KR100975410B1 - Filtration apparatus of sludge circulation type and backwash-water discharge type - Google Patents

Abstract

PURPOSE: A filtering device with a sludge circulating function and a super fast reverse washing function is provided to prevent contaminants from being directly inputted to a creek, thereby cleaning used and contaminated water. CONSTITUTION: A filtering device with a super fast reverse washing function includes a used water supply pipe(11), an aggregating agent inserting unit(20), a filtering layer unit(410), a flowing pipe(41), a draining pipe(43), and a draining water storage tank(50). An opening/closing unit connects a downflow filtering tank with the draining pipe. The opening/closing unit is adjacent to the top of the filtering layer unit. The opening/closing unit is under the middle point between the top of a downflow filtering tank and a filtering layer unit so that a sludge and reverse washing water are drained without flowing upward.

Description

Filtration apparatus of sludge circulation type and backwash-water discharge type}

The present invention not only controls the sludge circulation function that can more efficiently remove suspended solids (SS) and total phosphorus (TP) present in the treated water, but also controls the discharge state of backwash water and sludge generated after backwashing. The present invention relates to an ultrafast backwash filtration device with a sludge circulation function capable of implementing a discharge function.

In general, water, sewage, wastewater, and stormwater contain various pollutants and phosphorus, and phosphorus loads from such sewage are very high.

Conventionally, the water treatment apparatus used in the prior art adopts a method of separating the suspended solids and solids from the treated water by spirally swirling the treated water by centrifugal separation or by dropping it to the bottom by gravity.

As such, the conventional water treatment apparatus that removes suspended solids or solids by centrifugation or gravitational action causes a problem of polluting the ecosystem by being discharged into the water without sufficiently removing the solid particles or chemicals in the form of fine particles. It is considered that it is a necessary time.

In addition to these floats and solids, phosphorus introduced into the discharge water through sewage causes a large amount of algae in the water causing eutrophication as nutrients, which adversely affects the aquatic ecosystem.

When treating water with pollutants and phosphorus, which cause these problems, inject chemicals to remove turbid turbidity, suspended matter, or phosphorus in water to form floc particles and process them by flocculation and filtration. have.

Large-scale treatment facilities such as general waterworks or sewage treatment plants have separate flocculation tanks, condensation tanks, and sedimentation tanks for the above-mentioned processes, which require a considerable burden on facility area, and are difficult to operate and manage. This is followed.

The conventional treatment of combined sewage used in the conventional sewage treatment system, where the sewage that exceeds the facility capacity of the sewage terminal treatment plant where the condensate sewage flowing into the sewage terminal treatment plant from the sewage sewage terminal in the primary sedimentation tank is settled to the public waters without being completely treated The reality is that they are stocked.

Thus, the sewage that is discharged from the overflow and sewage is precipitated and removed only a large amount of solids in the process of simple sedimentation, causing a problem of polluting the downstream ecosystem by being discharged to public waters without a considerable amount of pollutants.

In the meantime, the domestic sewage treatment plant has been installed and operated with advanced treatment system through strengthening effluent water quality standard several times, and sewage is properly treated and discharged in Cheongcheon, but in case of rain, sewage exceeding facility capacity of sewage treatment plant is not completely treated As it is overflowed and discharged, it is adversely affecting the water pollution and ecosystem of downstream public waters, and it is urgently required to develop proper treatment technology to solve this problem.

In addition, since excessive chemicals are used in water treatment plants, it is difficult to secure water treatment costs and water quality.

In addition, the amount of pollutants introduced in the existing sewage treatment system is very different according to the flow rate and flow rate of the sewage, so that the filtration process cannot be effectively handled and the head loss caused by the media is different. Backwashing should be carried out regularly or irregularly by filtration time, and there is considerable difficulty in estimating the appropriate backwashing cycle.

If backwashing is not performed in a timely manner in a conventional filtration apparatus, the filtration efficiency is significantly reduced. In addition, the conventional filtration device consumes a lot of backwashing water because it continuously supplies the backwashing water during backwashing so as to overflow the filtration device and discharge sludge together with the washing water to the outside. The large amount of washing water generated in this way has a problem of being filtered by another main treatment process of sewage.

The present invention has been made to solve the above-mentioned problem.

It is an object of the present invention to provide a filtration apparatus that can quickly and effectively remove various types of contaminants, particularly SS and T-P, which will be released from point or nonpoint sources.

In addition, the present invention is designed to significantly reduce the amount of discharged water by circulating the discharged water containing SS to be discharged from the filtration apparatus to the initial filtration step to perform the pre-treatment filtration step again.

In the present invention, after backwashing in a downflow filtration tank, sludge (turbidity) and washing water separated from the porous filter medium are discharged to the outside, in this case, backwash water storage tank through an opening and a discharge pipe provided on the side wall of the downflow filtration tank. The sludge is recycled through the bypass again, and the sludge and the backwash water are quickly discharged before being precipitated or contacted again on the filtration layer to maximize the porosity of the porous media to maintain the treatment speed.

In particular, the present invention is to be able to clean the porous media even if the backwash water is filled up to a certain level in the downflow filter tank, specifically higher than the opening and closing means and does not overflow the downflow filter tank, compared to the backwashing device according to the prior art The consumption of backwash water can be significantly reduced and the backwash cycle or backwash time can be significantly shortened.

In addition, the present invention can selectively configure an upflow filter tank in the downflow filter tank, the sewage can be more effectively filtered through a two-stage filter tank. In particular, the upflow filtration tank can flow sewage upstream into a high concentration treatment filtration tank to filter sewage through a porous flotation filter, while the downflow filtration tank is a low concentration microfiltration filtration tank, and the treated water is treated in an upflow filtration tank. Flow down to allow the filtered water to be refiltered through the porous media.

In addition, the effluent of the backwash to be discharged through the downflow filtration tank according to the present invention is circulated back to the previous stage of the upflow filtration tank to reprocess the backwash effluent to reduce the amount of effluent.

According to the description of the present invention, the present invention is provided to prevent the treatment water, in particular rainwater, river water, lake water, sewage, wastewater, contaminants of various types contained in the constant water is not directly introduced into the water system. In other words, it can be usefully applied for the treatment of water and sewage, or for the treatment of wastewater and river water or polluted lakes.

Filtration device according to the present invention is to form a contaminant of the sewage as a floc through the flocculant to improve the filtering capacity.

In addition, the present invention can reduce the backwash discharge amount by circulating the backwash effluent containing SS in the downstream of the aftertreatment process, and concentrating the SS while performing the pretreatment and the aftertreatment filtration process again.

In addition, the filtration apparatus according to the present invention is provided to maximize the filtration efficiency by maintaining the filtration layer in an optimal state by backwashing the porous media in the downflow filtration tank.

In particular, the filtration device according to the present invention is to meet the characteristics of the present invention applied to water treatment by reducing unnecessary excessive consumption of backwash water.

The present invention to prevent the loss of the porous medium constituting the filter layer by controlling the flow rate of the backwash water to be discharged to the discharge pipe by controlling the opening degree of the opening and closing means as soon as possible after the backwash is not settled back to the filter layer after backwashing. It is supposed to be.

In addition, the present invention, through the filtration tank consisting of two stages, the pre-treatment and post-treatment can be filtered more effectively if necessary.

1 is a process diagram schematically showing a filtration device according to a first embodiment of the present invention.
2 is a process diagram schematically showing a filtration device according to a second embodiment of the present invention.

Now, the filtering device using the porous media of the present invention will be described in more detail with reference to the accompanying drawings. Since the drawings are conceptual diagrams and not schematic diagrams, the size of the device is smaller or larger in the drawings, and does not match the actual size.

1 is a process diagram schematically showing a filtration device according to a first embodiment of the present invention.

As shown, the filtration device of the present invention is the raw water tank 10, the flocculant input unit 20, the downflow filter tank 40, the discharge water storage tank 50 after backwashing, the treatment water tank 80, and the bypass ( 70), but optionally upstream downflow filtration tank (40) for high concentration treatment, more specifically between raw water tank (10) and downflow filtration tank (40), further upflow filtration tank (30) It can be provided. In the detailed description of the present invention, the description is based on a two-stage filtration tank having both an upflow filtration tank 30 and a downflow filtration tank 40 at the same time. Herein, the treatment subject is collectively called sewage.

The raw water tank 10 supplies or stores sewage to be treated in a post process by means of a pump. Sewage contained in the raw water tank (10) is supplied to the upflow filter tank (30) for performing the pretreatment process through the supply pipe (11). When not used with the upflow filtration tank 30, the feed pipe 11 is connected to the downflow filtration tank 40.

The sewage is mixed with the coagulant to be supplied from the coagulant inlet unit 20 in the supply pipe 11 between the raw water tank 10 and the upflow filter tank 30, and is sufficiently mixed with the coagulant through the sewage supply flow to provide floc as flocculent particles. Formed to activate contact with the porous flotation media to provide significant treatment efficiency.

Optionally, the filtration device according to the invention further comprises an instantaneous mixer 12 in the feed tube 11. The instantaneous mixer 12 induces rapid mixing of sewage and flocculant to be guided to the supply pipe 11, and by providing such an instantaneous mixer 12, it is possible to reduce the required site since it does not require the conventionally used mixing paper. On the other hand, since the mixing takes place rapidly, the consumption amount of the flocculant can be reduced. In addition, the instant mixing paper 12 can effectively adjust the amount of admixture of flocculant according to the amount of sewage supplied and the concentration of SS contained in the sewage.

The coagulant introduced into the coagulant inlet unit 20 is, for example, poly aluminum chloride (PAC) or alum, but various coagulants may be selected. This flocculant helps to coagulant sewage.

As the sewage moves from the raw water tank 10 to the upflow filter tank 30, the floc formed by mixing with the flocculant is effectively treated with SS (and BOD) by contact with the porous flotation media provided in the upflow filter tank 30. can do.

As described, the upflow filter tank 30 is provided with a porous flotation filter, and thus, a high concentration sewage treatment process may be performed through contact between the porous flotation filter and the sewage stream containing the floc.

Optionally, the upflow filtration tank 30 may be provided with a separate discharge pipe 31 at the bottom thereof so as to easily remove the concentrated sludge to be settled thereunder. Alternatively, it can be pulled out with a separate pump.

The sewage moving upward in the upflow filtration tank 30 guides the treated water while passing through the upflow filtration tank 30 to the downstream flow filtration tank 40 at its rear end.

The downflow filtration tank 40 causes the treated water filtered in the upflow filtration tank 30 to flow in a downward direction to contact the porous media disposed in the downflow filtration tank 40 to perform a post-treatment filtration process. The downflow filtration tank 40 may remove T-P by coagulation filtration by a coagulant by low concentration fine filtration by means of the filtration layer portion 410 made of porous filter with a high concentration of treated water through a pretreatment process.

The treatment water to be filtered again in the downflow filtration tank 40 is discharged to the treatment tank 80 or the external water system through the outflow pipe 41 provided at the bottom of the downflow filtration tank 40.

Through the continuous treatment of sewage, aggregates or sediments are stacked to block the filtration layer to decrease the filtration efficiency. When the inflow water supplied from the upflow filter tank 30 is filled up in the downflow filter tank 40, the upflow type The backwash water (and / or air) is supplied to block the inflow water supplied from the filtration tank 30 so as to flow upward from the bottom of the downflow filtration tank 40 toward the filtration layer 410.

For reference, the downflow filtration tank 40 may be selectively communicated with the lower portion thereof as necessary to form a space portion along the side wall surface. This space may not only be used as a space to stay before the filtered treated water is discharged to the outlet pipe 41, but more preferably, the backwashing means 440 is not operated when the backwashed water is filled with the backwash water from the outside into the space during backwashing. Without naturally contacting the back washing water evenly across the entire lower surface of the filtration layer 410 to be filled with the backwash water in the downflow filter tank 40.

The backwash water to be supplied by the backwashing means 440 or into the side space portion of the downflow filtration tank 40 is injected in a direction opposite to the flow direction in which the inflow water is filtered, and the suspended solids deposited on the filtration layer are separated from the filtration layer and filtered. The blockage of a layer part can be prevented.

The sludge separated by backwashing, for example, SS, floats to the water surface accommodated in the downflow filtration tank 40 and is led to the discharge water storage tank 50 of the backwashing through the discharge pipe 43 extended in the downflow filtration tank 40.

The effluent storage tank 50 may further mix the coagulant aid supplied from the coagulant aid input unit 60 with the SS to concentrate the SS. The coagulant aid stored in the coagulant aid input unit 60 is, for example, a polymer coagulant. The coagulant aid assists physical flocculant of the effluent containing SS.

In order to promote the mixing of the flocculating aid and the SS, the effluent storage tank 50 further includes an agitator 51.

As shown, the symbolic water of the effluent storage tank can be led through the bypass pipe 70 to the supply pipe 11 between the raw water tank 10 and the upflow filtration tank 30 or the supply pipe between the raw water tank and the downflow filtration tank. More preferably, the circulated water is guided upstream or downstream of the intersection of the coagulant feed pipe extending from the coagulant inlet 20 and the supply pipe 11 extending from the raw water tank 10 to the coagulant aid. The concentrated SS is further mixed with the flocculant and further concentrated to improve the high concentration treatment efficiency in the upflow filter tank 30 so as to reliably filter the treated water to be exported to the outside.

The upflow filtration tank 30 and the downflow filtration tank 40 according to the present invention will be described in more detail below.

Upflow  Filtration tank

The sewage is led to the upflow filter tank 30 through the supply pipe 11 in the raw water tank 10, the upflow filter tank 30 is a pretreatment treatment tank, the sewage flowed into the upflow filter tank 30 is collected and bottomed Settling the sludge to open the discharge pipe 31 to take out the concentrated sludge to the outside. In some cases, it can be discharged with a separate pump.

The upflow filtration tank 30 is supplied with sewage from the bottom of the upflow filtration tank 30 in order to secure a contact space with the porous flotation filter 310 at a high speed, and to be filtered upward. Designed to be discharged, the bottom surface is in communication with the supply pipe (11), near the upper surface of the filtered treated water to flow or guide the downflow filter tank for the post-treatment process.

Optionally, the upflow filtration tank 30 has a first screen 320 arranged across the upflow filtration tank 30 at the top and an upflow filtration tank 30 at the bottom to prevent loss of the porous flotation filter 310. And a second screen 330 arranged across it. The porous flocculent 310 is positioned between the first screen 320 and the second screen 330.

The upflow filtration tank 30 preferably includes a backwashing means 340 to be used for backwashing the porous flotation filter 310, and the backwashing means 340 includes one or more diffusers under the upflow filtration tank 30. Thus, air (or backwashing water, if necessary) can be supplied to the upflow filter tank 30. The air may turbulent flow of the treated water contained in the upflow filter tank 30 to exfoliate sludge, for example, SS, attached to the porous flocculant 310. Optionally, the backwashing means 340 may be disposed directly on the bottom surface of the upflow filtration tank 30 or on the second screen 330. In FIG. 1, the backwashing means is disposed on the second screen 330. .

When the porous flocculent filter 310 is blocked and the filtration efficiency is reduced, sludge is separated through the airflow supplied to the backwashing means 340. The separated sludge and the water filled in the upflow filter tank are transferred along the discharge pipe 31. Can be collected at any location or guided to the effluent storage tank 50, while alternatively it can be further guided to a post-treatment process that performs a low concentration microfiltration process, ie, a downflow filtration tank.

Downflow  Filtration tank

The treated water pretreated in the upflow filtration tank 30 or the sewage supplied directly through the supply pipe 11 in the raw water tank 10 flows into the downflow filtration tank 40, in particular, in the downflow filtration tank 40, the influent flows from above. It is designed to be filtered by passing through the filtration layer portion 410 in a downward flow flowing down. Preferably, the filtration layer 410 is spaced apart in parallel with the bottom surface of the downflow filter tank 40, it is filled with a porous filter 414.

The structure of the filtration layer portion 410 is illustrated in detail in arc A of FIG. Optionally, the filtration layer portion 410 is composed of a support 411, a wire mesh 412, a coarse sand layer 413, and a porous media 414. The support 411 is arranged across the downflow filtration tank 40 and is arranged to sufficiently support the porous media as well as the wire mesh and coarse sand layer to be seated thereon. Wire mesh 412 is arranged on support 411 as shown. The wire mesh 412 is preferably selected in a compact structure so as to prevent the constituent member to be seated thereon, such as coarse sand, from leaking down the filtration layer portion 410. As described above, the wire mesh 412 not only prevents the loss of coarse sand but also helps the upstream movement of the backwash water when backwashing the filtration layer 410. As is known to those skilled in the art, a porous plate or the like may be used instead of the wire mesh to guide the flow of backwashing water so that a thick layer of sand does not pass, which will be collectively referred to as wire mesh.

One or more wire meshes 412 may be stacked to more effectively prevent the outflow of coarse sand.

The porous media 414 is seated on the coarse sand layer 413 arranged on the wire mesh 412 to filter the treated water flowing down in the downflow filter tank (40).

During the filtration treatment, if the inflow from the upflow filtration tank is not quickly filtered by the turbidity deposited on the porous media, and the discharged amount of the treated water is significantly reduced, the inflow water level in the downflow filtration tank 40 is increased. The present invention is to measure the change in the inflow of the downflow filter tank 40 by means of the sensor 50, for example, measuring the inflow water level in the downflow filter tank, the flow rate of the treated water. As the result of measuring the flow rate of the treated water discharged along the outflow pipe 41 or detecting the variation in the inflow water level, more specifically, if the inflow water rises above a predetermined level, for example, When the flow rate of the water does not reach the predetermined flow rate, the backwashing water is supplied upward through the backwashing means 440 toward the filtration layer 410 at the bottom of the downflow filtration tank of the filtration apparatus according to the present invention. Optionally, the backwashing means 440 simultaneously supplies backwashing water and air to assist the backwashing process for separating the solutes.

Outflow pipe 41 is provided on the outer wall of the downstream filter tank 40, it is also possible to omit the outer wall and directly installed in the lower portion of the downstream filter tank (40).

The sensor 50 may detect the level of the backwash water supplied so that the backwash water may be kept higher than the filtration layer part without overflowing the upper portion of the downflow filter tank during backwashing. The level of backwash water may be adjusted so that the backwash water is supplied by a predetermined level. Of course, the backwash water may be supplied at a predetermined cycle without using a sensor, and a constant amount of backwash water may be supplied to backwash and then discharged. This also does not depart from the scope of the invention.

The backwash water is injected in a direction opposite to the flow direction in which the influent is filtered, dispersing the sludge stuck on the surface while dispersing the porous media 414 blocked by the sludge in the filtration layer 410 to prevent clogging of the filtration layer. prevent. When the backwash water is supplied, the sludge (pollutant) and the porous medium that are blocking the porous media 414 rise up, and when the supply of the backwash water stops, the porous media sinks again, and when the backwash water is discharged, the sludge is discharged. Done.

The sludge separated by the backwash is carried out to the discharge water storage tank 50 through the opening and closing means 42 for discharging the backwash water and the discharge pipe 43 provided in the downflow filter tank 40.

The present invention is provided with the opening and closing means 42 on the side wall surface of the downflow filter tank 40, in particular the opening and closing means 42 is higher than the filtration layer portion 410 and shown in the downflow filter tank 40 Located below the top, it is opened or closed to allow backwash water and sludge to be taken out as needed. Specifically, the opening and closing means 42 is positioned adjacent to the upper portion of the filtration layer portion 410, it is preferably located below the intermediate point between the top of the downflow filter tank and the filtration layer so that the filter medium is not swept away by the backwash discharge water. Do.

After backwashing, the opening and closing means 42 of the downflow filtration tank 40 is partially or completely open to carry out the backwashing water containing sludge to the outside. While the sludge is discharged to the outside by piggybacking on the flow flow of the backwash water moving to the open opening and closing means 42, the opening and closing means 42 according to the present invention is opened from the top first and the backwash water and sludge to the discharge pipe to be communicated. By controlling the flow rate of the porous filter 414 that is settled on the filtration layer portion can be prevented from being swept away by the backwash water discharged. Preferably, the sluice member 421 of the opening and closing means 42 may be gradually opened in consideration of the water level of the backwash water to be discharged. The opening and closing means 42 may control the degree of opening according to the level of the backwash water to be discharged from the downflow filtration tank so that the backwash water and the sludge can be discharged as much as possible.

As shown in arc B, the opening and closing means 42 is in the form of a hinged hydrologic gate. The sluice member 421 of the opening and closing means 42 is hingedly connected to the frame 422 surrounding the inlet of the discharge pipe 43 via the hinge portion 423, and the hinge portion 423 The discharge pipe 43 may be opened or closed by a rotational movement (shown by an arrow) of the sluice member 421 around the center. The frame 422 in close contact with the sluice member 421 is preferably a flexible material, but the frame 422 itself may be omitted.

In particular, the opening and closing means 42 is preferably arranged so that the hinge portion 423 is arranged at the lower end to open from the top of the water gate when the water gate member 421 is opened. In this arrangement, when the sludge is separated from the suspended porous media during backwashing and the supply of the backwash water is stopped, the porous media 414 is seated on the coarse sand layer 413, and the porous media 414 is sufficiently After settling, the sludge exfoliated from the porous media can be discharged quickly along the discharge pipe 43 through the open opening and closing means 42 before it sinks back onto the porous media, in particular the station filling the interior of the downflow filter tank. It is opened from the top side of the water gate to allow the drainage from the top of the wash water to slowly drain.

In order to slow down the sludge being blocked in the filter medium during the filtration process, the downflow filtration tank 40 of the present invention may further include an agitator 45, which may be mainly used during the filtration process. For example, the agitator 45 operates during the normal operation of the downflow filtration tank 40 to delay the deposition or deposition of sludge suspended in the treated water to maintain the treatment speed and increase the cycle of the backwashing process to increase the operational efficiency of the facility. To be able.

Optionally, the opening and closing means 42 may be opened and closed by rotatably moving the hydrological member 421 on the hinge shaft mechanically or electrically through a reciprocating movement of a driving means (not shown) such as a cylinder. That is, the hinge shaft connecting the hinge portion 423 and the sluice member 421 may be connected to, for example, a motor or a pneumatic cylinder to drive the sluice member 421.

Here, the porous filter 414 to be used in the downflow filter tank 40 of the present invention mixes a resin and a blowing agent in a glass powder having a small particle size, and heats the mixture to a high temperature (for example, 800 to 1,100 ° C.) It was pulverized by cooling, and had a particle size of 3 mm or less, porous particles having a volume density of 0.4 to 1.2 g / cm 3 at drying and a volume density of 1.2 to 2.0 g / cm 3 at water saturation. For reference, the volume density at the time of water saturation of the porous filter medium 414 to be applied to the present invention is 1.2 to 2.0 g / cm 3, and preferably 1.3 to 1.8 g / cm 3.

In addition, the porous flotation filter 310 to be used in the upflow filter tank 30 of the present invention mixes a resin and a foaming agent in a glass powder having a small particle size, heats the mixture to a high temperature, cools it and grinds it to dry. When the volume density is 0.2 ~ 0.6g / cm3, the porosity is 50 ~ 80%, the size is 20 ~ 50mm, and the volume density is less than 1g / cm3 when it saturates water, but it floats in water. It is better to be smaller than 0.8 g / cm 3.

In other words, the porous filter medium 414 and the porous flocculant 310 are formed by mixing a resin and a blowing agent in a glass powder, heating it to a high temperature, cooling and pulverizing it, and the porous filter material 414 is pulverized with small bubbles. Destroyed and precipitated, the porous flotation filter 310 is maintained in the air bubbles are maintained in the water.

In particular, considering the volume density during water saturation of the aforementioned porous media 414, when the volume density is 1.2 g / cm 3 or less, it is similar to the density of water and is easily swept by the flow of flowing water and thus on the filtration layer part. Only the present invention has a problem that the porous media to be evenly distributed to one side or sludge penetrates easily between the media, and when the bulk density is 2.0 g / cm 3 or more, it does not easily rise, resulting in the rise of the porous media. It is not recommended because the injection pressure of the backwash water must be increased considerably because it is not suitable for the unique backwashing process.

In other words, the porous media during water saturation is greater than the density of water (1 g / cm 3) and can be positioned without disturbing (scattering) the flow of inflow downstream during filtration, whereas it is relatively lighter than the density of ordinary sand. When backwashing, the backwashing water can be easily lifted and separated from contaminants. Therefore, the backwashing water and the backwashing time can be reduced.

For reference, the filtration process and the backwash process in the downflow filtration tank of the filtration device according to the first embodiment of the present invention will be briefly described.

Downflow filtration tank 40 according to the present invention preferentially supplies the influent to the housing as an inlet pipe. The supplied influent passes through the filtration layer 410 provided in the downflow filtration tank, and undergoes a process in which sludge is filtered by the porous media. During this filtration process, the inlet and outlet pipes are opened and the backwashing means and the opening and closing means are blocked.

With the continuous supply of influent, the downflow filtration tank continuously performs the filtration process, which results in lower filtration efficiency than the first time when it is operated for a long time or when the concentration of turbidity contained in the influent is high.

If the sludge is excessively trapped on the outer surface of the porous media 414 of the filter layer 410 and the filtration resistance is increased, the filtration efficiency is lowered, while the passage speed of the filter layer is significantly lowered, while the influent is continuously supplied. The level of influent to be accommodated in the downflow filtration tank will be high. That is, when the filtration layer portion is blocked, the treatment performance is lowered and the flow rate of the treated water to be discharged to the outlet pipe 41 will also be significantly reduced. The quantity change is detected by the sensor 50 as a means to determine the backwash cycle.

Any predetermined value (e.g., inflow water level, flow rate of treated water, etc.) determines the backwashing operation. In the case where backwashing is required, first, the inlet pipe is closed to shut off the inflow water supply. do.

Then, only the inflow water remaining in the housing of the downflow filtration tank is filtered to discharge water through the outlet pipe 41 to empty the inside of the downflow filtration tank. Optionally, only the upper water body of the filtration layer 410 may be discharged in order to reduce the amount of backwash water supplied.

With the inlet and outlet pipes 41 and the discharge pipe 43 closed, only the backwashing means 440 is opened to supply the backwash water upwards from below the filtration layer 410. The backwashing water is supplied in an upward flow to penetrate the filtration layer 410 from the bottom up as described above, wherein the backwashing water is distributed evenly over the filtration layer 410. If the backwashing water is not evenly distributed, the influent flows only to the washed portion during filtration, and the filtration speed is increased only at that portion, and conversely, partial blockage of the filter layer may occur at the insufficient washing portion.

The backwashing water is supplied to allow the porous media 414 to float together with the backwashing water in the filtration layer 410 to backwash the filtration layer 410. The sludge adhering to the porous media is separated by the friction between the porous media 414 or the shear force of the water through the backwash or the backwash / air injection.

For reference, the backwash water is preferably limited to the amount of backwash water so as not to overflow the downflow filtration tank of the present invention, more preferably, the amount of backwash water is higher than the opening and closing means 42 and lower than the top of the downflow filtration tank. Adjust and supply. The water level of the backwash water may also be detected through the sensor 50. The supply of the backwash water is not limited to the backwashing means 440 in the drawing, and means for supplying the backwashing water under the filtration layer 410 to another pipe or hose is included in the scope of the present invention.

The porous filter media 414 that flows by blocking the backwash water is stabilized by being precipitated on the thick sand layer, but the porous media filter 414 is heavier than the sludge and is quickly seated in the thick sand layer 413.

After the porous media 414 is sufficiently settled, the water gate member 421 of the opening / closing means 42 is slowly opened from the top in order to discharge the sludge separated from the porous media over promptly. Through the open discharge pipe 43, the sludge together with the backwash water may be taken out to the outside. During discharge, the water gate member 421 of the opening and closing means 42 is opened in correspondence with the level of the backwash water and the sludge contained in the housing. At this time, the inlet pipe, the outlet pipe 41 and the backwashing means 440 are closed.

2 is a process diagram schematically showing a filtration device according to a second embodiment of the present invention. The second embodiment of the present invention shown in FIG. 2 replaces the hinged opening / closing means 42 provided in the downflow filtration tank 40 in the first embodiment of the present invention shown in FIG. The structure is similar except that the lifting type opening and closing means 42 'is provided separately. Accordingly, descriptions of similar or identical components will be omitted herein for the sake of clarity of understanding.

Opening and closing means 42 'is the same as the opening and closing means 42 of FIG. (Ie, effluent storage tank 50) to be opened for export. Of course, the opening and closing means 42 'must be closed during filtration or during backwashing.

As shown in the arc C, the opening and closing means 42 'is in the form of a lifting gate. The sluice member 421 ′ of the opening and closing means 42 ′ may open or close the inlet of the discharge pipe 43 through reciprocating movement of lifting and / or lowering.

The opening and closing means 42 ′ is configured to vertically move the sluice member 421 ′ by means of various types of lifting devices M to open and close it. Here, the lifting device mentioned is, for example, by a motor or a pneumatic cylinder, and details thereof are not described herein.

Preferably, the opening and closing means 42 ′ is open from the top like the opening and closing means 42 of FIG. 1. Opening and closing means 42 ′ according to the present invention is controlled by the flow rate of the backwash water and the sludge as a discharge pipe to be opened first from the top to be swept away by the backwash water discharged from the backwash water discharged from the porous media that is submerged on the filtration layer portion Can be prevented. It is preferable that the sluice member 421 ′ of the opening and closing means 42 ′ is gradually lowered in consideration of the level of the backwash water to be discharged.

On the other hand, the opening and closing means 42 and 42 ′ may be opened and closed to discharge the backwash water together with the sludge after the backwashing is performed according to a preset backwashing cycle, which is also not outside the scope of the present invention. The same applies to the opening / closing means 42 and 42 'made of valve means.

It is also to be understood that the invention is not limited to the foregoing detailed description and accompanying drawings, but may be modified within the scope and scope of the following claims.

Claims (14)

A filtration apparatus for treating sewage through flocculation and filtration,
Supply pipe 11 for supplying the sewage to be treated; And
A coagulant inlet unit 20 for storing a coagulant and communicating with a conveying pipe for supplying the coagulant to the supply pipe 11;
In order to filter the sewage guided to the supply pipe 11 in a downward flow, the filter layer 410 having a porous media 414 spaced from the bottom by a predetermined distance from the bottom surface, and to discharge the treated water to the outside. The outflow pipe 41 located below, the back washing means positioned below the filtration layer portion to supply the back washing water, the discharge pipe 43 for discharging the sludge and the back washing water to the outside, and the lower than the filtration layer portion 410 A downflow filtration tank (40) having opening and closing means (42, 42 ') positioned on the sidewall surface of the flow filtration tank (40) to control the opening and closing of the discharge pipe (43); And
And a discharge water storage tank (50) for collecting the sludge guided to the discharge pipe (43) through the opening and closing means (42, 42 '),
The opening and closing means 42 and 42 ′ are opened and closed in a set backwash cycle or aperiodically to communicate the downflow filtration tank 40 and the discharge pipe 43.
The opening and closing means 42 and 42 ′ are positioned adjacent to the upper portion of the filtration layer portion 410, and are disposed between the upper portion and the filtration layer portion of the downflow filter tank 40 so that sludge and backwash water are discharged without overflowing to the upper portion. Ultra-fast backwashing device, characterized in that located below the intermediate point.
According to claim 1, Porous flocculent 310 for filtration treatment in contact with the sewage so as to pre-flow the sewage flowing through the supply pipe 11 to the upstream, and located on the bottom to send the sludge to the outside The upflow filter tank 30 having a discharge pipe 31 and a backwashing means 340 disposed below to backwash the porous flocculant 310 are disposed in front of the downflow filter tank 40. Filter made.
According to claim 2, having a first screen 320 arranged across the top of the upflow filter tank 30 and the second screen 330 arranged across the bottom of the upflow filter tank 30, Filtration device, characterized in that for positioning the porous flotation filter 310 between them (320,330).
The filter layer 410 of claim 1, wherein the filtration layer 410 includes a support 411 arranged across the downflow filtration tank 40, at least one wire mesh 412 disposed on the support 411, and the wire. Filtration device, characterized in that consisting of a coarse sand layer 413 that does not pass through the mesh, and a porous medium 414 disposed on the sand layer 413.
The method of claim 1, wherein the porous filter 414 is a granulated body obtained by heating a mixture of a resin and a blowing agent mixed with a glass powder having a small particle size to a high temperature and then cooling the mixture to a high temperature, the granular body having a particle diameter of 3 mm. Or less, and a dry density of 0.4 to 1.2 g / cm 3 and a dry density of 1.2 to 2.0 g / cm 3.
The method of claim 2, wherein the porous flocculant 310 is a glass powder having a small particle size is mixed with a resin and a blowing agent, and the mixture is heated to a high temperature to cool and pulverized it, the volume density during drying 0.2 ~ 0.6 g / cm 3, volume density during water saturation is less than 1 g / cm 3, porosity of 50 to 80%, the filtration device characterized in that the size of 20 to 50mm.
According to claim 1, wherein the supply pipe 11 is further provided with an instantaneous mixer 12, the instantaneous mixer 12 of the sewage to be supplied to the supply pipe 11 and the flocculant inlet 20 Filtration device, characterized in that to help the mixing of flocculant.
According to claim 1, wherein the filtration device is further provided with one or more water level or flow rate sensor 50 to determine the backwash time, the backwash water is higher than the discharge pipe 43 and does not overflow the filtration tank 40 Filtration device characterized in that it is possible to control the amount of backwash water.
The filtration apparatus according to claim 1 or 2, further comprising a bypass tube (70) for fluid communication from the discharge water storage tank (50) to the supply pipe (11).
The filtration apparatus according to claim 1, further comprising a coagulation aid input unit (60) for storing the coagulation aid to be supplied to the discharge water storage tank (50).
According to claim 1, The opening and closing means 42 is a watermark member 421 and the watermark member 421 connected to the side wall surface of the downflow filter tank 40 by the hinge portion 423 to the inlet of the discharge pipe 43 Filtration device, characterized in that in the form of a hinged hydrology consisting of a drive means to help the rotation of.
The water gate member 421 'and the water gate member 421 of claim 1, wherein the opening / closing means 42' moves up and down to open and close the discharge pipe 43 on the side wall of the downflow filtration tank 40. Filtration device, characterized in that the lifting type of the gate consisting of lifting means to help the lifting and lowering of ').
delete The filtration apparatus according to claim 1, wherein the downflow filtration tank (40) further comprises a stirrer (45).

Images