Abb Research Ltd.

Abb Technology Ltd

Abb Schweiz Ag

Petter Johansson

Claes-Goran Johansson

Thies Helbig

Carl-Olof Olsson

Roger Gustavsson

Claes-Göran Johansson

An apparatus and a method for attenuating water pressure pulses generated during sea piling when a percussion mechanism is used, including the stage of driving at least one pile into an earth by a percussion mechanism, while along at least a part of its axial extension, the pile is surrounded by water and at least partly by a tubular outer sleeve; and at least one gas-filled space is provided between the inner periphery of the outer sleeve and the outer periphery of the pile. The apparatus includes mechanisms for providing the gas-filled space.

Method and an apparatus for attenuating pressure pulses

An apparatus for enclosing a medium and/or high voltage unit connectable to an electric power system. The unit includes one or a plurality of electrical components and generates heat as a by-product during operation. The apparatus includes a housing including a main chamber housing a seat for holding the unit. The main chamber is arranged to house the unit. The housing includes at least one gas exit opening at an upper part of the housing and at least one gas entry opening. The housing includes a sound-absorptive gas exit chamber provided with the at least one gas exit opening. The housing includes a sound-absorptive gas entry chamber provided with the at least one gas entry opening. A first heat convection path is provided inside the housing between the at least one gas entry opening and the at least one gas exit opening, via the gas entry chamber, via the main chamber and via the gas exit chamber, in order to provide cooling. Each of the gas exit chamber and the gas entry chamber houses at least one sound-absorbing member for absorbing sound produced by the unit during operation. At least one of the gas exit chamber and the gas entry chamber has at least one heat conducting wall and at least one free space provided between the at least one sound-absorbing member and said wall such that the first heat convection path is provided inside the housing between the at least one gas entry opening and the at least one gas exit opening via the at least one free space.

Electrical housing having cooling and sound-absorbing means

A terminal bushing sealing element is adapted to be fitted between a terminal bushing and a barrier element. The sealing element is elastic, has an annular shape, and includes a wall with an inner surface and an outer surface. A first opening is provided at a first end of the sealing element and a second opening is provided at a second end of the sealing element, which is opposite to the first end and the wall extends between the first end and the second end. The wall includes a first wall portion that is inclined such that a diameter of the sealing element increases from the first end in the direction towards the second end. The sealing element provides for improved sound attenuation while maintaining a long creepage distance and may be used in sound attenuation casings that are included in power capacitor arrangements.

Terminal bushing sealing element

Growing community of inventors

Göteborg, Sweden

Petter Johansson