Solar sintering Introduction

n a world increasingly concerned with questions of energy production and raw material shortages, this project explores the potential of desert manufacturing, where energy and

material occur in abundance. In this experiment sunlight and sand are used as raw energy and material to produce glass objects using a 3D printing process, that combines natural energy and material with high-tech production technology. Solar-sintering aims to raise questions about the future of manufacturing and triggers dreams of the full utilization of the production potential of the world’s most efficient energy resource – the sun.

I

Whilst not providing definitive answers, this experiment aims to provide a point of departure for fresh thinking.

In the deserts of the world two elements dominate – sun and sand. The former offers a vast energy source of huge potential, the latter an almost unlimited supply of silica in the form of quartz. Silica sand when heated to melting point and allowed to cool solidifies as glass.

This process of converting a powdery substance via a heating process into a solid form is known as sintering and has in recent years become a central process in design prototyping known as 3D printing.

These 3D printers use laser technology and solar technology to create very precise 3D objects from a variety of powdered plastics, resins and metals – the objects being the exact physical counterparts of the computer-drawn 3D designs inputted by the designer. By using the sun’s rays instead of a laser and sand instead of resins, I had the basis of an entirely new solar-powered machine and production process for making glass objects that taps into the abundant supplies of sun and sand to be found in the deserts of the world.

Project objectives

Our main goal is to deliver affordable, high quality "3d objects out of glass” by using the tow available elements in desert (sand & sun).

Basic understanding of melting technology, creating 3D printing out of glass , self solar powered and knowledge of industry economics is essential if the glass manufacturing process is to be advanced to conserve energy, protect environmental quality, and secure capital investment.

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This study unravels the complexities of the glassmaking process in all segments of the industry. Solar powered Glass manufacturers, managers, administrators, scientists, engineers, and policy makers will find this report a ready reference for further study.

Government agencies will understand how best to support glass manufacturing and apply appropriate regulations to the industry.

Materials and equipment vendors can identify present and future needs to better serve glass manufactures. Educators and students in higher education can profit from past research and development to design pre-proprietary research.

Availability of solar energy in Jordan

In Jordan there are 300 sunny days out of 365 days a year Average solar radiation is 2000 kilowatt hours per square meter per year Will be the inclusion of solar energy in the energy mix in Jordan through the construction

of plants for the generation of energy through photovoltaic cells capacity of 10 MW 10% of Jordan's population uses solar heater for hot water Solar cells will be used to generate electric power soon in Jordan

Silica sand in Jordan

Silica sand is defined as a high purity industrial mineral in which the sand grains are made entirely of quartz. Impurities are very minor and commonly are clay minerals (kaolinite, illite), iron oxides and heavy minerals. The term silica sand is applied to quartz sand that conforms to the specifications of which the main composition is SiO2 > 99%, with very little contaminant contents and heavy minerals of < 0.1% .The Government of Jordan has granted a concession to the Jordan Mining Company to mine and export silica sand. The sand will be exported to European countries. Amman Resources will build and operate a terminal in Port of Aqaba for the receiving from trucks, storage and loading of the sand into ships.

The terminal will handle 1.5 million tons of sand initially, increasing to 3 million tons per year in 2003. Materials Handling Consultants was assigned to develop and design the export terminal, consisting of truck unloading facilities, storage shed (40,000 tons) with intake and outtake conveyors and ship loader for ships up to 45,000 DWT .

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Location

White silica sand deposits are found exposed on the surface of Early Ordovician and Lower Cretaceous sandstone in south of Jordan. Deposits are found in the following locations :

Ras En Naqb area Qa'Ed Disa area Petra/ in El Biada area Wade El Siq - Wade Rakia area Al Jayoshia area

QUARTZ………………………………………………...................................................................................... 3

general description

Quartz is a hard mineral found in many types of rocks. Pure quartz, traditionally called rock crystal, is colorless and transparent. As quartz crystals or rocks made from quartz break down, they form silica sand. Quartz crystals and silica sand have very high melting points, and safety precautions must be taken when melting the mineral at home. When exposed to extreme heat, the quartz or silica sand creates molten glass, which can then be reshaped before it re-hardens

How to Melt Quartz

1-Arrange the quartz crystal or silica sand that you would like to melt on a fireproof surface, such as cement or brick.

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2-Put on the safety goggles and leather gloves. The goggles will protect your eyes from the intense light, and the leather gloves will prevent your hands from getting burned.

3-Use a lighter to light the torch. Turn the flame to the highest setting and the flame to the quartz, moving it back and forth as necessary to reach the edges. Continue to heat the quartz until it melts, at which point it will look like molten glass.

4- Repurpose the quartz by using small carbon rods to manipulate the melted quartz into your desired shape. Allow the quartz to cool and you will now have a glass object.

What’s Quartz Glass?

Quartz glass is a kind of special glass which is made of single component-SiO2. Its series of special performance that other material can’t replace, make quartz glass an indispensable material in modern science and technology and modern industry.

Glass

Glass is older than recorded history, and yet it is as new as tomorrow! How, when, or where man first learned to make glass is not known, but we do know that the ancient Egyptians

were making glass articles as early as 2,600 B.C.E. (The making of glass beads may have begun as much as 3000 years earlier.) They used it to make jewelry and luxury items, such as decorative bowls and perfume bottles, available only to the wealthy.

Today, everyone uses glass. It is the stuff used to make jars, bottles, windows, light bulbs, and any number of other everyday objects. But it is also the material used to make television tubes, computer monitors, telescope lenses, spectrometer prisms, and all kinds of laboratory ware, as well as the optical fibers that are revolutionizing modern communication. Glass has even become a popular medium for artists, on a scale that is unprecedented.

Glass is really a physical state rather than a particular composition. It is a rigid material with the extrinsic properties of a solid but with a less ordered structure, more similar to that found in a liquid. When a liquid cools and hardens without forming crystals, it becomes a glass. For example, when sugar is melted with other ingredients and then allowed to cool, it solidifies as glassy “hard candies”. Many different substances can form glasses, but what most people have in mind when they talk about glass is the stuff used to make

Windows and bottles, the common glassy material that is made from sand.Osama farhat - Mutah University Solar Sintering Project

SINTERING …………………………………….……………………..………………………………………………………………………..……..4

Definition

Sintering is a method used to create objects from powders. It is based on atomic diffusion. Diffusion occurs in any material above absolute zero, but it occurs much faster at higher temperatures. In most sintering processes, the powdered material is held in a mold and then heated to a temperature below the melting point. The atoms in the powder particles diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece. Because the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points such as tungsten and molybdenum.

Sintering is traditionally used for manufacturing ceramic objects but finds applications in almost all fields of industry. The study of sintering and of powder-related processes is known as powder metallurgy. A simple, intuitive example of sintering can be observed when ice cubes in a glass of water adhere to each other.

Densification of a polycrystalline objects close to, but below the melting point (Molten phases may be present during the process.)

Shrinkage makes it difficult to prepare objects with a predefined shape and size.

If liquids are present they should be in minor amounts.

The verification range is the temperature interval between liquid formation and “slumping” due to excess liquid. Should be as large as possible to avoid large shape changes.

Phase diagrams are important.

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sintering technologies

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4.3 sintering temperature

Sintering mechanisms

Sintering occurs by diffusion of atoms through the microstructure. This diffusion is caused by a gradient of chemical potential – atoms move from an area of higher chemical potential to an area of lower chemical potential. The different paths the atoms take to get from one spot to another are the sintering mechanisms. The six common mechanisms are:

Surface diffusion – Diffusion of atoms along the surface of a particle Vapor transport – Evaporation of atoms which condense on a different surface Lattice diffusion from surface – atoms from surface diffuse through lattice Lattice diffusion from grain boundary – atom from grain boundary diffuses through lattice Grain boundary diffusion – atoms diffuse along grain boundary Plastic deformation – dislocation motion causes flow of matterAlso one must distinguish between densifying and non-densifying mechanisms. 1–3 above are non-densifying – they take atoms from the surface and rearrange them onto another surface or part of the same surface. These mechanisms simply rearrange matter inside of porosity and do not cause pores to shrink. Mechanisms 4–6 are densifying mechanisms – atoms are moved

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from the bulk to the surface of pores thereby eliminating porosity and increasing the density of the sample.

3D PRINTING ……………………………………………………………………………………5

5.1 general description

3D printing is a phrase used to describe the process of creating three dimensional objects from digital file using a materials printer, in a manner similar to printing images on paper. The term is most closely associated with additive manufacturing technology, where an object is created by laying down successive layers of material .Recently the term is increasingly being used to describe all types of additive manufacturing processes, or even other types of rapid prototyping technology.

Since 2003 there has been large growth in the sale of 3D printers. Additionally, the cost of 3D printers has gone down.http://en.wikipedia.org/wiki/3D_printing - cite_note-1 The technology also finds use in the fields of jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education,

geographic information systems, civil engineering, and many others.

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5.3 Applications Hybrid solar-laser fascinating CNC machine design , build and operate to create 3D structures of glass from sand and sand under the climate of Kingdom of Jordan The hybrid machile will be fully powered from sun

The device consists of a large Fresnel lens that focuses the sun's rays to a focal point onto a platform holding the silica sand. Two photovoltaic panels power a sun tracker that keeps the focal point on target. When one layer is completed, the platform drops down to allow for the sintering of the next layer, and so on until the object is completed.

Many traditional 3D printers use lasers to melt and soften materials, such as resin or plastic powder, until the particles adhere to each other in a process known as sinteringas a result we will use the sun's rays in place of a laser and silica sand in place of resin or plastic powder to create 3D glass objects.

For the printer to work efficiently, the focal point of the lens would have to be trained right onto the surface of the sand. As the sun would move and the focal point would shift during the process, so he ordered a single 4.5-foot-wide lens and built a motorized frame for it. The central sandbox, in which the objects are printed, shifts in all directions, and the entire machine rotates around its center. Two aluminum arms, holding the lens at one end and solar panels at the other, can pivot from straight overhead down to a 45-degree angle to chase the sun. directed by a CAD design from a connected laptop, the printer uses the concentrated beam of sunlight to slowly trace an object into the sandbox layer by layer. The sun melts the sand, which cools into glass.

When the electronics began overheating, the soup can will be opened and cut , sliced and bent its sides into fan blades, attached the creation to a spinning DC motor, and aimed it right at the circuit board. The sun melted only the sand, and, after more than four hours, he printed a glass bowl, and later several sculptures.

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METHODOLOGY………………………………………………………….…………………….6

Parts of solar sinter machine:

1 - a large Fresnel lens(48 inch×35 inch) .

2- CNC machine.

3- Light sensors (fixed tracker) .

4- Sand box (bed ) .

5- Two photovoltaic panels.

6- Solar-powered motor.

6.2 How it works

The Solar-Sinter machine is based on the mechanical principles of a 3D printer. A large Fresnel lens (100 CM) diameter is positioned so that it faces the sun at all times via an electronic sun-tracking device, which moves the lens in vertical and horizontal direction and rotates the entire machine about its base throughout the day. The lens is positioned with its focal point directed at the centre of the machine and at the height of the top of the sand box where the objects will be built up layer by layer. Stepper motors drive two aluminum frames that move the sand box in the X and Y axes. Within the box is a platform that can move the vat of sand along the vertical Z axis, lowering the box a set amount at the end of each layer cycle to allow fresh sand to be loaded and leveled at the focal point.

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Two photovoltaic panels provide electricity to charge a battery, which in turn drives the motors and electronics of the machine. The photovoltaic panels also act as a counterweight for the lens aided by additional weights made from bottles filled with sand.

6.3 METHODOLOGY

Focal Point

This is the point which is get the foucus for the solar radiation on the bed of CNC machine to start the sintering for the first layer  After all the layers are done, we dig the object out of the sandbox

Control Panel

We will control all the process by laptop which is work on (CAD CAM) program to control the movement of the bed of CNC machine

Printing First put the designs of the object that we want to print in a CAd program. Consequentially, the computer will send the instructions to the printer, which works from

the bottom up. After a layer has cooled into glass, sand will be added to the sandbox in the center of the

machine and flattens it out, and the printer begins heating the next layer.

PowerTwo photovoltaic panels, one on either side of the machine, keep the printer powered. since the panels are attached to the same arms as the lens, they also benefit from the sun tracking, which ensures that they always get direct light. The printer’s motors, the electronics, cameras and a laptop all run on batteries charged by the solar panels 

3D printing process with sand and sunlight :

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The machine is run off an electronic board and can be controlled using a keypad and an LCD screen. Computer drawn models of the objects to be produced are inputted into the machine via an SD card. These files carry the code that directs the machine to move the sand box along the X, Y coordinates at a carefully calibrated speed, whilst the lens focuses a beam of light that produces temperatures between 1400°C and 1600°C, more than enough to melt the sand. Over a number of hours, layer by layer, an object is built within the confines of the sand box, only its uppermost layer visible at any one time. When the print is completed the object is allowed to cool before being dug out of the sand box. The objects have rough sandy reverse side whilst the top surface is hard glass. The exact color of the resulting glass will depend on the composition of the sand, different deserts producing different results. By mixing sands, combinatory colour and material qualities may be achieved.

3D printing out of glass – modified CNC MachineOsama farhat - Mutah University Solar Sintering Project

LENS ……………………………………………………………………………………………7

Fresnel lens:

Definition

The Fresnel lens reduces the amount of material required compared to a conventional spherical lens by dividing the lens into a set of concentric annular sections known as "Fresnel zones." In theory there are infinitely many such zones.

In the first (and largest) variations of the lens, each zone was actually a separate prism. Though a Fresnel lens might appear like a single piece of glass, closer examination reveals that it is many small pieces. 'Single-piece' Fresnel lenses were later produced, being used for automobile headlamps, brake, parking, and turn signal lenses, and so on. In modern times, computer-controlled milling equipment (CNC) might be used to manufacture more complex lenses.

In each of these zones, the overall thickness of the lens is decreased, effectively dividing the continuous surface of a standard lens into a set of surfaces of the same curvature, with stepwise discontinuities between them. A Fresnel lens can be regarded as an array of prisms arranged in a circular fashion, with steeper prisms on the edges and a nearly flat convex center.

Fresnel lens design allows a substantial reduction in thickness (and thus mass and volume of material), at the expense of reducing the imaging quality of the lens, which is why precise imaging applications such as photography still use conventional bulky (non-Fresnel) lenses.

Fresnel lenses are usually made of glass or plastic; their size varies from large (old historical lighthouses, meter size) to medium (book-reading aids, OHP viewgraph projectors) to small (TLR/SLR camera screens, micro-optics). In many cases they are very thin and flat, almost flexible, with thicknesses in the 1 to 5 mm (0.039 to 0.20 in) range.

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7.2 A plastic Fresnel lens

Since plastic Fresnel lenses can be made larger than glass lenses, as well as being much cheaper and lighter, they are used to concentrate sunlight for heating in solar cookers, in solar forges, and in solar collectors used to heat water for domestic use.

The ability of melting of the plastic Fresnel lenses was tested and evaluated on the following object:

1. grid cooking2. plastic tank

7.3 Uses

Solar powergrid cooking, melting metals( nickel, aluminum, steel), glass recycling, generating solar steam and powering Stirling engines.

Also in the early 21st century, Fresnel reflectors began to be used in concentrating solar power (CSP) plants to concentrate solar energy. One application was to preheat water at the coal-fired Liddell Power Station, in Hunter Valley Australia.

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Other application

The use of Fresnel lenses for image projection reduces image quality, Fresnel lenses have been used to increase the visual size of CRT displays in pocket televisions, notably the SinclairTV80. They are also used in traffic lights. Fresnel lenses are also used to correct several visual disorders, including several ocular-motility disorders such asstrabismus.

Perhaps the most widespread use of Fresnel lenses, for a time, occurred inautomobile headlamps, where they can shape the roughly parallel beam from the parabolic reflector to meet requirements for dipped and main-beam patterns, often both in the same headlamp unit (such as the European H4 design). For reasons of cost, weight, and impact resistance, newer cars have dispensed with glass Fresnel lenses, using multifaceted reflectors with plain polycarbonate lenses. However, Fresnel lenses continue in wide used in automobile tail, marker, and backup lights.Fresnel lenses are also used in left-hand-drive European lorries entering the UK and Republic of Ireland (and vice versa, right-hand-drive Irish and British trucks entering mainland Europe) to overcome the blind spots caused by the driver operating the lorry while sitting on the "wrong" side of the cab and driving on the "wrong" side of the road. They attach to the passenger-side window.

Glass Fresnel lenses also are used in lighting instruments for theatre and motion pictures New applications have appeared in solar energy, where Fresnel lenses can concentrate sunlight (with a ratio of almost 500:1) onto solar cells. Thus the active solar-cell surface can be reduced to a fraction compared to conventional solar modules. This offers a considerable cost-saving potential by low material consumption, and it is possible to use high-quality and expensive solar cells, which achieve a very high efficiency under concentration due to thermodynamic effects.[14]

Fresnel reflectors are also currently being incorporated into next-generation solar thermal-energy systemsThe Fresnel lens has seen applications for enhancing passenger reading lights on Airbus aircraft: in a dark cabin, the focused beam of light does not dazzle neighboring passengers.Fresnel lenses have also been used in the field of popular entertainment.ProjectionFresnel lenses of different focal lengths (one collimator, and one collector) are used in commercial and DIY projection. The collimator lens has the lower focal length and is placed Osama farhat - Mutah University Solar Sintering Project

closer to the light source, and the collector lens, which focuses the light into the triplet lens, is placed after the projection image (an active matrix LCD panel in LCD projectors). Fresnel lenses are also used as collimators in overhead projectors.

CALCALUTION ……………………………….8

Introduction:

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Figure6.1 : solar sinter method

The main technological parameters to control the solar sinter process are:the pre-coated sand and its thermo-physical properties, such as density , specific heat cp, thermal conductivity k, resin polymerization temperature range Tp, sand glass transition temperature Tg, sand energy absorption a , reflection r and transmission coefficients , and other properties, such as average grain dimension;- The scan spacing;- The solar beam power P;- The solar spot diameter ;- The scan speed V.The four sand types under study, belonging to two categories (Table 6.1), are commonly used in shell-moulding as they have a good compatibility to the fused metallic material.

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Table6. I Commercial sand properties

The last three process parameters determine the thermal radiant power density, that depends directly on the solar power and inversely on the spot diameter and the scan speed; this latter has a direct impact on productivity. On the other hand, the shell mechanical resistance is influenced by the depth p of the heat affected zone (strictly related to the layer thickness in figure above) and by the temperature history determined by the laser radiation, and finally by the process parameters.In this particular solar sinter application, the solar beam raises the sand temperature allowing the agglomeration of grains, without local burning. Under the thermal viewpoint, the phenomenon can be schematically described as follows: solar sinter is basically a heat transmission phenomenon in which the input energy, the solar radiation, generates in the sand bed a mixed conduction and convection heat transfer. The grain agglomeration strongly depends on the energy absorbed by the sand bed and on the energy required for the resin polymerization, as well as on the chemical energy release during the heating process.

Solar sinter is a very dynamic process; hence its mathematical description involves the solution of the unsteady heat conduction equation. In our model, as in the majority of those proposed in the literature, the governing equation is the unsteady heat conduction equation. The resulting output data are:

- The temperature distribution and the maximum value on the surface Tmax;

- The depth p and the width of the heat-affected zone considered as the penetration of the isothermal front corresponding to the resin glass-transition temperature.

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Solar

radiatio

n

When the laser spot hits the sand bed, the surface interaction with the radiant energy can be described by the coefficients representing the fraction of absorbed a, reflected r, and transmitted energy (Figure 2.) of course,Osama farhat - Mutah University Solar Sintering Project

Figure6. 2 : Energy flow in the solar sinter general process

Reflection

Absorption

Transmission

Equation 1

The three coefficients depend on the sand used, on the resin, and on the radiation itself, but they are very difficult to obtain from the literature. For the pre-coated sands the absorptivity coefficient a is sensibly higher than 0.9 and the reflectivity is lower than 0.01 .

6.1 The analytical solution of the 1D heat conduction equation:

A first method to model the SLS process is represented by the one-dimensional heat conduction transfer equation. In this scheme, the heat transfer in a plane perpendicular to the laser radiation incidence is neglected and the heat transfer by conduction is studied only in the direction of the laser beam axis z; the material is considered as homogeneous. The phenomenon is governed by the general one-dimensional heat conduction equation in unsteady (transient) conditions:

Equation 2

With the following boundary conditions:

Where: - h is the convective heat transfer coefficient between surface and surrounding air (That can be conventionally assumed equal to 10 W/m2K for natural convection),- is the specific thermal power of solar radiation (in W/m2), - T∞is the environmental temperature,- t* is the radiation incidence duration.

A closed solution of the thermal conduction problem expressed by (2) can be obtained by supposing that the thermal influenced zone, exposed since the time t = 0 to a heat flux , is small with respect to the working area. Until t = t*, the temperature history during the radiation incidence can be expressed as follows:

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equation 3

Where ( = k / cp) is the sand thermal diffusivity, Ti the initial temperature of the sandBed and erfc is the complementary error function.

For t > t*:

equation 4

Where Tf is the surface temperature at the end of the heating process and erfc is the errorFunction.

To improve the one-dimensional schematization, it is possible to consider that the sand temperature Ti in the (equation 3) is the environmental temperature at the initial step only. In the next steps, it is necessary to take into account the effects connected with the solar incidence in the adjacent region.

In order to consider the two-dimensional effects of the thermal heat conduction, a different schematization of the solar incidence is then used: the well known «moving heat source». In this way it is possible to evaluate the temperature field deformation, when the heat source moves through the conductive medium, by adjusting the initial condition for the application of (equation 3) and by evaluating the influence of the solar radiation in a plane perpendicular to the z axis to estimate the width of the heat-affected zone also. With a heat source moving in the x direction, the temperature history in the (x, y) plane can be expressed by:Osama farhat - Mutah University Solar Sintering Project

Equation 5

Where '=P / p is the linear density of the heat flux expressed in W/m. The depth of theHeat-affected zone p is adjusted in order to provide the same value of the maximumTemperature obtained with the (equation3).

6.2 The numerical solution of the 3D heat conduction equation:

To simulate in a more complete way the heat transmission related to solar sinter, it is necessary to consider the three-dimensional heat conduction problem in a sufficiently large object, made of homogeneous material, with the moving heat source boundary conditions .This problem is not easy to solve and the hypothesis of a small thermal influenced zone with respect to the working area cannot be removed. An alternative method consists in applying to a finite sand bed volume the three-dimensional time dependent conduction problem expressed in the classical form as:

Equation 6

that is valid for isotropic, heterogeneous media, where qv(x, y, z, t) is the heat generated per unit of time and space, to be defined from the boundary conditions of the equation (2), and k, and cp depend on space and time, for their dependence on the temperature. In this case the radiation is considered as one-dimensional but the conduction within the sand is three-dimensional.

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Obviously an analytical solution of the (equation6) with this hypothesis is not currently available but a solution based on numerical methods is possible, through the discretisation of the spatial - by means of cubic cells – and of the temporal domains. The solution is a function T(x, y, z, and t) and a finite domain is considered. An attempt to solve the three-dimensional problem represented by the (equation6), transformed in the form of a transport equation for the static enthalpy, has been made in this work by means of a commercial computational code, FLUENT, with the SIMPLER algorithm .With this particular code, the sand porosity can also be considered, by activating the porous media modeling option. The program flexibility allows a complete schematization of the thermal phenomenon, including the influence produced by the increase of temperature in the proximity of the radiation incidence point, and consequently it allows a correct definition of the heat affected zone width, that cannot be considered directly in the one-dimensional model. While the analytical solution of the (equation2) by means of the (equations from 3 to 5) permits to investigate the influence of the solar power, the scan speed and the spot diameter, with the three-dimensional schematization it is also possible to investigate the influence of the scan spacing. But the modelisation of the moving heat source, representing the solar beam and its transformation in a time-dependent volumetric heat source, is a very critical aspect, with the available options of the numerical code.

6.3 EXPERIMENTAL TESTS:

To calculate the sand thermo-physical properties and to determine theactual heat amount absorbed by the sand bed.

The following thermo-physical sand properties have been determined in laboratory tests: the specific heat, the thermal conductivity and the energy absorption during the heating process.

Table 6.2 Sand properties determined in laboratory tests

A specific analysis concerning the energy distribution within the sand, to obtain the terms (a) and of the (equation 1), has been carried on too. A schematization of the experimental

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analysis is shown in (Figure 4). The values of the absorption and transmission coefficients have been obtained with the following method:- The nominal laser beam power is indicated on a power meter installed on the laser;- The effective laser beam power on the sand bed has been measured with a powerGauge, based on the thermal balance between incising and dispersed heat;- The transmitted energy has been measured with the same power gauge, after itsPositioning under sand layers of different thickness (detail of Figure 4);- The reflected energy r is lower than 1%.

The sand absorption coefficient (a) has been obtained with (equation1). Considering that only a small amount of the energy is reflected and not more than 2-4% is transmitted at higher depth than 0.2 mm, 95% of the radiant energy is absorbed by the sand finally, for the calculation:

6.4

calculation for time need to sinter sand:

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Solar radiation

: obtained from the figure below (in taffieleh, May) = 12 .

Area of lens = 48 inch ×35 inch = (48×0.0254) × (35×0.0254) = 1.0838688

MEASUMENT AXILARY DEVICES ……………………………….9

1-thermopile

A thermopile is an electronic device that converts thermal energy into electrical energy. It is composed of several thermocouples connected usually in series or, less commonly, in parallel.

Thermopiles do not respond to absolute temperature, but generate an output voltage proportional to a local temperature difference or temperature gradient.

Thermopiles are used to provide an output in response to temperature as part of a temperature measuring device, such as the infrared thermometers widely used by medical professionals to measure body temperature. They are also used widely in heat flux sensors (such as the Moll thermopile and Eppley pyrheliometer) and gas burner safety controls. The output of a thermopile is usually in the range of tens or hundreds of millivolts. As well as increasing the signal level, the device may be used to provide spatial temperature averaging.

Thermopiles are also used to generate electrical energy from, for instance, heat from electrical components. A pyrometer is a non-contacting device that intercepts and measures thermal radiation, a process known as pyrometry. This device can be used to determine the temperature of an object's surface.

2-pyrometerOsama farhat - Mutah University Solar Sintering Project

A pyrometer is a non-contacting device that intercepts and measures thermal radiation, a process known as pyrometry. This device can be used to determine the temperature of an object's surface

EXPERIMENTS……………………………………………….……………………………….10

1-On Silica sand

Ambient Temperature : 30 c

Sintering Temperature : 1600 c

Rate of solar radiation : 7.5 kw.h/. "daily"

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2. on recycling glass

Ambient Temperature : 25 c

Sintering Temperature : 1400- 1575 c

Rate of solar radiation : 5.5 kw.h/. "daily"

3. on

plastic

Ambient Temperature : 25 c

Sintering Temperature : 1150- 260 c

Rate of solar radiation : 5.5 kw.h/. "daily"

4.

on steel

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Ambient Temperature : 28 c

Sintering Temperature : 1500-1700 c

Rate of solar radiation : 7.0 kw.h/. "daily"

DISCUSION AND CONCLOSION……………………………….11

In our project we brought the Fresnel lens and we built the CNC machine then we did tests to find if we can melt the sand, glass and plastic by our lens then we found that we could melt the sand at 1600 c , the glass at 1500 c, the plastic between 115-260 c. above we have some pictures that will show you what happened when we focus the solar radiation on plastic gallon.

Osama farhat - Mutah University Solar Sintering Project

Osama farhat - Mutah University Solar Sintering Project