USING THE HEAT ENERGY OF THE HYDRAULIC DRIVE
OF A WALKING MECHANISM TO REMOVE FROZEN SOIL
N. M. Suslov,
1
S. Ya. Davydov,
1
and D. N. Suslov
1
Translated from Novye Ogneupory, No. 3, pp. 143 – 145, March, 2012.
Original article submitted December 19, 2011.
This article discusses the design of a unit developed to remove frozen layers of clayey bauxite-bearing soil
from the base of excavators operating during periods of the year when air temperatures fluctuate about zero.
Graphs are presented to describe the heating of hydraulic fluid for different air temperatures.
Keywords: base of excavator, freezing, clayey soil, hydrophilic walking mechanism, heat energy, hydraulic
drive, hydraulic fluid
As a dragline excavator is walked over clayey soils dur-
ing bauxite-mining operations being carried out in climate
regions characterized by fluctuations in air temperature
about zero, the soil sticks to the load-bearing surface of the
base of the dragline and freezes on it. All of the methods cur-
rently used to remove adherent and frozen layers of soil
make the dragline more productive but do not completely
eliminate freezing.
Studies [1] have shown that one effective means of re-
moving frozen soil from the load-bearing surface of such ex-
cavators is a physical method, i.e., the soil is removed by us
-
ing heat energy. This method is especially effective for exca
-
vators equipped with hydrophilic walking mechanisms. In
this case, chambers located in the central part of the
load-bearing base serve as the reservoir of the hydraulic sys
-
tem of the mechanism’s drive. Such a design element has
been incorporated into a unit that was developed to move an
excavator [2 – 5].
The unit (Fig. 1) includes a load-bearing frame that con
-
sists of columns 2, top planking 3, and bottom planking 4
and contains central pin 1. It also includes chamber 5 located
on the bottom planking and pump 6 mounted on a turntable.
Operating with distributor 7, pump 6 supplies hydraulic en
-
ergy to the hydraulic cylinders of the walking-mechanism’s
drive and returns the fluid to the reservoir through throttle 8.
For operations being performed on clayey soils with fluctua
-
tions between above- and below-zero temperatures — when
the soil sticks to the load-bearing part of the base — pump 6
sends the hydraulic fluid back to the reservoir through dis
-
tributor 7 and throttle 8 before movement of the excavator is
begun. The fluid is heated as a result of internal friction as it
passes through the throttle. Entering reservoir 5, the fluid in
turn heats the bottom planking 3 of the frame, which thaws
the soil under the load-bearing surface of the base.
The throttle may be completely closed as the fluid is be-
ing heated. In this case, all of the fluid will flow back into the
reservoir through a safety valve. The fluid will be heated
more rapidly in this event, as will the bottom planking of the
frame. The time required for thawing of the adherent layer of
soil will be reduced to a minimum under these conditions.
The energy potential of a hydraulic drive is fully charac
-
terized by its power. The drive undergoes an energy design to
more accurately determine its heat balance. The energy
Refractories and Industrial Ceramics Vol. 53, No. 2, July, 2012
94
1083-4877/12/05302-0094 © 2012 Springer Science+Business Media, Inc.
1
Ural State Mining University, Ekaterinburg, Russia.
Fig. 1. Unit for moving an excavator.