Abstract: A fluid driven tank cleaning device is provided. The device includes an inlet that connects to a source of cleaning solution under pressure and a stem coupled to the inlet having a fluid receiving chamber. A hermetically sealed gear box is also provided which is coupled to the stem and has a secondary chamber separated from the receiving chamber by a common wall. A primary drive shaft rotatably mounted within the fluid receiving chamber is driven by an impeller which rotates in response to fluid entering the fluid receiving chamber. The primary drive shaft is magnetically coupled to a secondary drive shaft rotatably mounted within the secondary chamber. A gear train reduces the speed of the secondary shaft. A first output shaft rotatably mounted within the secondary chamber is connected to the secondary drive shaft via the gear train. The output shaft is magnetically coupled to a second output shaft which rotates a main housing relative to the stem about a first axis.

Abstract: A method suitable for removing settled sludge from the bottom of a storage tank uses a machine (1) including a central body (15) rotatable about which is a casing (2, 3) provided with two substantially diametric nozzles (4, 5) arranged so that liquid emerging therefrom sweeps substantially only in one plane, a turbine (12) rotating the casing about the central body (15) and half cylinder (18) ensuring that when the casing (2, 3) is continuously rotated, alternately one nozzle is closed for substantially 180.degree. rotation while the other nozzle is open. Such machines may be suspended above the floor of the tank adjacent to a wall thereof. Liquid is emitted from the nozzles in a sweep substantially parallel to the bottom plane of the storage tank, thereby resuspending the sludge which thereafter is withdrawn as a suspension.

Abstract: A machine (1) suitable for removing sludge from the bottom of a storage tank which comprises a central body (15) rotatable about which is a casing (2, 3) provided with two substantially diametric nozzles (4, 5) arranged so that liquid emerging therefrom sweeps substantially only in one plane, a turbine (12) rotating the casing about the central body (15) and means (18) ensuring that when the casing (2, 3) is continuously rotated, alternately one nozzle is closed for substantially 180.degree. rotation while the other nozzle is open. Such machines may be suspended above the floor of the tank adjacent to a wall thereof.

Abstract: A seal for an opening through which an object (e.g. hose pipe) extends which comprises a stack of flexible sheets (1, 2, 3 and 4) one on top of each other, each of at least two adjoining sheets (1, 2) having an aperture therein of dimensions smaller than those of the cross-section of that part of the object contacting the seal and a series of slits radiating from said aperture towards the perimeter of the sheet and each of at least two other adjoining sheets (3, 4) having a series of slits radiating towards the perimeter of the sheet from the center of the sheet, the series of slits in at least two adjacent sheets being offset with respect to each other.

Abstract: A rotatable brush suitable for removing growths and encrustations from submerged surfaces comprises a support, bristles attached to one face of the support adjacent to the periphery thereof and extending away from said one face, and a flexible or elastic membrane surrounding the bristles and which extends substantially from the support to substantially within 10 mm to 40 mm from the free ends of the bristles remote from said one face. The support may have one or more orifices each perforating both faces. The bristles may be formed of steel strips and the membrane may be made of rubberized canvas or nylon.