2.1 Principle A simple way for distillation water is a solar still which uses sun’s heat to derive evaporation from humid soil and atmospheric air to cool a condenser layer. The energy of sun heats water to evaporation point. When the water evaporates, vapours of water increases, condensing on the glass surface for collection. In a double slope solar still, solar radiation passes both sides of the glass cover. This energy coming from the sun is almost absorbed by the black painted basin while it is partially absorbed in the thin layer of salt water. Thus, the solar energy heats the saline water and basin. The heat is convicted from the black surface into the saline water and the saline water temperature raises.
Hence at the interface
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2.3 Methodology
Solar distillation is one of the most available method for salt water distillation and for run that process sun light is one of the several form of heat energy that can be used to run that process . The purpose behind the solar still is very simple ; salt water inside a basin which is painted black enclosed in a air tight area formed by a glass cover is heated up and evaporated due to solar radiation that passes through the glass cover consequently vapour is directed on the glass and condensed in drinkable water as it comes in contact with inside surface of the cover . Evaporation occurs when molecules of water obtain enough kinetic energy on the surface of the water to change its state from liquids to vapour .Water vapour adds the evaporated molecules between the glass and water and makes a higher temperature difference.
This temperature difference affects the water vapours temperature between the water and the glass which creates natural convection.
A higher temperature difference give support more convection . When vapours directed on the glass cover it will condense due to loss in kinetic energy which is required to be in the vapour
At a constant temperature, a pure liquid has a vapor pressure that describes the pressure of escaped gaseous molecules that exist in equilibrium at the liquid’s surface. Adding energy to a pure liquid gives more molecules the kinetic energy to break the intermolecular forces maintaining the liquid and raises the overall temperature of the liquid. Eventually, adding energy boosts the liquid’s vapor pressure until it equals the surrounding atmospheric pressure. When this occurs, the pure liquid boils at a temperature called the boiling point.
to loss of entropy of the water molecules. It is this entropy loss rather than bond energy that leads
Tampa Bay Water is a seawater desalination plant located in Tampa, Florida. Their method of desalination of ocean water or brackish groundwater is another method to obtaining water from fresh surfaces or groundwater sources. This could be used to replace the need for a water supply dam. There are several different technologies that exist to remove salt and other impurities from ocean water. The two most commonly used methods are thermal distillation and desalination. Thermal distillation copies the natural water cycle by using heat to create a vapor that is converted into freshwater. Desalination is a process that removes some amount of salt and other minerals from saline water. The traditional process used is vacuum distillation, which boils water at less than atmospheric pressure making the water sit at a much lower temperature than normal. This is due to the fact that the boiling of liquid occurs when the vapor pressure equals the outside pressure and vapor pressure increases with temperature. Due to the reduced temperature, low-temperature "waste" heat from electrical power generation or industrial processes can be used. The processes use membranes to desalinate, by applying standard reverse osmosis technology. These membrane processes use semi-permeable membranes and pressure to separate salts from water.
Convection is a transfer of internal energy into or out of an object by the physical movement of a surrounding fluid that transfers the internal energy along with its mass. According to Oxford Dictionary, convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder or denser material to sink under gravity's influence, that results in transfer of heat. Two fluids are liquid and gas.The fluid above a hot surface expands, becomes less dense, and rises.This applies to objects such as steam from a hot cup of coffee turning cool, ice melting like heat moving to ice from the air, or frozen material becoming raw like how frozen food thaws more quickly under cold running water. When
After finishing the trials, our group subtracted the mass of the glassware without water from the mass of the glassware with water in order to find the mass of the water in grams. Then, we divided the mass of the water by the density(g/cm^3) of the water in order to find the volume (mL). An example calculation from the 5.00mL pipet is: (4.9285mL+4.8839mL+4.9367mL+4.9265mL+4.9134mL)/5 = 4.9178. In most cases, the temperature of the water was around 23 degrees celsius, making the density about .998408 g/cm^3 for many of the trials. The densities we used were found online. The next calculations we performed were to determine the average volume of the water in each person’s five trials by adding up all of the volumes(mL) and dividing that number by five. Using the average volume, we then calculated the
Also, when we put the insulation cans in warn water the water heated up the can. And lastly, in the insulated can experiments, both cooling and heating, when the cans temperature was changed it in turn changed the air temperature
Water desalination is the process of removing salts and minerals from water that has a high concentration of salt dissolved in it, and can therefore not be consumed as drinking water. Desalination of saline water can be achieved by a technique known as reverse osmosis. In osmosis the net movement of solvent molecules occurs from an area of low solute concentration to a more concentrated one through a semi-permeable membrane to balance the concentration of solute on either side of the membrane. However, in reverse osmosis the net flow of solvent is in the opposite direction this can be achieved by applying an external pressure that is great enough to stop osmosis from occurring, this is known as the osmotic pressure. If a pressure greater than
The air in between the layers of glass should be thick and dense, so that it can save energy. One of the most common airs used in-between glass is argon. When argon is used heat loss is reduced. You could also use carbon dioxide or sulfur hexa-fluoride between glass.
A warm water was prepared by heating approximately 100mL of distilled water in a 400mL beaker along with few boiling chips to 45-50 ℃.
Evaporation is part of our everyday lives. After washing the dishes, after taking a shower, and many more signs of evaporation in our everyday lives, but does every type of liquid evaporate at the same rate? Sometimes liquids may be sitting in one dry place and its molecules might turn into gas molecules, that is the process of evaporation. When energy in certain molecules reaches a specific level, those molecules have a phase change. Evaporation occurs when molecules escape from their liquid and form into vapor. If there was a puddle of water outside, and it was a windy day, the air from the wind can cause an increased rate of evaporation. When a molecule
Process bc : This high pressure and high temperature vapour then enters a condenser where the temperature of the vapour first drops to saturation temperature and subsequently the vapour refrigerant condenses to liquid state .
Slightly lower than fresh water, its density is slightly higher, its electrical conductivity is much higher, and it is slightly basic. we cannot used brine water for domestic purpose. So it is needed to convert it into soft water. In this paper we observe the techniques of softening water. Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of approximately 3.5%, or 35 parts per thousand. This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it.
Hot Water Heaters: The easiest way to exploit solar radiation is as thermal energy. One way to harness this solar energy is to heat water. Aro...
As air humidity is in an instance of increasing, its ability to absorb water vapor decreases and evaporation rate slows down. For evaporation to undergo there must be a difference in humidity (Tenalem Ayenew and Tamiru Alemayehu, 2001; Fetter C.W, 1994).
6. When water is distilled, it does not vaporize all at once when the boiling point is reached. When some water molecules evaporate, the kinetic energy of the remaining liquid goes down and the temperature drops slightly. As a result, the rest of the water needs to be heated again before more molecules of water evaporate. A constant source of heat is needed.