Water treatment apparatus and water treatment method

Abstract: The special features of the water treatment apparatus in the present invention are that a tank (1) fitted with a raw water inlet (3) and a treated water outlet (4) on the upper part, has within said tank an upper chamber (11) and lower chamber (12) which divide said tank into two sections, upper and lower, and is fitted with a separating wall (2) which can be raised and lowered to adjust the water level in said upper and lower chamber, the upper chamber above said separating wall and the lower chamber below said separating wall both being filled with water. By use of this apparatus, a novel water treatment apparatus is provided which can be extremely easily assembled into a water treatment facility. The invention also relates to a water treatment method using said apparatus and including a coagulation step.

Description: BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a water treatment apparatus and a water treatment method, more particularly to a novel water treatment apparatus and method which can process water at low cost in a wide range of applications, such as general factory wastewater, service water, gray water, sewer wastewater, as well as sea, rivers, lakes and marshes, while having the potential to reduce costs substantially. Description of the related art Conventionally, large scale facilities and their related equipment have been necessary for the processing of water, requiring large areas of land and necessitating large scale construction work. Especially, in the case of purification of a raw water from rivers, lakes and marshes it is necessary to first extract the raw water from the river, lake or marsh by pump to the processing facility established on land, and then having processed the raw water using said processing facility, return the purified water by pump to the river, lake or marsh, thus necessitating high power costs for the transport of water. DE 195 12 315 A1 describes a two-part container which can store fresh water and which can simultaneously carry waste water after the removal of said fresh water. The separation between fresh water area and waste water area is carried out by a foil which is disposed inside the container and which simultaneously seals the container parts from each other. The position of the foil acts upon the ratio of fresh water and waste water. SUMMARY OF THE INVENTION An object of the present invention is to provide a novel water treatment apparatus and method from which a water processing facility can be assembled extremely easily. And an another object of the present invention is to provide a novel water treatment apparatus and method being of small scale and extremely easy to assemble, and which can process water from a wide range of sources such as sea, rivers and lakes with simple equipment and at low power cost. The novel features of the present invention are set forth in the appended claims. However, the present invention itself and further objects and advantages thereof will become clearer by the following description of the invention and a preferred embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is frontal section of the water treatment tank, FIG. 1B is Lateral section of the water treatment tank; FIG. 2-5 are explanatory diagrams showing a processing sequence of a water treatment apparatus using the water treatment tank; DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENT This invention will be described in further detail by way of example with reference to the accompanying drawings. FIG. 1 shows a water treatment tank of the present invention. FIG. 1A is a frontal section, FIG. 1B is a lateral section. The diagrams show the tank in different states of use. Numeral 1 is a tank, which is an airtight container formed from metallic materials, the surface of which is coated with a fluorine-containing resin coating or a hard vinyl chloride resin coating, stainless steel or synthetic resins such as polyester resins. The form of the lateral section of the tank 1 may be rectangular, or circular, or may take other forms. Numeral 2 is a separating wall, which creates a division of the tank 1 into two parts, upper and lower, an upper chamber 11 and the lower chamber 12 , and consists of a separating wall panel 21 and a flexible sheet 22 , which is fitted between said separating wall panel 21 and the tank 1 . The separating wall panel 21 consists of a rectangular or circular flat panel corresponding to the form of the lateral section of the tank 1 , the outer diameter of the panel being smaller than the inner diameter of the tank 1 so that there will be a fixed gap between the outer edge of said separating wall panel 21 and the interior surface of the tank 1 . Synthetic resins such as a hard vinyl chloride resin, metallic materials such as stainless steel, or metallic materials, the surface of which is coated with a vinyl chloride or fluorine-containing resin coating, may be used as the materials for this separating wall panel 21. The flexible sheet 22 is made from water resistant and chemical resistant flexible resin materials, such as synthetic polyester fiber, synthetic polyethylene sheet and the like one edge of which is affixed to the perimeter of said separating wall panel 21 , the other edge being affixed to the inner surface of the surrounding wall of the tank 1 at roughly middle level height-direction. Further, the flexible sheet 22 forms a gradual sloping surface showing FIG.1. The separating wall panel 21 may rise and fall within the tank 1 , resulting in two states, one state where the volume of the upper chamber 11 is minimized when the panel is at its highest extent (FIG. 1A ) and one state where the volume of the upper chamber 11 is maximized when the panel is at its lowest extent (FIG. 1B ). Therefore, the separating wall 2 , consisting of the separating wall panel 21 and the flexible sheet 22 , allows alterations in the relative volumes of the upper chamber 11 and the lower chamber 12 . Further, the inner surface of the upper chamber 11 of the tank 1 is covered with a protective sheet 13 , which should be of soft synthetic resinous material having water resistance and chemical resistance, preferably a material which is easily joined to said flexible sheet 22 , for example a synthetic polyester fiber or synthetic polyester sheet, the lower edge of this protective sheet 13 being joined to one edge of said flexible sheet 22 . Numeral 3 is a raw water inlet, and is connected to a raw water line 31 . It is set up so that it is possible to supply raw water to the upper chamber 11 from said raw water line 31. Numeral 4 is a treated water outlet, and is connected to a treated water line 41 . It is set up so that it is possible to expel treated water from the upper chamber 11 through said treated water line 41 to the exterior of the tank 1 . By the use of automatic open-shut valves for a raw water valve 32 and a treated water valve 42 , fitted respectively between the raw water inlet 3 and the raw water line 31 , and the treated water inlet 4 and the treated water line 41 , automatic control of supply of raw water to the upper chamber 11 and expulsion of treated water from the upper chamber 11 is made possible. Numeral 5 is a isolation valve placed between both the raw water inlet 3 and the treated water outlet 4 and the upper chamber 11 . By making said isolation valve 5 an automatic open-shut valve, automatic control of the opening and closing of the water flow between both the raw water inlet 3 and the treated water outlet 4 and the upper chamber 11 is made possible. Numeral 6 is a stirring device, and is suspended into the upper chamber 11 from the upper part of the tank 1 . Said stirring device 6 consists of rotating blades, is operated from a power source located on the upper part of the tank 1 , and is capable of stirring raw water in the upper chamber 11 at a fixed speed of revolutions. Numeral 7 is an inlet-outlet for water for level adjustment, is connected to the lower chamber 12 , and adjusts the water level in the lower chamber 12 by introducing water, causing the separating wall panel 21 to be located at its highest position as shown in FIG. 1A , or expelling water from said lower chamber 12 , causing the separating wall panel 21 to be located at its lowest position as shown in FIG. 1B . By means of the separating wall panel 21 rising and falling, the separating wall 2 is made to rise and fall, making relative volumes of the upper chamber 11 and lower chamber 12 alterable by use of said separating wall 2 . Inlet-outlets 7 are installed in several places (four in the example figure) on the lower part of the surrounding wall of the tank 1 , and it is possible to introduce water for level adjustment into the lower chamber 12 or expel water for level adjustment from said lower chamber 12 by the use of any or all of them. Further, a floatation adjustment bag 23 is fitted around the upper and/or lower outer edge of the separating wall panel 21 , and the buoyancy of the separating wall panel 21 is adjusted by inflation or deflation by means of an air supply/removal device not shown in the figure. By means of this, when causing the separating wall panel 21 to rise as mentioned above, air is introduced into the floatation adjustment bag in order to make use of its buoyancy, and when it is caused to fall, air is appropriately removed, allowing the separating wall panel 21 to fall under its own weight, making possible smooth vertical operation of the separating wall panel 21 . Numeral 8 is an air escape valve which allows air to escape from the upper chamber 11 when raw water is being supplied. Next, the operation of the water treatment tank pertaining to the present invention will be described. Firstly, closing a treated water valve 42 , and opening the raw water valve 32 and the isolation valve 5 , raw water from a raw water line 31 is supplied to the upper chamber 11 from the raw water inlet 3 . As this occurs, water for level adjustment is expelled from the lower chamber 12 , divided from the upper chamber 11 by the separating wall 2 , through the inlet-outlet 7 , and supply of raw water to the upper chamber 11 and expulsion of water for level adjustment from the lower chamber 12 are carried out until the separating wall panel 21 is at its minimum level as shown in FIG. 1 (b). At this time, it is preferable that the air is removed from the floatation adjustment bag fitted to the separating wall panel 21 , causing it to deflate, allowing the smooth descent of the separating wall panel by use of the separating wall panel's own weight. When the separating wall 2 has fallen to its maximum extent and the upper chamber 11 is filled with the maximum volume of raw water, the raw water valve 32 and the isolation valve 5 are closed, and processing of the raw water is then carried out in the upper chamber 11 . Processing of the raw water is carried out by mixing a coagulant and the like with said raw water, and carrying out a stirred flocculation process for a fixed amount of time by rotation of the stirring device 6. Following the stirring process, the stirring device 6 is stopped and allowed to reach a stationary state, the sludge is allowed to precipitate and separate out from the upper, clear treated water in the upper chamber 11 . Following precipitation and separation, the treated water valve 42 and the isolation valve 5 are opened, accompanied by introduction of water for level adjustment to the lower chamber 12 causing the separating wall 2 to rise, raising the level of water in the lower chamber 12 . As this occurs, treated water is expelled from the upper chamber 11 through the treated water outlet 4 , water for level adjustment is continually introduced into lower chamber 12 until the separating wall panel 21 has reached its highest position as shown in FIG. 1A. By means of the rising movement of the separating wall 2 , treated water is expelled from the upper chamber 11 through the treated water outlet 4. At this time, it is preferable that air is supplied to the floatation adjustment bag 23 , to inflate it so that smooth vertical movement of the separating wall panel 21 is achieved by use of buoyancy. Further, following expulsion of the treated water, precipitated excess sludge is removed. At that time, it is preferable to switch over the expulsion line using a valve in tandem with a turbidity sensor and the like to differentiate between the treated water and the sludge. Next, the process returns to the first step of supplying raw water to the upper chamber 11 , followed by repetition of said processing sequence. In this way according to the water treatment tank related to the present invention, the whole series of processes; supply of raw water, stirred flocculation process, precipitation and separation, and the expulsion of treated water can be carried out using one tank. Thus, large scale purification equipment is unnecessary, equipment installation works are simplified, land area for equipment is greatly reduced, and it becomes extremely simple to assemble the water purification facility. Also, by adjustment of the water level in the lower chamber 12 , whether the position of the separating wall 2 is at its highest or lowest point, the upper chamber 11 and the lower chamber 12 are always filled with water by having raw water or water for level adjustment respectively introduced into them. Thus when the separating wall 2 is at its highest position, as shown in FIG. 1 A, the volume of water for level adjustment in the lower chamber 12 is greater than that of the raw water in the upper chamber 11 , and when the separating wall 2 is in its lowest position, as shown in FIG. 1B , in contrast, the volume of water for level adjustment in the lower chamber 12 is smaller than that of the raw water in the upper chamber 11 , but only the relative volumes of water in the interiors of the two chambers, 11 and 12 , varies, and since the total volume of water always fills the tank 1 and is stable in that state, excellent balance is achieved by virtue of its own weight. In other words, the center of gravity position in the height direction is always fixed, and it, and a vertical load to the ground is always fixed, and moment of rotation doesn't occur in it because the whole is full-filled water even if each water level of the upper chamber and the lower chamber changes. Therefore, it is excellent in a weight balance. Further, as the tank 1 is airtight, treated water does not come into contact with the atmosphere, there is no adherence of pollutants, and no production of odors, and thus it is possible to maintain a hygienic environment. Also, since the tank is set up to expel treated water in the upper chamber 11 from the treated water outlet 4 on the upper part of the tank 1 by means of pushing the separating wall 2 up vertically, the clear upper liquid is always expelled first, and it is always possible to extract clear treated water regardless of the amount of sludge present. Further, even in the case that floating constituents which do not easily precipitate, such as oil and the like, are present in the water, differentiating between clear water and contaminants at the time of expulsion by use of a turbidity sensor and the like and using this to switch over a valve, by switching between the treated water line and the sludge line, trouble related to mixing of treated water with contaminants does not easily occur. Next, an example of a water treatment apparatus using the water treatment tank pertaining to the present invention will be described with reference to FIG. 2-5 . FIG. 2-5 show diagrammatic outlines of a water treatment apparatus consisting of four water purification tanks as shown in FIG. 1 linked together. FIG. 2-5 show one cycle of the process sequence for the whole of the water treatment apparatus. Further, it is preferable for there to be a plurality of water treatment tanks linked in the water treatment apparatus mentioned in the present invention, and is not limited by the four shown in the figure. Respective lower chambers 12 A to 12 D of each water treatment tank 1 A to 1 D are connected together with a pipe 100 making it possible for water level adjusting water to flow between the lower chambers. The water for level adjustment inlet-outlets 7 (see FIG. 1 ) fitted to each of the water treatment tanks 1 A to 1 D are used when connecting the respective lower chambers 12 A to 12 D together with the pipe 100. Because the main body of each tank 1 is fitted with a plurality of inlet-outlets 7 it is possible to connect the lower chamber 12 of one water treatment tank with the lower chamber 12 of several other water treatment tanks simultaneously, making it easy to increase the number of tanks linked. Also, the pipe 100 is linked to one storage tank 200 which contains water for level adjustment, and which is common to each water treatment tank 1 A to 1 D. In this way, it is possible for the water for level adjustment to flow between the storage tank 200 and the lower chambers 12 A to 12 D.storage tank 200 performs the role of equalizing the amounts of water for level adjustment introduced into the lower chambers 12 A to 12 D. Upper chambers 11 A to 11 D are connected to the raw water line and the treated water line. Thus the upper chambers 11 A to 11 D can be supplied with raw water, and treated water can be expelled from each of the upper chambers 11 A to 11 D. The water treatment apparatus mentioned is set up so that each of the water process tanks 1 A to 1 D carries out water processing independently, and moreover the timing of the step of the raw water treating sequence is adjusted among each tank. Namely, taking the sequence in FIG.2 as an example, lower chamber 12 A is filled to capacity with water for level adjustment in water treatment tank 1 A, the separating wall 2 A is located at its highest position and raw water is about to be supplied to upper chamber 11 A; in water treatment tank 1 B, the separating wall 2 B is located in its lowest position, the upper chamber 11 B is filled to capacity with raw water, and coagulant is about to be added and a stirring device rotated to carry out a stirred flocculation process. In a water treatment tank 1 C, the stirring device has been stopped and has reached a stationary state, then a coagulated sludge is precipitated and gets treatment water. And in a water treatment tank 1 D, a separating wall 2 D is about to be raised from its lowest position, expelling the treated water from the upper chamber 11 D. Thus processing of raw water is carried out with the timing of the process phases being different for each of the water treatment tanks 1 A to 1 D. For the said water treatment apparatus, the situation in FIG. 3 is that a water treatment tank 1 A is carrying out the stirred flocculation process that was being carried out in a water treatment tank 1 B, said water treatment tank 1 B is carrying out the precipitation and separation that was being carried out in a water treatment tank 1 C in FIG. 2 and said water treatment tank 1 C is carrying out the treated water expulsion that was being carried out by 1 D in FIG. 2 , and said water treatment tank 1 D is carrying out the raw water supply that was being carried out by water treatment tank 1 A in FIG. 2 . In this case, as raw water is supplied to the upper chamber 11 D, the separating wall 2 D is lowered and the water for level adjustment is expelled through the pipe 100. At this time, the water treatment tanks 1 A and 1 B are into a processing phase, and because their isolation valves are in their closed state, the separating walls 2 A and 2 B cannot rise, water adjustment level water is not taken in lower chambers 12 A and 12B through pipe 100 , and water for level adjustment is only introduced into a lower chamber 12 C, whose treated water valve and isolation valve are open in order to expel treated water. In this way, the separating wall 2 C rises, and as it does the treated water is expelled from upper chamber 11 C. Next, the situation in FIG. 4 is that a water treatment tank 1 A is carrying out precipitation and separation, a water treatment tank 1 B is expelling a treated water, a water treatment tank 1 C introduces a raw water, and a water treatment tank 1 D is carrying out the stirred flocculation process. At this time, as mentioned above, the separating wall 2 B is rising, and the water for level adjustment is being introduced through the pipe 100 from the lower chamber 12 C, from which the water is being expelled. Further, the situation in FIG. 5 is that treated water is being expelled from a water treatment tank 1 A, a water treatment tank 1 B introduces a raw water, a water treatment tank 1 C is carrying out the stirred flocculation process, and a water treatment tank 1 D is carrying out precipitation and separation. At this time also, as mentioned above, the separating wall 2 A is rising, and water for level adjustment is being introduced through the pipe 100 from the lower chamber 12 B, from which the treated water is being expelled. Following this, the process sequence moves back to FIG. 2 and is repeated as above. Further, if the volume of water for level adjustment expelled from the lower chamber of any of the water treatment, tanks, is insufficient, or contrastingly overabundant, to raise the separating wall of the other water treatment tanks to the highest level, the balance within the whole system is maintained by providing the water from the storage tank 200 by allowing it to pass through the pipe 100 in the case of insufficiency, or in the case of excess by sending water back to the storage tank 200 . Conventional serial water treatment has serious problem ; in the conventional serial water treatment, each of step such as a mix step ,a coagulate step, a precipitation-separation step needs own treatment vessel. That is conventional water treatment needs a plurality of treatment vessel. It requires the power to transfer a raw and/or a treating water from one treatment vessel to another treatment vessel. And in the process of transfer a raw and/or a treating water, a stable processing is affected by changes in the water temperature. Contrastively, the present invention solves the above mentioned problem. The present invention does not need a plurality of treatment vessel. Therefor, it does not require the power to transfer a water such as conventional system, and a stable processing is not affected by changes in the water temperature. Also, only a very small area of land is needed for equipment, and because the equipment can be set up easily by linking water treatment tanks on land, equipment installation works can be carried out easily. By linking a plurality of water treatment tanks in this way, and by arranging for the timing of the processing sequence to be different in each tank, it is possible to carry out continuous processing of raw water. Furthermore, because the expulsion of treated water from the upper chamber of each of the water treatment tanks is carried out by use of water for level adjustment being expelled by the downward movement of the separating wall during the supply of raw water to the upper chamber of other water treatment tanks, power to expel the treated water is not especially required, and power costs can be greatly diminished. Thus, wind generators or solar power generators can be used, making it possible to adopt thorough energy saving measures. Due to this, along with the ease of installation, use in areas lacking in electricity supply facilities, or use as emergency water processing equipment in times of disaster, etc. is possible. Also, processing capacity is easily adjusted by increasing or decreasing the number of water treatment tanks, making it easy to design equipment in accordance with amounts to be treated. In the above explanation, a flat panel was used for the separating wall panel 21 , but it is not limited by this. For example, although no figure is given, it is also preferable to turn up the outer rim of the panel to form a container-like form with an outer wall, and to affix one edge of the flexible sheet 22 to the perimeter edge of the outer wall. If the container-like separating wall panel is used, since the separating wall panel rises with the sludge precipitated in the lower part of the upper chamber 11 accommodated within the separating wall panel, this separating wall panel is effective in preventing dispersion of the sludge inside the upper chamber 11 . Also, the above explanation was carried out with reference to carrying out the processing by mixing coagulant with the raw water, but it is also possible to carry out the processing of raw water by the use of activated sludge.

Claims: A water treatment apparatus comprising an airtight tank (1) having a separating wall (2) which divides said tank (1) into an upper chamber (11) and a lower chamber (12); the water treatment apparatus further comprising a raw water inlet (3) connected to the upper chamber (11), a treated water outlet (4) connected to the upper chamber (11) and an air escape valve (8) connected to the upper chamber (11), wherein the separating wall (2) can move up and down in order to vary the volume of the upper chamber (11) and the lower chamber (12), characterised in that a stirring device (6) is disposed inside the upper chamber (11) and the lower chamber (12) is provided with inlet and outlet (7) for water for level adjustment. A water treatment apparatus according to claim 1 , wherein the separating wall (2) comprises a separating wall panel (21) and a flexible sheet (22). A water treatment apparatus according to claim 2, wherein the separating wall panel (21) consists of a rectangular or circular flat panel corresponding to the form of the lateral section of the tank (1) and the outer diameter of the separating wall panel (21) being smaller than the inner diameter of the tank (1) so that there will be a fixed gap between the outer edge of said separating wall panel (21) and the interior surface of the tank (1). A water treatment apparatus according at least one of the preceding claims, wherein a floatation adjustment bag (23) is fitted to the lower part of the flexible wall panel (21). A water treatment apparatus according to claim 6, wherein the floatation adjustment bag (23) comprises air supply and removal means connected to the floatation adjustment bag (23). A water treatment system which comprises a plurality of airtight tanks (1), according to one of the preceding claims. A water treatment apparatus according to claim 6, wherein the lower chambers (12) of each of the tanks (1) are linked such that water can flow between the lower chambers (12) of the tanks (1). A water treatment apparatus according to claim 7, wherein the lower chambers (12) are linked to a storage tank (200). A water treatment method, using an apparatus according to one of the preceding claims which comprises the following steps: supplying raw water to the upper chamber (11) of the airtight tank (1) by expelling water from the lower chamber (12) of the tank (1) via the outlet (7) for level adjustment, mixing a coagulant to the raw water in the upper chamber (11) and carrying out a stirred flocculation process of the raw water inside the chamber (11), precipitation and separation of the treated water, and expelling the treated water from the upper chamber (11) by introducing water for level adjustment into the lower chamber (12) via the inlet (7).

Inventors: IZAWA YOSHINOBU, IZAWA, YOSHINOBU
Applicants: IZAWA YOSHINOBU, YAMAZAKI AKEHIKO, IZAWA, YOSHINOBU, YAMAZAKI, AKEHIKO
Application year: 2001
Main classification: C02F1
IPC codes: C02F1, B01D21, B65D88