Question

A field chaff cutter with cutter head has 4 knives and diameter of 650 mm. The given peripheral speed is 30 m/s and throat size is 45*15 cm. For 20 mm length of cut with corn silage what will be the linear speed and rated feeding capacity?

(a) 1.16 m/s; 11.41 tonnes/hr

(b) 1.17 m/s; 21.41 tonnes/hr

(c) 1.18 m/s; 31.41 tonnes/hr

(d) 1.19 m/s; 41.41 tonnes/hr

The question was asked at a job interview.

I would like to ask this question from Processing Equipments topic in chapter Processing Equipments of Farm Machinery

Answer 1

Right answer is (b) 1.17 m/s; 21.41 tonnes/hr

The best explanation: Nf=\(\frac{v*60}{π*Df}=\frac{30*60}{\pi*0.65} \) = 881.47 rpm

Linear speed = \(\frac{n*Nf*L}{60}=\frac{4*881.47*0.02}{60} \)= 1.17 m/s

Feeding capacity = W*H*n*Nf*L*d

= 0.45*0.15*4*881*47*0.02*300

= 21.419 tonnes/hr.