In a method for adsorptively drying purified biogas and regenerating laden absorbents, foreign matter is not allowed to enter the purified biogas, the content of methane in the gas remains virtually unchanged and the effort involved in regenerating the laden adsorbent is reduced. A longitudinal groove is formed in a side surface of the clamp body so as to communicate with both a spatter discharge hole and a hole for supporting a fulcrum pin. The motor drives the tool bit and includes an armature, a coordinator, a plurality of segments and a plurality of armature windings. The innovations described herein minimize the defects on the perimeter pixels by effectively damming the waviness of the front of the seal near the perimeter pixels on the tiles. The RS encoder performs RS encoding on the multiplexed data packets for second forward error correction, and the trellis encoder performs trellis encoding on the RS-coded data packets. Other embodiments are described and claimed.