Additional information about CrossFlow Turbines
As shown in the drawing, the Cross Flow turbine mainly consists of:
The side walls (2) are a welded steel fabrication and are bolted to the inlet case (1), the draft tube (4) and to the runner casing (3). The side walls house the bearing supports and the shaft seals.
The runner case (3) is a welded steel fabrication, designed to allow free flow of water with out interference to the runner. It is bolted to the side walls and the draft tube and is fitted with lifting eyes to allow easy access to the runner for maintenance.
The draft tube and base plate are of welded steel construction and are fitted with rectangular flanges for bolting to the turbine and bolting to the foundation slab. The runner is manufactured in stainless steel with carefully shaped blades welded to the lateral and central discs. The discs are then welded to the shaft and the assembly is stress relieved prior to final machining. Following machining, the runner/shaft assembly is balanced at runaway speed to ISO 1940-1973, Grade G3.2 Standard.
The inlet adaptor (with round to rectangular transition), is fitted with an inspection cover to enable the removal of foreign bodies from the entry to the turbine.
These turbines are always manufactured with a horizontal shaft and the runner is not subjected to axial thrust. Therefore, expensive and delicate thrust bearings are avoided.
The machine is fitted with grease lubricated ball or roller bearings with a calculated bearing life of at least 100,000 hours.
The governing system is relatively simple and compact, whilst remaining extremely flexible and efficient. Double acting hydraulic actuators are connected via a shaft to the guide vanes. The hydraulic actuators are operated by a hydraulic power pack.
Prior to final machining, all welded steel fabrications are stress relieved by heat treatment. To protect against corrosion, a sandblasting and surface treatment procedure is adopted in compliance with Svensk Standard SIS 1967. This ensures a long lasting and durable surface is provided.
All parts, which are to be in contact with concrete, are treated with milk of lime. All parts in contact with water (internal turbine surfaces) are painted with non-toxic paints with a high abrasion resistance.
For further information about this product, feel free to contact us.