Abstract: A bubble generation device is provided which is capable of discharging bubbles of about the same size from each of a plurality of bubble discharge ports. The device is provided with a bubble discharge chamber communicating with each of a plurality of bubble discharge ports, a turnaround path including a first communication port communicating with a gas storage chamber and a second communication port communicating with the bubble discharge chamber on a downstream side in a gas traveling direction of a turn-around point of the turnaround path, opening areas of the plurality of bubble discharge ports being the same as each other, and a total of the opening areas of the plurality of bubble discharge ports being smaller than an opening area of the second communication port.

Abstract: A bubble generation device is provided which is capable of discharging bubbles of about the same size from each of a plurality of bubble discharge ports. The device is provided with a bubble discharge chamber communicating with each of a plurality of bubble discharge ports, a turnaround path including a first communication port communicating with a gas storage chamber and a second communication port communicating with the bubble discharge chamber on a downstream side in a gas traveling direction of a turn-around point of the turnaround path, opening areas of the plurality of bubble discharge ports being the same as each other, and a total of the opening areas of the plurality of bubble discharge ports being smaller than an opening area of the second communication port.

Abstract: A bubble generation device is provided which is capable of efficiently peeling off contaminants from a surface of a filtration membrane. There is provided a bubble discharge chamber disposed above a turnaround portion of a turnaround path. The turnaround path includes a first communication port communicating with a gas storage chamber and a second communication port communicating with the bubble discharge chamber on a downstream side of the turnaround portion. Each of the gas storage chamber and the bubble discharge chamber includes an opening facing downward at a lower end. A cross-sectional area of the bubble discharge chamber in a horizontal direction is equal to or larger than an opening area (a sum of the opening areas of the two second communication ports in an illustrated example) of the second communication port.

Abstract: A membrane element having a filtration main body, a header (a water collection portion) that collects treated water from an end portion of the filtration main body and a treated water lead-out portion that leads out the treated water is used. The treated water lead-out portion is connected to a tubular peripheral wall of a water collection pipe that collects treated water solid-liquid-separated by the membrane element, and communicates with an inside of the tubular peripheral wall. The tubular peripheral wall has a thick portion that is thicker in a horizontal direction at an upper-side peripheral wall portion located at an upper side (or at a lower-side peripheral wall portion located at a lower side) in the radial direction of the tubular peripheral wall, and a connecting hole that penetrates the thick portion.

Abstract: A membrane element having a filtration main body, a header (a water collection portion) that collects treated water from an end portion of the filtration main body and a treated water lead-out portion that leads out the treated water is used. The treated water lead-out portion is connected to a tubular peripheral wall of a water collection pipe that collects treated water solid-liquid-separated by the membrane element, and communicates with an inside of the tubular peripheral wall. The tubular peripheral wall has a thick portion that is thicker in a horizontal direction at an upper-side peripheral wall portion located at an upper side (or at a lower-side peripheral wall portion located at a lower side) in the radial direction of the tubular peripheral wall, and a connecting hole that penetrates the thick portion.