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Cashew nut sheller design – A review

In document Cashew Nut Processing Mills (Page 56-59)

compatibility before installing and commissioning the work. The work activities in the industry commonly involve highly repetitive actions, awkward postures, and forceful exertions (Kumar et al., 2016; Niu, 2010; Qureshi, Manivannan, Khanzode, &

Kulkarni, 2019; Sakthi Nagaraj et al., 2019). Workers are often characterized by varied anthropometry and physical capacities, and they perform the same task thousands of times in a day. As a consequence, workers often suffer from musculoskeletal disorders. In such a scenario, the ergonomics perspective is of great importance in modern industrial settings when designing work equipment and assessing the improvements.

However, investigations on redesigning existing cashew nut sheller to improve the health and productivity of shelling workers are scarce in Indian scenario. The study reported in this chapter proposes a redesigned cashew nut sheller. A combination of methods, including a postural assessment tool, interviews, questionnaire study, virtual prototyping, and digital human modeling and simulation (DHMS), were used to achieve the stated aim.

cashew nuts against the hard surface of sheller. It also has the arrangement for collecting shelled nuts.

Thivavarnvongs, Okamoto, & Kitani(1995) designed two types of manual cashew nut sheller models (AE (KKU) 1 and AE (KKU) 2), and one semi-automated sheller model (AE (KKU) SA 1). The working principle of both manual shellers was based on press-twist movement of hand lever. In AE (KKU) SA 1, the cashew nut feeding is manual, and shelling is automatic. Thivavarnvongs, Sakai, & Kitani(1995) evaluated manual and semi-automated shellers. They reported that The AE (KKU) 2 was easy to operate and had a whole kernel recovery of 79.3 %, whereas automatic model (AE (KKU) SA 1) had a whole kernel recovery of 80.0%.

Ajav (1996) developed a low-cost manual cashew nut cracker. It consists of frame, pillar pole, cracking jug assembly, cutting case, blades, hand lever, and spring.

The efficiency of this machine when tested with small, medium, and large size nuts was reported to be 69.4 %, 75.5 %, and 75.7 %, respectively.

Jain & Kumar (1997) developed a power-operated cashew nut sheller. It consists of different sections for feeding, shelling, discharge, power supply, and transmission. The sheller mainly consists of two round wooden disks of 25 mm thickness. One disk is fixed to the sidewall of the sheller, and the other disk is a spring-loaded rotating one. The cashew nuts that are fed into the sheller are compressed and subjected to shearing by rotation of disk. The shelled nuts are collected at the discharge section.

Bulaong, Gregorio, & Jallorina (2000) designed an automated cashew nut sheller. It consists of two blades (upper blade and lower blade) with a contour shape of cashew nut. Using micro switch, the lower blade is penetrated into cashew nut up to desired thickness, and the upper blade is twisted to shear the cashew nut. In this process, one nut is shelled at a time.

Swain (2005) developed manual and power-operated shellers. The maximum shelling efficiency of manual sheller was 84.0 %, whereas power-operated sheller was 77.6 %. Considering performance evaluation the use power-operated sheller was suitable for effective improvement of cashew nut shelling task.

Osunde & Oladeru (2006) designed a manual cashew nut sheller. It works in the press and twist principle. The test results indicated that the shelling efficiency and whole kernel recovery were 80% and 66.7 %, respectively.

Ojolo & Ogunsina (2007) designed a box-type cashew nut shelling machine. It consists of a hinge and a spring-loaded cracking lid. The cashew nuts are placed in the round grooves and pressed gently using the spring-loaded lid. At a time, 25 roasted cashew nuts can be cracked using this box-type sheller.

Ojolo, Damisa, Orisaleye, & Ogbonnaya (2010) developed an impact shelling machine. It consists of an impeller which is rotated by an electric motor. The cashew nuts are cracked by impact force by the impeller. Machine throughput, shelling efficiency, and whole kernel recovery was 15.57 kg/hr, 95%, and 70 %, respectively.

Balsubramanian (2011) presented a radial arm type manual cashew nut sheller.

During shelling operation, the cashew nut is subjected to cutting-shearing action to extract the kernel. This is done in a single operation, and the shelling rate is considerably low.

Uchiyama, Ho, Yamanaka, Sano, & Tran (2014) developed an automated cashew nut shelling system that consists of a vibrating cashew feeder, conveyor belt, rollers, cashew milling cutters, and cashew shell splitter. In this sheller, the force controller attached to the cashew milling cutters can accommodate variance in cashew nut size.

Fu et al. (2016) developed an automated cashew nut sheller. It consists of adaptive cashew nut shelling cutters, a support frame cutter, and a scraper. The cashew nut is placed on a V-shaped groove, and the scraper is used to drag the cashew nut against adaptive cutters. Particularly, the spring-loaded upper blade can move up and down in order to accommodate the size variance of cashew nuts.

Oluwaseun Kilanko et al. (2018) designed and constructed a centrifugal cashew nut sheller. It mainly consists of a hooper, impeller, shaft, and electric motor.

It works on optimal kinetic energy for breaking the cashew nuts. The whole kernel recovery for large, medium, and small cashew nuts was reported to be 65.4 %, 51.62

%, and 37.95 % at 3110 rpm, 3487 rpm, and 3487 rpm, respectively.

Kilanko et al. (2019) designed a shelling machine using the impact method.

The sheller was evaluated using three different sized nuts (small, medium, large) and three levels of impeller speeds. The results showed that the large-sized nuts exhibited higher whole kernel recovery (82.0 %) compared to small and medium nuts.

These research works carried out by different researchers on the development of cashew sheller were briefly discussed in this section. Though a good number of cashew nut sheller designs were reported, however, most of the researchers worked on shelling principle, shelling efficiency, whole kernel recovery, and performance of sheller. There is a paucity of research on sheller design that considers ergonomic aspects in design and the occupational health of workers.

In document Cashew Nut Processing Mills (Page 56-59)