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Rice polishing machine gives superior whiteness to rice and is well suited for raw and single boiled rices. In the complete maintenance of rice polisher machine, we can disassemble the motor and maintain it, clean the motor bearing and infuse oil, check the insulation monitoring, make the cooling system perfect, ensure the motor work in the good condition and so on.

Rice milling industry is one of the most energy consuming industries. Like capital, labour and material, energy is one of the production factors which used to produce final product. In economical term, energy is demand-derived goods and can be regarded as intermediate good whose demand depends on the demand of final product. This paper deals with various types of energy pattern used in rice milling industries viz., thermal energy, mechanical energy, electrical energy and human energy. The important utilities in a rice mill are water, air, steam, electricity and labour. In a rice mill some of the operations are done manually namely, cleaning, sun drying, feeding paddy to the bucket elevators, weighing and packaging, etc. So the man-hours are also included in energy accounting. Water is used for soaking and steam generation. Electricity is the main energy source for these rice mills and is imported form the state electricity board grids. Electricity is used to run motors, pumps, blowers, conveyors, fans, lights, etc. The variations in the consumption rate of energy through the use of utilities during processing must also accounted for final cost of the finished product.

The paddy milling consumes significant quantity of fuels and electricity. The major energy consuming equipments in the rice milling units are; boilers and steam distribution, blowers, pumps, conveyers, elevators, motors, transmission systems, weighing, etc. Though, wide variety of technologies has been evolved for efficient use of energy for various equipments of rice mills, so far, only a few have improved their energy efficiency levels. Most of the rice mills use old and locally available technologies and are also completely dependent on locally available technical personnel.

paddy separator using air blower system with the capacity to suck husk but unable to suck brown rice. The condition can occur because of differences in density between brown rice and husk, brown rice which have the higher density. When brown rice that has been separated by the rubber roll out of the husk and fell through the air flow, then the husk will be pushed into the airways and out through the husk outlet, while brown rice will keep falling towards the rice outlet.

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Before using the paddy husker make the rice milling work, there are always an important step to do, by hand or use machine work both ok, but it is necessary, it is to clean the paddy rice first, especially to clean the stone outside of the paddy rice. As when collect the paddy rice from ground, there are a lot of stone will complex in the rice, if not clean it out, it may damage the rice mill machine or influence the final white rice standard.
How to operate rice mill machine is as follows:
Make sure the 'shutter' in a closed condition, prior to un-hulled rice (paddy) is inserted.
Put paddy rice into hopper.
Turn on drive system (electric motors or diesel engine), make sure the rubber roll and air blower has been active.
Open the 'shutter' slowly, so that paddy can be entered to rubber roll.
Set velocity flow of the paddy with a twist 'feed adjuster'.
Set distance between roll by turning the 'roll gap adjusters' to match thickness of paddy. If distance between roll is too large will cause a lot of paddy were not peeled, while distance between roll that is too small will cause a lot of paddy broken (brown rice is not intact)
Adjust speed of wind by turning the 'wind adjuster'. Wind speed that is too large will cause a lot of brown rice sucked, whereas if the wind speed is too small will cause a lot of husk were not sucked (with brown rice together).
Place the rice container under 'rice outlets' and the husk container under 'husk outlet'.
If there husk still united with paddy rice which are not broken, then input back into the hopper.
One-pass vertical friction-type rice whitener was evaluated by introducing a whitening index defined as the ratio of the vertical resistance exerted by the whitener and the rice flow rate. As a result, there existed a curvilinear relationship between the flow rate and the vertical resistance. The configuration of the whitening screen did not affect much the characteristics of this whitener although the hexagonal screen exhibited a relatively higher performance compared with the rest. Also, the angle of slit has no significant effect over the characteristics of this whitener.
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Friction and impact are two factors affecting paddy hulling performance of impeller type paddy husker. It was hypothesized that reducing the impact as much as possible while increasing the frictional energy will increase the paddy hulling performance. Based on mathematical calculations, the amount of frictional energy almost only depends on the center angle of arch of the blade. Increasing the center angle of arch of the blade will improve the paddy hulling performance. Then, an improved impeller was made and comparative experiments were conducted using the new impeller and the commercial one mounted to both vertical and horizontal axis type husker. The test results showed that under the same hulling ratio, the broken rice ratio of the new impeller is lower than the commercial one by about 6% and 8% in the vertical and horizontal axis type husker, respectively.
The operating parameters for machines of this design are usually determined and set empirically. In this article, some experiments and calculations had been carried out in order to explore the mechanisms involved in husking rice grains using this method. A simple sliding friction rig with load cell and high-speed camera was used to observe the mechanisms that occur during husking. The husking performance of different rubbers was compared for changes in the applied normal load.
It was found that grains rotate between the rubber counterfaces on initial motion before being husked. In addition, harder rubbers were found to husk a higher proportion of entrained grains at lower applied normal load. By measuring the coefficient of friction between rice and rubber samples, the shear force required to husk a given percentage of grains could be calculated and was shown to be constant regardless of rubber type. Based on the mechanism seen in the high-speed video, it was evident that there was a limiting shear stress that was the governing factor over the husked ratio.
In recent years, with the emerging of large-scale rice processing production line, the most of them have realized the automation of production process. which has solved the rice processing line flow control and production process monitoring, improving production efficiency, and greatly reducing the labor intensity of workers. However, the operation of the rice whitener in the rice processing line is entirely dependent on skilled workers at present. The rice whitening machine, which determines the quality of processing, is the key milling equipment in the rice processing line.

 

 

The intrinsic factors of grain includes, color, composition, bulk density, odor, aroma, size and shape. Color is an important primary factor for characterization and grading, trade, and processing of grain. It is a common criterion used in wheat trade. The main compositions of grain are carbohydrates (energy), protein, lipids, mineral, fiber, phytic acid, and tannins. It varies significant depends on the type of grain, genetics, varieties, agricultural practice, and handling of the grain. Grain composition plays a significant role in grading and marketing of grains. Bulk density is defined as the ratio of the mass to a given volume of a grain sample including the interstitial voids between the particles. Size and shape are important factors in grain quality and grading; it varies between grain to grain and between varieties of the same species. It is commonly used in rice grader and key factors in milling industry. The extrinsic factors include: age, broken grain, immature grain, foreign matter, infected grain and moisture content.

As a main source of nourishment for over half the world's population, rice is by far one of the most important commercial food crops. Its annual yield worldwide is approximately 535 million tons. Fifty countries produce rice, with China and India supporting 50% of total production. Southeast Asian countries separately support an annual production rate of 9-23 million metric tons of which they export very little. Collectively, they are termed the Rice Bowl. Over 300 million acres of Asian land is used for growing rice. Rice production is so important to Asian cultures that oftentimes the word for rice in a particular Asian language also means food itself.

Typically, grass species are annual plants or are herbaceous perennials that die back to the ground at the end of the growing season and then regenerate the next season by shoots developing from underground root systems. Shoots generally are characterized by swollen nodes or bases. Leaves are long and narrow, varying in width from 0.28-0.79 in (7-20 mm). Flowers are small and are called florets. Grasses pollinate by using the wind to widely and opportunistically disperse grass pollen. The fruits are known as a caryopsis or grain, are one-seeded, and can contain a large concentration of starch.

There are three different types of rice: japonica, javanica, and indica. Japonica rice varieties are high yielding and tend to be resistant to disease. Javanica types of rice fall between japonica and indica varieties in terms of yield, use, and hardiness. Although quite hardy, indica yield less than japonica types and are most often grown in the tropics.

rice destoner is used to eliminate the stones, metals, glass & other heavy impurities from the rice. It is based & operates on vacuum principle. Vibrating fluid bed gives floating bounce to the incoming materials and thus pulses is continuously separated from heavier materials on specific weight basis.

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In the developed system, first, images of milled rice grader samples are captured. The image processing operations are then executed to eliminate undesirable noises from images. After kernel segmentation, a primary feature vector is created based on some shape, size and color features. To have a high classification accuracy, it is necessary to prepare a proper input vector for the classifiers. For this purpose, the primary extracted features are subjected to a correlation-based feature selection procedure to reject the inferior features. Finally, the best classifier is selected for milled rice grading by examining four commonly used metaheuristic approaches. The entire applied methodology is described in the following sections.

Rice is a member of the grass family (Gramineae). There are more that 10,000 species of grasses distributed among 600 genera. Grasses occur worldwide in a variety of habitats. They are dominant species in such ecosystems as prairies and steppes, and they are an important source of forage for herbivorous animals. Many grass species are also primary agricultural crops for humans. As well as rice, they include maize, wheat, sorghum, barley, oats, and sugar cane.

Quality testing parameters including the milling parameters head rice recovery (HR%), broken fraction (%), husk (%), bran (%); physical characteristics kernel length (mm), breadth (mm), thickness (mm), shape ( length breadth ratio LBR), color, appearance, quality index; cooking characteristics cooked kernel length (mm), elongation ration (ratio of post cooked kernel length to pre-cooked kernel length), cooking time, bursting %, stickiness(%), water uptake were determined for each lot basmati, coarse and hybrid category separately. Generally, a good quality rice should have a high percentage of whole unbroken grains, little or no chalk, translucent appearance, uniform coloration and good for the purpose for which it has been produced (white for raw-milled rice and with a yellowish tinge for parboiled rice), shape (length and length-width ratio) should be right for the variety type, excellent cooking properties- should satisfy the consumers' preference for cooked rice for the particular kind of food preparation (Anonymous, 2014). Keeping in view these points, moisture was determined using Kett® moisture testing meter PB ID2 after calibration through moisture testing standard plate PB ID2 Tester 15±0.1 accompanied with the instrument. Length (l), breadth (b), thickness (t), length breadth ratio-lbr(shape), and type-quality index (lbr/t) average for randomly selected 1000 or more grains of replicate was measured on the office table glass of known length (cm) by placing kernels in end to end or side to side arrangement for length and width respectively. Steel scale 30cm long was used to measure width of the kernels placed in queue on the office table glass.

From the analysis of the separator of indent cylinder type, the separating factors were clearly defined and their effects were discussed. In addition, the separating mechanisms were modelled, the fractional recovery curve was calculated and compared with the experimental values. The obtained results were as follows: 1) Besides the factor of grain length, the separating factors included the shape and coefficient of friction of grain. The distribution form of the values of physical properties of these factors also had strong effects on the separating performance. 2) The factors which had effects on the separating performance are: size, shape and arrangement density of indent parts; size, number of revolution and material of cylinder; separating time, hopper angle and supplied quantity. It is possible to improve the separating performance if these factors are suitably selected. 3) The boundary value of width of broken and whole grain, and half of this value can be used to determine the width and depth of indent parts respectively. 4) The separating performance was good when the coefficient of friction of grain-cylinder was high, and the improvement of this performance was assured if the grain of which thickness is small was removed by a thickness grader before separating. 5) The separating accuracy was good when the separating time was long, and the hopper angle could be properly selected by regulating this angle in such a way to get the value PB which should be high and small in terms of broken and whole grain respectively. PB was the probability of grain entering the hopper being carried by indent parts.

To assess the effectiveness of using Teflon material in search of locally available quality/effective roller material for a prototype rice destoner machine developed in Nigeria making use of four locally cultivated rice varieties. This required determination of the effectiveness of Teflon material as roller for the developed prototype dehusker/destoner. Microsoft Excel 2007 and Minitab 16 were used to analyze the ANOVA of two main factors (paddy varieties and moisture content). The dehusker cleaning efficiency was found to be 94.73 %, coefficient of dehusking was 0.63, coefficient of wholeness was 0.85, dehusking efficiency was 50.54 %, dehusking capacity was 10.56 kg/h. Also the effect of moisture content and test paddy on coefficient of wholeness and dehusking efficiency were significant at p ≤ 0.05, while only moisture content effect was significant on cleaning efficiency. Further search for better roller material to replace the Teflon material to improve the prototype dehusking performance for different rice varieties was recommended.

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The development of a frictional Rice Polishing Machine (RPM) is a major effort made to increase the acceptability of local rice owing to the importation ban placed on the imported rice and the willingness of the government to encourage the adequate processing of the local rice. This work is intended to: bridge the wide gap existing between the local/traditional ways of polishing rice and the modern methods; reduce the amount of premium placed on the use of sophisticated imported rice polisher and the local fabricated machines; improve the attractive shinning appearance of polished rice and packing properties; and remove final traces of dust, bran and flour from the rice surface.

Rice has been part of the staple diet in eastern countries for thousands of years. According to legend, rice was first eaten in China some 5,000 years ago. Rice (Oryza sativa) arrived in Egypt in the 4th century BC and around that time India was exporting it to Greece. The Japanese rated rice very highly, as reflected in the many thousands of shrines, which may be seen across the countryside, which are built to Inari, their rice god (Anping 1989).

For centuries, rice was a standard of wealth and was often used in place of money. When Japan invaded China, "coolies" were paid in rice. In fact, the growing of rice and the success or failure of the crop affected the history, art, literature, ceremonials and the very way of life of the people of India, China and Japan for centuries (Yan and Wenming 1989). Hence, any research on the improvement of rice is not misdirected.

Available modern rice processing machines include: Paddy Cleaner-This machine separates all the impurities like straw, dust, sand, and stones, etc., from paddy, where a blower is attached to the machine for proper cleaning; Paddy Husker-This machine is used for dehusking or shelling process. This machine is also called a Paddy Sheller. Rice Polishing Machine(RPM) or commonly known as the Rice Polisher is one of the newly developed rice processing machines used in rice processing industry. This machine was designed to make the milled rice more attractive in appearance and also to improve the packing properties as well as to remove the final traces of dust, bran, and flour from rice surface.

There was a significant difference between the paddy separator from the viewpoint of percentage of paddy and brown rice. Tray type separator had more percentage of paddy (76.03%) and brown rice (99.89%) compared to compartment type paddy separator with 28.32% and 99.5% of percentage of paddy and brown rice, respectively. Furthermore, rice breakage of tray type separator (18.34%) was significantly less than that of compartment type (21.75%).

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Whole polished rice grader were ground using cryogenic and hammer milling to understand the mechanisms of degradation of starch granule structure, whole (branched) molecular structure, and individual branches of the molecules during particle size reduction (grinding). Hammer milling caused greater degradation to starch granules than cryogenic milling when the grains were ground to a similar volume-median diameter. Molecular degradation of starch was not evident in the cryogenically milled flours, but it was observed in the hammer-milled flours with preferential cleavage of longer (amylose) branches. This can be attributed to the increased grain brittleness and fracturability at cryogenic temperatures, reducing the mechanical energy required to diminish the grain size and thus reducing the probability of chain scission. The results indicate, for the first time, that branching, whole molecule, and granule structures of starch can be independently altered by varying grinding conditions, such as grinding force and temperature.

As a main source of nourishment for over half the world's population, rice is by far one of the most important commercial food crops. Its annual yield worldwide is approximately 535 million tons. Fifty countries produce rice, with China and India supporting 50% of total production. Southeast Asian countries separately support an annual production rate of 9-23 million metric tons of which they export very little. Collectively, they are termed the Rice Bowl. Over 300 million acres of Asian land is used for growing rice. Rice production is so important to Asian cultures that oftentimes the word for rice in a particular Asian language also means food itself. Rice is a member of the grass family (Gramineae). There are more that 10,000 species of grasses distributed among 600 genera. Grasses occur worldwide in a variety of habitats. They are dominant species in such ecosystems as prairies and steppes, and they are an important source of forage for herbivorous animals. Many grass species are also primary agricultural crops for humans. As well as rice, they include maize, wheat, sorghum, barley, oats, and sugar cane.

A study was carried out to explain the mechanisms of the broken rice separator of indent cylinder type. The results obtained were as follows: 1. The separating by indent cylinder type consists of two different mechanisms: the first mechanism is similar to that of a screen, and the second mechanism is that of a separator in which the grain length is a separating factor. 2. The probability P that the grains enter into the hopper equals the probability PA of grains caught by the indent parts multiplied by the probability PB that the grains can enter the hopper. 3. In case of the second mechanism, the grains (mostly whole grains) are rolled and failed at the angle α as expressed in Equation (23) when δ<μ. The grains (mostly broken grains) are slided and failed at the angle α' as expressed in Equation (25) when δ>μ. Where μ is the coefficient of static friction. 4. In order to get a better separation of whole and broken rice, the angle of falling point of broken rice should be greater than that of whole rice. The center of gravity and the friction coefficient are important factors in determining this angle. Besides the grain length, there are also many other physical properties which have erects on the probability PB of the second mechanism. 5. The values of PB are determined from the distribution of the physical properties and hopper angle.

Rice processing begins in a milling plant, where the harvested grains run through a production line where the rice is boiled, dried, de-stoned, husked, hulled and shelled. It then is taken to the color sorter machine. At this point, the rice mixture will travel by elevator belt into a hopper on top of the machine, from which it will flow down along chutes in the colour sorter, streamlining their flow to so that they may be scanned by CCD sensors. The moment the camera detects any color defects, the camera instructs ejectors fitted in the machine to open the nozzle. The nozzle is connected to valves containing compressed air. This air is then used to shoot out the color defected material from the input rice. The types of defects in rice include black tipped, chalky, yellow, mouse droppings, immature grain, etc.

The rice destoner is one of the most important pieces of rice mills machinery. Stones or other bulky impurities are commonly present in grain products. The destoner separates impurities such as stones and sand from the paddies. However, it does not use typical sifting technology to accomplish this. Instead, it employs a method called bulk density comparison. Sand and stones are separated from the product bulk through a primary sieve. A fan then drives the product through a secondary sieve. The lighter product is reclaimed by the airflow, while the heavier debris separates and is discharged from the sieve.

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The threshing of paddy cleaner which was usually done by manual feeding in threshers led to the reduction of threshing capacity due to half filling of threshing drum. This drawback had given rise to mechanical feeding system for wheat threshers which increased their threshing capacity. In this study, in order that the threshing capacity should increase, a feeder chain type feeding system for axial flow paddy thresher was developed. The type of feeder housing used in this thresher was of trapezoidal shape. The length of chain was 2830 mm and two sprockets having diameter 320 mm each. After preliminary testing, it’s performance evaluation was studied on PR-124 to ascertain the effect of cylinder speed (12.27, 14.44 and 16.61 m/s), conveyor speed (2.52, 2.96 and 3.4 m/s) and feed rate (4.08, 4.8 and 5.52 t/h). The threshing efficiency, non-collectable loss, broken grain, cleaning efficiency, sieve overflow and torque were 98.90%, 0.55%, 0.23%, 98.44%, 0.38% and 336.3 Nm respectively at the best combination of cylinder speed, feed rate and conveyor speed of 16.61 m/s, 5.52 t/h and 2.52 m/s respectively.

An evaluation was conducted in eastern India over three years, 2005–2007, to compare the performance of certain System of Rice Intensification (SRI) practices: transplanting single, young (10-day-old) seedlings in a square pattern; no continuous flooding; and use of a mechanical weeder – with those currently endorsed by the Central Rice Research Institute of India, referred to here as recommended management practices (RMP). All plots received the same fertilization, a combination of organic and inorganic nutrients, and the SRI spacing used was 20% less than usually recommended. Accordingly, the results reported here are designated as a modification of SRI recommendations (SRIm). The objective of this research was to understand the benefits in terms of yield and other physiological parameters, if any, from using most if not all recommended SRI practices compared to RMP. These selected SRI practices out-yielded RMP by 42%, with the higher yield associated with various phenotypical alterations, which are reported here. Significant measurable changes were observed in physiological processes and plant characteristics, such as longer panicles, more grains panicle−1 and higher % of grain-filling. The decreased plant density with SRIm management was compensated for by increased per-plant productivity.

Thermal energy for drying and electricity for milling operations typically comprise a significant 55% of a rice mill operating cost. Optimal design of rice mill utility system that efficiently utilizes rice husk biomass has potential to increase profitability of rice milling industry. This paper presents a mathematical approach for simultaneous optimal planning of rice husk logistic network as well as optimal design of a rice mill utility system that efficiently utilizes rice husk supplied from various locations in order to satisfy the electricity and drying requirements of the rice mill throughout the year. A mixed integer linear programming (MILP) problem was formulated to determine: (1) the optimal logistic network for the rice husk supply, (2) the economic scale of the rice husk cogeneration system, and (3) an optimal utility supply network for a series of dryers consisting of a combination of cyclonic husk furnace (CHF) and cogeneration systems. Solution to the MILP problem yields an optimal utility system configuration consisting of a specified network of rice husk logistic network, a 15 tons boiler for the cogeneration system and 8 units of CHFs to satisfy the rice mill heat and power requirements. Compared to the baseline, the optimal utility network manages to reduce 18.5% of the total rice mill annualized cost which include the costs of capital, fuel, and electricity.

Presently, due to an increase in usage of large scale mechanical threshers and combine harvesters, moisture content of freshly harvested paddy is being high as much as 18-24%. The mechanical threshers or combine harvesters with elevated capacity enable for both harvesting and threshing at once. Thus the paddy harvested all over persists with high moisture content that affects adversely in unit operations of paddy processing such as cleaning, storing, and milling. The research was conducted to overcome this problem by developing a mobile paddy dryer that can be used at field level for freshly harvested paddy. A mobile dryer, one ton capacity, was developed and tested for drying freshly harvested paddy. The performance of the mobile dryer was evaluated in terms of overall thermal efficiency, heat utilization factor, coefficient of performance, total heat efficiency and head rice yields. The overall thermal efficiency of this dryer was 46.83%. The average heating efficiencies namely heat utilization factor and total heat efficiency were 0.82 and 0.72 respectively. The coefficient of performance of the developed dryer was 0.18. The head rice yields of freshly harvested paddy after drying at 60 °C air temperature was of 73.78%. The overall drying performance of the dryer was found to be good.

The conventional way to husk rice is to pass it between two rubber roller husker that are rotating with a surface speed differential. The resulting normal pressure and shear stress causes the husk to be peeled away from the kernel. The process is suited to high-rice flow rates, but is energy intensive and can result in considerable wear to the surfaces of the rollers. The operating parameters for machines of this design are usually determined and set empirically. In this article, some experiments and calculations had been carried out in order to explore the mechanisms involved in husking rice grains using this method. A simple sliding friction rig with load cell and high-speed camera was used to observe the mechanisms that occur during husking. The husking performance of different rubbers was compared for changes in the applied normal load. It was found that grains rotate between the rubber counterfaces on initial motion before being husked. In addition, harder rubbers were found to husk a higher proportion of entrained grains at lower applied normal load. By measuring the coefficient of friction between rice and rubber samples, the shear force required to husk a given percentage of grains could be calculated and was shown to be constant regardless of rubber type. Based on the mechanism seen in the high-speed video, it was evident that there was a limiting shear stress that was the governing factor over the husked ratio.

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rice polisher machine gives superior whiteness to rice and is well suited for raw and single boiled rices. In the complete maintenance of rice polisher machine, we can disassemble the motor and maintain it, clean the motor bearing and infuse oil, check the insulation monitoring, make the cooling system perfect, ensure the motor work in the good condition and so on.

Grain dust has also long history diseases and its adverse effects on various organs such as eyes, nose, skin, lung and the airways. Asthma has been well documented as being a result of dust exposure. However, few studies have been reported on the effect of dust exposure in rice mill. The major dust hazards for workers in rice mills are the dust emissions from different sections i.e. dumping of rice at a place for subsequent collection in gunny bags, feed of paddy from gunny bags to the dumping pit, cleaning of paddy grains, removal of husk from the paddy and polishing of rice. In addition, a dusty mill increases the risk of workers’ injury and fire hazard, which results in less production, higher insurance rates, and lawsuits. The increasing global attention on control of air pollution has made the containment of nuisance dust from rice milling operations within enclosures more imperative.

The outer layers of a grain of rice contain proteins, fats and lipids which although good for eating, are bad for brewing because they produce off flavours in the end product. So as to create as refined and clean a flavour as possible, the outer layers are removed in a process called polishing. In the case of the more premium brews, the rice may be milled to leave just little more than the centre of the grain remaining: a nucleus packed with starch called the 'White Heart' or Shinpaku in Japanese. The ratio always refers to the bit that remains after polishing. For example, rice that has had 30% of the grain removed will have a ratio of 70%.

Rice polishing/bran is an alternative feedstuff for many developing countries where rice is a major cereal grain. The yield of rice polishing\\bran ranged from 5 to 10% and this depends on the degree of milling of the brown rice. Both full fat rice polishing\\bran and defatted rice polishing\\bran is a rich source of nutrients and a range of bioactive phytochemicals. The optimum utilisation of rice polishing/bran may be restricted by its antinutritional substances i.e. NSP, phytin and low availability of amino acid.

Separation of paddy and rice on an oscillating type separator takes place due to difference in specific gravity and surface characteristics of paddy and rice. When a mixture of paddy and rice falls on paddy separator having a serrated surface and is oscillated at the appropriate frequency, rice settles down under the layer of paddy. If the inclination of deck exceeds the angle of friction between the rice and paddy, the paddy moves down the deck on top of the layer of rice. This angle of inclination exceeds the angle of rolling friction between the paddy and the material of the deck and the paddy after having been separated from the layer of rice rolls down on the deck surface. Serrations provided on the deck surface are so shaped that they prevent the rice from sliding down. The values of amplitude of frequency of deck oscillation are such that rice can slide up the deck surface in successive steps per cycle of deck motion and finally reach the rice outlet where the grains escape. The equations of motion of rice on a deck surface have been analysed and the conveying velocity computed. The observed and computed velocities have been found to be in reasonable agreement with each other.

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paddy cleaner provides absolute paddy cleaning solutions. It finds application in separating husk from the paddy grains. For the easy flow of operation, these machines are manufactured using top-notch quality raw material.

The quantity and quality of final milled rice depend on the efficiency of farming management, field operations and post-harvest operations. Decisions are taken from planting through to consumption of the rice crop. Initial decisions about the variety to be planted determine intrinsically desirable characteristics and depend upon consumer preference as well as the technical capacity of the farmers during production and post-production operations. These characteristics in turn become factors which influence efficiency, grain loss magnitude, choice of harvesting and threshing technology, rate and quality of the drying and dehusking process, and eventually total recovery of the milled rice. Then there are the wrong practices at the planting stage which can lead to losses: planting of red rice admixture, attacks by rodents and birds, poor weeding and a harvest maturity date which can be too early or too late.

The paddy is dried to a safe level of moisture (14%) before milling. The energy needed for drying of parboiled paddy comes from two sources. The major portion of parboiled rice is dried under direct sunlight. The solar energy needed for drying was calculated as latent heat of water evaporated from the moist paddy. The mechanical drying needs both the thermal and mechanical energy. The thermal energy comes from rice husk and the need of mechanical energy is satisfied with electrical energy. The primary energy consumption for mechanical drying was found to be 1,540 MJ/tonne of paddy dried to reduce moisture level from 32% to 14% under a hot air temperature range of 65 – 130°C. The specific energy consumption was 6.25 MJ/ kg of water evaporated from the grain. It was reported that the specific energy consumption for paddy drying operating within air temperature 50-200°C was 4-10 MJ/kg of water evaporated and within air temperature 103-149°C 2-8 MJ/kg of water evaporated. A combination of sun and mechanical drying was also observed during the study. In this process, the free water from moist paddy is dried under sunshine during the daytime and then the paddy is dried in a mechanical dryer (LSU type) during the evening. The electrical energy for mechanical drying was found to be 17.4 kWh/tonne. It was reported that electrical energy required for mechanical drying varied from 9.30 kWh/tonne to 30.46 kWh/tonne. The electrical energy consumption was found to be 8.7 kWh/tonne for the combination of sun and mechanical drying system, indicating an energy saving option for drying operations.

Paddy is among major staple food cereal crops of the world. The whole grain has higher percentage of vitamins, minerals and fiber as compared to milled rice grain. The present study was undertaken to study the physicochemical, functional, pasting and morphological characteristics of paddy (Gurjari variety) and its processed products were obtained during flaking. The major dimensions were highest for extra thin flaked rice (ETFR) with 17.08 mm length and 8.50 mm breadth at the expense of thickness found to be lowest 1.16. Thousand kernel weight (TKW), bulk density (BD), true density (TD) and porosity (POR) of ETFR were lowest as compared to other products. Frictional properties did not show any significant difference (p < 0.05%) except for angle of repose. Significant difference was observed in chemical and functional properties of ETFR with exception to water absorption index (WAI) and water solubility index (WSI). Peak and final viscosity was highest for brown rice and lowest for roasted rice. Morphological changes occurring due to disintegration of starch granules within ETFR were clearly visible within its matrix caused by high mechanical force and temperature.

rubber roller husker for dehusking rice must have a hardness of higher than 80 IRHD. A roller of lower hardness could not give 50 % or more dehusking efficiency. It will also give higher wear rate. Optimum nip between rollers is 0.4-0.6 mm. The wider gives low efficiency. If there is no gap and put on pressure between rollers, were rate and percent of broken rice will be increased rapidly.

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As rice is most consumable crop in world there is huge need of optimization in the rice milling process. In rice polisher most of the rice grains are break due to extensive force applied to grain to remove bran. Optimization in polishing chamber leads to reduction in the rice breakage. Shape of polishing chamber is more important parameter. As the polishing rotor is prone to wearas milling progress, hence the consideration of easy replacement and minimum downtime is another important factor. Cylindrical polishing chamber is always preferred over conical chamber. Second parameter is the rotating speed of polishing wheel. Peripheral speed more than 600m/s is mostly preferred; however the broken percent of rice kernel nearly doubles when Rotating speed is increased from 600 to 1200 rpm.

A huge number of workers are employed in traditional rice mills where they are potentially exposed to dust. The feeding and sieving section of the mill was identified as major dust creating zone. The dust was captured by creating suitable air stream at feeding and sieving sections of the mill and collected in cyclone dust collector. The air stream was created by blower which was selected on the basis to get minimum air speed of 0.5 m/s in the working zones of workers. It was observed that the developed system is successfully collects the significant amount of dust and able to reduce the dust concentration up to 58%. Further, the respirable dust concentration reduced to below 5 mg/m3 throughout the mill which is within the recommended limit of dust exposure.

The story would stop there were it not for the technological “modernization,” starting about a century and a half ago, of corporations developing technology to refine rice (and other grains) further. In the case of rice, milling technology created the possibility of peeling the bran off the grain and polishing what is left into shiny, white rice.But polishing rice from so-called “dirty rice” into the sparkling white form that most people prefer has caused—yes, caused—a number of major, adverse impacts on health.First, polishing removes most of the vitamins and minerals vital to one’s health. One example: the rice bran contains vitamin B and thiamine, both key to preventing beriberi. Indeed, in the largest World War II prison camp in the Philippines (where John’s grandfather was interned), American prisoners suffered from beriberi until they convinced the Japanese prison guards to let them cook the bran shavings that came off the polished rice; then the beriberi went away.

Grain dust has a long history of association with disease, and its effects on various organs have been reported for many years. Inflammatory diseases of the eyes, nose, and skin may be caused by both direct irritation and immunebased reactions. The lung and airways frequently suffer adverse effects. Asthma is well documented as being a result of exposure. Several studies show increased incidences of respiratory symptoms and of reduced pulmonary function in grain workers. Grain dust should be regarded as a dust with toxic properties, not just a nuisance dust.

In the past few years, there has been a steady growth in the rice mill industry. Milling is a step that happens during the post production of rice. Paddy cannot be consumed in its raw form and has to undergo certain procedures in order to be fit for consumption. The purpose of a milling plant is to rid rice of all its impurities by removing the husk and bran layers. The increase in the population means more mouth to feed. This requires an increase in the production of rice and more rice mills for the processing of the raw product. Paddy separator is an important machinery in every rice mill plant whose function is to separate fine contaminants from stock paddles. Rice is fed to the paddy separator where rice is separated from the residue paddy. This machinery requires little space and maintenance.

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rice grader are used for separating milled rice or coarse rice according to size differences of rice to achieve further progressing. It can finish high quality and larger capacity rice production by four rice graded classes. This rice grader is not only widely applied for rice, but the other grains in rice milling production line or grain processing industry.

Rice is rapidly becoming a major food in much of sub-Saharan Africa and is set to overtake maize, cassava, sorghum, and other cereals in the near future. The demand is driven as much by population growth as by urbanization. In addition, the high cost of fuel makes rice attractive as it can be prepared quickly and with less energy requirement. Within Kenya, the demand for rice continues to grow as more Kenyans make changes in their eating habits, and as urban population increases. Rice is currently the third most important cereal crop after maize and wheat. Rice is gaining popularity among the rural folk as well and consumption has risen dramatically over the last three years to stand at 300,000 metric tons per annum. But the annual ranges between 40,000 and 80,000 t. The deficit is met through imports.

From the analysis of the separator of indent cylinder type, the separating factors were clearly defined and their effects were discussed. In addition, the separating mechanisms were modelled, the fractional recovery curve was calculated and compared with the experimental values. The obtained results were as follows: (1) Besides the factor of grain length, the separating factors included the shape and coefficient of friction of grain. The distribution form of the values of physical properties of these factors also had strong effects on the separating performance. (2) The factors which had effects on the separating performance are: size, shape and arrangement density of indent parts; size, number of revolution and material of cylinder; separating time, hopper angle and supplied quantity. It is possible to improve the separating performance if these factors are suitably selected. (3) The boundary value of width of broken and whole grain, and half of this value can be used to determine the width and depth of indent parts respectively. (4) The separating performance was good when the coefficient of friction of grain-cylinder was high, and the improvement of this performance was assured if the grain of which thickness is small was removed by a thickness grader before separating. (5) The separating accuracy was good when the separating time was long, and the hopper angle could be properly selected by regulating this angle in such a way to get the value PB which should be high and small in terms of broken and whole grain respectively. PB was the probability of grain entering the hopper being carried by indent parts.

Optimizing rice production can be achieved through sustainable agriculture or farming. The concept of sustainable agriculture or farming involves producing quality products in an environmentally benign, socially acceptable and economically efficient way, ensuring optimum utilization of the available natural resource for efficient agricultural production. In order to comply with these principles of sustainable agriculture, one has to grow the crops where they suit best and for which first and the foremost requirement is to carry out land suitability analysis. Suitability is a function of crop requirements and land characteristics. Matching the land characteristics with the crop requirements gives the suitability. So, ‘Suitability is a measure of how well the qualities of a land unit match the requirements of a particular form of land use’. Land suitability analysis has to be carried out in such a way that local needs and conditions are reflected well in the final decisions.

rice destoner is for removing stones and broken grains from a batch of milled rice. This research was carried out to modify an existing rice destoner for the purpose of increasing its capacity and efficiency. Modification introduced addressed challenges associated with the existing machine, such as low stone removal efficiency and low air flow channel, which affects the aerodynamic lifting of the rice grains. Performance was evaluated for 3 kg of locally milled rice samples based on the design capacity of the machine, cleaning efficiency and degree of grain flow. The result showed that the design capacity (1.8 kg/h) of the modified destoner was higher than that of the existing (0.86 kg/h). Also, the modified machine has 40.8% destoning efficiency which is higher than that of existing machine (2.58%).

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