**6.2 Case study 2: two-wheel tractor mounted mobile maize sheller**

According to [9], a study was conducted to develop a cost effective two wheel tractor mounted mobile maize sheller for small-scale farmers in Bangladesh in South Asia. Two-wheel tractor (power tiller) is a common tillage tool in Bangladesh agriculture because it can easily access fragmented land that is affordable to small scale farmers. Traditionally, maize shellers need to be carried from place to place by hooking with two-wheel tractor (2WT) and set it up again for shelling operation. This takes longer time for preparation of maize shelling.

To consider this problem and constraint, a small cost-effective mobile maize sheller was developed, which is mounted on the front side of the two-wheel tractor (**Figures 7** and **8**).

So, the driver of the 2WT carry and move the sheller along in the 2WT driving position. The engine of 2WT is used as a power source for operating the maize sheller.

The mobile maize sheller eradicates the transportation problem and can start shelling operation instantly at any place since it is attached together with 2WT. It is counter clockwise rotating cylinder, axial flow type sheller and grain separated with a resistance between spike tooth and the concave. The maize sheller is attached with nuts and bolts in front of the engine base of 2WT. The operating power of the sheller comes from the fly wheel of the engine of the tractor through a V-belt and a pulley.

The shelling performance of the mobile maize sheller is shown in **Table 4**. The shelling capacity, shelling broken kernel and cylinder loss of the mobile maize sheller were 2100 kg/h, 2.3 and 0.35%, respectively. The efficiency of the mobile maize sheller was 97%.

Effective operating hours of mobile maize sheller is more than that of the traditional maize sheller (**Table 5**). This is because shelling unit of the mobile maize sheller is assembled with the transportation power unit and service providers freely carry the maize sheller to different farmers' home yards in assembly position. This therefore, reduces the maize sheller installation and starting time. The effective operating hours/day were 6.5 and 4.5 hours for the mobile maize sheller and immobile maize sheller, respectively. Mobile maize sheller saves 2 hours/day that is this sheller can be used for an additional 2 hours in day compared to the immobile maize sheller. The shelling cost for mobile maize sheller was 0.0026 USD/kg of grain which was lower than 0.012 USD/kg for the immobile maize sheller (**Table 6**).

**Figure 7.** *Side view of the two-wheel tractor with the mobile maize sheller [9].*

### **Figure 8.**

*Operational view of the two-wheel tractor mobile maize sheller [9].*


### **Table 4.**

*Shelling performance of the mobile maize sheller [9].*


### **Table 5.**

*Effective use hours of mobile maize sheller versus immobile maize sheller [9].*


### **Table 6.**

*Shelling cost of the mobile and immobile [9].*

The lower shelling cost of the mobile sheller can be attributed to the extra two hours that it can operated per day compared to the immobile maize sheller. The benefit–cost ratio (BCR) of the mobile maize sheller was 5.15.

*Improving Maize Shelling Operation Using Motorized Mobile Shellers… DOI: http://dx.doi.org/10.5772/intechopen.101039*

**Figure 9.** *Operational view of the Munyegera Agro-Machinery mobile maize sheller [10].*

### **6.3 Case study 3: Munyegera Agro-Machinery mobile maize sheller**

The last case study is from [10] about a mobile maize sheller (**Figure 9**) designed and fabricated by an enterprising fabricator Munyegera Agro-Machinery in Eastern Uganda with encouragement, advice, training, and initial funding from Non-Government Organization (NGO) Sasakawa 2000.

Although there is not much scientific information on its design, fabrication, and evaluation, it can be noted that this mobile maize sheller capacity is 2000–3000 kg/h [10] which is higher than most motorized immobile maize shellers. This can be attributed to the bigger shelling unit of the mobile maize sheller compared to the motorized immobile maize shellers. Operation of this mobile maize sheller requires three to four workers. Hence, whether a self-employed agent or large-scale farmer service enterprise like the Bugiri Agribusiness Initiative Development Association, youth are typically hired to operate and maintain the maize shellers which has contributed to rural enterprise growth and job creation.

Feed the Future Uganda Commodity Production and Marketing (CPM) initially cost-shared 70 these mobile maize shellers in 2015, particularly with large traders and farmer organizations linked to village agents to demonstrate the benefits of this technology [10]. On observing the benefits, some traders started buying the mobile shellers and have their village agents operate them. Apex farmer organization also purchased the mobile maize shellers to provide the mobile maize shelling service to their members. As of March 2016, many CPM clients acquired 280 mobile maize shellers [10]. CPM worked with Munyegera Agro-Machinery to train more than 200 operators in operations and maintenance, as well as maize quality control with an idea that shellers will be offering premium prices on behalf of their buyers.

### **7. Conclusion**

This book chapter's main aim was to describe the maize shelling operations in low developing countries with focus on the need for a paradigm shift from immobile maize shellers to mobile maize shellers. Compared with immobile maize shellers, mobile maize shellers have the potential to solve the power problem as well as sheller transportation problem and the extra energy required to lift the maize

shellers up and down during the shelling process. In addition, mobile maize shellers save time hence increasing their effective use hours in the field. To maximize the shelling operation, it is recommended that the moisture content of maize is maintained between 12 and 13% at a shelling speed of 880 rpm. Also, the clearance between the spikes and the concave should always be designed depending on the maximum and minimum diameters of the maize cobs.
