To prevent a tunnel drainage pipe from crystal
clogging, the primary technical indices of a permanent magnet drainage pipe are
proposed. Then, an indoor and field test is conducted on a selfmade
permanent magnet drainage pipe to examine the influence of magnetic field
intensity, flow rate, and magnet spacing on the crystallization of a permanent
magnet drainage pipe. Finally, experimental analysis is conducted according to
the mass variation of crystals under various conditions and using scanning
electron microscopic images. The results demonstrate the following: (1) When
the magnetic field intensity ranges from 0.1 to 0.3 T, the permanent magnet
drainage pipe has a good anticrystallization effect. When the magnetic field
intensity exceeds 0.2 T, the anticrystallization effect gradually decreases.
When the magnetic field intensity exceeds 0.4 T, the crystallization effect on
the permanent magnet drainage pipe is greater than that in an ordinary drainage
pipe. (2) With increasing solution flow rate in the test pipe section, the
anticrystallization effect of the permanent magnet drainage pipe will be
enhanced. When the flow rate exceeds 450 mL/s, the anticrystallization effect
will not be enhanced with an increasing flow rate. (3) After the permanent
magnetic treatment, the crystallites in the pipeline change from regular cubeshaped objects to rough and loose irregular objects, and
subsequently, from hard blocks to powder, with a tendency to transform from
calcite to aragonite and bulgonepheline. (4) As the placement spacing of
permanent magnets decreases, the final crystallization amount in the pipeline
shows a downward trend. Among placement spacings of 10, 40, and 70 cm for
permanent magnets, 40 cm is the optimal placement spacing.
CHEN Yuchi
,
CHEN Xiangge
,
ZHANG Xuefu
,
LIU Shiyang
,
WANG Cheng
. Anticrystallization Test of a Permanent Magnet
Drainage Pipe in Tunnel Based on Magnetic Treatment
Method[J]. Tunnel Construction, 2022
, 42(12)
: 2105
-2111
.
DOI: 10.3973/j.issn.2096-4498.2022.12.012
