This invention relates to a method of increasing the size of particulates in a gas comprising particulates, e.g. a gas that is formed from the combustion of fuels. The method comprises mixing an ionised gas stream with the gas comprising particulates.

This invention relates to a method of increasing the size of particulates in a gas comprising particulates, e.g. a gas that is formed from the combustion of fuels. The method comprises mixing an ionised gas stream with the gas comprising particulates.

A pollution control system for removing particle and gas phase pollutants in a waste airstream exhausted from commercial cooking operations may include a plurality of filters arranged within a housing for filtering particle and gas phase pollutants in the waste airstream. Various ones of the filters may be composed of a variety of different materials, and ozone may be provided within the housing to assist with removal of the pollutants. In some examples, a wash mechanism may be included to wash surfaces of a filter to remove grease therefrom. In some examples, the system may further include means to spray droplets (such as in a fog or mist form) into the waste airstream to condense a portion of gas phase pollutants into condensed particles.

A pollution control system for removing particle and gas phase pollutants in a waste airstream exhausted from commercial cooking operations may include a plurality of filters arranged within a housing for filtering particle and gas phase pollutants in the waste airstream. Various ones of the filters may be composed of a variety of different materials, and ozone may be provided within the housing to assist with removal of the pollutants. In some examples, a wash mechanism may be included to wash surfaces of a filter to remove grease therefrom. In some examples, the system may further include means to spray droplets (such as in a fog or mist form) into the waste airstream to condense a portion of gas phase pollutants into condensed particles.

A particle control method configured prevent an extremely small quantity of particles descending on a stream of a laminar flow in a clean zone through which the laminar flow flows (as in a RABS or isolator device) from descending to a specific position or to guide the particles so as to have them descend to a specific position by controlling movement of the particles.

[Solution]

A particle descent position is separated away from a board surface of the oscillation board by using an acoustic radiation pressure generated by prompting ultrasonic vibration of the oscillation board disposed with a board surface substantially in parallel with a flow direction of the laminar flow. Moreover, by using a node of a standing wave field generated by prompting the ultrasonic vibration of two oscillation boards disposed with the board surfaces faced with each other, the particle is guided to a direction of a node of a standing wave field. Moreover, by using a focal point of the ultrasonic wave generated by prompting the ultrasonic wave of four oscillation boards, that is, two pairs disposed with the board surfaces faced with each other, the particle is guided to the focal point of the ultrasonic wave.

A particle control method is provided which can prevent an extremely small quantity of particles descending on a stream of a laminar flow in a clean zone through which the laminar flow flows as in a RABS or isolator device from descending to a specific position or can guide it so as to descend to the specific position by controlling movement of the particles. A particle descent position is separated away from a board surface of the oscillation board by using an acoustic radiation pressure generated by prompting ultrasonic vibration of the oscillation board disposed with a board surface substantially in parallel with a flow direction of the laminar flow.

Provided are a method and device for producing negative oxygen ions, and a method and device for purifying air. Said method for producing negative oxygen ions comprises: respectively introducing air and water into an air-water reactor so that the introduced air and water reach a relative movement speed of not less than 20 m/s in said air-water reactor and react within said air-water reactor so as to produce negative oxygen ions; and separating the air containing the negative oxygen ions after the reaction from the water after the reaction, and releasing the air containing the negative oxygen ions after the reaction into a required space. Said method and device can produce a large number of negative oxygen ions and purified air with a high efficiency at a low cost, without producing any harmful substances such as ozone and oxynitrides, and are long-acting and free of maintenance.

Provided are a method and device for producing negative oxygen ions, and a method and device for purifying air. Said method for producing negative oxygen ions comprises: respectively introducing air and water into an air-water reactor so that the introduced air and water reach a relative movement speed of not less than 20 m/s in said air-water reactor and react within said air-water reactor so as to produce negative oxygen ions; and separating the air containing the negative oxygen ions after the reaction from the water after the reaction, and releasing the air containing the negative oxygen ions after the reaction into a required space. Said method and device can produce a large number of negative oxygen ions and purified air with a high efficiency at a low cost, without producing any harmful substances such as ozone and oxynitrides, and are long-acting and free of maintenance.

The air filter medium of the present invention is an air filter medium including a stack of a porous polytetrafluoroethylene (PTFE) membrane and an air-permeable support member, a repulsive force generated in the medium when the medium is compressed in a thickness direction thereof is equal to or greater than 30 kPa and equal to or less than 150 kPa at a compression ratio of 30%, and at least one main surface of the air filter medium is formed by the air-permeable support member and has a maximum coefficient of friction of 24 gf or less. The air filter medium of the present invention is an air filter medium that uses a porous PTFE membrane and in which a decrease in collection efficiency due to pleating is inhibited.

The air filter medium of the present invention is an air filter medium including a stack of a porous polytetrafluoroethylene (PTFE) membrane and an air-permeable support member, a repulsive force generated in the medium when the medium is compressed in a thickness direction thereof is equal to or greater than 30 kPa and equal to or less than 150 kPa at a compression ratio of 30%, and at least one main surface of the air filter medium is formed by the air-permeable support member and has a maximum coefficient of friction of 24 gf or less. The air filter medium of the present invention is an air filter medium that uses a porous PTFE membrane and in which a decrease in collection efficiency due to pleating is inhibited.