JP3388378B2 - Filtration equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter facility such as a filter pond and a filter tank provided in a water purification facility, and more particularly to a method for efficiently cleaning a filter medium layer. Related to the structure. 2. Description of the Related Art As shown in FIG. 2 , a water purification facility is generally provided with a sand basin 1 from a river or the like.
The flocculant A and the oxidant B are injected into the water taken into the landing well 2 through the, and the floc is separated in the flocculation settling basin 3. It is configured to inject the agent C to make clean water and supply it from the reservoir 5. [0003] In such a water purification facility, when the organic pollution of the raw water is progressing, in addition to the above facilities, a biological treatment facility for removing various organic substances, ammonia, etc., a deodorization, a decolorization, and a sterilization. Ozone treatment equipment that is effective in removing BOD and COD, and advanced water purification treatment equipment such as activated carbon treatment equipment that removes off-flavors and the like are provided. [0004] However, in a newly constructed water purification facility, the above-mentioned advanced water treatment facilities can be installed from the beginning according to the quality of the raw water. Is difficult to add. [0005] For this reason, in existing water purifying equipment, low-boiling organic compounds such as off-flavor-causing substances, synthetic detergents, phenols, trihalomethanes and their precursors, and trichloroethylene which cannot be removed by ordinary water purification treatments such as coagulation, sedimentation and sand filtration. Activated carbon capable of removing trace harmful substances such as chlorine compounds and pesticides, chemical substances temporarily mixed in accidents in water source areas, and other harmful substances is put into the landing well 2 and the like. In this case, so-called powdered activated carbon of about 200 mesh is used as the activated carbon used at this time. [0006] The treatment using the activated carbon powder has the advantages that not only can the existing facility be used as it is, but it is economical when the activated carbon treatment is carried out for a short period of time, but it has a long-term advantage. It becomes uneconomical when used for
In addition, black sludge containing activated carbon is generated, so that special attention must be paid to disposal and treatment management. On the other hand, when granular activated carbon having a particle size of 0.2 mm or more is used as the activated carbon, the activated carbon can be used repeatedly by regenerating the activated carbon. Because there is no occurrence of
There is an advantage that processing management is easy. However, when the above-mentioned granular activated carbon is used, it is usually necessary to separately install a filtration tank dedicated to activated carbon, so that it was not possible to cope with the existing water purification facility as described above. That is, when newly installing activated carbon filtration equipment in an existing water purification facility, for example, half of the existing filtration equipment (sand filtration pond) will be used as the activated carbon filtration pond. And the water purification capacity of the whole water purification facility is reduced by half. This is substantially the same when the activated carbon filtration equipment is installed in another equipment part, and the processing capacity of the water purification equipment is greatly deteriorated. Further, it may be necessary to newly install or change ancillary equipment such as a pump, which may cause a cost problem. Therefore, the present invention can perform the activated carbon treatment while using the filtration facilities such as a filtration pond and a filtration tank provided in an existing water purification facility as they are, and
It is an object of the present invention to provide a filtration facility that can be reused by using granular activated carbon and that can efficiently clean a filter medium layer. [0010] In order to achieve the above-mentioned object, the filtration equipment of the present invention is a filtration equipment for supplying water to be treated from above a filter medium layer and extracting treated water from below the filter medium layer. In a filtration facility such as a pond or a filtration tank, the filter medium layer is formed by laminating a gravel layer, a sand layer, and a granular activated carbon layer in this order from below , and a main pipe connected to a washing water supply source is provided above the filter medium layer. branches a plurality of branch pipes from the main pipe, as well as branches a plurality of branch pipes from the main pipe provided in the upper portion of the filter layer, and the tip of the branches pipe is opened to the gravel layer. [0011] Then, the intermediate portion of the branch pipe, as a drive source a washing water supplied from the main pipe provided with a ejector for sucking air from the air supply pipe which is provided separately from the tip opening of the branch pipe And a nozzle for jetting a water-air mixture. [0012] In particular, the present invention relates to the present invention, wherein the above-mentioned filtering equipment is an existing sand filter, and a part of the sand constituting the filter medium layer is extracted.
In filtration equipment forming the granular activated carbon layer by laying the granular activated carbon where a predetermined thickness, as it uses the surface cleaning tube is provided in the common sand filter as main, the main <br/> tube With the connected to the existing washing water supply source, an ejector for air suction is installed in the middle of the branch pipe to the gravel layer below the filter medium layer, and the ejector sucks air using the water flow supplied from the main pipe as a drive source. This air is ejected from the nozzle at the tip of the branch pipe for air cleaning. According to the above arrangement, the water to be treated is treated with activated carbon in a granular activated carbon layer to remove off-flavor substances and the like, and then subjected to a filtration treatment by ordinary sand filtration. Further, when the backwashing the filter medium, supplies the backwash water by jetting tip or et water air mixture of the lateral pipe, it is possible to perform the air cleaning regular backwashing. In particular, if the existing filter pond is modified to change the upper part of the sand layer to a granular activated carbon layer, the filter medium layer will be thickened and the tendency of deep filtration will increase. By doing so, a sufficient cleaning effect can be obtained. When the existing filtration equipment is modified to the above configuration, the air cleaning can be easily performed without major modification by using the surface cleaning pipe provided in the existing filtration equipment as the main pipe. be able to. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment of a sand filtration pond as a filtration facility to which the present invention is applied, and shows an embodiment in which an existing sand filtration pond is modified into a method using a combination of activated carbon treatment. The sand filter 11 is provided with a gravel layer 13 and a sand layer 1 on a perforated block type water collecting device 12 provided at the bottom.
4, a granular activated carbon layer 15 is stacked and arranged, a treated water outflow pipe 16 also serving as a backwash water introduction pipe is provided at the bottom, and a treated water inflow pipe 18 and a drainage trough 19 for backwash water discharge are provided at the top. A main pipe 21 having a plurality of branch pipes 20 for cleaning air is provided in the granular activated carbon layer 15. The sand filtration basin 11 is an existing sand filtration basin that has been used as an ordinary sand filtration basin without the granular activated carbon layer 15 and the sand layer 14 is larger than that shown in the figure. This is provided with a granular activated carbon layer 15. Further, the main pipe 21 is used as a surface cleaning pipe for cleaning the surface of the sand layer 14 and is provided slightly above the previous sand layer 14. That is, the sand filtration pond 11 shown in this embodiment
Is an existing facility used as a normal sand filter with a thickness of the gravel layer 13 as a support material of 200 mm and a thickness of the sand layer 14 of 600 to 700 mm. In the present embodiment, the sand of the sand layer 14 is used. Is removed by 200 to 300 mm to 400 mm in thickness, and a granular activated carbon layer 15 is laid on the upper surface of the sand layer 14 to a thickness of 700 mm. Along with the remodeling of the filter medium layer for providing the granular activated carbon layer 15, a plurality of branch pipes each having a tip extending into the gravel layer 13 are added to the main pipe 21 used as a surface cleaning pipe. 20 branches formed at predetermined intervals, said branch pipe
An ejector 31 for air suction is provided at an intermediate portion of 20,
The cleaning air is sucked by the ejector 31 and the branch pipe is drawn.
So that the water-air mixture is ejected from the tip nozzle 32
It is composed . The ejector 31 is supplied from the main pipe 21.
Separate air supply using the supplied cleaning water as a drive source
It sucks air from the pipe 33 and becomes a driving source
The cleaning water used the main pipe 21 as a surface cleaning pipe.
Water from the same source can be used
Wear. That is, as described above, the present embodiment
To carry out the remodeling to provide a granular activated carbon layer 15 in the filtration pond
Accordingly, the main pipe 21 used as the surface cleaning pipe is
At the end there is a nozzle 32 arranged in the gravel layer 13,
A plurality of branch pipes 20 having an ejector 31 in the middle part
At predetermined intervals, and the ejector
31 is provided with an air supply pipe 33. in this way
By configuring, the surface cleaning connected to the main pipe 21 can be performed.
The water supply system for purification can be used as it is.
Air cleaning without using new power.
And become possible . As described above, the nozzle 32 is provided in the gravel layer 13.
The sand layer 14
And the thickness of the filter medium layer composed of the granular activated carbon layer 15 is
Even if all of them increase, backwash water flows from treated water discharge pipe 16 during backwash.
And a jet of water-air mixture from nozzle 22
The sand and the granular activated carbon layer 15 of the sand layer 14 are discharged.
Can be efficiently backwashed . The activity used for the granular activated carbon layer 15
As charcoal, granules with a particle size in the range of 1.2 to 1.5 mm
Preferably, activated carbon is used. Granularity in this particle size range
By using activated carbon, the settling velocity of granular
Slightly slower or about the same as
Suitable for backwashing of sand layer 14 and granular activated carbon layer 15
It is possible to obtain a proper expansion. Moreover, processing capacity and communication
Water resistance can also be set to an appropriate value, and filtration speed
From 120 to 15 which is a suitable range for the sand filtration pond 11.
0 m / day. For example, if the diameter of the granular activated carbon is small, the sedimentation speed becomes slow, the activated carbon rises to the drainage trough 19 with the rise of the backwash water, and the activated carbon flows out of the drainage trough 19 together with the backwash water.
Further, if the diameter is too small, the flow resistance increases, which affects the amount of treated water. On the other hand, if the particle size is large, the expansion of the activated carbon during cleaning becomes small, and the cleaning effect becomes insufficient. In addition, the capacity per unit capacity of the activated carbon is reduced. As described above, by providing the granular activated carbon layer 15 on the upper surface of the sand layer 14, it is possible to perform the activated carbon treatment of the water to be treated without providing an activated carbon treatment tank separately from the sand filtration pond 11. At this time, the granular activated carbon itself also acts as a part of the filter medium. Therefore, even if the sand layer 14 is partially removed and the thickness of the sand layer itself is reduced, the granular activated carbon layer 15 is present on the upper surface of the sand layer 14. The filtration capacity of the pond 11 is rather improved, and the activated carbon treatment and the filtration treatment can be performed simultaneously. The thickness of the granular activated carbon layer 15 may be determined according to the relationship between the filtration rate and the space velocity.
The upper and lower positions of 9 may be determined from the relationship between the expansion due to backwashing at the determined thickness of the granular activated carbon layer 15, the backwash speed, and the terminal speed of the turbid matter. As shown in the above embodiment, a granular activated carbon layer 15 using a granular activated carbon having a particle size of 1.2 to 1.5 mm is formed on the upper surface of the sand layer 14 of the ordinary sand filtration pond 11 at a predetermined thickness. By laying, the activated carbon treatment can be performed simultaneously in addition to the filtration treatment, and a sufficient cleaning effect can be obtained by adopting a structure capable of performing air cleaning. Also,
Even in the existing sand filter 11, it is possible to easily carry out the process by replacing a part of the sand in the sand layer 14 with granular activated carbon and using a normally installed surface cleaning pipe as a cleaning air introduction unit. Activated carbon treatment of the water to be treated can be performed without greatly changing the equipment itself, and the off-flavor substances and the like in the water to be treated can be removed. Further, by using the granular activated carbon having the above-mentioned particle size range and taking out the activated carbon at predetermined intervals and performing a regeneration treatment, the activated carbon itself can be used for a long period of time and sludge is not generated. Therefore, maintenance is easy. Further, even in the existing facilities, the sand layer 14
Part of the sand is replaced with granular activated carbon, the position of the drainage trough 19 is changed according to the thickness of the granular activated carbon layer 15, and a branch pipe 20 is provided in the surface cleaning pipe to connect the surface cleaning pipe to a blower or the like. It is only necessary to use the existing equipment for backwashing such as a washing pump and a flow meter, so that the cost by adding the activated carbon treatment is small. Therefore, the activated carbon treatment can be carried out without changing the sand filtration pond provided in the existing water purification facility as it is, and the existing water purification facility can be improved. The same can be applied to water purification facilities. [0029] [0030] [0031] [0032] In the above you施例, a particularly preferred embodiment of the present invention has been described by way of example to modify the existing filtration equipment, similar to that of new It is also possible to adopt a structure. As described above, in the filtration equipment of the present invention, the granular activated carbon layer is laid on the upper surface of the filter medium layer, so that the activated carbon treatment can be performed without separately providing activated carbon treatment equipment. In particular, existing filtration equipment can be easily diverted as equipment for performing activated carbon treatment and filtration treatment. Further, even if the thickness of the filter medium layer is increased by the air blowing means, a sufficient cleaning effect can be obtained. Therefore, the activated carbon treatment can be easily performed even in the existing water purification facility, and since the granular activated carbon is used without using the powdered activated carbon, safe treatment can be continuously performed, and the activated carbon can be regenerated. Since it can be used repeatedly by performing, it is economical even for a long-term treatment, and there is no generation of sludge, so that maintenance is easy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a filtration facility showing one embodiment of the present invention. FIG. 2 is a flowchart showing a general configuration of a water purification facility . [Explanation of Signs] 11: sand filter pond, 12: water collecting device, 13: gravel layer, 14
... sand layer, 15 ... granular activated carbon layer, 16 ... treated water outflow pipe, 1
8 ... inflow pipe for treated water, 19 ... drainage trough, 20 ... branch pipe,
21: Main pipe, 31: Ejector, 32: Nozzle, 33
... Air supply pipe

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 24/02 B01D 24/46 B01D 29/62 C02F 1/28

Claims (1)

(1) In a filtration facility such as a filter pond or a filter tank for supplying water to be treated from above the filter medium layer and drawing out the treated water from below the filter medium layer, the filter medium layer comprises: Are formed by laminating a gravel layer, a sand layer, and a granular activated carbon layer in this order from below , and a main pipe connected to a cleaning water supply source is provided above the filter medium layer , and a plurality of branch pipes are formed from the main pipe. Branch, in the middle of the branch pipe,
Separately provided with cleaning water supplied from the main pipe as a drive source
Equipped with an ejector that sucks air from the air supply pipe
In addition, a tip end of the branch pipe is opened to the gravel layer, and a nozzle for jetting a water-air mixture is provided at the tip end opening.
Filtration equipment, characterized in that was example.