Dune-shaped pneumatic cut tobacco feeding technology based on velocity ratio between cut tobacco and air

To avoid segregation and breakage of cut tobacco during pneumatic feeding caused by excessively high air velocity and uncontrollable tobacco velocity, the pneumatic tobacco feeding system was modified via adopting a dune-shaped pneumatic cut tobacco feeding method. This method was based on the control of velocity ratio between cut tobacco and air (△VAT). Septwolves (Red) brand cigarettes were tested in Longyan Tobacco Industrial Limited Corporation at an increased tobacco feeding flow, △VAT was introduced as a control parameter and an automatic anti-blocking module was added. The results showed that: 1) When the pneumatic tobacco feeding velocity was controlled within 7-11 m/s, dune-shaped pneumatic cut tobacco feeding at a lower air velocity was realized and excessive friction between tobacco and feeding pipe was avoided to effectively protect cut tobacco. 2) When the ratio of △VAT was controlled between 0.70 and 0.85, best cut tobacco conveying status was achieved. 3) The modification of pneumatic feeding system realized dune-shaped pneumatic tobacco feeding at a lower air velocity, the air velocity was reduced from uncontrollable to 11.32 m/s, cut tobacco velocity was reduced to 9.5 m/s, and △VAT was 0.84, which effectively prevented tobacco segregation and improved the output quality. 4) After the modification, the blending uniformity of cut tobacco decreased from 5.41 to 5.16; meanwhile the reduction of air velocity effectively decreased tobacco consumption. The absolute value of reduction of integral strand proportion changed from 1.27% to 0.74%, and the tobacco consumption per 50 000 cigarettes decreased from 32.17 kg to 31.34 kg.