JPH06170364A - Filter device using permeation membrane - Google Patents

Abstract

PURPOSE:To filter water for treatment using a micro-filter membrane and an ultrafiltration membrane. CONSTITUTION:In a filter device for water treatment using a hollow fiber permeation membrane such as a micro-filter membrane or an ultrafiltration membrane, a permeation membrane module 4 is installed vertically or obliquely, the supply water is allowed to flow past from below upward, and an air vent valve 15 is provided communicating with a hollow fiber supply side right above a permeation membrane module 4. In addition, a cleaning/water drain valve 9 is provided below the permeation membrane module 4, and the valve 9 is opened when cleaning by reverse flow and draining water. Thus the reverse cleaning drain water is discharged from the supply water side of the permeation membrane module 4 to an area outside the system by natural flow downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment filtration operation using a microfiltration membrane, an ultrafiltration membrane and the like.

[0002]

2. Description of the Related Art Hitherto, it has been attempted to carry out a filtration operation for water treatment using a permeable membrane such as a microfiltration membrane or an ultrafiltration membrane.

Except for the immersion type, the filtration device for water treatment using a permeable membrane is usually in a closed circuit, and the supply side in the module casing is always filled with raw water or backwashing wastewater. Here, in the case of discharging the raw water or the backwashing wastewater to the outside of the system by opening the washing drainage valve at the time of backwashing, a discharge pressure is required.

[0006] Normally, during backwashing, the raw water supply pump is stopped, so that the backwashing pump discharges the raw water. Since this operation is linked with the wash drain valve, the raw water remains at the start of the backwash and the backwash drain remains at the end of the backwash.

Therefore, the substances contained in the raw water and the backwashing wastewater that have to be removed remain in the system, and the removal efficiency deteriorates. Further, cleaning water for discharging the substance that must be removed, that is, permeated water is required, and there is a disadvantage that the treated water is wasted.

[0006] Further, if the substance to be removed remains, the inlet of the hollow fiber on the supply side is likely to be clogged, and the permeation performance of the hollow fiber is deteriorated.

[0007]

In a filtration device for water treatment using a permeable membrane, the raw water or the backwashing wastewater remains in the module casing before and after backwashing, so that the permeation efficiency is lowered and the water is discharged. The effect also decreases.

[0008] Further, if the substance that must be removed remains, the inlet of the hollow fiber on the supply side is likely to be blocked, and the permeation performance of the hollow fiber is deteriorated.

[0009]

The present invention is directed to a permeable membrane module for a water treatment filtration device using a hollow fiber type permeable membrane such as a microfiltration membrane or an ultrafiltration membrane.
Installed vertically or at an angle, let the feed water flow from below to above, communicate with the hollow fiber supply side directly above the permeable membrane module, provide an air vent valve, and below the permeable membrane module. A wash drain valve is provided, and by opening this wash drain valve during backwash, the backwash wash drain in the permeable membrane module is discharged from the permeable membrane module supply water side to the outside of the system by natural flow. It proposes a filtration device with a permeable membrane.

[0010]

The raw water or backwashing wastewater that has to be discharged in the module casing composed of a closed circuit is opened to the atmosphere at the start of backwashing and the end of backwashing, and the outflow portion is allowed to flow naturally. So that it can be drained.

In this case, it is not necessary to use the power for flowing out the residual raw water if the backwashing pump is started and the cleaning is started after a certain period of time for the residual raw water to flow out. Further, after the washing pump is stopped, the outflow time is set again, the residual washing waste water is discharged, and then the supply pump is started, so that the residual substance for removal in the circuit disappears.

[0012] Here, as a device for releasing the atmosphere, it also has a function of releasing the atmosphere that has entered the circuit when it is restarted. Withdrawal valve is used.

[0013]

[Embodiment] This embodiment is a closed-circuit type membrane permeation apparatus so that residual raw water and backwashing wastewater are naturally discharged when the atmosphere is opened.
This is the case when an air vent valve and a cleaning drain valve are installed. In the permeation step, raw water is made to flow from the raw water pipe 1 into the water receiving tank 2. The permeated water supplied to the permeable membrane module 4 by the permeable membrane supply pump 3 passes through the pipe 5 and the permeated water meter 6 and then passes through the treated water tank 7
Outflow to.

During this time, the cleaning drain valve 9 and the valve 10 are closed, and the valve 1
1 is in the open state. In the full-volume transmission method, the valve 8 is closed at this time, or the valve 8 and the pipe 12 are not present.
In the cross flow permeation method, the valve 8 is opened and the water is returned to the water receiving tank 2 via the pipe 12 as circulating water. If this state is continued, the permeable membrane module 4 will become clogged, and therefore backwashing is regularly performed.

In the backwashing step, the backwashing pump 13 is started, the washing and draining valves 9 and 10 are opened, and the valves 11 and 8 are closed, so that the clogging substances adhering to the permeable membrane module 4 are drained. Spill to 14.

Here, at the start of backwashing and at the end of backwashing, if the washing drain valve 9 is opened and a discharge time is set, air enters from the air vent valve 15 and the raw water remaining on the supply side of the permeable membrane module 4 or The cleaning wastewater can flow out to the drain tank 14.

Returning to the permeation step, the raw water supplied by the raw water supply pump 3 pushes up the air in the permeable membrane module 4 and discharges it from the air vent valve 15. By installing the air vent valve 15, it is possible to eliminate residual substances, and the amount of water and power for discharging are reduced. In addition, the supply side of the hollow fibers can be prevented from being blocked, and the deterioration of the permeation performance of the hollow fibers can be reduced.

[0018]

EFFECTS OF THE INVENTION According to the filtration device having the above-described structure of the present invention, the substances contained in the raw water and the backwash water that have to be removed do not remain in the system, so that the permeation of this type of filtration device is eliminated. The effect of preventing the deterioration of performance is obtained.

[Brief description of drawings]

FIG. 1 is a system diagram of an apparatus according to the present invention.

[Explanation of symbols]

 4 Permeable membrane module 9 Wash drain valve 15 Air vent valve

Claims (1)

[Claims] 1. A permeable membrane module is installed vertically or inclined in a water treatment filtration device using a hollow fiber type permeable membrane such as a microfiltration membrane or an ultrafiltration membrane, and feed water is fed from the bottom to the top. By letting it flow through and communicating with the hollow fiber supply side just above the permeable membrane module, an air vent valve is provided, and a wash drain valve is provided below the permeable membrane module, and this wash drain valve is opened during backwashing. A filtration device using a permeable membrane, wherein the backwashing wastewater in the permeable membrane module is discharged from the system through the permeable membrane module supply water side by natural flow.