This will not happen in our silos. Because a 45° inclined enlarged gate is mounted on the cone bottom of our silo, resulting a increased bottom cross section. Thus the materials are not easy to be piled up. We can also install a vibrating device on the outside of the silo. After proportioning, carry out the operation of vibration of uniform force directly in the central control room. If using a hammer to knock on the silo housing, it is easy to deform the cone bottom of the silo for inhomogeneous force. As a result, more materials are remained, requiring much time and effort.