Abstract: A microchannel double pipe device comprises a channel for inner nozzle (4), a channel for outer nozzle (5) and a mechanical probe (8). The channel for outer nozzle (5) concentrically surrounds the channel for inner nozzle (4), and the channel for inner nozzle (4) concentrically surrounds the mechanical probe (8). Constricted at the outlet of the channel for inner nozzle (4), the channel for inner nozzle (4) extends to form an inner nozzle core (9). Constricted at the outlet of the channel for outer nozzle (5), the channel for outer nozzle (5) extends to form an outer nozzle core (10). The outer nozzle core (10) essentially concentrically surrounds the inner nozzle core (9), and the outlets of the inner nozzle core (9) and the outer nozzle core (10) are at the same level essentially. The mechanical probe (8) is configured to intermittently empty the inner nozzle core (9).