Siberian Federal University (Krasnoyarsk, Russia):

Korzun O. A., Senior Lecturer, Candidate of Engineering Sciences, e-mail: korzun_aaa@mail.ru
Kislyakov V. E., Professor, Doctor of Engineering Sciences

Nowadays, the working season of suction-tube dredgers, which carry out the mining of various deposits on the territory of Northern regions of Russia, is limited by the fact of intensive icing of technological basin (myna) with the beginning of winter. Authors of this article offer two ways of this problem solving: covering of myna with heat insulation material and giving the ice-breaker shape to the suction-tube dredger's reservoir pontoon. During the usage of the first method, the intensity of heat transfer of water surface with frost atmosphere is sharply decreased due to the induced decay of convection in upper layers. According to this, formation of solid-ice on the surface of the basin is delayed at the beginning of winter. At the same time, there appears the possibility of free maneuvering of suction-tube dredger for a long time. Elements of heat insulation materials are made of polymer materials in the shape of hollow balls and cylinders. There are given the recommendations on the calculation of the density of covering and parameters (size, mass) of elements of heat insulation materials. Application of covering can approximately extend the working season by 1.5 months. During the following decreasing of air temperature, the solid-ice, which complicates the movement of suction-tube dredger with traditional rectangular shape of reservoir pontoon, begins its formation between elements of heat insulation materials. The proposition of construction of reservoir pontoon edge under the 60° angle, relatively to the vertical line, will allow the suction-tube dredger to pass the high thick ice crust, because ice will be under strain not by monoaxial compression, but by bending. The calculations have shown, that, depending on the types of suction-tube dredgers, their icebreaking capability is increased by 1.4-1.6 times, due to which, it is possible to extend the working season by 1-1.5 months. According to this, in aggregate, application of both offered methods extends the working season of suction-tube dredgers by 2.5-3 months, which is confirmed on practice. For example, during the extension of season by 2.5 months, the annual production capacity of suction-tube dredgers on extraction of sand-gravel compound on Terentevskiy open pit of construction materials (Krasnoyarsk Krai) was increased from 660 to 965.7 th. m³. Under the same conditions, the cost of final products (in annual balance) was decreased from 52.7 to 35.82 rub/m³.

1. Kislyakov V. E., Korzun O. A., Shershnev A. A., Guzeev A. A. Sposob obrazovaniya mayny v zimniy period (Method of myna formation in winter period). Patent RF, No. 2414561. Applied: November 11, 2009.
2. Kislyakov V. E., Korzun O. A., Guzeev A. A. Ustroystvo dlya zashchity mayny drag i zemsnaryadov ot zamerzaniya (Unit for protection of dredges and suction-tube dredgers myna from freezing). Patent RF, No. 2421571. Applied: December 29, 2009.
3. Kislyakov V. E., Korzun O. A. Ustroystvo dlya zashchity mayny drag i zemsnaryadov ot zamerzaniya (Unit for protection of dredges and suction-type dredgers myna from freezing). Patent RF, No. 2424399. Applied: March 17, 2010.
4. Kislyakov V. E., Korzun O. A., Guzeev A. A. Zemsnaryad (Suction-type dredger). Patent RF, No. 107193. Applied: March 15, 2011.