The Compressive Wafering of Leguminous Hay (II)

Study of Ring Type Roller-Die Wafering Machine

Abstract

The characteristics of a ring type roller-die wafering machine for alfalfa were studied and the following results were obtained.
1. The die rotating torque was almost coustant but the power requirements increased linearly with the increase of moisture contents of hay. The maximum value of power requirements was 2-3.5 times that of mean values.
When the moisture content was 27.5% and the die rotating speed was 50rpm, the power requirements without load, the mean power and the maximum power were 1.1, 4.3 and 12.8 horse powers, respectively.
2. When the moisture content of hay was high (50%) or low (12%), the falling shock durability, tensile strength, density of wafer and magnification of density were generally all low, and the wafers formed were of no utility. The most desirable moisture content was 27.5% within the range of moisture contents of this experiment.
3. There was a similar tendency between the falling shock durability, tensile strength and density of wafer. The magnification of density was about 24 for useful ranges.
4. The shape of wafer, the imperfections of feed auger and the shortage of die rotating power had to be improved, but it was considered that this device was useful for wafering leguminous hay such as alfalfa.
5. The fundamental or essential excellences of this type were as follows: it could work continuously, it was much smaller and lighter in shape and weight and required less power than most foreign-made machines did, it was quite suitable to our small sized farms and to climatic conditions of our country, and also it had comparatively good feeding of hay to die holes.
6. On the other hand, the defects of this type were as follows: the centre of gravity was high making the machine unstable, the vibration was somewhat intense, hay readily clogged the die holes or between die-rings resulting in ununiform discharge, torque fluctuations were great, the conservation, cleaning, overhaul, repair of the machine and discharge of remained wafer were difficult, there were some problems in the structure and strength of the die-ring covers, imperfect protection against dust of hay for faces of guide rollers and gears, and also hay had to be cut to lengths of about 30-100mm.