The development of a small scale stone crusher is the actual solution to the disparity between the large scale stone crushing and the manual stone crushing since it will reduce the human effort requirements and increase output. It i....

Rock is an abundantly available natural resource that is used for aggregate production. The demand for aggregate has been on the rise recently due to the increased activity in the building and construction industry. The crushing of stones has been characterized by high input undertakings in terms of capital investment usually done by the construction companies themselves which incur high transport costs since they use heavy and centralized stone crushing machines. With ever increasing demand, people have resorted to extracting this resource for revenue earning. For a long time now the local people have used crude ways of reducing large rocks into the required size of aggregates. Due to the kind of tools they use, their output cannot meet the daily market demand for this commodity . This undertaking is also hazardous to their health since no protective devices are used. Faced with the challenge of bridging this gap, the idea of a small scale mechanized stone crushing machine was conceptualized. The aim is to design a machine that can increase the crushing power of the „hammer and anvil‟ stone crusher without pricing itself out of the range for which such workers can afford. The machine should also increase the output volume of crushed stone in order to match the increased demand. The fact that such a machine would be available to small scale stone crushers saves construction companies transport costs that they would have otherwise incurred while doing the large scale centralized crushing. At this point, it is important to note that there are existing models of stone crushers, so the aim here is not to reinvent the wheel, but to develop a machine that is suitable to our particular situation as outlined above. Due to the fact that Kenya is a developing country, most of the people in volved in the stone crushing industry are not able to acquire machines which can produce aggregates in large scale. Hence, this has been left to foreign companies which have the financial capability to purchase such equipment. This production is characterized by a high degree of automation, high crushing rate and large output. The finished products have even granularity, excellent shape and reasonable grain distribution. Furthermore, various sizes of aggregates are produced. Contrary observations were noted in a visit to Makongeni in Thika town where people crush stones using the hammer and anvil. The rate of production was slow due to the kind of tools they use. Actually, a hardworking individual could produce up to seven wheelbarrows of aggregate a day (equivalent to 0.408 tonnes of aggregates daily) which could earn him only Kshs. 200 on average . A truck carrying 7 tonnes of manually crushed aggregates costs Ksh.3500. Thus, it takes approximately 20 days to crush seven tonnes of aggregate. Crushing is done on an open area, exposing people to the harsh sunshine, rainfall and extreme coldness. In addition, there is hazard of injury from hammer blows to the fingers, injury from flying fragments of stone and ailment from inhalation of stone dust. It was therefore noted that there is need to develop a small scale machine that could increase the rate of aggregate production in order to meet the high market demand while improving the living standards of the people.

About the author
Eric Achu Ndangoh
Mechanical Engineering Expert

I am a mechanical engineer scientist and inventor from the university of Liverpool, England, UK. In the las 16 years I have written and invented about 40 projects in science and technology for some of whic I already have a patent. I also have experiene as a teacher of the sciences and a University lecturer where I have taught Physics, Mathematics, Solid Mechanics and Mechanics of Perfect Fluids. At the moment I a keeping my options open and I would very grateful if any companies needing my services can gi ve me a call. I believe in dedication and hard work and as an Aries I ave the extra energy to put in and I am always ready to go the extra mile for the sake of others. Thanks.