As the acute Angle styled opener often tends to hang the roots and jam during direct seeding in the corn field with big roots, we adopt a new way which USES the stagger double-disk opener.

In the investigated cooling channel with different Angle stagger jets, the big jets cause swirl flow in the middle of channel and make the swirl flow stronger.

Oar-blade set is composed of main oar-blade 4 and subsidiary one 2. which lean and stagger some angle with the level and are laid relatively in direction.