Pdf design and performance analysis of a small solar. Recycled highdensity polyethylene and rice husk as a wetted pad in evaporative cooling system article in american journal of applied sciences 82. The water consumption is much lower than in direct systems. Pdf evaporative cooling of wet soil surface under different. Types of mass wasting a rock fall are the fastest of all landslide types and occurs when a rock falls through the air until it comes to rest on the groundnot too complicated. Us20070151278a1 subwet bulb evaporative chiller with pre. Porous face bricks on the outside of a building wall exhibit evaporative cooling after absorbing water. Pdf a heat exchanger is a heat transfer device that exchanges heat between two or more process fluids.
Experimental performance analysis of a solar evaporative cooler with three different types of pads article in journal of renewable and sustainable energy 56. Another factor that determines mass wasting is the slopes materia. An evaporative chiller cooling water to below ambient wet bulb temperature. In the fargomoorhead region, three types of mass wasting impact slopes bordering the red river and its tributaries. The incoming air is ambient air at ambient air temperature that is cooled using the coolness of the lower temperature outgoing air exiting the saturator. Which of the following types of mass wasting best describes this slope failure. In this type of system the air temperature can be lowered to match the wet bulb temperature. It involves the movement of air past or through a moist material. Evaporative cooling system for storage of fruits and vegetables a.
When water is used as the heat transfer medium, wet, or evaporative, cooling towers. Evaporative cooling is a cost effective, efficient method of cooling air compared to conventional airconditioning. Mass wasting processes such as creep, landslides, and debris flows are distinguished from each other in part by whether they occur rapidly or slowly. The slope in its upper part is a cliff subject to rock falls and in its lower part a talus slope or fan deposit built by debris flows. Kind of mass really doesnt matter as long as there is enough of it. In utah, they are common in the spring and fall because of freezethaw weathering. Ice, although it is solid, does have the ability to flow, and freezing and thawing cycles can also contribute to movement. At a local landfill, the liner beneath the trash was being repaired. Evaporative cooling is used in both biological and mechanical processes. Types of mass movement processes the downslope movement of material, whether it be bedrock, regolith, or a mixture of these, is commonly referred to as a landslide.
Mass wasting definition mass wasting refers to a downhill. Design and performance analysis of a small solar evaporative cooler. Landslides are capable of transporting massive amounts of rock and soil downslope for miles in very short periods e. Slump can result in major and rapid slope retreat, especially in regions of river cutbanks. Heat and mass transfer in open evaporative cooling system.
Mass wasting, also known as slope movement or mass movement, is the geomorphic process. That includes all earth materials, rock and regolith. An evaporative cooler is a device that cools air through the evaporation of water. Types of mass wasting processes defined by the movement of the material the character of the movement fall slide flow types of mass wasting processes defined by the movement of the material the rate of the movement fast slow forms of mass wasting slump rockslide debris flow earth flow creep solifluction. Mass wasting is the downslope movement of material under the influence of gravity.
We cannot prevent mass wasting, but we can delay it through efforts to strengthen the materials on slopes. Different types of evaporative devices such as wetted pads and water sprays are attached to wind towers in order to improve their performance, accelerating the direct evaporative cooling process by expanding direct contact between the incoming outdoor air and water added to the air stream via evaporation. Direct evaporative cooling equipment cool the air by direct contact with a liquid surface or with a wet solid surface, or even with sprays camargo, 2000. Conventional iec heat and mass exchanger a working principle of the indirect evaporative cooling b configuration of the type iec heat and mass exchanger c psychrometric illustration of the air treatment process in the iec heat and mass exchange iii. Pdf laboratory evaporation studies were conducted to assess the roles. Subwet bulb chilling is achieved by pre cooling incoming air upstream of the saturator. So, in a dec, water is vaporized in the airstreams and the heat and mass exchanged between air and water decrease the air dry bulb temperature dbt and increase its humidity, keeping constant the. During a brisk run, an adult human generates heat at a rate. Indirect evaporative cooling techniques also exist, in which the air is cooled without increasing its water vapor content. Our bodies are designed to sweat to release heat and keep our body at its natural temperature when it gets too hot. The important types of mass wasting are creep, slump, translational slide, rotational slide, fall, and debris flow or mudflow.
We cant always predict or prevent the occurrence of masswasting events, a knowledge of the processes and their relationship to local geology can lead to intelligent planning that will help reduce losses of life and property controls and triggers of mass wasting important factors include. Match the description with the appropriate label on the diagram of mass wasting types. When earth material moves down a hillside as a fluidlike mass, it is called an earthflow. Debris flows and torrents commonly entrain large quantities of inorganic and organic material from the stream bed and banks. This is one of the central concepts of this course. Dec 23, 20 during a brisk run, an adult human generates heat at a rate of about 20 w. Pdf evaporative cooling of water in a mechanical draft cooling tower. The model epx indirect evaporative cooler uses a highefficiency, airtoair heat exchanger and indirect evaporative cooling to introduce 100% outdoor air while reducing cooling load tonnage. For each item below, use the pulldown menu to select the letter that labels the correct part of the image. Steep slopes, widely varying altitude ranges relief, the thickness of the loose earth material, planes of weakness parallel to the slopes, frequent freezing and thawing, high water content in the earth material, dry conditions with occasional heavy rainfall, and sparse vegetation are the factors that.
The research areas of our faculty members, as well as their current and recent research projects, are listed below. Varieties of these are called earthflows, mudflows, and debris avalanches. Mass wasting in cold climates mass wasting in cold climates. To remove this heat by evaporative cooling, what mass of water per second mt must be evaporated from the body as sweat. Heat and mass transfer in open evaporative cooling system using various types of fills in oil industry dr.
Nonsaturated air is cooled by heat and mass transfer increases by forcing the movement of air through an enlarged liquid water surface area for evaporation by utilizing blowers or fans. Theoretical analysis on heat and mass transfer in a direct. Identify the two fluids used in the evaporative cooling system. Mass wasting of regolith in semiarid climates leads to hill slopes that are concave up. The latent heat of vaporization of water at 37 c typical body temperature is 24. Mass wasting is more prone on slopes that contain clay and shale. The three criteria used to describe slope failures are. When warm, dry unsaturated air is pulled through a water soaked pad, water is evaporated and is absorbed as water vapor into the air. Frost heaving this process is large contributor to creep in cold climates. After an unusually heavy rainfall, the slope failed very quickly along a curved surface. The type of material that failed typically either bedrock or unconsolidated sediment. Direct evaporative cooling the principle underlying direct evaporative cooling is the conversion of sensible heat to latent heat.
Suppose that the swimmers velocity relative to the water makes an angle of. When momentum is lost, scoured debris may be deposited as a tangled mass of large organic debris in a matrix of sediment and finer organic material. Experimental study on the impact of mass moisture content on the evaporative cooling effect of porous face brick. Cooling tower management cooling towers dissipate heat from recirculating water used to cool chillers, air conditioners, or other process equipment to the ambient air. The occurrence and characterization of fouling during. Examples include the space shuttle, the apollo command and service. Types of mass wasting include creep, slides, flows, topples, and falls, each with its. Recycled highdensity polyethylene and rice husk as a. Describe one change in the evaporative cooling system that would allow more cool air to be produced. The quiz will test you on the characteristics of mass wasting. Evaporative cooling design guidelines manual for new mexico schools. The one thing i will say on that issue though is color of the mass being heated by the sun does matter. Mass wasting downhill movement of masses of bedrock, rock debris or soil, driven by the pull of gravity landslides have been far more costly in the u. What roles do climate and weathering play in mass wasting.
Several experiments are carried out measuring frost mass, air side pressure drop and cooling capacity for different applied. As with gases, ficks diffusion equation describes the movement of water across the skin. Mass wasting in cold climates mass wasting in cold climates is governed by the fact that water is frozen as ice during long periods of the year. Identify whether the evaporative cooling system is an open system or a closed system. To maintain conservation of mass, descent must accompany the storms.
A variety of conditions affect the development of mass wasting in a particular area. Gravitydriven processes mass wasting mass wasting processes. Evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Significance of parameters affecting the performance of a. The evaporative cooled storage structure has proved to be useful for. Iec modelling a schematic diagram of the countercurrent type iec is. Review and cite solar cooling protocol, troubleshooting and other methodology information contact experts in solar cooling to get answers. Although cooling towers can be classified several ways, the primary classification is into dry.
We are designing a home evaporative cooling system. Occasionally, the channel may be scoured to bedrock. Many types of heat exchangers have been developed for use in steam power plants. Research geological sciences department california state. Creep and earthflow, generally induce lesser amounts of damage, although these processes can occur on any slope.
In the process, trash from the base of the slope was removed and piled on top of the landfill. Evaporative cooling of wet soil surface under different agricultural land. The basis of the installation is the evaporative cooling system,1. Model epx uses a corrosionresistant polymer heat exchanger to produce dry, cool air without using refrigeration. Mass movements mass movements also called mass wasting is the downslope movement of regolith loose uncemented mixture of soil and rock particles that covers the earths surface by the force of gravity without the aid of a transporting medium such as water, ice, or wind. Gravity 159 m, the distance d2 from c to b is 121 m, and the speed vr of the current in the river is 5 kmhr. Evaporative cooling is the safest measure and includes cooling the patient with. Most mass movements are aided by weathering and involve surficial material.
Evaporative cooling an overview sciencedirect topics. However, the additional air movement provided into the space can improve. Personal thermal comfort is a function of personal health factors medical, psychological, sociological and situational, ambient air temperature, mean radiant temperature, air movement wind chill, turbulence and relative humidity affecting human evaporative cooling. Some questions will give a definition and then you will need to select the corresponding term. It shows that there is stay water not used for evaporative cooling in the system after capillary absorption channel from the pavement downside to the surface are disconnected. An evaporative and desiccant cooling system for an. Without going into great detail here, the shape and composition of individual clay particles can absorb water and prevent water from peculating through the ground. Nagam obaid kariem college of engineering al mustansiry university abstract this research work is to study the performance of evaporative cooling system using new type of packing with different shapes. The work of gravity earth 9thedition chapter 15 mass wasting. Thus, these bricks are promising for use as a passive energysaving building technology. Mass emission measurements performed on kerrmcgee chemical. Experimental study of pavement body configurations of the. Several types of mass wasting are geologic hazards that are frequently responsible for loss of life. Water is a critical factor in mass wasting page 209.
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