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1. WO2020110139 - "FILTRE À SABLE À COLONNES MULTIPLES ET SON PROCÉDÉ"

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]
“MULTI-COLUMN SAND FILTER AND A METHOD THEREOF”

TECHNICAL FIELD

This invention relates to a filtration system and in particularly relates to sand filtration system for treating wastewater and method thereof.

BACKGROUND OF THE INVENTION

Sand filters are used for the removal of suspended, floating and sinkable matter or particles. The basic principle lies in the passing of wastewater through a bed of sand.

The principal processes by which the particulate matter is brought into contact with the sand grains consist of (a) screening, (b) sedimentation, (c) inertial and centrifugal forces, (d) diffusion, (e) mass attraction, and (f) electrostatic and electro-kinetic attraction. The sand filtration systems are simple and easy to use, environment friendly and give considerable yields. A sand filtration system can be used for pretreatment of harvested rainwater/collected runoff, side stream filtration and as a polishing filter.

Freshwater (potable quality) is an essential commodity for the existence of life.

However, every application of water does not require potable quality water. Hence, instead of using freshwater of potable quality for such applications, it is best to opt for treated or partially treated wastewater. However, the traditional sand bed filter can provide water of desired quality within only one range (depending upon the particle size distribution of the procured sand). Additionally, the traditional sand bed filters remain non-functional during the cleaning of sand bed. Further, in traditional filtration systems, filter bed contains sand (naturally procured), which is a mixture of different sized particles.

For every application of water, it is not necessary that water should be completely free from any kind of foreign matter. For example, the presence of foreign matter up to certain limit does not interfere with the operation of irrigation systems such as drip/sprinkler. . It is a well-known fact that the treatment efficiency of any porous medium and filtration rate depends upon the size of particulate matter present in the wastewater.

Therefore, there exists the need for a better and efficient sand filtration system that will be able to provide water at the desired level of treatment for multiple applications.

OBJECTIVES OF THE INVENTION

The objective of the invention is to provide a novel multi-column sand filtration system for treating wastewater whose columns are in hydraulic contact but contains different size-range sand grains.

Another objective of the invention is to provide a sand filtration system that is efficient and provides a viable means of treating wastewater.

Further objective of the present invention is to provide a sand filtration system capable of reducing the turbidity of wastewater below the minimum standard prescribed by WHO i.e. less than one NTU.

Yet further objective of the invention is to provide a sand filtration system from which desired quality water can be procured at any preliminary stage of treatment.

Another objective of the invention is to provide a sand filtration system that can be cleaned in a column-wise manner without obstructing the functioning of rest of the columns.

Another objective of the present invention is to provide a method for manufacturing multi-column sand filtration system.

SUMMARY OF THE INVENTION

The invention provides a multi-column sand filtration system and a method for the same. The multi-column sand filtration system is capable of treating wastewater and provides treated water of different quality ranges as per requirement. The presence of multiple columns with sand grains of different size-range makes the filtration system more efficient and multipurpose. Further, the multi-column sand filtration system can reduce the turbidity of wastewater below the minimum standard prescribed by the

WHO i.e. less than one NTU, which is the major expectation from a filtration system if the treated water is to be used for groundwater recharging.

The present invention provides a multi-column sand filtration system capable of treating the wastewater comprising of an overhead wastewater supply tank connected to multiple singular columns in series. The multiple singular columns are connected together through connecting pipes. The flow of water is controlled by control and bypass valves. Also, there are air vents to allow the escape of entrapped air over each of the singular columns. These transparent air vent pipes also act as piezometers for the respective columns. The treated water is collected in collecting unit that can be stored for future use or can be used as desired.

Further, the present invention discloses a sand filtration system that can provide the treated water of different quality ranges, which can be used for different applications.

Also, the multi-column sand filtration system can be cleaned in a column-wise manner while keeping rest of the columns in operational mode, thus increasing the run time of the system. Further, it is not necessary to keep all the filter columns functional at the same time. One or more columns can be bypassed while keeping other columns in operation (depending upon the presence of foreign matter in wastewater and according to the requirement of treated water of desired quality).

Furthermore, the present invention discloses a method of manufacturing multi-column sand filtration system. Firstly, an overhead wastewater supply tank is connected with the first filtration column through pipes and the flow of water is controlled by control and bypass valves. In fact first column can be attached with any wastewater supply line subject to the condition that the sufficient head is available for operating the multi-column filtration system. Next, the outlet of the first column is connected with the bypass valve and inlet of the second column; the outlet of the second column is connected with the bypass valve and inlet of the third column and so on through connecting pipes and the flow of water is being controlled by control and bypass valves fitted therein. Further, the air vents are fitted at the top of each filtration column to allow the escape of entrapped air in the porous media of filter columns. The treated water from the outlet of the last column is stored in the relevant collection unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of various embodiments, is better understood when read in conjunction with the drawings

provided herein. For the purpose of illustration, there is shown in the drawings exemplary embodiments; however, the presently disclosed subject matter is not limited to the specific methods and instrumentalities disclosed.

Figure 1 is a line diagram illustrating the set up of multi-column sand filter, in accordance with an embodiment of the invention.

Figure 2 is a line diagram illustrating single column of the multi-column sand filter, in accordance with an embodiment of the invention.

Figure 3 is an image illustrating complete set up of multi-column sand filter, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of the invention will now be described herein, with reference to the accompanying examples and drawings. It will be understood by those skilled in the art that the foregoing general description and the following detailed descriptions are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

The present invention provides a multi-column sand filtration system and a method of manufacturing multi-column sand filtration system. The system includes multiple sand columns connected together in series to produce treated water in a variety of quality ranges.

According to an embodiment of the present invention, multi-column sand filtration system (300) capable of treating the wastewater has been provided comprising of an overhead wastewater supply tank (301) connected to multiple singular columns (302).

The multiple singular columns (302) are connected together in series through connecting pipes (303). The flow of water is controlled by control valve (304) and bypass valve (305). Also, there are air vents (306) to allow the escape of entrapped air, which are fitted over each of the singular columns (302). The treated water is collected in collecting unit (307) and can be stored for future use or can be used as desired.

In a further embodiment of the present invention, a method of manufacturing multi-column sand filtration system had been provided. Firstly, an overhead wastewater supply tank is connected with the first filtration column through pipes and the flow of water is being controlled by control and bypass valves. Next, the outlet of the first column is connected with the bypass valve and the inlet of the second column; the outlet of the second column is connected with the bypass valve and the inlet of the third column and so on through connecting pipes and the flow of water is being controlled by control and bypass valves fitted therein. Further, the air vents are fitted to each filtration column to allow the escape of entrapped air. The treated water from the outlet of the last column is stored in the relevant collection unit.

According to a preferred embodiment of the present invention, the single column of the sand filter includes an inlet for inflow of wastewater to be treated. The wastewater entering through the inlet then passes through a mosquito net; separating inlet chamber and sand column. The sand column contains sand grains of particular sizerange depending upon the desired quality of treated water. The water is treated while passing through the sand medium and then passes off the mosquito net; separating sand column and gravel chamber. The gravel chamber contains pea-size gravels and also includes a perforated pipe that acts as an outlet for the treated water. The water thus treated by a particular column can be either flown to next column via inlet to subsequent column for further treatment or can be withdrawn by opening bypass valve for partially treated water for use in various applications. For the escape of entrapped air through the columns of the sand filtration system, air vents have been provided at the top of all the columns.

In another embodiment of the present invention, an efficient and viable multi-column sand filtration system has been designed that efficiently treats wastewater to give treated water with different quality ranges at the same time. Alternatively, single quality water after complete/final filtration can be procured at the end of the process.

In another embodiment of the present invention, the different columns of the said filtration system contain sand grains of different size-ranges depending upon the quality of water required. The filtration columns are arranged according to the decreasing size-range of the sand grains or increasing fineness of sand grains. In a preferred embodiment of the present invention, the size-range of sand grains used in filtration columns are 1 mm- 2 mm in column 1, 600 pm - 1 mm in column 2, 425 pm - 600 pm in column 3, 300 pm - 425 pm in column 4 and 212 pm - 300 pm in column 5. The sand grains used herein are obtained by sieving the ordinary riverbed sand having mixed sand grains using different sieves of appropriate mesh sizes.

In yet another embodiment of the present invention, the multi-column filtration system is capable of reducing the turbidity of wastewater below the minimum standard prescribed by WHO i.e. one Nephelometric Turbidity Unit (NTU). The wastewater to be treated is passed through the hydraulically connected filtration columns and the water obtained at the final stage is safe to be used for various purposes such as, but not limited to, groundwater recharging, irrigation of food and non-food crops, green spaces, recovering arid lands, fire systems, industrial cooling or industrial processing, sanitation and even as indirect and possibly direct sources of drinking water.

In yet another embodiment of the present invention, the different size-ranged grains of the naturally procured river-bed sand are separated out and filled in the separate columns of the sand filtration system. The number of filtration columns having different size-range sand grains can be increased or decreased depending upon the quality of water desired at the end of the filtration process. In a preferred embodiment of the present invention, the number of columns used to obtain treated water having turbidity of less than one NTU is five.

In yet another embodiment of the present invention, the partially treated water can be procured at any preliminary stage of operation of the sand filter without disrupting the operation of the filtration system. There are various uses of water, which can be fulfilled with partially treated water. Thus, water obtained/ procured at preliminary stage can be used for such purposes and finely treated water can be used for other purposes, where water with turbidity less than 1 NTU is required (such as groundwater recharging to avoid aquifer clogging). Hence, the multi-column sand filtration system can be used to procure water that can serve the need for various purposes requiring treated waters of different quality ranges. Also, any one or more columns of the filtration system can be detached and cleaned without obstructing the functioning of rest of the columns, thus keeping the system functional every time.

In yet another embodiment of the present invention, one or more columns of the multi-column filtration system can be made non-operational thus make it nonessential to operate all the columns while operating the system. Thus, depending upon the treatment efficiency and capacity of selected filtration column and need of desired quality water, few columns may be disconnected by bypassing the inflow.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the products and methods of the present invention without departing from the spirit or scope of the invention. Thus, various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims. Additionally, the foregoing examples are appended for the purpose of illustrating the claimed invention, and should not be construed so as to limit the scope of the claimed invention.