HP-DHK series double-layer preheating kneading machine (Invention patent No.: ZL 2009 1 0014580.9) doubles the production efficiency, saves 50% of electricity, and 50% equipment investment.In 2009, it was approved by China Carbon Industry Association, the well-known Shenyang Aluminum Magnesium Design Institute Co., Ltd., Guiyang Aluminum Magnesium Design and Research Institute Co., Ltd., and several domestic well-known carbon experts to participate in the assessment of provincial and ministerial scientific and technological achievement. The double-layer preheating kneader is the first of its kind in domestics and abroad, reaching the international leading level of similar products.