Thursday, December 6, 2012

IMPORTANCE OF LUBRICANTS IN FARM MACHINES


* Dr. Mukesh Singh

India is predominant in agricultural economy. After the onset of Green revolution, our food grain production shoots up very rapidly. Now there is a big question that how could we sustain our food production with steady growth to feed the rapid growth of population. Today our farmers are utilizing many types of farm machines for the production of agricultural crops. These machines operate under varying loads, temperature and weather conditions. The day to day operation under field condition requires a thorough maintenance of the machines. The lubrication for farm machinery is very important because they always work under off road operating conditions. Selection of proper lubricants such as Oil and grease form an integral part of maintenance. There are several types & makes of lubricants, to suit the lubrication requirements for varying conditions, generally obtained from animal fats, vegetable oil, mineral oils and synthetic polymers.

Animal fats are used as lubricants for a very limited use in mechanical devices. The common animal lubricants are lard oil, fish oil and tallow. The principal disadvantage of these lubricants is that they cannot stand heat & oxidize to become gummy. The castor oil, cotton seed oil and linseed oils have been utilized in a bullock driven equipments, however, only castor oil has proved its use for engine lubrication. The use of vegetable oil may be helpful for lubrication of slow moving machines.

The petroleum products serve as the source of lubricating materials. The lubricating oils is used in transmission and engines, where as the greases are used in bearings, nipples, joints etc. of the agricultural machines.

There are several characteristics for the testing of the lubricants such as kinematic viscosity, specific gravity, cloud and pour point, flash & fire point, carbon ratio and acid value. The temperature is the prime cause for change in kinematic viscosity; therefore a lubricant must possess sufficient viscosity and lubricating ability. Generally, the lube oil used for engine lubrication in summer is of higher viscosity than that of winter; however the transmission oil also has a higher grade of viscosity.

Greases are mixtures of metallic soap and petroleum oil. Several additives are being used to provide stabilization, oxidation resistance, rust-prevention and thickness of Grease. The soap serves as a thickening agent, particularly at certain temperature during operation. The greases are classified either on the basis of soap such as sodium base, aluminum-base, lime-base and mixed base or consistency as fluid. Zero number grease stands for semi solid / fluid. Very soft for No. 1, soft for No. 2, medium for No. 3 and hard for No. 4. Greases are also classified according to use as cup greases, ball and roller bearing grease, gear greases, chassis greases etc. These semi solid lubricants are commonly used for slow moving parts, when pressure is high. They are also being used for the concealed or inaccessible such as wheel bearing, springs, universal joints, water pumps, axle and bearings etc.

Nowadays several multinationals have been playing in the lubricating oil manufacturing sectors along with the Indian ones. Everybody is popularizing the products, so as farmers we have to look at the cost and operating cost of each product. Especially for farm machines, because it operates in dirty and muddy situation. Proper sealing as well as regular refilling is needed for better, trouble free and economic operations of agricultural machines.

*Senior Scientist (F.M. & P.) L.P.M. Section, I.V.R.I., Izatnagar.

(Extracted from AgriGold India's SwarnaSedyam)

GLOBAL WARMING – SCENARIO



-Dr. J. Kannan and A.R. Mohamed Haroon


Atmospheric green house gases trap the outgoing energy and enhance the heat-trapping capability of the earth causing global temperature increase. Problem arises because of increase in the concentration of green house gases, like carbon dioxide, water vapour, ozone, methane, nitrous oxides and chloro-fluoro carbons. The combustion of fossil fuels and other human activities are the primary reason for the increased concentration of carbon dioxide. Burning of solid wastes, oil, natural
gas, coal, wood and wood products release CO2 into atmosphere Globally, 5 billion metric tonnes of carbon is released every year into atmosphere that works out to approximately 1 metric ton / person. 

In the global warming scenario, industrial processes contribute to 49%. Next major source being the energy usage, the renewable energy production can reduce the global warming potential. It is also better to switch over from coal usage to natural gas. Even though, carbon dioxide is the major source gas for global warming, the hydro-fluoro carbon, nitrous oxide and methane potential are higher than the carbon dioxide. Industrial processes generating hydro fluoro carbons and sulphur hexafluoride should be stopped and sought for alternates. Global warming potential depends on the heat trapping
efficiency of different gases. For example, Nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide. Nitrous oxide emitted from agricultural and industrial activities can be reduced by following scientific farming methods.

The present concentration of 446 ppm of carbon dioxide causes global warming all over the world. If the concentration exceeds 600 ppm, the survival of human beings may become a question. The gases emitted from countries like USA and European countries contribute to half of the green house gases. The impact of global warming includes increase in earth's temperature, melting of glaciers, increase in sea level, losses of coastal low lands, erosion of beaches leading to increased salinity in estuaries. This may cause the 50% loss of wetlands, loss of biodiversity and affects the marine living organisms.

Agriculture

In the agricultural sector, global warming can change the length of growing season of various crops. The yield of crops like corn, wheat and soybean may decrease eventhough the photosynthesis can be
increased by solar radiation. This is due to wagering of monsoon and unpredicted rainfall and droughts in the region. Heat stress and reduced precipitation, may also be reason for reduced yields. 

Increased temperature not only increases photosynthesis, but also the respiration. The cattle population suffers from mortality due to increased disease occurrence. Global warming also reduces the milk production. This may also lead to wide-spreading of insects and vectors disposing diseases.

Humans

Human beings may suffer from increase in malnutrition, damage to housing, loss of properties and increased human health risk. Reduction in water supplies, weather extremes like heat waves & droughts causes seawater warming leading to hurricanes and typhoons. Threats to human health include the spread of malaria, encephalitis, yellow fever and dengue fever.

Loss of biodiversity

Global warming leads to the death and extinction of tree frogs due to outbreak of fungal diseases.
Disappearance of habitats of Asian tiger may lead to reduction in number and even extinction. Changes in ocean temperature may affect the Australia's great barrier coral reef. Polar bear may become extinct due to loss of habitat. Sea turtles population may be reduced due to the reduction in male population. North Atlantic whale may face the problem of extinction. Agricultural scientists predict that 1oC increase may lead to reduction of paddy yield of 75 kg / ha. Prevention of global warming can be done by substitution of solar energy and wind energy instead of petrol, diesel and coal. In kitchen, it is better to use solar and electric cooker. Solid wastes may be converted as organic manure instead of burning. Afforestation and growing of more trees can help to control global warming. Soil erosion may be controlled by growing vettivers and shelter belts.

(Extracted from AgriGold India's SwarnaSedyam)