screen assembly 110 can be easily incorporated into Figure 1-4 It will be further appreciated that multiple valves are required to control the flow through the dual screen assembly 110 in order to collect media during the media cleaning phase and to recover media during the media recovery phase.

[0036] Another form of the medium collector 30 is Fig. 7A and Figure 7B120. It is referred to as a modified Y-type filter, and is generally represented by numeral 120. The filter is arranged at an angle relative to the inlet line and the outlet line. During the media cleaning stage, the cleaning liquid enters through the inlet line and passes through the filter to the outlet line. In the process, the modified Y-type filter collects the medium entrained in the backwash flow, and the medium is captured and falls into the medium collection chamber 30A forming a part of the filter. Once the cleaning stage is completed, the cleaning liquid is guided into the inlet line and the medium collected in the medium collection chamber 30A is recovered by the filter and by the medium collection chamber 30A, and the cleaning liquid obtains the medium at the medium collection chamber. Then, the cleaning liquid is guided out from the outlet of the adjacent medium collection chamber 30A and returned to the container 12 via the fluidizing nozzle 28. Again, it should be recognized that a plurality of valves are associated with the modified Y-type filter assembly so as to selectively guide the flow of the cleaning liquid during the media cleaning stage and the media recovery stage.

[0037] The media filter 10 is designed to retain the media in the container 12 during cleaning. As an option, to facilitate the retention of the media, the container 12 is provided with a baffle structure 12A arranged in the upper portion of the container. Figure 1 In the embodiment of the present invention, the baffle structure 12A is arranged above the fluidizing nozzle 28 and just below the top of the container. Therefore, during fluidization of the medium, the medium will move upward along the side of the container 12, where the baffle structure 12A will contact or contact the medium and prevent at least some of the upward movement of the medium.

[0038] It is helpful to briefly review the basic sequence or stages that typically occur in the operation of the media filter 10. Prior to startup, it is helpful to hydrate the media for a selected period of time. The hydration time can vary, but in one example, the media is hydrated for approximately 24 hours. This reduces the buoyancy of the media and has a positive impact on the amount of media recirculation.

[0039] In service, the influent or liquid to be filtered is directed into the upper portion of the vessel 12. Figure 2. From there, the influent passes downward through the media, resulting in the removal of suspended solids and other contaminants from the influent. Filtrate is produced at the bottom of the container and is discharged therefrom via line 18. Gas and oil accumulated in the upper portion of the container 12 are periodically discharged from the container via discharge line 20 prior to the service phase and media cleaning. The duration of the media cleaning can vary, but in one example, the duration of the media cleaning is about 10 to about 20 minutes. After the media cleaning, the media recovery phase discussed above is turned on. As described above, this requires circulating the cleaning fluid from the container through the media collector 30 to recover the media collected during the media cleaning operation. This phase is relatively short, and in addition to recovering the media from the media collector, this operating phase also agitates and cleans the media in the container 12. After the media is collected from the media collector 30, typical operation of the media filter 10 provides a period of time for the media to settle. After settling, it is preferred to thoroughly rinse the media before returning to the service phase using pipeline 19.

[0040] As discussed earlier, one particular advantage of the media filter 10 is that it incorporates a fluidizing pump 26 that can be used to fluidize media in other containers. Figure 8 Because the fluidizing pump 26 is only operated intermittently, the fluidizing pump can be used to fluidize the media in multiple separate containers 12. This feature of the present invention can significantly reduce the capital cost of the media filter for a particular site where more than one media filter is used.

[0041] exist Figure 8 In the embodiment, the fluidizing pump 26 is used to fluidize the media in the four separate containers. Figure 8 A brief description of the system shown in FIG. 1 is appropriate. For example, if it is desired to clean the media in the leftmost container (clean media mode), the fluidizing pump 26 is actuated and this causes the cleaning liquid to be drawn from the leftmost container through the fluidizing pump 26 into the media collector 100, 110 or 120. The media entrained in the cleaning liquid is captured in the media collector. During this mode of operation, the effluent from the media collector is directed to the wastewater discharge. It should be recognized that certain valves will be incorporated into the Figure 8In the system shown in , the leftmost container 12 is isolated and the cleaning liquid is discharged from the medium collector as wastewater. Once the medium is cleaned, various valves are reset to the medium recovery mode. Various valves in the system are set so that the cleaning liquid extracted from the leftmost container is guided through the fluidizing pump 26 and through the medium collector 100, 110 or 120 again, and returns to the fluidizing nozzle of the leftmost container. Therefore, in this mode, the purpose is to recycle the medium collected in the medium collector. There is no wastewater discharge. In this operating mode, the cleaning liquid (together with the recovered medium) through the medium collector is returned to the leftmost container 12 via the fluidizing nozzle.

[0042] The description and claims use the term “configured.” As used herein, “configured” means “designed to.”

[0043] Of course, without departing from the scope and essential features of the present invention, the present invention may be implemented in other specific ways different from those set forth herein. Therefore, the present embodiment disclosed herein should be interpreted as illustrative in all aspects, rather than restrictive, and all changes within the meaning and equivalent scope of the appended claims are intended to be included therein.

Claims

1. A cleaning process for cleaning a contaminated medium contained in a container, the container being used to filter a contaminated liquid flow, the cleaning process comprising: Clean the media confined in the container by: a. directing the cleaning fluid into the container; b. pumping the cleaning liquid out of the container and splitting the cleaning liquid into a first stream and a second stream; c. directing the first stream to a fluidizing nozzle directed downwardly in the container; d. wherein the fluidizing nozzle discharges the first flow downward in the form of a jet, the jet contacts the medium in the container, causing the cleaning liquid and the medium to move upward through the container, causing the medium to fluidize in the container; e. continuously fluidizing and agitating the medium in the container over a selected period of time, and causing contaminants associated with the medium to separate therefrom and become contained in the cleaning fluid; f. During the cleaning process, most of the medium is confined within the container so that the cleaning process is carried out in the container; g. wherein the second stream comprises contaminants separated from the medium and some medium; h. directing the second flow into contact with a medium collector and collecting the medium from the second flow in the medium collector; i. after collecting the media from the second stream, discharging a second stream comprising pollutants separated from the media; and j. Returning the media in the media collector to the container by pumping the cleaning liquid from the container through the media collector and collecting the media with the cleaning liquid and returning the cleaning liquid and media to the container.

2. The method according to claim 1, wherein: The media collector is taken from the group consisting of a modified Y-type filter, a double filter and a hydrocyclone.

3. The method according to claim 1, wherein: The container includes one or more baffles, which are arranged in an upper portion of the container and protrude inwardly from a wall forming a portion of the container; and wherein the cleaning process includes inhibiting upper movement of the fluidizing medium by causing the fluidizing medium to contact the one or more baffles.

4. A media filter comprising: A container for containing a medium; an inlet associated with the container for directing liquid to be filtered into the container; wherein the liquid to be filtered passes through the medium and is filtered in the process; an outlet associated with the container for discharging the filtered liquid; A media cleaning system, the media cleaning system being associated with the container and configured to clean the media, comprising: a. an inlet associated with the container and configured to receive a cleaning fluid; b. a fluidizing pump configured to pump the cleaning fluid upward through the medium and out of the container; c. a fluidizing nozzle disposed in the container and directed downwardly therein; d. a fluidizing line disposed outside the container and operably connected to the fluidizing pump and the fluidizing nozzle and configured to direct the cleaning fluid from the container to the fluidizing nozzle; e. the fluidizing nozzle is configured to discharge the cleaning liquid downwardly in the form of a jet, generate turbulence in the container, and clean the medium by contacting and agitating the medium and moving the cleaning liquid and the medium upward through the container, wherein the medium is fluidized in the container; f. a wastewater discharge line branching from the fluidizing line and configured to direct a portion of the cleaning fluid to a discharge point; g. a medium collector disposed in a wastewater discharge line and configured to collect medium entrained in a cleaning fluid passing through the wastewater discharge line; and h. a medium return line operably associated with the medium collector and the fluidizing pump, wherein the fluidizing pump is configured to pump a cleaning liquid from the container through the medium collector and return the cleaning liquid and the collected medium to the container through the medium return line, where the cleaning liquid acquires the medium collected by the medium collector.

5. A cleaning process for cleaning a contaminated medium contained in a container, the container being used to filter a contaminated liquid stream, the cleaning process comprising: directing a cleaning fluid into the container; The medium in the container is fluidized by using a fluidizing pump, the fluidizing pump draws the cleaning liquid from the container, and the cleaning liquid moves upward in the container, and returning the cleaning fluid to a fluidizing nozzle directed downwardly in the container; wherein the fluidizing nozzle directs the cleaning liquid downward in the form of a jet, the jet creates turbulence in the container and cleans the medium by contacting and agitating the medium; continuously fluidizing and agitating the medium in the container for a selected period of time and causing contaminants associated with the medium to separate therefrom and become contained in the cleaning fluid; confining substantially all of the medium within the container during the cleaning process such that the cleaning process is performed within the container; discharging a cleaning solution containing contaminants separated from the medium from the container; and The medium entrained in the discharged cleaning liquid is collected and returned to the container, wherein the medium is collected in a medium collector arranged outside the container.

6. The method according to claim 5, wherein: The media is collected by directing discharged cleaning fluid through the media collector; and wherein the collected media is recovered and returned to the container by pumping the cleaning fluid from the container, through the media collector and back to the container.

7. The method according to claim 6, wherein: The medium collector includes a Y-type filter, a double filter or a hydrocyclone.

8. The method according to claim 5, wherein: The cleaning liquid pumped from the container by the fluidizing pump is split into a first stream and a second stream, the first stream is directed to the fluidizing nozzle, and the second stream is directed through a medium collector that collects the medium entrained in the second stream.

9. The method according to claim 8, wherein: The medium collected in the medium collector is returned to the container by pumping a cleaning solution from the container through the medium collector using the fluidizing pump, the cleaning solution picking up the collected medium at the medium collector and returning the collected medium to the container via the fluidizing nozzle.

10. The method according to claim 5, wherein: The container includes one or more baffles, which are arranged in an upper portion of the container and protrude inwardly from a wall forming a portion of the container; and wherein the cleaning process includes inhibiting upper movement of the fluidizing medium by causing the fluidizing medium to contact the one or more baffles.

11. The cleaning process according to claim 5, wherein: Two or more containers containing medium are provided, the two or more containers being served by the fluidizing pump and the medium collector.

12. The cleaning process according to claim 7, wherein: The media in the two or more containers are cleaned sequentially, wherein during each sequence of media cleaning, the cleaning liquid is pumped out of at least one of the two or more containers, and wherein at least a portion of the cleaning liquid is directed through a media collector that collects the media, and thereafter the cleaning liquid is directed through the media collector, where the cleaning liquid recovers the media and returns the media to the at least one container.

13. A media filter comprising: a container configured to contain a medium for filtering a liquid; A medium cleaning system, the medium cleaning system comprising: a. an inlet associated with the container for directing a cleaning liquid into the container; b. a fluidizing pump associated with said container; c. a fluidizing nozzle arranged in the container for fluidizing the medium; d. a medium collector, the medium collector being arranged outside the container and configured to collect the medium; e. a piping network operably connected to the container, the fluidizing pump, the fluidizing nozzle and the medium collector; f. wherein the media cleaning system is configured to operate in a first mode and a second mode; g. In the first mode, the fluidizing pump is configured as:

1. Pumping a first portion of the cleaning liquid from the container to the fluidizing nozzle, which fluidizes, agitates and cleans the medium, 2. pumping a second portion of the cleaning fluid through the media collector, where the media entrained in the cleaning fluid is collected, and 3. Pumping the wastewater generated downstream of the media collector to a discharge point; and h. In the second mode, the fluidizing pump is configured to pump the cleaning fluid from the container through the media collector, where the cleaning fluid collects the media therein and returns the media to the container.

14. The media filter according to claim 13, wherein: The medium collector includes a Y-type filter, a double filter or a hydrocyclone.

15. The media filter according to claim 13, wherein: The media collector is configured to allow the cleaning fluid to flow therethrough and is further configured to cause media entrained in the cleaning fluid to be separated from the cleaning fluid and collected in a collection area forming a portion of the media collector.

16. A media filter system comprising: two or more containers, wherein each container includes a medium and is configured to filter a liquid; A medium cleaning system for cleaning the medium in the two or more containers, comprising: a fluidizing nozzle associated with each vessel; a fluidizing pump operably connected to each of the two or more containers; a media collector operably associated with the fluidizing pump and the two or more containers; wherein the fluidizing pump and the medium collector are configured to serve each of the two or more containers; and Wherein, the fluidizing pump is configured to pump cleaning liquid from at least one of the two or more containers in a medium cleaning mode and guide the cleaning liquid through a medium collector that collects the medium entrained with the cleaning liquid, and in a medium recovery mode, the fluidizing pump is configured to pump cleaning liquid from at least one of the two or more containers through the medium collector in which the medium is collected, and thereafter the cleaning liquid together with the recovered medium is returned to at least one of the two or more containers.

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