FABRICATION AND PERFORMANCE EVALUATION OF WILD ...

FABRICATION AND PERFORMANCE EVALUATION OF WILD WALNUT (Juglans nigra) Heijuga CRACKING MACHINE

INTRODUCTION Wild walnut (Juglansnigra) a member of Juglandaceae family is one of the finest nuts of temperate regions. It is grown spontaneously in Himalayans range, India. Oil yielding crop plants are very important for economic growth of the agricultural sector. The oil nut containing unusual fatty acids are industrially important, as they are used as an ingredient in food, while the hard wild walnut shell is used commercially in abrasive cleaning, cosmetics, and oil well drilling and water filtration. Wild walnut production is expected to gradually rise in the next 5 years from 100.60 MT to 172.24 MT in the year from 2004 to 2012. But very little percent of production is consumed and remaining production of wild walnuts is waste due to its hard covering. Wild walnut has thicker shells that are harder to crack. Commercial walnuts are mostly eaten as desserts nuts or used in cakes, desserts and confectionary. Walnuts are rich in fat, a diet supplemented with walnuts had a beneficial effect on blood lipids, lowering blood cholesterols and lowering the ratio of serum concentrations of low density lipoprotein: high density lipoprotein by 12 %. In 2004, the Food and Drug Administration stated: “Supportive research shows that eating 1.5 ounces per day of walnuts, as part of a low saturated fat and low cholesterol diet may reduce the risk of coronary heart disease”. Walnuts are a rich source of heart-healthy monounsaturated fats an excellent source of those hard to find omega- 3 and omega-9 fatty acids which helpful in keeping heart healthy. Wild walnut has around 60 to 65 % oil. The serving size of walnut oil is less than the amount of wild walnuts needed to get the same nutritional benefit. For example: A 35 gram serving of walnut oil provides the same nutritional benefits as 50 grams of walnuts. Walnuts are also rich in antioxidants. Antioxidants are substances that counter the effects of free radicals, which are substances that cause cell damage and accelerate the aging process. (Toshiyuki et al., 2003). 1

The utilization of wild walnut is limited due to inconveniences in cracking the hard shell. It need a hammer or a hard base to crack it. But yes, the taste is superb and are definitely rewarded for the labour put in to crack them. The objective of this was to evaluate the performance of the walnut cracking machine. MATERIAL AND METHODS This chapter includes all the details regarding the materials and methods which were used for designing, fabricating and performance evaluation of walnut cracking machine. Design of machine The machine was designed for the purpose of cracking walnut. Cracking of walnut is the most essential and tedious step in walnut. The machine was designed with the purpose to be well accepted in the small scale industries. In small scale industries usually women labourers are employed. Thus the machine was designed to be easily operated with the minimum energy and greater efficiency. The machine was designed in such a way that the minimum amount of material was required to make it a low cost machine.The machine was designed which could be fitted to any place according to one’s own comfort. Parts of the machine Hopper Hopper was fabricated trapezoidal in shape. Hopper was made of Mild Steel sheet of thickness 10 mm. The length of the hopper was 30 cm and width 26 cm.The opening of the hopper was length 30 cm and 26 cm.The slope was 100 (degree) to facilitate the movement of walnut, the hopper opening was kept wide to pass the walnut to the roller. Roller

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The walnut cracker was designed and fabricated with an iron roller. The roller rotates on its axis inside a casing. The shaft was kept horizontal. Materials are fed from the top of the casing and is broken by the rotating roller and fall out through the bottom. The material or feed is broken by the compressive force. Spikes On the cast iron roller iron spikes are provided in spiral throughout the entire length of the roller. The tips of the spikes are made curved for holding and puncturing the walnuts.Walnut is fed into the hopper and to rotational direction of the flutes, it is moved around the iron roller and the casing, finally towards the outlet, compressive force between the walnuts and machine parts (roller and casing) cause the walnut shell to break.The clearance between the roller and the casing decides compressive and frictional forces generated on the walnut.

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Receiving platform The receiving platform was attached just below the iron roller and it was inclined at an angle of 110 (degree) from the horizontal for the easy movement of the broken walnut.The platform was fabricated rectangular in shape and made of Mild Steel sheet of thickness 12 mm. The size of the platform were 22 cm in length and 12 cm in width. Power transmission unit Provision was made to transmit the power by hand or an electric motor. The power transmitted to the flywheel and driving shaft. Driving shaft was made of Mild Steel rod of 8 cm diameter and 22cm length. The driving shaft gives the drive to the iron roller. Frame The main frame of the walnut cracker was fabricated rectangular in shape to provide the strength and firmness to the machine. It was made of angel of size 2 cm.The size of the frame was 28 cm length and 33cm height. Sufficient working space was available for cracking the walnuts. The height of machine was suitable for working. Material A walnut cracking machine was developed for cracking walnut. A study was conducted on locally available cultivated walnut variety. Approx. 3 kg of walnut was used for cracking and performance evaluation of the walnut cracker. In order to evaluate the success of the walnut cracker the following were measured. Walnut The walnut was purchased from the local market of Allahabad. It was a commercial variety. The walnut was purchased in a load. Total walnut required were 3kg for the optimum feed rate. The reading was taken in triplet and an average was recorded. The dimensions of walnut

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were taken using a Vanier calliper with a least count of .01cm.The size of the walnut varied between minimum Geometric Mean (G.M.) 2.6 cm and maximum 4.2 cm with an average of 3.8cm.As walnuts start to fall on iron roller from the hopper, started the stop watch to measure the feed time when the last walnut is cracked or falls on the receiving platform the stop watch stopped. The time taken for total cracked walnut was noted down. Three trials were taken.

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Plate no. 1 Walnut cracking machine

RESULTS AND DISCUSSION A walnut cracking machine was designed and fabricated in the Department of Food Process Engineering, Vaugh School of Agricultural Engineering and Technology, SHIATS-Deemed University, Allahabad. The performance of the walnut cracking machine was evaluated on commercially available cultivated walnut variety. The performance of the walnut cracking machine was evaluated at 30, 35, 50 and 55 rpm. The Geometric Mean (G.M.) of individual walnut was measured and the cracking efficiency of the machine at different speed were measured. For each speed the data on cracking efficiency were collected and statistically analysed. The result of this study are presented and discussed as follows. Overall performance of the walnut cracking machine The walnut were somewhat spherical in shape. The mean diameter of the individual walnuts were calculated as shown in Table (Appendix -A-1). The walnuts fall in between the roller and casing clearance and broken. The performance of the walnut cracking machine showed

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very good at any of the speeds (i.e. 30, 35, 50 and 55 rpm). The walnuts were falling from the hopper to the roller at the provided angle of hopper 100 (degree). Effect of walnut cracking machine’s speed on cracking efficiency The cracking efficiencies of walnut at various speeds have been shown in Table 4.1. The maximum average overall cracking efficiencies were 84, 87, 85 and 88 percent at the walnut cracking machine’s speeds 30, 35, 50 and 55 rpm respectively. Table 1. Effect of walnut cracker’s speed on cracking efficiency S.No.

Speed (rpm)

Efficiency(%)

1.

30

84

2.

35

85

3.

50

87

4.

55

88

The overall cracking efficiency increases with the increase in speed. The average overall cracking efficiency ranges from 84 % to 87 % whereas the speed ranges from 30 to 55 rpm. The increase in average overall cracking efficiency with increasing speed was due to combined compressive and frictional forces between the walnuts and the machine. The clearance provided between the roller and casing as well as the spike dimensions were appropriate for the average shape and size of the walnuts.

4.1.2 Effect of walnut cracking machine’s speed on average size of the walnut meat The average size of the walnut meat after cracking the shell were measured at different speeds. The average size of the walnut meat at different speeds 30, 35, 50, 55 rpm were 2.5 cm, 2.3 cm, 2.4 cm and 2.2 cm respectively. The maximum average size was observed 2.5 cm at speed of 30 rpm and minimum size was observed 2.2 cm at 55 rpm. Thus we can say increase in speed of the walnut cracking machine has effect on the average size of the walnut nut after cracking. Though there is decrease is average size of the walnut meat with the 7

increase in the speed but the it is very less, i.e. at rpm deviation of 25rpm from 30 rpm to 55 rpm the difference in size is only 0.3 cm (2.5 cm at 30 rpm and 2.2 cm at 55 rpm). Table 4.2 Effect of walnut cracker’s speed on mean size of walnut meat S .

N o . S p e e d

( r p m )

L e n g t h

1.

30

2.5

2.

35

2.3

3.

50

2.4

4.

55

2.2

( c m )

CONCLUSION The present study was conducted to fabricate and to evaluate the performance of walnut cracking machine in the Department of Food Process Engineering, SHIATS- Deemed University, Allahabad.

Based on the experimental results, the following inferences could be shown. The performance of the walnut cracking machine showed very good at any of the speeds (i.e. 30, 35, 50 and 55 rpm). The walnuts were falling from the hopper to the roller at the provided angle of hopper 100 (degree).The maximum average overall cracking efficiencies were 84, 87, 85 and 88 percent at the walnut cracking machine’s speeds 30, 35, 50 and 55 rpm respectively.The average overall cracking efficiency increases with the increase in speed. The average overall cracking efficiency ranges from 84 % to 87 % whereas the speed ranges from 30 to 55 rpm.The average size of the walnut meat at different speeds 30, 35, 50, 55 rpm were 2.5 cm, 2.3 cm, 2.4 cm and 2.2 cm respectively. The maximum average size was observed 2.5 cm at speed of 30 rpm and minimum size was observed 2.2 cm at 55 rpm.

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