Suction dredger is a heavy pump, assembled on floating pontoons.
Hydraulic dredgers are successfully applied in different branches:
cleaning of water bodies (ponds, rivers, lakes etc.);
strengthening the shore, dams and hydraulic structures;
extraction of sand and gravel from the open-pit mine, sapropel from the lake,
precious metals (gold and diamonds) extraxtion;
alluviation of earth dams, dikes and beeches;
mitigation flood- pumping water from flooded soil landslide facilities, the construction of hydraulic structures protective purposes;
works to level the the bottom to building hydraulic structures and underwater objects;
development of underwater trenches for pipelines (pipe canal) and cables installation and its alleviation;
alleviation of roads and areas for industrial and civil building;
development of ashy and sludge tanks;
development of coal sludge pits , iron and steel plants, coke-chemical enterprises;
production of fine-grained concentrate from sludge pits of mining and concentration complexes;
cleaning of industrial and agricultural sludge tanks from sludge, sand and other depositions;
cleaning of sediment from a large number of conservative contaminants from urbanwater bodies in geotuby with follow-up and disposal;
hydro-mechanized works during the erection of ship and irrigation canals, water area buildings, sea and river ports.
The variety of kinds of performed works and areas of using causes the variety of models of suction dredgers, depending on:
- natural conditions under which the suction dredge is used;
- categories of soils;
- depth of development;
- distance of transportation and height of soil lifting;
- possibilities of energy supply;
- type of aggregate for suction;
- way of soil intake;
- way of soil transportation;
- controlling system;
- hull construction;
- place of location of the main equipment (bilge or suction dredgers with sunk dredge pumps);
- quantity of dredge pumps (one-pumped or two-pumped suction dredgers);
- availability or absence of living and domestic structures of the board of the suction dredger.
Hydraulic dredgers are designed for development of soil of I-VI categories by means of cutterhead, hydraulic washing-out (jet) or by free suction and soil transportation in the form of dredged spoil to the place of stowage.
soil of the I category consists of: 90% of compacted sand, 10% of light-textured loam soil
soil of the II category consists of 60% of sand and 40% of medium-textured loam soil.
soil of the III-IV category consists of 70% of heavy-textured loam soil, light clay and 30% of sand
soil of the V-VI categories: 90 of heavy clay, medium clay and 10% of sand.
Externally, the dredger is a powerful pump and power units mounted on floatingpontoons, four, or two side pontoons (HCC 800/40, HCC 2000/63) or molded bilge(HCC 60/23 - HCC 800/40). On the main pontoon mounted soil intake device control mechanisms, cutting, auxiliary equipment. Dredgers HCC1600/25-3 and HCC 2000/63 can be equipped with residential and domestic premises.
Board equipment from power units to metering apparatus is modern. The control of all mechanisms of hydraulic dredgers is performed from the deckhouse of the burgomaster by means of control panel located there and equipped with the correspondent devices. All regular disconnections conditioned by the technological process of works performing are executed by means of control panel. The control panel allows performing of an emergency stop almost of all mechanisms of the hydraulic dredger.
Suction head (F) – a cutter - is a construction meant for development of the soil of the I – VI categories with the help of hydraulic cutterhead with the capacity from 16 to 100 kWt and rotation frequency from 4 to 40 rev. \min at 1200-3500 n\m3. The foundation is a displacement-type frame. The distinctive feature of the frame is the availability of pontoons in metallic structure that allows to perform soil development on the depth up to 15 m due to load reduction of the hull and suspension of hydraulic dredger. The cutter is a space frame and is mounted of the sections on which hydraulic motor for cutter drive unit, piping of supply \suction of water to hydro cap \main pump, slurry pipeline, fences, two pontoons (pipes with corks for revision), main and additional suspensions, bearers for slurry pipeline fixing are assembled. The connection of other sections between each other are flanged and/or bolted.
Hydraulic washing-out (hydraulic ripper or jet) indicated with the letters GR is meant for development of soil of the I-IV categories. The capacity of installed pump that supplies water to the end of the arrow of suction drum is different from 2 kWt to 40 kWt; water supply is from 12 up to 200 m3 per hour at hydraulic drop of water column from 30 to 80 m. The capacity of hydraulic ripper depends on the brand of hydraulic dredger and depth of soil development.
Capsular hydraulic dredger (K) – is a hydraulic dredger with the capsule (dimensions according to the pump) in the engine department which sinks under the water to the depth from 1 to 3 m of hydraulic dredger draught with the help of hydraulic cylinder. In the process the concentration of pulp increases for 15-20% of concentration of pulp of an ordinary hydraulic dredger. The depth of soil development increases up to 15 and more meters. The concentration of pulp increases at the expense of absence of atmospheric resistance during the suction of soil. The drive unit of the main pump in such suction drives is only hydraulic that allows to reduce the dimensions and to make the unit more compact. Such modification of the hydraulic dredger allows to perform underwater operations by an ordinary horizontal pump without any injector devices.
Modified dredger (M) - modified capsular dredge excavation to the depth of 20 m and the concentration of the pulp density from 1.4 to 1.8 kg / l, but this decreases the transportation distance of the pulp.
The distance of soil transportation along the slurry pipeline is indicated in accordance with the factory characteristics of the pumps. On condition of horizontal transportation and minimal pipe bend the distance of soil supply along the pipeline may be increased up to 20% without productivity losses.
Possible to manufacture dredgers brand HCC 160/30-F, HCC 250/40-F, HCC 400/20-F, HCC 800/40-F with soil pump is installed on open or semi-open impeller.
The enterprise follows the main guidelines such as:
the State Standard of the Union of Soviet Socialistic Republics “Hydraulic dredgers of general purposed. Terms and definitions. All-Union Sate Standard 17520-72”, All-Union Sate Standard 26433.0-85 “Order of measurement performing. General provisions”, State All-union Standard 26433-89 “Order of measurement performing. Elements of prefabrications”, Ukrainian National Construction Regulation B.1.1-7-2002 “Firefighting regulations”, “Rules of building and equipping of the ships”, Normative Document 31.0.020-2004, “Rules of classification and building of inland-waterways’ vessels”, “Rules of classification and building of small crafts”, “Rules of classification of surveys of the vessels”, “Manual of engineering supervision of application of welding in shipbuilding and ship repair”, “Small crafts. Main features” ISO 866:2002, “Small crafts. Classification and estimation of stability and floatability. Part I.”, “Non-wind-driven ships with the length of 6 m and more” ISO 12217-1:2002, “Small crafts. Maximum load according to the volume” ISO 14946, “Small crafts. Stationary diesel engines. Fuel and Electrical instrumentation and equipment hanged to the engine” ISO 16147:2002, “Single safety regulations during the development of deposits of commercial minerals by open-pit mining” Safety Regulations 03-498-02.