An object of the present invention is to provide a filter unit in which hollow fiber membranes can be effectively cleaned. A filter unit of the present invention includes a plurality of filtration modules and one or more air bubble generation modules that supply bubbles to the filtration modules from below. Each filtration modules includes a plurality of hollow fiber membranes extending in an up-down direction and arranged side by side in a curtain shape and which are arranged at intervals. The one or more air bubble generation modules supply coarse bubbles to the filtration modules.

According to an aspect, a detonator positioning device is provided for use with a wireless detonator in a perforating gun assembly. The detonator positioning device includes a single mechanism for physical electrical connection, while the remaining electrical connections are made via electrically contactable components. A method of assembling the perforating gun assembly is also provided, including a detonator positioning device configured to receive and hold the wireless detonator.

The present invention relates to a flat-sheet separation membrane element having formed therein a separation membrane pair in which separation membranes are disposed such that permeation-side faces thereof face each other and in which a channel material is provided, wherein the area of a high-elasticity region satisfying a bending modulus of 100-1000 MPa and a maximum bending stress of 1-15 MPa at least in one direction is not less than 10% of the area of a filtration region of the pair of separation membranes.

A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. The housing is integrated with the potting head of a module. The conduit passes through the potting head.

An aeration tube according to the present invention, which is configured to supply a cleaning gas for a filtration unit, includes a straight tubular aeration portion, into one end of which the cleaning gas is force-fed and which has a plurality of aeration holes, and a tubular solid content discharge portion which extends from another end of the aeration portion. In a vertical cross section including a central axis of the aeration portion, a central axis of a discharge side of the solid content discharge portion is inclined downward with respect to the central axis of the aeration portion, and an angle of inclination of the central axis of the discharge side with respect to the central axis of the aeration portion is 20 to 80. Preferably, the aeration holes are arranged on an upper side of the aeration portion, and centers of the aeration holes coincide with the vertical cross section including the central axis of the aeration portion. Preferably, the aeration portion does not have an opening other than the aeration holes in a circumferential surface thereof. Preferably, a central axis of a connection side of the solid content discharge portion connected to the aeration portion is curved.

An efficient method is provided for cleaning hollow fiber membrane modules, the method being capable of efficiently removing substances accumulated inside hollow fiber membrane modules. The internal liquid on the raw liquid side of the hollow fiber membrane module (3) is discharged from a lower end face nozzle (19) of the hollow fiber membrane module (3) while air-cleaning is performed. The method for cleaning hollow fiber membrane modules is characterized in that the rate of liquid discharge from the lower end face nozzle of the hollow fiber membrane module (3) when discharging the internal liquid from the lower end face nozzle is adjusted so that the air supplied from the lower end face nozzle of the hollow fiber membrane module (3) through the aeration holes is supplied to the hollow fiber membrane module (3).

While productivity in generation of treated water is improved, a membrane cleaning effect through relaxation is sufficiently exerted. While aeration is carried out with respect to at least one membrane cartridge (18), a cycle of a filtration operation and a filtration stoppage operation is repeated. A gas vent valve (62) connected to a gas retention chamber (52) is used, and the gas vent valve (62) is opened and then closed in accordance with a timing of start of the filtration stoppage operation in each cycle.

A water treatment device (1) is provided with: a biological treatment tank (2) for storing a stored liquid (5); a pump (7) for generating a circulating liquid flow formed of the stored liquid (5); a gas-liquid two-phase flow generation device (8) for using the circulating liquid flow to suction a gas containing oxygen, whereby a gas-liquid two-phase flow in which the gas is dispersed in the circulating liquid flow is generated; and a nozzle (12) for injecting the gas-liquid two-phase flow into the biological treatment tank (2). Such a water treatment device (1) is capable of adequately circulating the stored liquid (5) in the biological treatment tank (2), adequately aerating the stored liquid (5), and adequately treating the stored liquid (5).

The hollow fiber membrane module contains a hollow fiber membrane bundle having bundled hollow fiber membranes, a housing with an internal space formed in which the hollow fiber membrane bundle is housed and a gas supply portion which disperses cleaning gas for the hollow fiber membrane in the internal space. The internal space has an upper space in which an upper-side part of the hollow fiber membrane is positioned and a lower space in which a lower-side part of the hollow fiber membrane is positioned. The gas supply portion is provided with pipe vent holes which disperse gas in the housing at a position in the upper space and diffusing vent holes which disperse gas in the housing at a position below the lower space.

A detonator positioning device for use with a wireless detonator in a perforating gun assembly includes a single mechanism for physical electrical connection, while the remaining electrical connections are made via electrically contactable components.