Ground wellhole dedicated protective pipe for gas extraction of mining-induced area
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United States of America Patent
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Jan 5, 2021
Grant Date -
Jul 9, 2020
app pub date -
Jul 13, 2018
filing date -
Sep 1, 2017
priority date (Note) -
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Abstract
A ground wellhole dedicated protective pipe, disposed inside a ground wellhole for gas extraction of a mining-induced area, includes a casing, and a chain inside the casing and slidable relative to the casing. The chain includes a chain formed by a plurality of chain drums through serial connection, and a detachable connecting piece connecting between chains. A plurality of air holes is opened in the chain drum along an axial direction of the chain drum.
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