LABORATORY STUDY OF A NEW SUCTION DREDGE WITH FEEDBACK LOOP FOR CONCENTRATION CONTROL-4. FUNDAMENTAL STUDY ON EXPLOITATION APPARATUS OF UNCONSOLIDATED SEAFLOOR SEDIMENTS (4TH REPORT)

Device differs from regular suction dredges in a special suction-head attached to the forward end of a suction pipe joined to a sand pump, in a venture-type detector of concentration in the suction pipe, and in the mechanism of automatic control for concentration. A body finding a shape in which circumferences of two circular cones (or convex surfaces) stick together mutually is fixed in the inside of a conical suction pipe, with keeping the suitable space between the body and the conical suction pipe, and a mouth is at the center of the convex bottom surface of the body. In the suction-head, the convex bottom comes in contact with a sand bed. When pressurized water is poured through the mouth into the sand bed, the sand bed of some thickness under the suction-head causes phenomenon of quick sand, and the suction-head may suck up sand of quick sand state. As a result, the suction-head goes down due to its weight, and may suck up sand falling down about circumference of the suction-head. When flow of the pressurized water stops in the suction, the suction-head also stops going down into the sand bed, and sucking up sand. The automatic control for concentration in pipe in pumping up sand-water mixture from the sand bed is done by on-off operation of the flow of the pressurized water, and upward and downward movements of the suction-head in a vertical line, which are controlled by signal of concentration in pipe being out-put of concentration meter. Theory of operation, static characteristics, and dynamic characteristics of the dredging of loose and thick sand bed by means of the suction dredge are discussed. The tests of the laboratory model of the suction dredge built as a trial show that automatic control for concentration in pipe is done successfully.

• Corporate Authors:

  Mining and Metallurgical Institute of Japan

  ,   Japan 
• Authors:
  • YOKOTA, A
  • ISHIBASHI, O
  • Yamada, N
• Publication Date: 1976-6

Language

• Japanese

Media Info

• Features: References;
• Pagination: p. 415-420
• Serial:
  • Mining and Metallurgical Inst of Japan, Journal of
  • Volume: 90
  • Issue Number: 1060
  • Publisher: Mining and Metallurgical Institute of Japan

Subject/Index Terms

• TRT Terms: Automatic control; Design; Dredges; Dredging; Pumps; Suction pumps
• Old TRIS Terms: Automatic control systems
• Subject Areas: Design; Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00149742
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Apr 13 1977 12:00AM