Bentonite Processing Assignment Example | Topics and Well Written Essays - 2250 words

Bentonite Processing - Assignment Example Drying operation reduces the moisture content in bentonite rock to the required percentage. Different driers can be used in the moisture reduction. Drying effectively vaporizes the liquid level contain in the rocks. The vaporization is achieved through heat supply to the wet bentonite rock feedstock. The heat from the burner is supplied either through convention, radiation or conduction. The convection method is applied when direct driers are used while conduction method is applied when contact or indirect dryers are used. Most of the driers use hot air as the drying medium. This moisture removal process is an energy-intensive operation since the amount of latent heat of vaporization required is depended on the intensity of the heating (Gillson & Bances,   87).Drying curve  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   A representation curve is required so as to describe the various drying properties for different product at different specific temperature, pressure and velocit y conditions. The drying curve for bentonite rock has three different phases. These phases are useful in the energy saving process and are independent. The products are passed through these phases in shifts. After passing from one phase, the product is moved to the next phase.First phase  Ã‚  This phase is also called initial period. In this phase, there is transfer of heat from the dryer to the products and the contained moisture. Inlet condition from the dryer heats up the products and this condition further enable subsequent processes to occur. This phase can be substituted by pre-processing. Pre-processing is achieved through preheating the bentonite rock with energy from the waste material. The amount of energy from the waste material would be able to cause dislodgement of moisture contents from the bentonite surface. Second phase This phase is also called constant rate period. In this phase, free moisture attaches themselves on the surfaces. Alteration of the rate of evaporation reduces the moisture content. In this period, high drying rates are achieved through increase in the temperature of the inlet air. This phase accords the product with very little temperature increase. However, this little temperature increase is enough to cause some kinetic energy rise within the rock particles. Third phase This phase is also known as the falling rate period. Intrinsically attached moisture evaporates from the product. The product drying rate is limited by the outer surface. The outer surface provides a barrier that prevents successive evaporation rate. The evaporated moisture would be accumulated within the dryer. Moisture content The drying process employed is control by the moisture content of the bentonite rock. The dryer in this case is required to reduce the moisture content from 11% to 4%. The exact moisture content required is measured by the electrical resistance meter. However, this meter is limited to moisture content in grains, woods, food and

Should GMO foods be banned in the United States Essay

Should GMO foods be banned in the United States - Essay Example As a result, various research studies try to convince us concerning the truth about the GMO foods from these two perspectives. Regarding this point, the idea about GMO foods could hardly become an exact science. This thought convinces me to go with the idea that GMO foods should be banned in the United States, for as long as there is still no clear point of truth concerning its safety, and for as long as there are prevailing studies trying to convince us of its associated potential health hazards. To illustrate the above point further, the analogy of testing the depth and safety of an ocean is appropriate. One may not automatically take the plunge into it knowing that there are primary or some major considerations that have to be taken into account. Aside from testing its depth, one major concern is its safety. Would it be safer to take the plunge knowing the idea that there might be some creepy creatures down there prowling for their prey? With its deep blue color, nothing from the deeper portion could be vividly observed from the surface, but whatever is down there will have the great chance to see anything coming into their sight. We always have fear of the unknown. Let us consider if this fear of the unknown we have right now for GMO foods is justifiable. ... In some certain level, they both might have all the points. However, this continuous inquiry and investigation is a fundamental way for us to know further down to the truth. The ongoing contradiction against GMO foods is a healthy process towards understanding a far deeper truth about them. Thus, for the mean time that everything might turn out as not an exact science concerning the GMO foods, it is better not to acquire it for commercial use in the United States. The relevant findings for now might just add up to the level of fear we have for the unknown concerning GMO foods. Let us take the case of an alarming pesticide residue in a growing number of products. This was very alarming in the area of US agriculture. According to Chavez, â€Å"We have known for many years that pesticides used in agriculture pollute the air, earth and water, contaminate animals and humans, and are found in the tissue of new born infants and mothers’ milk† (McKibben 691). Some genetically m odified foods contain genetic materials from natural organisms like in the case of BT corn to contain a natural pesticide that would not create any harm to the environment. In fact, aside from the point of gaining higher yield, this was the sophisticated approach to minimize the detrimental impact of chemicals to the ecological balance by deliberately using commercial pesticides. Monarch butterfly and BT corn controversy marked a significant point prior to the level of acceptance we have for GMO foods today. In an experiment, it was found that Monarch butterflies feeding on the pollen of BT corn were found to have high mortality rate. BT corn is a transgenic crop, by which a genetic code of an organism that could kill pest was inserted to the corn’s DNA