This invention belongs to the field of
saline-alkali
land management technology, and particularly relates to a
filtration device for
saline-alkali
land improvement, comprising: a heat exchange
station; several geothermal collection and
desalination devices connected to the heat exchange
station, the geothermal collection and
desalination devices being buried in the
saline-alkali land, with the buried bottom of the devices extending into the geothermal layer; the geothermal collection and
desalination devices comprising: a hollow
pile, the side wall of which has an inlet communicating with the saline-alkali land; a heat exchange
pile, coaxially fixed to the inner side of the hollow
pile, the bottom of which extends into the geothermal layer, a saline-alkali cold water cavity being provided between the outer wall of the heat exchange pile and the hollow pile, the saline-alkali cold water cavity being connected to the outlet of the heat exchange
station through a cold water return
pipe; a heat insulation part, which is wrapped around the outside of the heat exchange pile and located inside the saline-alkali cold water cavity; a heat exchange
filtration part, used for filtering hot brine and allowing the filtered hot brine to enter the heat exchange station; a heat absorption part, used for absorbing
geothermal energy; and a condensation part, used for condensing the
water vapor generated by the hot brine and guiding it to the surface of the saline-alkali land.