With the increase in fuel prices, there has been increased interest in the use of scoop systems for ships' heat exchangers. These systems can enable electrically-operated circulating pumps to be switched off when the ship is at cruising speed. The scoop system obtains its energy from the boundary layer, and has to be designed for very low pressure-losses. The Author explains the theory underlying these systems, under the headings: Scoop Inlet Head; Scoop Outlet; Head Increase by Velocity Reduction; Scoop Performance Curve; Scoop Resistance Curve. Under the last two headings, the curves are discussed with particular reference to a scoop system for a main condenser in a steam-turbine ship. Design calculations are presented for the scoop system for the freshwater cooler of a 1,500-kW main Diesel engine. The system was designed for the Ymir, built by Nobiskrug, and a brief account (with performance curves) is given of the system's performance during sea trials in May 1980. The scoop system was kept in operation during a crash-astern manoeuvre, and worked satisfactorily with reversed flow at full-astern power. It is concluded that scoop systems are an inexpensive but effective way of lowering the electrical load in motor ships under "full away" conditions; the decrease in the Ymir was from 125 to 100 kW. Order from BSRA as No. 54,596.

  • Corporate Authors:

    Schroedter (C) and Company

    Stubbenhuk 10
    Hamburg 11,   Germany 
  • Authors:
    • Grossmann, G
  • Publication Date: 1980

Media Info

  • Features: References;
  • Pagination: p. 1376
  • Serial:
    • HANSA
    • Volume: 117
    • Issue Number: 18
    • Publisher: Deutsche Bahn AG

Subject/Index Terms

Filing Info

  • Accession Number: 00329875
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Mar 12 1981 12:00AM