The JKR series are advanced twin-stage vacuum extruder which draw lessons from the developed domestic, abroad experiences and design to make. They are mainly made of high quality steel with features of reasonable structure, sturdy and durability. And they have strong applicability, high efficiency, easy maintenance but lower energy consumption. The machine's axles, gear and other important spare parts extend the service life which are made by carbon steel and alloy steel through modulation or quench's heat treatment procession. The dialing mud plate's transfer and material level control are fixed with protecting device which improves the plant efficiency of breakdown maintenance. And it also makes sure that it can't easily damage the main spare parts during usage. The reamer adopt the floating shaft structure which can eliminate and reduce the machine's shaking and rocking times because of curve in principal axle after long time usage. The blades of the reamer adopt the wear-resistant metallic material coating technology which makes its life four times to seven times longer than the common reamer. The lead has the function of slight pressure delivery and high pressure extrusion which make the machine save energy from fifteen percent to thirty percent. They are applicable for the production of high-rate hollow bricks with the materials of coal gangue, shale, high-volume fly-ash, urban construction waste, gangue waste, inferior soil.