Patent GB-1380535-A (GB)
Title: Slurry carrying vessel
IPC: B65G53/30
Filed: 1973-07-09
Abstract: 1380535 Slurry carrying vessels HITACHI SHIPBUILDING & ENG CO Ltd 9 July 1973 [30 Jan 1973] 32545/73 Headings B7A and B7M [Also in Divisions B1 and B8] A hold of a slurry carrying vessel has an overflow drain port 18 for removing surface water which has separated from the bulk cargo, e.g. iron or sand, during loading of the slurried cargo, a valve-controlled port 19 for draining surface water overlying the settled bulk cargo after it has been loaded to a predetermined level H and a plurality of filter equipped drain ports 26, 32 in the bottom of the hold for gradually draining away water still remaining in the bulk cargo. In a preferred construction the ports 18 and 19 are connected to vertical trunks 14 on the hold's transverse wall 9, the ports 26 lead to horozontal drain passageways 23 along the bottom of each longitudinal side wall of the hold and the ports 32 are located adjacent the side walls in the ceiling of the hold's double bottom 12. The trunks 14 and passageways 23 lead to a reservoir space 17 which is emptied via a pie 27 and the ports 32 discharge into a bilge well 30. Alternatively the passageways 23 may lead to the bilge well 30 which is separate from the space 17. An emergency valve controlled port 21 may be provided in the trunks 14 to remove surface water if this starts to surge due to ship motion. In addition and to complement the drainage ports 32, filter equipped ports may be provided on the trunks 14 and reservoir 17. Auxiliary valve controlled overflow ports may also be located on the trunks 14 to drain away surface water before it reaches the level of the ports 18 and these ports are closed before the cargo level rises above them. The valve controlled ports may be fitted with filters to protect the valves from cargo particles.  In other constructions, the ports 26 may only, or additionally, be installed along the transverse walls 9 in which case the reservoir 17 replaces the passageways 23 for drainage purposes. The ports 18 may also or only be located in the hold's longitudinal side walls and are connected to pipes passing through wing tanks so that surface water is discharged directly overboard. Alternatively the ports 18 may first lead to a settling tank before the surface water drains through the trunks 14, so that any cargo particles may settle in the tank and pass back into the hold through an opening in the tank's bottom. The ports 18 on the trunks 14 may be surrounded by a housing having a louvred inlet and a bottom opening for the removal of any cargo particles which collect in the housing. Construction of the horizontal drain passageways.-The passageways 23 may comprise a housing located in the hold along the corners between the longitudinal side walls and the double bottom 12 and having a vertical side wall in which the drain ports 26 are located. Alternatively they each comprise a curved plate having a substantially semicircular cross-section which interconnects the side wall's bottom to the double bottom 12 and is covered by an inclined filter assembly forming the drain ports. In other constructions the passageway is recessed in the double bottom and is formed by a similarly curved plate or an L-shaped plate. The holds of the slurry carrying vessel are loaded in a certain sequence and it is preferred if the hold to be loaded last is smaller and has either a larger number of drain ports 26, 32 or the same number of drain ports with a larger area than the other holds. A number of different filter assemblies for the drain ports 26, 32 are disclosed (see Division B1).