Background Art As well known to those skilled in the art, a water reservoir is a type of equipment for storing water before supplying water from a water treatment system to a household.

A conventional reservoir tank used as a water reservoir usually includes concrete walls situated underground to secure a space for storing water.

The conventional reservoir tank is usually formed as a rectangular box in view of minimizing installation costs, and is structured such that zigzag-shaped partition walls are formed in the tank so as to increase a contact time between water and disinfectants.

Additionally, an inner surface of the wall of the reservoir tank is coated with asphalt, rubberized asphalt sheet, or epoxy resin to be waterproofed.

However, the conventional reservoir tank is disadvantageous in that a coated layer on the inner surface of the wall may be corroded because of storing water containing disinfectants such as chlorine in the reservoir tank for a long time.

Other disadvantages are that it is inconvenient to maintain and repair the tank because it is positioned under the ground, and its installation period is relatively long and its installation process is complicated because it is made of concrete.

Further, the wall of the conventional reservoir tank has an uneven inner

surface even though it is subjected to a waterproofing-or lining-treatment on its inner surface, so microorganisms or contaminants are easily attached to the uneven inner surface. Accordingly, it is very difficult to secure cleanness of the inner surface of the wall.

Furthermore, the conventional reservoir tank sometimes cannot ensure clearness and sterility of stored water. For example, water may stagnate at a comer of the tank or at a comer of the partition wall to form a dead-water.

Moreover, the conventional tank has disadvantages in that it does not ensure a smooth stream of water due to its shape, thus a contact time between water and chlorine disinfectant is not constant. Accordingly, it is difficult to desirably control a concentration of chlorine in water.

For example, when the concentration of chlorine in water is more than 5 mg/, that is to say, a maximum allowable concentration recommended by the World Health Organization (WHO), water containing chlorine may emit a bad smell and be unsuitable to drink, or generation of carcinogenic trihalomethane (THM) may be undesirably increased.

Disclosure of the Invention Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a liquid reservoir tank with multiple partition walls, which allows water to smoothly flow in the tank, increases a contact time between water and disinfectants, and acts as a water reservoir securing a maximum sterilization effect (CT) when disinfectants such as chlorine are dissolved in water.

Another object of the present invention is to provide a liquid reservoir tank with multiple partition walls, which is rapidly installed by layering cylindrical units, and conveniently maintained and repaired.

In order to accomplish the above object, the present invention provides a liquid reservoir tank with multiple partition walls, comprising an outside wall tightly closed by a top wall and a bottom wall, a plurality of annular ring-shaped

partition walls tightly closed by the top wall and the bottom wall and concentrically arranged in the interior of the outside wall at regular intervals, a plurality of partitioned chambers formed by the outside wall and the partition walls, and flow channels formed respectively on the partition walls. At this time, the liquid reservoir tank functions to smoothly and circumferentially stream a liquid through the flow channels in such chambers for a relatively long period when the liquid is sequentially filled in the chambers.

Brief Description of the Drawings FIG. 1 is a schematic front view of a liquid reservoir tank with multiple partition walls according to a first embodiment of the present invention; FIG. 2 is a sectional view of the liquid reservoir tank with multiple partition walls taken in the direction of the arrows along the line A-A'of FIG. 1, showing its interior construction ; FIG. 3 is a front view of a device for producing cylindrical units, that is to say, basic units constituting the liquid reservoir tank with multiple partition walls according to the present invention; FIG. 4 is a perspective view of a cylindrical unit produced by the device of FIG. 3; FIGs. 5 to 9 are perspective views showing the construction of the liquid reservoir tank with multiple partition walls according to the present invention; FIG. 10 is a sectional view taken in the direction of the arrows along the line B-B'of FIG. 2, showing the directions of flow of water in the liquid reservoir tank with multiple partition walls; FIG. 11 is a sectional view of a liquid reservoir tank with multiple partition walls according to a second embodiment of the present invention; FIG. 12 is a partial perspective view, partly broken away to show the interior construction of a liquid reservoir tank with multiple partition walls according to a third embodiment of the present invention;

FIG. 13 is a perspective view, partly broken away to show the interior construction of a liquid reservoir tank with multiple partition walls according to a fourth embodiment of the present invention ; and FIG. 14 is an exploded perspective view of a liquid reservoir tank with multiple partition walls according to a fifth embodiment of the present invention.

Best Mode for Carrying Out the Invention Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

FIG. 1 is a schematic front view of a liquid reservoir tank with multiple partition walls according to a first embodiment of the present invention.

The liquid reservoir tank with multiple partition walls is made of stainless steel or a duplex material, and is structured such that it stores large quantities of water and increases a flow length of water due to a provision of multiple partition walls and multiple chambers, thus increasing a contact time between water and chlorine, and thereby desirably acting as a water reservoir installed on a limited area.

Additionally, the liquid reservoir tank comprises a cylindrical main body 100 positioned on a concrete base 102 with a height of 1 m on the ground 101.

The cylindrical main body 100 is structured such that it is closed by top and bottom walls 170 and 180 welded at the top and bottom of an outside wall 140 and provided with a flow-meter (not shown) so as to receive water in a predetermined amount.

The concrete base 102 comprises cleaning pipes 105 communicating with each chamber, and an outlet pipe 106 communicating with a first chamber defined at the center of the cylindrical main body 100.

Further, an inlet pipe 104 is positioned at a lower part of the cylindrical main body 100 so as to receive water from a water source 20 (or impurity adsorption tank) positioned at a relatively higher level than the ground.

Furthermore, a chlorine supplying unit 21 communicates with a pipe connecting the water source 20 to the inlet pipe 104 to supply chlorine to the water.

The cylindrical main body 100 comprises the bottom wall 180, the outside wall 140, and the top wall 170, and has a height of 4 to 5 m, a diameter of 18 to 20 m, an inside volume of 1000 to 1600 m3, and a water storage capacity of 900 to 1100 tons. Additionally, the cylindrical main body 100 further includes multiple partition walls and multiple chambers which are to be described in detail, below.

For example, multiple cylindrical partition walls with the same or different heights may be concentrically arranged in a shape of annular ring in the interior of the main body 100. Alternatively, multiple partition walls may be arranged in a spiral shape when seen from a bird's-eye-view, thereby forming a spiral chamber in the interior of the main body 100.

In other words, strips each having the same height as the outside wall 140 of the main body 100 and bent top and bottom edges are arranged to form a spiral- shaped partition wall defining the spiral chamber.

When flowing into the main body 100, water is sequentially filled in a plurality of chambers partitioned by the partition walls. Accordingly, time required by water flowing from the inlet pipe 104 to the outlet pipe 106 of the main body 100 is controlled by adjusting the number and length of the partition walls, and the water smoothly flows in the main body 100 and a flow speed of water is readily controlled because the main body 100 forms a cylinder.

A diameter of a cylindrical unit (refer to FIG. 4) is controlled by a device for producing the cylindrical units (refer to FIG. 3), thus the main body 100 is selectively produced in a small size or a large size.

Moreover, the main body 100 further comprises a ladder 107 fixed on an outer surface of the main body 100 and extended from the concrete base 102 to the top wall 170 of the main body 100, a rail 107a with a predetermined height positioned along the edge of the top wall 170, and vents 108 and manholes 109 communicating with each chamber.

With reference to FIG. 2, the main body 100 is installed by layering

multiple cylindrical units with different diameters, and comprises partition walls 110, 120,130 acting as structural modules for supporting the top wall 170 along with the outside wall 140 as shown in FIG. 1.

These partition walls 110 to 130 are concentrically arranged in a shape of annular ring in the main body 100 to partition the interior of the main body 100 into a first chamber to a fourth chamber 118, 128, 138, 148.

In particular, according to a first embodiment of the present invention, a first partition wall to a third partition wall 110 to 130 are each provided with inclined guide pipes 201, 202, 203, acting as flow channels, for inducing under currents and over currents in the flow directions a, b, c, d.

For example, a plurality of first inclined guide pipes 201 are welded on an inner surface of the first partition wall 110. These first inclined guide pipes 201 function to force water to flow from the second chamber 128 to the first chamber 118, and are arranged in numbers of 5 to 10 along the circumference such that the first inclined guide pipes 201 are positioned opposite to the inlet pipe 104.

Additionally, the first inclined guide pipes 201 are welded on the first partition wall 110 in such a way that each first inclined guide pipe 201 communicates with each hole 119 formed on the first partition wall 110 and is inclined in a direction of flow of water to form a predetermined angle of a with a tangent line of the circumference, as shown in an expanded dotted circle of FIG. 2.

The angle a is 30 to 45°, and the first inclined guide pipes 201 positioned at the angle of a on the first partition wall 110 function to only allow water to circumferentially flow, but neither reduce nor increase a flow speed of water.

Furthermore, the number and inner diameter of the first inclined guide pipes 201 depend on an inner diameter of the inlet pipe 104, and are designed so that water smoothly flows through the inlet pipe 104 into the main body 100 without flowing backward.

Second and third inclined guide pipes 202 and 203 are respectively set on the second and third partition walls 120 and 130 in the same manner as the first inclined guide pipe 201.

At this time, the second inclined guide pipes 202 are positioned opposite

to the first inclined guide pipes 201 and penetrate the second partition wall 120.

Similarly, the third inclined guide pipes 203 are positioned opposite to the second inclined guide pipes 202 and penetrate the third partition wall 130.

Furthermore, the outside wall 140 is installed by vertically layering a plurality of multiple cylindrical units. The inlet pipe 104 penetrating the outside wall 140 has a discharge end part 104a bent at a predetermined angle, for example 45 to 60°, to allow water to flow counterclockwise in the fourth chamber 148.

Accordingly, when flowing through the inlet pipe 104 into the main body 100 (water in: W/1), counterclockwise flow of water'a'is formed in the fourth chamber 148 due to the bent discharge end part 104a of the inlet pipe 104, and thereafter, the water sequentially flows through the inclined guide pipes 201,202, and 203 in the form of under currents and over currents.

At this time, water smoothly flows along the directions b, c, d and is filled in each chamber 118 to 148, and when the main body 100 is fully filled with water, a discharge valve (not shown) is opened, and water is discharged through an exit hole 186 and the outlet pipelO6 (water out : W/O).

A more detailed description of the production process of the cylindrical unit will be given, below.

The cylindrical units are produced by a device 30 as shown in FIG. 3.

The device 30 for producing the cylindrical units was invented by the present inventor so as to greatly shorten an installation time period of the liquid reservoir tank with multiple partition walls, and disclosed in Korean Patent Laid- open Publication No. 2001-67860.

Referring to FIG. 3, the device 30 for producing the cylindrical units is vertically set on a base 39, and comprises a strip supplier 40, a roller leveler 50, a strip cutter 60, a flange bender 70, and a strip bending machine 80, which are sequentially arranged on the base 39.

The base 39 is provided with driving motors 31,32 needed to operate the device 30, and power transmission units 33 to 36 combined with rotating shafts of the driving motors, such as chain or gear transmission units positioned in the interior of the base 39. Additionally, the base 39 is further provided with a PLC

controller (programmable logic controller, not shown) electrically connected to an external power source and positioned outside the base so as to control the device 30, the driving motors, and the power transmissions. The strip cutter 60 further comprises an actuator for operating a cutter, an oil pressure supplier for supplying oil pressure to the actuator, and a length measuring unit so as to cut a strip 10 in a predetermined length.

The strip supplier 40 functions to rotate a reel 41 using a rotation force supplied through the first power transmission units 33 from the first driving motor 31 and supply the strip 10 of a strip coil 1 Oa wound around the reel 41 to the roller leveler 50.

The roller leveler 50 rotates rollers 51,52 using the rotation force supplied through the second power transmission units 34 from the driving motor 31, and move the strip 10 passing between the rollers 51,52 to the cutter 60 while smoothing the strip 10.

The strip cutter 60 cuts the strip 10 by the cutter after measuring a length of a desired strip required to produce a cylindrical unit using the length measuring unit (not shown).

The cut strip 10 is then moved through the flange bender 70 comprising several rollers 71 provided with bending heads 72,73, 74,75, 76,77, 78 at upper and lower ends thereof. In such a case, the bending heads 72 to 78 each form an angle with an associated roller 71, wherein the angles are varied from an obtuse angle at the junction of 71/72 to an angle of 90° at 71/78. These heads 72 to 78 of the rollers 71 receive a rotation force through the third power transmission unit 35 from the second driving motor 32, and rotate at the same rpm to integrally form flanges with a predetermined width at an upper and a lower end of the strip 10 fed from the strip cutter 60.

At this time, the strip 10 has flanges 13,14 positioned at the upper and lower ends thereof in such a way that each flange is at a right angle to the main body of the strip 10. The strip 10 is, thereafter, moved to the strip bending machine 80.

The strip bending machine 80 is provided with three bending rollers 81,

82, 83, in which grooves for receiving the flanges 13,14, of the strip 10 are formed at an upper and a lower end of each bending roller 81,82, 83. The bending rollers 81 to 83 are operated using the rotating force supplied through the fourth power transmission unit 36 from the second driving motor 32.

At this time, the bending rollers 81 to 83 function to bend the cut strip 10, inserted into the grooves at the flanges 13,14, in a shape of cylinder because the bending rollers rotate at different rotating speeds.

Turning now to FIG. 4, the strip 10 passing through the strip bending machine 80 forms an initial cylindrical unit 111 having the flanges 13,14 integrally formed along the upper and lower ends of a cylindrical body 12 of the cylindrical unit 111.

Subsequently, both vertical ends 15,16 of the initial cylindrical unit 111 are welded to each other, thereby accomplishing production of the cylindrical unit 111 made of stainless steel and used as a structural module for the liquid reservoir tank with multiple partition walls.

Therefore, as described above, the cylindrical unit 111 is produced by vertically seating a strip coil 1 Oa on the strip supplier 40, and processing the strip 10 of the strip coil lOa using the roller leveler 50, the strip cutter 60, the flange bender 70, and the strip bending machine 80.

In comparison with a conventional cylindrical unit produced by only bending the strip in a shape of cylinder, the cylindrical unit 111 of the present invention has a relatively high vertical strength due to the flanges 13,14.

Therefore, according to the present invention, a small-sized or a large- sized cylindrical unit 111 is produced without being deformed or distorted.

For example, a diameter of the cylindrical unit 111 according to the present invention is 3 to 20 m.

Because being produced according to a unique process in which the strip 10 is machined while being vertically positioned in the device 30 for producing the cylindrical unit and the strip 10 is bent to form the flanges 13,14, the cylindrical unit 111 of the present invention is scarcely deformed or distorted even though it is produced in a large size.

Therefore, the device 30 for producing the cylindrical units contributes to rapid installation of the liquid reservoir tank with multiple partition walls according to the present invention.

In other words, the device 30 for producing the cylindrical units produces the cylindrical units 111 used as basic units constituting the liquid reservoir tank with multiple partition walls in large quantities, and is capable of producing various cylindrical units 111 with different diameters, that is to say, small-sized and large-sized units.

A detailed description of the installation process of the liquid reservoir tank with multiple partition walls will be given, below. As described above, cylindrical units are layered and welded to each other to form partition walls and an outside wall.

With reference to FIG. 5, a concrete support and a base 102, and a plurality of pipes, that is to say, the cleaning pipes 105, and the outlet pipe 106 are firstly installed.

A bottom wall 180, previously made of stainless steel, is seated on the base 102. A plurality of holes, that is to say cleaning pipe holes 185 and an outlet pipe hole 186, are formed in the bottom wall 180 to allow a pipe arrangement.

In other words, the cleaning pipe holes 185 communicate with the cleaning pipes 105, and the outlet pipe hole 186 communicates with the outlet pipe 106.

A lower cylindrical unit 111 is then seated on the center of the bottom wall 180 so as to serve as a base to support the construction of a first partition wall 110.

The lower cylindrical unit 111 is welded onto the bottom wall 180 using a welding tool 400, thereby integrating the lower cylindrical unit 111 with the bottom wall 180.

Accordingly, the lower cylindrical unit 111 integrated with the bottom wall 180 forms a portion of a watertight tank having continuous welded junctions capable of holding water.

Referring to FIG. 6, three cylindrical units 112 to 114 are sequentially and

vertically laid on the lower cylindrical unit 111 to accomplish the first partition wall 110 comprising four cylindrical units.

At this time, the three cylindrical units 112 to 114 are welded together on the lower cylindrical unit 111 according to a partial welding process or a spot welding process, thus forming spot-welded junctions.

The welded cylindrical units 111 to 114 form one body and are structured such that water passes through gaps formed at the spot-welded junctions. The partial or spot welding process reduces the installation time of the partition wall 110.

Particularly, a plurality of first inflow holes 119 acting as a flow channel are formed on an inner circumference of the upper cylindrical unit 114 in such a way that the first inflow holes 119 are at right angles to an axis of the outlet pipe 106.

The first inflow holes 119 function to transfer water to the inside of the circular first partition wall 110 when water positioned outside the first partition wall rises to the first inflow holes 119 of the first partition wall, and an amount of water flowing to the inside of the first partition wall 110 is controlled by adjusting the number and diameter of the first inflow holes 119.

The inclined guide pipes 201 are welded to the first inflow holes 119.

Referring to FIG. 7, the second partition wall 120 is installed in the same manner as the first partition wall 110, and positioned at a predetermined interval from the first partition wall 110. For example, in the case of a tank with an outer diameter of 18 m, the interval between the first partition wall 110 and the second partition wall 120 is 2.5 m.

The second partition wall 120 is fabricated using a plurality of cylindrical units 121 to 124 with a relatively larger diameter than the first partition wall 110.

Particularly, second inflow holes 129 are formed on a lower cylindrical unit 121 to allow water to flow to the inside of the circular second partition wall 120.

At this time, the second inflow holes 129 may be positioned opposite to the first inflow holes 119 as shown in the drawings. Alternatively, the second inflow holes 129 may be formed on the second partition wall 120 such that the

second inflow holes 129 are positioned at a nearest location from the first inflow holes 119 to shorten a flow length of water.

The inclined guide pipes 202 are welded to the second inflow holes 129.

As shown in FIG. 8, the third partition wall 130 and the outside wall 140 are installed on the bottom wall 180 in the same manner as the first and second partition walls.

Unlike the first to third partition walls 110 to 130, in the case of welding the outside wall 140 to the bottom wall 180, flanges 145,147 of cylindrical units 142,143 constituting the outside wall 140 have continuous welded junctions 144a, 144b, thus the outside wall 140 has a watertight welded structure. Additionally, the outside wall 140 is surrounded with an insulating material 146 such as flame retardant glass fibers, and then coated with a thin film 147, for example an aluminum film, thus having excellent insulating function and elegant appearance (refer to FIG. 10).

A plurality of third inflow holes 139 communicating with the inclined guide pipes 203 are formed on an inner surface of an upper cylindrical unit 134 constituting the third partition wall 130.

The inlet pipe 104 penetrates a lower part of the outside wall 140 to position a feed part 104a of the inlet pipe 104 in the outside wall 140.

Additionally, a projection, 190,191, 192,193, for preventing overflowing of water, are formed on the bottom wall 180 so as to easily clean an inside of the tank, in other words, to easily discharge contaminants generated in cleaning the inside of the tank, along with water to the outside of the tank.

Accordingly, the main body 100 of the tank of the present invention comprises several chambers 118 to 148 formed by the partition walls 110 to 130 and the outside wall 140.

Turning now to FIG. 9, each chamber 118 to 148 of the main body 100 has an inner ladder 177 for use in cleaning and repairing the inside of the tank.

Each inner ladder 177 is set in the chamber such that its upper end is positioned around each manhole 109 of the top wall 170 and its lower end is fixed to the bottom wall 180.

A plurality of reinforcement beams 171,172 having radial lengths corresponding to the intervals between upper parts of the chambers 118 to 148 are positioned between the partition walls 110 to 130 and between the third partition wall 130 and the outside wall 140.

For example, each of the reinforcement beams 171 is welded to the upper part of the third partition wall 130 at an end thereof and to the upper part of the outside wall 140 at another end thereof.

Accordingly, the reinforcement beams 171,172 function to combine the outside wall 140 and the partition walls 110 to 130 with each other and support snow, rain water, and etc which may accumulate on the upper wall 170, as well as the weight of the upper wall 170, thereby improving structural stability of the liquid reservoir tank of the present invention.

After the upper wall 170 is positioned on the reinforcement beams 171, 172, the outside wall 140, and the partition walls 110 to 130, the upper wall 170 is welded thereto, thus sealing the top opening of the tank.

The manholes 109 acting as exits of the chambers 118 to 148 are formed on the upper wall 170, and a plurality of"U"-shaped vents 108 are formed on the upper wall 170 such that gas is easily emitted from the chambers 118 to 148 but rain water and etc. do not enter through the vents 108.

FIG. 10 shows the interior structure of the liquid reservoir tank with multiple partition walls.

The inclined guide pipes 201,202, 203 are respectively positioned on the upper parts or lower parts of the partition walls 110,120, 130 defining the chambers 118 to 148.

In other words, the first inclined guide pipes 201 are positioned on an upper right side of the first partition wall 110, the second inclined guide pipes 202 are positioned on a lower left side of the second partition wall 112, the third inclined guide pipes 203 are positioned on an upper right side of the third partition wall 113, and the inlet pipe 104 is positioned on a lower left side of the outside wall 114.

Accordingly, flow of water from the inlet pipe 104 (W/I) to the outlet pipe

106 (W/O) forms a spiral current (e') through the inclined guide pipes 201,202, 203.

Furthermore, the cylindrical units are integrated to form the partition walls 110,120, 130 by a spot welding process, thus a plurality of slits 220,221, 222 for communicating the chambers with each other are formed on the partition walls 110,120, 130.

Therefore, water in one chamber flows into adjacent chamber in a small amount through the slits 220,221, 222 as shown by the small curved arrow e"of FIG. 10.

A detailed description of the flow path of water in the liquid reservoir tank will be given, below.

Feeding from a water source through the inlet pipe 104 to the fourth chamber 148, water flows along an inner circumference of the fourth chamber 148 in a counterclockwise direction while rising from the bottom wall 180 of the fourth chamber 148.

As shown by the small curved arrows e"of FIG. 10, water in the fourth chamber 148 flows through the slits 220 formed in the partition wall 130 into the third chamber 138.

Because an amount of water fed through the inlet pipe 104 is relatively larger than that of water flowing through slits 220, water continuously rises to a top of the fourth chamber 148. When rising to the third inclined guide pipes 203, water flows through the third inclined guide pipes 203 into the third chamber 138.

Water flowing into the third chamber 138 in a counterclockwise direction, that is to say, in the same direction as the inclination direction of the third inclined guide pipes 203, flows to reach the second inclined guide pipes 202.

Water then flows through the second inclined guide pipes 202 and slits 221 into the second chamber 128.

Rising from a bottom of the second chamber 128, water flows through the slits 222 into the first chamber 118 and continuously rises in the second chamber 128.

Additionally, when rising to the first inclined guide pipes 201, water

overflows through the first inclined guide pipes 201 into the first chamber 118.

Water then rises to a level while being measured by a flow-meter in the first chamber 118 when a discharge valve is closed. On the other hand, when the discharge valve is open, water in the first chamber 118 is discharged through an outlet hole 186 and the outlet pipe 106 (W/O).

The liquid reservoir tank with multiple partition walls of the present invention having the water currents e', e"as described above functions to move water through the inclined guide pipes 201 to 203 and store water in the chambers 118 to 148 for ones of hours to tens of hours, and to hold disinfectants in water for a long period of time.

Hereinafter, the reasons why the liquid reservoir tank with multiple partition walls of the present invention is very useful as a water reservoir and has excellent performance as a liquid storage means will be given, below.

According to the present invention, if the main body 100 of the liquid reservoir tank with multiple partition walls comprises the outside wall with a diameter of 18 m and three circular partition walls positioned at regular intervals of 2.5 m in the outside wall, each water flow passage has a width of 2.5 m.

Roughly speaking, the circumferences of the fourth chamber, the third chamber, and the second chamber are about 56.5, 40. 8, and 25.1 m, respectively.

Accordingly, the main body 100 has a total water flow passage length of 120 m or longer.

If five partition walls are set in the main body 100 with a diameter of 18 m, each interval between the partition walls is reduced to 1.5 m.

As described above, when each interval between partition walls is reduced to 1.5 m, the total length of the flow passage approaches about 200 m.

These main bodies according to the present invention have maximum sterilizing ability (CT) when disinfectant such as chlorine is dissolved in water stored in them.

The sterilizing ability (CT) is defined by following Equation 1.

Equation 1

CT = a concentration of the disinfectant in water (mg/L) x contact time between the disinfectant and water (min) Wherein, the concentration of the disinfectant in water is a minimum value selected among concentrations of the disinfectant in water measured daily, and the contact time between water and the disinfectant being measured between an initial disinfectant injection location and output of the clean water reservoir tank or a location where the deactivation ratio is approved when a maximum amount of water per day is used.

Specifically, the contact time is the time required until 10 % of the tracers injected at the initial disinfectant injection location are detected at the output of the clean water reservoir tank or where the deactivation ratio is approved.

In using a theoretical contact time, a real contact time is obtained by multiplying the hydraulic residence time according to the structure of the clean water reservoir (a value obtained by dividing the clean water reservoir capacity by the maximum flow of water passing through the clean water reservoir per hour) by a guide wall scale factor as shown in Table 1.

TABLE 1 Scale factor Aspect ratio 0. 10 less than 2 0. 20 2 up to 5 0. 30 5 up to 10 0. 40 l0upto 15 0. 50 15 up to 20 0. 60 20 up to 30 0. 65 30 up to 40 0. 70 40 up to 50 0. 75 50 up to 60 0. 80 60 up to 70 0. 85 70 up to 90 0. 90 90 or more

In Table 1, the aspect ratio is a ratio of a length of a water flow path to a width of the water flow path in the clean water reservoir.

In the case of using the clean water reservoir in which the guide wall scale factor depending on the aspect ratio is difficult to determine, the guide wall scale factor may be determined by a professional. At this time, a scale factor of pipeline flow is considered to be 1.0.

When the main body 100 of the present invention has a water flow path of 120 m in length, a width between the partition walls is 2.5 m, and when the water flow path is 200 m in length, the width is 1.5 m, so each aspect ratio is 48 and 133, and the scale factor is 0.7 to 0.9 for both cases.

Particularly, in the main body 100 of the present invention, water linearly flows in the main body 100 (dead water pockets do not occur), thus its guide wall scale factor approaches the scale factor of pipeline flow, 1. 0.

Therefore, the guide wall scale factor of the main body 100 of the present invention is high, so the tank has an extended contact time, and having excellent sterilizing ability.

According to a modified embodiment of the present invention, inclined guide pipes 201,202, 203 may be set in a direction opposite to those of the first embodiment of the present invention, and the feed part 104a of the inlet pipe 104 may be directed in a clockwise direction. At this time, water flows in the main body 100 in the clockwise direction.

A detailed description of a liquid reservoir tank with multiple partition walls according to a second embodiment of the present invention will be given, below.

According to the second embodiment as shown in FIG. 11, the structure of a main body is the same as that of the first embodiment except that directions of an inflow (W/I) and an outflow (W/O) of water and arrangement of inclined guide pipes 201', 202', 203'are different from those of the first embodiment.

Therefore, the same or similar reference numerals are used throughout FIGs. 1 to 11 to designate the same or similar components, and a detailed description of these components will be omitted in the second embodiment.

Each inclined guide pipe 201', 202', 203'is formed on an outer circumference of each partition wall 110,120, 130, unlike the first embodiment.

Furthermore, an inlet pipe 104'connected to an external water source is formed on the center of the main body 100, that is to say, on a bottom wall of a first chamber 118, and an outlet pipe 106'connected to an outer discharge pipe is formed on a bottom wall of a fourth chamber 148 positioned at an outer part in the main body.

Water is sequentially filled into the first chamber 118, a second chamber 128, a third chamber 138, and the fourth chamber 148, and then discharged through the outlet pipe 106' (W/O) to the outside of the tank.

Additionally, water circumferentially and smoothly flows in the first, second, third, and fourth chambers 118,128, 138,148 as shown by the arrows f, g, h of the drawings.

According to a third embodiment of the present invention, rectangular openings for transferring overflow water between partition walls are formed on an upper and a lower part of each partition wall.

As in FIG. 12, the outside wall 140 and partition walls 110 to 130 partitioning the chambers 118 to 148 are formed by integrally welding cylindrical units, like the first and second embodiment.

Meanwhile, some cylindrical units 116 having a shorter circumferential length than other cylindrical units 117 are produced using the device 30 for producing the cylindrical units as described above.

For example, the third partition wall 130 comprises a fourth cylindrical unit 116 having a relatively shorter circumferential length than a first, a second, and a third cylindrical unit 117 positioned under the fourth cylindrical unit 116, thus a rectangular opening 205c is formed on the third partition wall 130.

In the same manner, a rectangular opening 205a is formed on an upper right cylindrical unit of the first partition wall 110, and a rectangular opening 205b is formed on a lower left cylindrical unit of the second partition wall 120.

As described above, the rectangular openings 205a, 205b, 205c are formed in a zigzag arrangement on the partition walls 110 to 130, so water flows

from the inlet pipe 104 to the outlet pipe 106 while circulating in each chamber and flowing between the chambers as shown by the arrows'm'and'n'of FIG. 12.

In the liquid reservoir tank of the present invention, water is sequentially filled in each chamber, so the tank is advantageous in that disinfectants are uniformly dissolved in water and remain mixed in the water for an extended time period, desirable overflow of water frequently occurs, and production cost of the tank is reduced.

A description of a liquid reservoir tank with multiple partition walls according to a fourth embodiment of the present invention will be given, below.

FIG. 13 is a perspective view, partly broken away to show the interior construction of a liquid reservoir tank with multiple partition walls according to the fourth embodiment of the present invention.

In FIG. 13, several"C"-shaped partition walls 110', 120', 130'are concentrically arranged in the interior of the main body 100 to form several chambers 118,128, 138, 148 having annular shapes and communicating with each other.

Each partition wall 110', 120', 130'has an opening 260a, 260b, 260c which is opened from top to bottom of each partition wall to form a rectangular profile with a predetermined width. At this time, each opening faces a different direction.

If entering through a manhole in a top wall of the liquid reservoir tank, a cleaner may freely pass through the openings 260a, 260b, 260c of the partition walls 110', 120', 130'in the main body.

The openings of the partition walls 110', 120', 130'may face opposite directions or multiple directions.

Because each partition wall 110', 120', 130'has a"C"-shaped structure, water is simultaneously filled in each chamber 118, 128, 138, 148. But the C- shaped structure of the partition walls also sufficiently functions to induce water to circumferentially flow in each chamber.

Furthermore, each partition wall may have two openings or four openings, and the heights of the partition walls may be stepwisely increased in a direction

toward the center of the main body. Additionally, if necessary, an infrared ray sterilizing lamp may be set in the main body 100 to improve sterilizing performance of the liquid reservoir tank.

Referring to FIG. 14, a liquid reservoir tank with multiple partition walls according to a fifth embodiment of the present invention comprises baffle walls 311,312, 321,322, 331,332 and supporting walls 313,323, 333 for steadying flow of water and reinforcing structural strength of the main body; and channels 314, 324, 334.

Like the first to fourth embodiments of the present invention, a top wall 170 and a bottom wall 180 are watertightly attached to a top end and a bottom end of an outside wall 140, and a first partition wall to a third partition wall 110,120, 130 with the same height as each other are concentrically arranged in the form of annular ring to form several chambers in the main body 100. At this time, water is sequentially filled in each chamber in such a way that water in one chamber overflows into an adjacent chamber.

Each C-shaped partition wall 110, 120, 130 is structured such that the walls do not form complete cylinders, but have openings 314,324, 334 of predetermined areas.

Each baffle wall 311,312, 321,322, 331,332 is perpendicularly welded to outer and inner surfaces of partition walls 110,120, 130 and the outside wall 140 to perpendicularly intercept the flow of water.

For example, one of first baffle walls 311 is perpendicularly welded between an outer surface of the first partition wall 110 and an inner surface of the second partition wall 120, and is also welded to an upper side of the bottom wall 180 and a lower side of the top wall 170 so as to resist the force of water.

In the same manner, other baffle walls 312,321, 322,331, 332 are arranged in such a way that they are spaced at angular intervals of 120°, thus securing stability and structural strength of the main body 100.

Meanwhile, the baffle walls 313,323, 333 are perpendicularly welded to the inner and outer surfaces of the partition walls 120,130 and the outside wall 140 forming channels 314,324, 334.

The supporting walls 313,323, 333 function to smoothly guide water from one chamber to an adjacent chamber, and act as structural members for combining the partition walls 110,120, 130 to each other and the partition wall 130 with the outside wall 140, and for supporting the top wall 170.

Water flows in through the inlet pipe 104 (W/I), and flows out through the outlet hole and the outlet pipe formed at the center of the main body 100 (W/O).

In other words, after being fed through a curved part of the inlet pipe 104, water is forced to flow in a counterclockwise direction in the chamber by the third supporting wall 333. The water flowing in the fourth chamber gradually creates a steady flow by passing through the two third baffle walls 331,332. After turning around in the fourth chamber, the water faces the other side of the third supporting wall 333, and flows through the channel 334 positioned in the vicinity of the third supporting wall 333 into a third chamber. By a second supporting wall 323, water counterclockwisely flows through two second baffle walls 321,322 to form a more stable steady flow. In the same manner, water in the second chamber passes through two first baffle walls 311, 312 and reaches a center chamber.

Accordingly, vibration and noise are reduced by the baffle walls 311,312, 321, 322,331, 332.

Alternatively, when the positions of the supporting walls 313,323, 333 and the inlet pipe 104 are changed, water may flows in a clockwise direction in each chamber. Additionally, many modifications of the positions of the supporting walls and the inlet pipe may be feasible.

Therefore, the main body 100 according to the present invention is useful as a reservoir tank and a clean water reservoir of an advanced water treatment system, and functions to extend a contact time between water and disinfectants such as chlorine and smoothly move water into the main body, thus uniformly dispersing chlorine acting as a disinfectant in the water.

Industrial Applicability As described above, a liquid reservoir tank with multiple partition walls

according to the present invention is advantageous in that the liquid reservoir tank is provided with multiple chambers in the shape of annular ring formed by multiple partition walls to store water allowing linear currents of water, a contact time between water and chlorine is extended to 7 to 8 hours because water flows over the partition walls to move between the chambers in the main body, and an amount of chlorine remaining in water is maintained at a desired level of 0.2 mg/Q, that is to say, a lower limit of the amount of chlorine remaining in water recommended by World Health Organization (WHO) when water is discharged from the liquid reservoir tank.

Other advantages are that the liquid reservoir tank with multiple partition walls is produced by laying cylindrical units which are produced by bending strips made of stainless steel, thus reducing an installation period of the liquid reservoir tank, improving its structural strength, reducing dead water pockets to make the flow of water smooth, and minimizing water contamination due to high corrosion resistance of the tank.

Further, the liquid reservoir tank is provided with a projection, for preventing overflowing of water, with a predetermined length and height in the vicinity of a cleaning pipe, thus easily discharging settled contaminants along with water during cleaning the interior of the liquid reservoir tank.

Furthermore, the liquid reservoir tank is provided with reinforcing rods welded to upper parts of the partition walls and the outside wall, a top wall is laid on reinforcing rods, valves and pipes are set in a concrete base except for an inlet pipe, the exterior of the liquid reservoir tank is covered with insulating materials such as fire-retardant glass fiber and also with a thin film such as an aluminum film, thus having excellent insulating performance and good appearance.

Additionally, because the liquid reservoir tank is set on the ground unlike a conventional reservoir tank, inflow of contaminated water into the tank is readily prevented, and an outer ladder is set from the ground to an upper part of the tank and inner ladders are connected to each chamber, so it is possible to readily maintain and repair the tank.

Moreover, the liquid reservoir tank is provided with inclined guide pipes,

an inlet pipe, rectangular openings, and flow channels for controlling flow direction, a flow amount, and storage time of water, thereby satisfying users and being applied to various industrial fields.

Besides, the liquid reservoir tank is advantageous in that it is produced by laying cylindrical units produced using a device for producing the cylindrical units, so reducing a time for installation of the tank.

What is more, the liquid reservoir tank has advantages of excellent structural strength due to baffle walls, supporting walls, and flow channels, and of minimized vibration and noise due to steady flow of water in the tank.

The present invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be used otherwise than as specifically described.