JPH0593593U - Membrane module - Google Patents

Abstract

(57) [Summary] [Purpose] In a membrane module for filtering tap water after adsorbing and removing the disinfectant in tap water with activated carbon, a drop in raw water pressure due to the addition of activated carbon and air resistance during air leak testing. Membrane module that can prevent the increase of water flow, ensure a high filtration flow rate, can easily perform air leak test, and can also suppress the growth of various bacteria in the raw water chamber when water flow is stopped.
To provide [Structure] A filter membrane was provided in a case having a raw water inlet at one end and a filtered water outlet at the other end, and the filter membrane was covered with sheet-like fiber activated carbon on the raw water chamber side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a membrane module, and is particularly useful for filtering drinking water.

[0002]

[Prior Art]

 When tap water is filtered with a full-volume filtration membrane module, the chlorine-based disinfectant is adsorbed and removed with activated carbon in order to prevent membrane deterioration due to the chlorine-based disinfectant in tap water and prolong the life of the membrane. Therefore, it is necessary to perform membrane filtration. For this reason, in this type of conventional membrane module, a space separated by a fine-screen screen is provided between the raw water chamber containing the membrane and the raw water inlet, and the space is divided into particles. What is filled with activated carbon is used.

[0003]

[Problems to be solved by the device]

In the membrane module, the total area of the membrane is S ₁ , the filtration flow rate per unit area of the membrane is a ₁ , the flow passage cross-sectional area of the activated carbon filling space is S ₂ , and the flow passage of the activated carbon filling space is If the raw water flow rate per unit area of the cross section is a ₂ , then a ₂ = a ₁ S ₁ / S ₂ , and the total area S _{1 of the} membrane is usually smaller than the flow path cross-sectional area S ₂ of the activated carbon filled space. Since it is remarkably large, the raw water flow rate a ₂ per unit area of the flow channel of the space filled with activated carbon, that is, the raw water flow velocity is considerably high.

Thus, in the above-mentioned conventional membrane module, granular activated carbon is filled in such a high-velocity flow velocity portion and a fine screen is provided, so that raw water passes through the activated carbon filling space. The pressure drop during the operation is large and the effective transmembrane pressure difference is so low that the filtration flow rate cannot be avoided.

Further, even in the air leak test that must be performed before using the membrane module, the air flow resistance becomes large due to the activated carbon filling space, and the air pressure in the raw water chamber becomes a predetermined pressure. In order to do so, the air pressure used must be increased considerably, and the air leak test becomes difficult.

Further, since the activated carbon is present on the front side (raw water inlet side) of the raw water chamber, the raw water in the raw water chamber does not contain a disinfectant, and when the water flow is stopped for a long time, various bacteria are accumulated in the raw water in the raw water chamber. Since it propagates at a tremendous speed, the adsorption capacity of activated carbon is reduced in a short period of time, and the malodor of dead bacteria is often leaked through the membrane.

The object of the present invention is to remove the disinfectant in tap water by adsorbing and removing it with activated carbon and then filtering the tap water. (EN) A membrane module that can prevent an increase in air resistance, can ensure a high filtration flow rate, can easily perform an air leak test, and can well suppress the growth of various bacteria in the raw water chamber when water flow is stopped. It is in.

[0008]

[Means for Solving the Problems]

 The membrane module of the present invention is provided with a filtration membrane in a case having a raw water inlet at one end and a filtered water outlet at the other end, and the filtration membrane is covered with sheet-like activated carbon on the raw water chamber side. This is a characteristic feature.

[0009]

[Action]

 The flow velocity of raw water on the surface of the membrane to which activated carbon is attached is much smaller than the flow velocity of raw water at the raw water inlet, and the shape of activated carbon itself is a sheet-like fiber form with many pores, which is low for the passage of raw water. Since it is a resistor, the effective transmembrane pressure can be kept high, and the reduction in filtration flow rate can be eliminated well.

Further, since the air resistor is not substantially interposed between the raw water inlet and the raw water chamber, and the air pressure can act in the raw water chamber without pressure loss, the air leak test can be easily performed. Furthermore, since the tap water in the raw water chamber contains the disinfectant, it is possible to sufficiently prevent the growth of bacteria in the accumulated water in the raw water chamber when the water flow is stopped.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a case, which is composed of a case body 11 having a filtered water outlet 111 and a cap 12 having a raw water inlet 121. Reference numeral 2 denotes a hollow fiber membrane (a bundle of hollow fiber membranes having one end opened and the other end closed, or a bundle of hollow fiber membranes bent in a U-shape), which is housed in a case 1 in a bundle, One end of the hollow fiber membrane 2 is fixed to the case body 11 with the casting resin 3, and the open end 21 of the hollow fiber membrane 2 is opened to the upper surface side of the casting resin 3. The casting resin 3 divides the inside of the case 1 into a filtered water chamber 41 and a raw water chamber 42.

Reference numeral 5 is a sheet-like activated carbon fiber covering a predetermined number of hollow fiber membranes, which is attached to both sides of a predetermined number of hollow fiber membranes (hollow fiber membrane group) and is bound at the lower end side. .. Both ends of the width of the sheet-like activated carbon on both sides may be bound, but may be left open. Reference numeral 6 is a mesh channel material interposed between the hollow fiber membrane groups, and a mesh of polyethylene, polypropylene, nylon, polysulfone or the like can be used. The upper end of the reticulated channel material 6 and the upper end of the sheet-like fiber activated carbon 5 may be embedded in the casting resin 3.

In the above, an appropriate amount of antibacterial powder 51, for example, powder of copper, silver, zinc, chitosan or the like can be attached to the sheet-like fiber activated carbon 5. In the above description, a mesh channel material is interposed in the hollow fiber membrane bundle so as to form a concentric circular, spiral, or parallel slit-shaped stock solution passage gap, and each of the hollows separated by the mesh channel material. The yarn film group may be covered with the sheet-like fiber activated carbon.

In the above description, the density of the sheet-like fiber activated carbon is determined so that a required surface area of the activated carbon required per unit area of the membrane can be secured, but the total area of all sheet-like fiber activated carbon is wide. Therefore, the density can be made coarse and the flow path resistance of the sheet fiber can be made sufficiently small. In the above embodiments, a hollow fiber membrane is used as the membrane, but instead of this membrane, two flat membranes are formed into a bag shape and the inside of the bag is used as a filtered water passage, and this is used as a spiral. It is also possible to use a roll wound into a shape, a stack of a large number of bags, or the like.

[0015]

[Effect of the device]

 As described above, the membrane module of the present invention has a structure in which the activated carbon for adsorbing and removing the activated carbon in the raw water is made into a fibrous shape, which is woven to form a sheet and covered on the raw water side surface of the membrane. Since the flow velocity of raw water on the membrane surface is significantly smaller than that of the raw water inlet, and the activated carbon itself is a fiber woven form with low fluid passage resistance, it can be applied to the membrane surface with almost no decrease in raw water supply pressure. As a result, the effective transmembrane pressure can be increased, and a high filtration flow rate can be maintained.

In addition, since there is nothing that substantially acts as a resistance to the air flow from the raw water inlet to the raw water chamber, the air pressure can be directly applied from the raw water inlet to the raw water chamber. The air leak test can be easily performed.

Further, since the tap water (raw water) in the raw water chamber still contains the disinfectant, it is possible to well suppress the growth of various bacteria in the raw water chamber while the water flow is stopped. If the antibacterial powder is attached to the activated carbon, the proliferation of various bacteria can be prevented more effectively, so that the adsorption performance of the activated carbon can be maintained for a long period of time and the generation of malodor can be eliminated.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 case 2 membrane 42 raw water chamber 5 sheet-like fiber activated carbon

Claims (2)

[Scope of utility model registration request] 1. A filter membrane is provided in a case having a raw water inlet at one end and a filtered water outlet at the other end, and the filter membrane is covered with sheet-like activated carbon on the raw water chamber side. Membrane module to do. 2. The membrane module according to claim 1, wherein antibacterial powder is attached to the sheet-shaped activated carbon.