JPS5836612B2 - Moving bed filtration device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a moving bed filtration device.

Filtration is a solid-liquid separation operation that has been used since ancient times in a wide range of fields, from the mineral mining industry to the chemical industry to the industrial wastewater treatment sector. As the importance of the field of tertiary water treatment such as water removal increases, the processing capacity also increases, and in some cases, methods and devices for rationally and efficiently filtering even extremely difficult-to-filter suspensions are becoming increasingly important. It is becoming more and more needed.

Currently, the main filtration method used in the field of tertiary water treatment is, in principle, the so-called sand filtration method, and in the past, slow sand filtration was used, but recently, pollution of water sources has become more prevalent. The rapid sand filtration method is becoming the mainstream due to the adoption of pseudo-sedimentation equipment and site and management issues associated with the change in the number of sand filters.

However, even with this rapid sand filtration method, most of the methods are fixed bed methods, and suspended solids in the water to be treated (hereinafter referred to as SS) are used.

) is removed at the surface of the filtration layer, so not only does the entire filtration layer not function effectively, but after filtration for a certain period of time,
Filtration must be temporarily stopped and surface cleaning, backwashing, etc. must be performed to remove SS trapped in the filter layer.
Management was extremely complicated.

Further, in the conventional fixed bed method, it has not been possible to quickly and effectively deal with fluctuations in the SS concentration or the amount of the liquid to be treated.

The present invention was made to solve the above-mentioned problems in conventional filtration methods, and allows continuous filtration without interrupting the filtration process. It is an object of the present invention to provide a filtration device that can effectively perform filtration.

The moving bed type filtration device of the present invention has a filter media supply port at the top that can continuously supply filter media into the interior, a waste filter media outlet for extracting waste filter media at the bottom end, and a continuous flow of the liquid to be treated into the interior at the bottom. There is a filtration tank equipped with a treated liquid supply port for supplying the treated liquid, and a filtration tank equipped with a treated liquid outlet at the top that continuously discharges the liquid that has risen inside the filtration layer to the outside of the tank, and a waste filter medium extraction port. Means for supplying slurry-like waste filter media to an upper filter media supply tank through a liquid pump, a transfer pipe, and a filter media regeneration device without being exposed to the outside air, and powder for monitoring the stacking height of filter media in the filtration tank. A face meter, and in the filtration tank, there are provided a distributor connected to the treated liquid supply port, a water collector connected to the treated liquid outlet, and a baffle plate placed directly above the waste filter medium outlet. A dispersion plate placed directly below the filter medium supply port is provided, a filtration layer is stacked in the filtration tank from the bottom of the tank to the level of the treated liquid outlet, and a layer is further stacked at a constant height on top of the filtration layer. Filter media layers are stacked, and the filter media is supplied and extracted in accordance with monitoring by the powder level meter so that a space for receiving the filter media is always formed between the filter media layer and the top of the filter tank. It is characterized by

As the filtering medium, sand, anthracite, glass, activated carbon, activated alumina, silica gel, porcelain, synthetic zeolite, hexane resin, etc. can be used.

Below, drawings of embodiments of the filtration device of the present invention will be described in detail.

The filtration tank 1 has a cylindrical shape with an inverted conical bottom, a waste filter media outlet 10 is provided at the lower end, and a filter media supply port 8 is provided at the top.
A liquid supply port 2 to be treated is provided at the bottom, and a port h1 above it is provided.
A treatment liquid outlet 6 is provided in the tank, a distributor 4 is connected to the supply port 2 in the tank, a water collector 5 is connected to the outlet 6, and a dispersion plate 9 is provided directly below the filter medium supply port 8 at the top. A baffle plate 13 is disposed directly above the waste filter medium outlet 10 at the lower end.

An extraction port 10 at the lower end of the filtration tank 1 is connected to a pump such as a water ejector 15 via an extraction valve 11 and a waste filter medium receiver 14, and is connected to a centrifugal separator such as a cyclone 17 via a pipe 16. Here, the SS is separated from the filter medium and the regenerated filter medium is returned to the filter medium supply port 8.

The filter medium filling surface 12 in the filtration tank 1 is monitored by a powder level meter (not shown), and by supplying and extracting the filter medium according to the monitoring by this powder level meter, the filter medium filling surface 12 is connected to the processing liquid outlet 6. is maintained above h2.

A pipe (not shown) connected to the processing liquid outlet 6 rises upward, and the filter medium filling surface 12 is always submerged in water.

Next, the effect of this operation will be explained.

The water to be treated containing SS is introduced into a filtration layer 3 filled with a particulate filter medium inside the tank body 1 through a liquid supply port 2 provided at the bottom of the tank body 1 .

At this time, the distributor 4 evenly distributes the liquid to be treated over the entire cross section of the tank 1.

The liquid to be treated passes through the filtration layer 3 in an upward flow, is filtered and separated from the filter medium by the filtrate collector 5, and flows out of the tank 1 from the treated liquid outlet 6.

In addition, when using a filter medium with a relatively small specific gravity, the weight of the filter layer 7 filled up to the upper part of the processing liquid outlet 6 presses the filter medium of the filter layer 3. Does not cause swelling or fluidization.

Normally, it is sufficient for the height h2 of the filter medium layer to prevent this expansion and fluidization to be at most several percent of the height h1 of the filter layer.

The filter medium is continuously or indirectly supplied to the filter tank 1 as a slurry from the filter medium supply port 8 at the top of the filter tank 1 by an appropriate means such as a pump, a water ejector, a pressure tank (not shown), etc.

In this case, the filter medium may be slurried with the treatment liquid.

The filter medium is evenly distributed over the entire cross section of the filter tank 1 by the dispersion plate 9.

The filter material filling surface 12 is monitored by a powder level meter (not shown), and the filter material filling layer height h1+h2 including the filter material layer height h2 is controlled to be substantially constant.

On the other hand, the filter medium that has captured SS is continuously or intermittently extracted in the form of slurry from the waste filter medium outlet 10 provided at the lower end of the filter tank 1, passes through the waste filter medium receiver 14, the water ejector 15, and then passes through the pipe 16. The inside is sent to cyclone 17 as a slurry,
Only then is the SS separated, and the regenerated filter medium is appropriately returned to the filter tank 1 from the filter medium supply port 8 in a wet state.

The filter medium regeneration circulation circuit from the waste filter medium outlet 10 to the filter medium supply port 8 does not come into contact with outside air, and moreover, the filter medium is transported in the form of slurry throughout.

When waste filter media is extracted intermittently, mud balls formed by SS trapped in the filter media on the inlet side of the liquid to be treated are loosened by the force of the intermittent extraction and are discharged outside the filtration tank. This has the advantage of being easier to use.

Furthermore, if waste filter media and SS are separated in the receiver 14 by stirring, washing with water, etc., even during the subsequent transfer process within the pipe, there will be no collision of filter media particles with each other or the pipe wall, friction, or washing action due to liquid flow. Since the SS is separated from the filter medium, the filter medium can be reused without the need for a particularly large-capacity waste filter medium relay tank or large-scale waste filter medium regeneration equipment.

In addition, when using filter media particles with a relatively large specific gravity, the difference in specific gravity between the SS and the filter media particles becomes even larger. , SS can be almost completely desorbed from the filter medium, and therefore filtration and waste filter medium regeneration can be performed with extremely simple operations, which is another advantage of using a filter medium with a relatively high specific gravity.

Further, in the present invention, by maintaining the height of the filter medium layer 7 at h2, a space for receiving the filter medium is always formed between the filter medium layer I and the top of the filter tank 1.

Therefore, the filter medium can be continuously supplied from the filter medium supply port 8.

According to the present invention, as described above, in the method of trapping and separating SS by passing a liquid to be treated containing SS through a packed bed of particulate filter media in an upward flow, Unlike conventional sand filtration methods, filtration can be temporarily interrupted and the filtration layer can be backwashed because the filter media can be continuously supplied and the waste filter media that has captured SS can be extracted from below intermittently or continuously. Not only can continuous filtration be performed without the need for continuous filtration, but it can also be quickly and effectively adapted to fluctuations in the SS concentration of the liquid to be treated and the amount of liquid to be treated by, for example, adjusting the amount of filter material to be extracted and the amount of supply. It has the significant advantage of being able to deal with

Further, even if the filter medium is likely to form mud balls due to SS, the formation of mud balls can be prevented by increasing the amount of waste filter material extracted.

Further, according to the present invention, the filter medium is supplied from above the filter medium packed bed to form a moving layer that moves downward. Therefore, as long as the filter medium is heavier than water, particles of any desired properties can be used regardless of the specific gravity. In particular, filter media particles having a significantly large specific gravity that cannot be used in a system in which a moving bed is moved upward can be used as a rather desirable filter media in the present invention.

That is, when filter medium particles having a large specific gravity are used, the filter medium does not expand or become fluidized by the upwardly flowing liquid, so that stable filtration operation can be continued even when the flow rate of the liquid to be treated varies.

In addition, since the present invention maintains the filling surface of the filter medium above h2 from the processing liquid outlet, even when using a filter medium with a small specific gravity, it does not expand or fluidize due to the upward flow of liquid, and a stable state is maintained. A continuous filtration process is performed.

Moreover, in the present invention, since the filter material at the bottom of the filter layer 3 where the largest amount of SS is captured is intermittently or continuously discharged as waste filter material, the filter layer always has a constant large filtration capacity. However, SS of any nature can be filtered extremely effectively.

Further, in the present invention, since the liquid to be treated can be supplied and discharged while the filter medium is supplied and discharged, continuous operation is possible and the filtration process can be performed very smoothly and quickly.

Furthermore, according to the present invention, the waste filter medium is extracted from the lower end of the filter tank,
If the SS is transferred through the pipe using a water ejector, etc., the SS can easily be removed from the filter material, so the filter material from which the SS has been separated can be directly supplied to the filtration tank by an appropriate means. The system is simple, and the method according to the invention is therefore considerably easier to operate and manage, and is also advantageous in terms of economy.

Further, since the filter medium regeneration and circulation circuit from the waste filter medium outlet 10 to the filter medium supply port 8 is not exposed to outside air, it can be applied to the filtration treatment of foods, drinking water, medicines, etc.

Example: In a cylindrical filter tank with an inner diameter of 365 mounds, an average particle size of 1.411
! 771, spherical activated carbon with a wet specific gravity of 1.32 in water “Takeda
-700J (sold by Takeda Pharmaceutical Co., Ltd.) with filtration layer height (
h1) 3m, filter medium layer height (h2) 30cIrL, filled with very high viscosity SS from the bottom of the filtration tank at an average of 16.6p
pm industrial wastewater was passed through the filtration tank at an upward flow superficial velocity of 15 m/h, while 0.0 m/h per liquid to be treated.
After approximately 3 weeks of continuous operation while supplying and discharging 82 kg of filter media, there was no expansion of the filter media, and the SS concentration in the treated liquid was 3.4 ppm on average per week (SS removal rate 79.5%). Met.

In addition, in a separate experiment using the same filter medium as above, in a cylindrical tank with an inner diameter of 105 mm, when the upward superficial velocity of the liquid to be treated is 15 to 25 m/h, the filter medium layer height h2 It has been confirmed that setting the height of the filter layer to about 2 to 5% of the height h1 of the filter layer is sufficient to prevent expansion and fluidization of the filter layer.

[Brief explanation of the drawing]

The drawing is a partial sectional view showing the configuration of an embodiment of the present invention. 1...Filtering tank, 2...Liquid to be treated supply port, 3...Filtration layer, 6...Processing liquid outlet, 10...・Waste filter media outlet. 8... Filter media supply port,

Claims (1)

[Claims] 1. A filter media supply port is provided at the neck portion to continuously supply the filter media into the interior, a waste filter media outlet is provided at the lower end to extract the waste filter media, and the liquid to be treated is continuously supplied to the interior at the bottom. A filtration tank is equipped with a supply port and a treated liquid outlet at the top that continuously discharges the liquid that has risen in the filtration layer to the outside of the tank, and the slurry waste filter media extracted from the waste filter media outlet is discharged into the outside air. A means for supplying the liquid to the upper filter medium supply chamber via a liquid pump, a transfer pipe and a filter medium regenerating device, and a powder level meter for monitoring the height of the filter medium stack in the filtration tank. The filtration tank includes a distributor connected to the treated liquid supply port, a water collector connected to the treated liquid outlet, a baffle plate placed directly above the waste filter medium outlet, and a baffle plate placed directly below the filter medium supply port. A dispersion plate is provided, a filtration layer is stacked in the filtration tank from the bottom end of the tank to the level of the treated liquid outlet, and a filter medium layer is further stacked on top of the filtration layer with a constant stacking height. A moving layer characterized in that the filter medium is supplied and extracted according to monitoring by the powder level meter so as to form a large space for receiving the filter medium between the filter medium layer and the top of the filtration tank. type filtration device.