JPH0121038Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention removes phosphates present in sewage, human waste water, industrial wastewater, and other liquids by using a solid particle layer in a fluidized state. This invention relates to a fluidized bed catalytic dephosphorization device.

[Prior art]

Various phosphorus removal methods are being considered to remove phosphates from liquids, but a fluidized bed catalytic dephosphorization device has been proposed as one of the dephosphorization devices that uses a new physicochemical method. has been done.
This fluidized bed type catalytic dephosphorization equipment removes phosphorus by passing a phosphorus-containing liquid through a bed of solid particles in a fluidized state while adjusting the pH, calcium concentration, etc. As a result of this action, phosphorus in the liquid can be efficiently fixed and removed in a fluidized bed of solid particles, so there is no generation of large amounts of sludge, unlike in coagulation-sedimentation equipment, and there is no need for conventional sludge treatment facilities. This is an excellent dephosphorization device that can recover phosphorus as a resource.

[Problem that the invention attempts to solve]

By the way, the conventional fluidized bed type catalytic dephosphorization apparatus, which is an excellent dephosphorization apparatus, also has the following drawbacks. In other words, the dephosphorization tower, which forms a fluidized bed of solid particles, does not have any ingenuity, so the highly reactive solid particles packed in the tower and fluidized come together during the crystallization process, causing large particles to form. In some cases, solid particles grew into lumps or stuck to the inner wall of the dephosphorization tower. When aggregates of solid particles are formed, they not only do not flow at a given flow rate but are deposited at the bottom of the column.
The raw water inlet pipe connected to the bottom of the tower became clogged, which inhibited the stable fluidization of solid particles and made water flow impossible. In addition, if solid particles or scale adhere to the tower wall or the chemical injection pipe that opens into the tower, the chemical injection pipe will become clogged, stopping the chemical supply, causing partial flow drift or short passes, and reducing treatment efficiency. There was also a phenomenon of

These conventional drawbacks are even more noticeable when the phosphorus concentration in the liquid to be treated, the pH in the bed, and the calcium concentration are high, or when the linear velocity of water flow is low and the bed expansion coefficient is small. This could be fatal for fluidized bed catalytic dephosphorization.

The present invention aims to solve the problems of the conventional apparatus and provide an efficient and stable fluidized bed catalytic dephosphorization apparatus.

[Means for solving problems]

This invention connects the raw water inflow pipe to the bottom of the tower filled with solid particles, and connects the treated water outflow pipe to the top of the tower, and is equipped with chemical injection equipment for alkaline and calcium agents, and the raw water is distributed upward. In a fluidized bed type catalytic dephosphorization device that performs dephosphorization treatment while forming a fluidized bed of solid particles with water, a stirrer is provided at the lower part of the fluidized bed, and a liquid phase in the column above the interface of the fluidized bed is installed. This is a fluidized bed type catalytic dephosphorization device characterized in that the lower part of the tower is connected to the lower part of the tower through a circulating water pipe.

〔Example〕

An embodiment of the present invention will be explained based on the drawings. Reference numeral 1 denotes a dephosphorization tower filled with solid particles 2 such as phosphate rock, bone coal, sand, anthracite, and activated carbon. A raw water inflow pipe 4 is connected to the supply pump 3, and a treated water outflow pipe 5 is connected to the upper part.
are connected so that a fluidized bed of solid particles 2 is formed by the upward flow of raw water. In addition, near the tower 1 of the raw water inflow pipe 4 at the lower part of the tower 1,
Although the alkaline agent injection tube 6 and the calcium agent injection tube 7 are open, the alkaline agent injection tube 6 and the calcium agent injection tube 7 can also be used for the same purpose.
Alternatively, piping may be arranged to directly inject into the column 1.

Furthermore, a stirrer 8 is installed in the lower part of the fluidized bed in the column 1, and when an alkali agent or a calcium agent is directly injected into the column 1, the liquid near the injection point in the column 1 or above it is disposed. It is effective to place the stirrer 8 in the area where the reactivity is highest, and it goes without saying that a simple stirring blade may be used as the stirrer 8, as well as stirring by air blowing, water jet stirring by inserting a pump, or pressure by installing an ejector. A water introduction device or the like may also be used.

In addition, the liquid phase part above the interface of the fluidized bed in the column 1 and the lower part in the column 1 are connected by a circulating water pipe 10 with a circulation pump 9 interposed, and the treated water in the upper liquid phase part in the column 1 is A part of it is circulated to the lower part of the tower 1.

However, its action is to cause raw water to flow into the tower 1 from the raw water inlet pipe 4, and the solid particles 2 to be formed by the upward flowing water.
The alkali agent and calcium agent are injected from the alkaline agent injection pipe 6 and the calcium agent injection tube 7, and the agitator 8 is driven continuously or intermittently to promote mixing of the alkali agent and calcium agent. death,
While the crystallization reaction is carried out uniformly, the solid particles 2
A stable fluidized bed is formed by forcibly suppressing their association. In this way, phosphorus in the raw water is efficiently and stably removed, and the treated water flows out from the treated water outflow pipe 5.

At the same time, the circulation pump 9 is driven and the circulation water pipe 10
A part of the dephosphorized treated water in the liquid phase above the fluidized bed interface in the column 1 is circulated to the lower part of the column 1,
By diluting the raw water in the lower part of the tower 1, the phosphorus concentration in the raw water can be lowered and the dephosphorization treatment can be performed more effectively. In this case, the alkaline agent injection pipe 6 and the calcium agent injection pipe 7 are connected to the circulating water pipe 10.
It can also be opened inside.

The second illustrated example shows another embodiment of the present invention, in which when the alkaline agent injection pipe 6 is directly opened into the column 1, a stirrer 8' is attached near the injection point or above it. The same is true when the calcium agent injection pipe 7 is opened directly into the tower 1, and solid particle lumps are deposited on the inner wall surface of the tower 1 or at the openings of the alkaline agent injection pipe 6 and the calcium agent injection pipe 7 that are opened into the tower. The fixation of calcium phosphate, calcium carbonate, and other scales can be suppressed, and the other aspects are the same as in the first illustrated example.

In addition, in each of the above embodiments, stirring the lower part of the fluidized bed with the stirrer 8 promotes mixing of the alkali agent and calcium agent and at the same time supplies mixing energy to the fluidized bed of the solid particles 2. The pressure resistance of the raw water supply pump 3 (also of the circulation pump 9 in the circulation water pipe 10) is reduced, and the supply of liquid is stabilized.

[Effect of idea]

As described above, according to the present invention, it is possible to accurately prevent the association of solid particles, which was a drawback of conventional fluidized bed type catalytic dephosphorization equipment, and to maintain a stable fluidized bed. Effective dephosphorization is possible by diluting raw water based on treated water circulation,
Extremely efficient and highly stable dephosphorization treatment can be carried out continuously over a long period of time.

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views showing embodiments of the present invention, respectively. 1... Dephosphorization tower, 2... Solid particles, 3... Raw water supply pump, 4... Raw water inflow pipe, 5... Treated water outflow pipe, 6... Alkaline agent injection pipe, 7... Calcium agent injection pipe , 8, 8'... Stirrer, 9... Circulation pump, 10... Circulating water pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A raw water inflow pipe is connected to the bottom of a tower filled with solid particles, a treated water outflow pipe is connected to the top of the tower, and chemical injection equipment for alkaline agents and calcium agents is installed. In a fluidized bed type catalytic dephosphorization device that performs dephosphorization treatment while forming a fluidized bed of the solid particles with upward flowing water of raw water, a stirrer is disposed at the lower part of the fluidized bed and from the interface of the fluidized bed. A fluidized bed type catalytic dephosphorization apparatus characterized in that an upper liquid phase part in the column and a lower part in the column are connected through a circulating water pipe. (2) Claim 1 of the utility model registration, which is that the drug injection equipment is opened to the raw water inflow pipe.
Fluidized bed type catalytic dephosphorization equipment as described in . (3) The fluidized bed catalytic dephosphorization apparatus according to claim 1, wherein the chemical injection equipment is opened into the tower. (4) The fluidized bed catalytic dephosphorization apparatus according to claim 3, wherein the agitator is disposed near an opening in the column of the chemical injection equipment.