Design & construction of a pineapple juicing machine for small and medium scale processors.

Abstract

The extractor was successfully constructed and tested with an extraction efficiency of 68.6% and capacity or 1600kg/hr and. initial- investment. cost of 115M. The machine can be used in production by both small, medium and large scale processors for quick, cheap and hygienic way to extract pineapple fruit juice in a single. process due to high extraction efficiency and capacity, Also the machine is cheap and affordable in terms power requirement; its maximum power requirement is 5HP, however, the machine was tried with a 7HP motor and yielded the same results. The pomace, juice and peels were simultaneously separated in a very short time compared to human beings with much lower unit production costs of ugx. 2000 per hour. The machine was able to separate the juice from pomace and peels without any particles or pomace escaping into the pulp. On the other side however, after testing, the machine had some limitations basically losses such as un-extracted pomace in the crushing chamber with the peels and this amounted to only 7% of the feed. This is the major loss of the. machine and it is attributed to the. unequal space between the crushing rollers and the perforated frame (squeezing chamber). This loss was seen to increase with the amount of feed in a given time. Also the machine was noticed to make some noise from the crushing unit drive mechanism. This was due to improper meshing of the spur gears used to counter rotate the rollers. During testing, one safely concern was noticed; the open rotating gears, pulleys and belts. The machine was constructed using mild steel thus Stainless steel for a commercial machine, is recommended. Optimization of the squeezing gap between the rollers and the perforated frame to increase efficiency and reduce losses with peels. is also recommended and a Crushing roller speed of 600rpm is recommended. with the use of imbibition Water to enhance- the efficiency of the extraction chamber. Faster feeding but the number of pineapple fruits not exceeding is recommended. Fully covering the rotary parts of the machine; the gears, pulleys and drive belts to enhance safety of the machine. Finally, optimization of the crushing roller diameter and the collection chamber volume is recommended to reduce on- the volume of the machine and hence its overall weight.