| 摘要 |
An underwater excavation apparatus comprising a first chamber 13, a second chamber 15 in fluid communication with the first chamber and an impeller 7 which draws water into the first chamber via the second chamber and generates a flow out of the apparatus. The second chamber is configured to redirect water as it passes through the second chamber to counteract torque produced by the impeller. The second chamber may surround the first chamber. The second chamber may comprise one or more guides 23 located on inner and outer walls of the second chamber. The guides may comprise of elongated members which may follow a helical path. The guides may comprises one or more grooves. The guides may be oriented in an opposite sense or direction to the blades of the impeller. The second chamber may have one or more inlets 3 and outlets 21. A hydraulic motor 9 may be connected to the impeller. The impeller may draw water directly into the first chamber. Guide vanes 11 may be located between the one or more inlets to the first chamber. The apparatus may be of a modular structure and comprise a nozzle which provides an outlet from the first chamber. |
