JPS61141992A - Apparatus for separating drain liquid - Google Patents

Abstract

PURPOSE:To enhance filtering capacity, by providing vent holes to the upper part of the partition wall for partitioning a process for falling a drain liquid and the next process for raising the same. CONSTITUTION:The drain liquid W flowed in from a waste solution inlet 2 reaches upper openings 23,23,... of flow channels while is separated by filter membranes 22, 22 provided to membrane mount plates 2, 2 under tension. Subsequently, the drain liquid W introduced into a second filter chamber R-2 through the upper openings A2 of flow channels. The upper openings A2 of flow channels of a partition wall A are almost communicated with the upper openings 23, 23... of flow channels of the membrane mount plates 2, 2... and the drain liquid W is fallen between the membrane mount plates 2, 2... of the filter chamber R-2 while receives the same pressure as the pressure received in a first filter chamber R-1. The lower part of a partition wall B is provided with vent holes B3 by drilling and air bubbles inter a third filter chamber R-3 through the vent holes B3. By this method, the amounts of sludge adhered to the filter membranes and remaining in the filter chambers are uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an apparatus for separating solute components in domestic wastewater using an ultrafiltration membrane, a reverse osmosis membrane, or a microfilter.

(Prior Art) As devices for separating solute components from domestic wastewater, ultrafiltration membrane devices, reverse osmosis membrane devices, and even precision filtration membrane devices such as microfilters are often used.

These filtration membranes are flat membrane type (plate and frame type)
, tubular type, hollow fiber type, spiral wind type, etc., multiple filtration membranes are erected in parallel and the wastewater is passed between the filtration membranes. The so-called parallel flow (cross flow) method, in which the fluid flows parallel to the surface, is usually used.

In the case of this parallel flow method, solutes in the liquid are separated by a step of raising the drained liquid between the filter membranes and then a step of lowering it.

(Problem to be solved by the invention) However, in this parallel flow method, in the process of lowering the wastewater between the filtration membranes, the pumped wastewater is depressurized and bubbles are generated. This may be because the flow velocity above the stagnation and descending wastewater becomes uneven, resulting in partial acceleration of fouling of the membrane. In particular, there was more sludge adhesion than when the wastewater was raised, and even though the filtration membrane used when the wastewater was raised maintained sufficient filtration performance, the filtration performance of the entire separation device decreased. .

Therefore, in order to maintain a constant filtration ability, it is necessary to periodically perform chemical cleaning with a chemical solution or physical cleaning with a sponge ball.

That is, the above-mentioned separation device cannot fully and fully utilize the filtration performance of the filtration membranes, and has presented problems such as differences in the rate of deterioration between the filtration membranes.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a ventilation hole in the upper part of the partition wall that separates the step of lowering the water control fluid from the next step of raising it. The present invention relates to a separation device that separates solutes by keeping both processes in communication with each other.

(Function) As mentioned above, in this separator, the process of lowering the wastewater and the process of raising the wastewater are communicated, which may make the flow velocity above the wastewater in both processes non-uniform. The progress will be approximately the same.

(Example) FIG. 1 is a flowchart 1 diagram illustrating a system for separating wastewater undiluted solution Wo into filtrate W+ and concentrated solution 2.

The undiluted wastewater solution Wo flows into the activated sludge treatment tank K, is stirred by aeration air a to homogenize the undiluted wastewater solution WO, and the wastewater W subjected to biological treatment with the activated sludge is sent to the pump P.
is introduced into a separation device 1 such as an ultrafiltration membrane device.

As will be described later, the separation device 1 separates solute components by passing the wastewater W in the vertical direction of membrane-attached plates that are erected in parallel. That is, the wastewater W is filtered in the process of flowing parallel to the filter membrane, and separated into the filtrate WI and the concentrated liquid W2.

Next, this concentrated liquid W2 is returned to the activated sludge treatment tank K again.

The above steps are repeated to separate and treat the required amount of wastewater W.

FIG. 2 is a schematic diagram illustrating the structure of the minute # device 1. As shown in FIG.

The separation device 1 has a tank body surrounded by outer walls 11, 11..., and a plurality of membrane plates 2, 2... are erected in parallel in this tank body. .

Further, each of the required number of membrane-coated plates 2, 2, . . . is divided by a partition wall to form each filtration chamber. In this filtration chamber, the waste water W flowing in from the waste water population 12 rises.

As it descends, it is separated and the filtrate W1 is collected, and the concentrated liquid W2 flows out from the outlet 13.

FIG. 3 is a front view of the membrane-attached plate 2.

The membrane-attached plate 2 has a rectangular outer periphery formed by a frame body 21, and a filtration membrane 22 is stretched approximately at the center of the frame body 21.

This filtration membrane 22 is a thin film having micropores on a molecular level,
For example, it is composed of an ultrafiltration membrane or the like, and its main function is to separate the wastewater W into filtrate W+ and concentrated liquid W2.

A channel upper port 23 and a channel lower port 24 are opened at the top and bottom of the filtration membrane 22 .

In the separation apparatus 1, as described above, the membrane-attached plates 2, 2, . . . are separated by partition walls A and B at appropriate intervals to form each filtration chamber. For example, as shown in FIG.
．． A second filtration chamber R-2 is formed by the partition wall A and another partition wall B.

The filtration chambers R-3, R-4, . . . are sequentially formed as described above.

As shown in the front view of FIG. 4, the partition wall A that partitions the membrane-attached plates 2, 2, . A flow outlet A2 is opened at the top.

That is, in the first filtration chamber R-1, the drain liquid inlet 12
The drainage liquid W flowing in from the membrane plates 2, 2... passes through the flow path lower ports 24, 24..., rises between the membrane plates 2, 2..., and reaches the flow path upper port 23. .

On the other hand, the partition wall B, which forms the second filtration chamber R-2 by partitioning the membrane-attached plates 2, 2... from the partition wall A, is almost the same as the partition wall A, as shown in the front view of FIG. It is formed by partition bases BI having the same shape, and a flow path lower mouth B2 is opened at the lower part of the partition base BI. Moreover, a ventilation hole B3 having a required area is bored in the upper part.

Similarly, the third filtration chamber R-3 is the first filtration chamber R-]
Similarly, the fourth filtration chamber R-4 is connected to the second filtration chamber R-4.
-2 are formed sequentially in the same manner as in 2.

] In the separation device 1 having the description 22, the water utilization liquid population 1
As mentioned above, the drainage liquid W flowing in from 2 flows into the first filtration chamber R-1 through the flow path lower mouth of the H-shaped plates 2, 2... 24°24
...and then passes through the membrane plates 2, 2... and ascends by 1. That is, the drained liquid W reaches the upper flow openings 23, 23, . . . while being separated by the filtration membranes 22, 22, .

The drainage liquid W flowing into the drainage liquid inlet 12 is pumped by the pump P, so that it rises by 1 in response to the pressurizing force of the pump P in the first filtration chamber R-1.

Next, the drainage liquid W flows through a flow path opened in the partition wall A.
2 and is introduced into the second filtration chamber R-2.

In the filtration chamber R-2, the flow opening A2 of the partition wall A and the membrane plate 2.
Since the flow upper ports 23, 23... of 2... are almost in communication with each other, the wastewater W is filtered under the same pressure as the pressure that the wastewater W receives in the first filtration chamber R-1. Membrane plate 2 of room R-2
, 2... is lowered in between. At this time, the first filtration chamber R-
The drained liquid W that has risen to the second part becomes a so-called depressurized state, and the bubbles in the liquid expand and are discharged to the outside of the liquid, and the second filtration chamber R-
Stagnated in 2J second division.

However, since the upper part of the partition wall B that separates the third filtration chamber R-3 is provided with the ventilation hole B3 of the required area as described above, the air bubbles pass through the ventilation hole B3 and enter the third filtration chamber. R
-3.

Therefore, the second filtration chamber R-2 and the first and third filtration chambers R
-1, R-3 filtration membranes 22, 22... The flow speeds of the drainage fluid flowing over the filtration chambers R-2. Filtration chamber R
The amount of sludge remaining on the filter membranes 22, 22, . . . of R-1 or R-3 is approximately uniform.

(Effects) As mentioned above, according to the water utilization liquid separation device of the present invention,
Since the sludge remaining on the filtration membranes in each filtration chamber, that is, the membrane contamination, is almost uniform, the filtration performance of the filtration membranes installed in the separation equipment can be fully utilized as a whole, and the deterioration of the filtration membranes themselves can be prevented. As a result of equalization, the cleaning interval of the filtration membrane becomes longer, which is extremely rational in terms of operation management of the separation device.

Example In the system shown in FIG.
) was used to separate domestic wastewater.

The separation device is divided into 6 filtration chambers, each filtration chamber has 17
Two membrane-covered plates were erected.

In addition, ventilation holes with an area ratio of 1150 to the area of the bottom of the flow path were bored in the partition wall.

As a result, almost no sludge was observed on the filtration membrane of the filtration chamber, where the wastewater was allowed to descend from the upper part of the membrane-equipped plates. As shown in FIG. 6, the rate of transmission over time (solid line) was also significantly slower than that of the conventional device (dotted line).

As a result, the cleaning work for the filtration membrane could be extended to about once every three months.

[Brief explanation of the drawing]

FIG. 1 is a feature 1 diagram illustrating the process of separating wastewater, FIG. 2 is a schematic diagram illustrating the structure of the separation device, and FIG. 3 is a front view of the membrane plate. FIG. 4 is a front view of a partition wall. FIG. 5 is a front view of a partition wall having ventilation holes in two parts. FIG. 6 is a graph showing changes in permeation rate over time in Examples. 1... Separation device, 2... Membrane plate. 22... Filtration membrane, 23... Channel upper opening. 24... Lower mouth of flow path, A... Partition wall. A2...Flower opening, B...Partition wall. B2...lower mouth of flow path, B3...ventilation hole.

Claims (1)

[Claims] In a drainage liquid separation device in which a plurality of membrane plates are installed in parallel to form a filtration chamber, the drainage liquid is lowered from the upper part between the membrane plates to the filtration chamber, and the drainage liquid is raised from the lower part between the membrane plates. A drainage liquid separation device characterized in that a partition wall is provided upright between the next filtration chamber and a ventilation hole is provided in the upper part of the partition wall.