ㆍPipe relationship wear does not happen hardly by(o.5~2m/sec) vulgarity transport that is diffrent from usual mehtod.
ㆍBecause do low speed transfer, sand's particle breakdown does not happen.
ㆍBecause interior air is exhausted by lower part level, sand relationship filling becomes festinately.
ㆍAIR consumption is few than usual method.