Abstract: A method comprising operating an electrolysis apparatus comprising a plurality of electrolyzers is provided. Each electrolyzer on the anode side has at least one liquid drain and at least one gas outlet, and separately therefrom on the cathode side has at least one liquid drain and at least one gas outlet. The anode spaces of these electrolyzers are connected to one another and separately therefrom the cathode spaces of these electrolyzers are connected to one another, in each case at least via a liquid feed, a gas discharge and a liquid discharge. The liquid drains from the anode spaces and/or the cathode spaces of the electrolyzers are effected, per electrolyzer, via a pipeline siphon into the pipeline system of the liquid discharge. An electrolysis apparatus and a method comprising decoupling an operating pressure on a liquid drain side of an electrolyzer are also provided.

Abstract: A mobile high-pressure cleaning apparatus is provided with a vehicle trailer, on the chassis of which at least two running wheels are held so as to be rotatable, and with a high-pressure cleaning appliance having a motor and a pump, and also with at least one water storage tank for storing water for the high-pressure cleaning appliance. So that water can be provided to the apparatus from the at least one water storage tank or from a water supply mains, without risk of water from the water supply mains being returned thereto, the high-pressure cleaning apparatus has a decoupling tank with at least one inlet which can be connected to the water supply mains, and at least one outlet which is connected to the high-pressure cleaning appliance and to at least one water supply tank via a shut-off member which can be actuated by the user.

Abstract: A device for cleaning grooved surfaces, such as moving escalators or gangways, comprising a rotatingly driven roll brush arranged in a casing, a spraying device for spraying cleaning liquid, a suction device for removing loosened dirt particles from the rotation space of the roll brush and a plurality of comb-like devices arranged in front of and behind the roll brush in the direction of movement of the escalator or gangway. The comb-like devices engage the spaces between the grooves of the escalator or gangway and, in combination with the casing, seal the rotation space of the roll brush from the outside. The spraying device wets the grooved surface, the roll brush loosens dirt on the grooved surface and collects the loosened dirt, and the suction device removes the cleaning liquid and loosened dirt from the roll brush, thus accomplishing efficient cleaning of the grooved surface.