Muffle Furnace - Energy Engineering lab manual PDF

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Energy Engineering lab manual...

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ENERGY LAB EQUIPMENTS

TABLE OF CONTENTS TABLE OF FIGURES .............................................................................................................. 3 MUFFLE FURNACE ............................................................................................................... 4 CONSTRUCTION: .............................................................................................................. 4 WORKING PRINCIPLE: ..................................................................................................... 4 APPLICATIONS: ................................................................................................................. 5 BOMB CALORIMETER ......................................................................................................... 6 CONSTRUCTION: .............................................................................................................. 6 WORKING PRINCIPLE: ..................................................................................................... 7 APPLICATIONS: ................................................................................................................. 7 PENSKY MARTENS APPARATUS ...................................................................................... 8 CONSTRUCTION: .............................................................................................................. 8 SAMPLE CUP: ................................................................................................................. 8 LID: ................................................................................................................................... 8 STIRRER: ......................................................................................................................... 8 COVER: ............................................................................................................................ 8 SHUTTER: ....................................................................................................................... 8 FLAME EXPOSURE DEVICE: ...................................................................................... 8 HEATER:.......................................................................................................................... 9 WORKING PRINCIPLE: ..................................................................................................... 9 APPLICATIONS: ............................................................................................................... 10 REDWOOD VISCOMETER ................................................................................................. 10 CONSTRUCTION: ............................................................................................................ 10 WORKING PRINCIPLE: ................................................................................................... 11 APPLICATIONS: ............................................................................................................... 11 SAYBOLY VISCOMETER ................................................................................................... 11 CONSTRUCTION: ............................................................................................................ 11 WORKING PRINCIPLE: ................................................................................................... 11 APPLICATIONS: ............................................................................................................... 12 ENGLER VISCOMETER ...................................................................................................... 13 1

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CONSTRUCTION: ............................................................................................................ 13 THERMOSTAT: ............................................................................................................ 13 THERMOMETER: ......................................................................................................... 13 COVER: .......................................................................................................................... 13 VALVE: .......................................................................................................................... 13 STIRRER: ....................................................................................................................... 13 JET: ................................................................................................................................. 14 LEVEL GAUGE: ............................................................................................................ 14 LEVELING SCREW: ..................................................................................................... 14 WORKING PRINCIPLE: ................................................................................................... 14 APPLICATIONS: ............................................................................................................... 15 BROOKFIELD VISCOMETER ............................................................................................ 15 CONSTRUCTION: ............................................................................................................ 15 WORKING PRINCIPLE: ................................................................................................... 16 APPLICATIONS: ............................................................................................................... 16 ANILINE POINT APPARATUS ........................................................................................... 17 CONSTRUCTION: ............................................................................................................ 17 TEST TUBE AND CORK: ............................................................................................ 17 STIRRER: ....................................................................................................................... 17 THERMOMETER: ......................................................................................................... 17 PIPETTES:...................................................................................................................... 17 HEATING AND COOLING BATH: ............................................................................. 17 WORKING PRINCIPLE: ................................................................................................... 17 APPLICATIONS: ............................................................................................................... 18 FLUE GAS ANALYZER ....................................................................................................... 19 DESCRIPTION: ................................................................................................................. 19 APPLICATIONS: ............................................................................................................... 19 APPLIANCE TESTING:................................................................................................ 19 AMBIENT AIR MONITORING: .................................................................................. 19 References ............................................................................................................................... 20

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TABLE OF FIGURES Figure 1: MUFFLE FURNACE ............................................................................................ 6 Figure 2: BOMB CALORIMETER ...................................................................................... 7 Figure 3: PENSKY MARTENS APPARATUS ................................................................... 9 Figure 4: REDWOOD VISCOMETER .............................................................................. 10 Figure 5: SAYBOLT VISCOMETER ................................................................................ 12 Figure 6: ENGLER VISCOMETER .................................................................................. 14 Figure 7: BROOKFIELD VISCOMETER ........................................................................ 16 Figure 8: ANILINE POINT APPARATUS ........................................................................ 18 Figure 9: FLUE GAS ANALYSER APPARATUS............................................................ 19

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MUFFLE FURNACE Muffle Furnace is a kind of front loading box type kiln, which is used to create extremely high temperature required to perform various heat treatment processes such as annealing, ash determination and coal analysis etc. The heating temperature inside muffle furnace chamber may vary between 900°C to 1400°C and high temperature 1600°C to 1800°C. The walls of the furnace radiantly heat the contents of the chamber, so that the material being heated has no contact with the flame. The key usage of a laboratory muffle furnace is to evaluate characteristics of materials under high heat; therefore, it is widely used in industrial and laboratory research facilities and some educational projects.

CONSTRUCTION: Muffle furnace consists of:              

A vented heating chamber. A temperature controller. A door safety switch for operator safety. A horizontal and rectangular light-weight chamber with Triple walled construction. Working chamber is made up of ceramic with Alumina. Chamber is also made up of Mild Steel finished with High Temperature Resistant Aluminum Paint. Exterior part is made up of powdered coated mild steel. High Dense Insulation between two walls (Asbestos free). With exhaust pipe fitted with r ear side of the Furnace. High quality heating system, embedded in ceramic muffle. Long service life. Fully openable Door System. Temperature up to Maximum: 1600 0C Temperature is controlled by Microprocessor Based PID Digital Controller.

WORKING PRINCIPLE: A muffle furnace is a piece of oven-type equipment that can reach high temperatures. It usually works by putting a high-temperature heating coil in an insulated material. The insulating material effectively acts as a muffle, preventing heat from escaping.

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Furnace is usually heated to desired temperatures by:  Conduction.  Convection.  Blackbody radiation from electrical-resistance heating elements. Air is heated inside the chamber by above mentioned basic fundamentals. The name muffle furnace is derived from the fact that the internal ceramic chamber of the furnace which is also known as muffle is wrapped up in vast layers of insulation so as to prevent heat loss and achieve high temperatures. The high temperatures inside a muffle furnace attained by utilizing heating properties of Nichrome (nickel-chromium) wires which are called electrically operated heating elements. The temperature regulation in a furnace is highly dependent on the efficiency of electronic controller unit, although best results can only be obtained by applying PID controlled units, PID stands for proportional integral derivative controller. The muffle furnace is used when a controlled atmosphere is desired to prevent oxidation during heat treatment in high temperatures.

APPLICATIONS: Muffle furnace is used for high-temperature applications:                 

Research and development. Heating ceramics. Heating semiconductors. Heat Treatments. Brazing and Soldering. Air and Space Industry. Petro chemistry. Material Testing and Quality Control Laboratories. Automotive. Coal and Mining. Plastics. Fusing glass. Medicine. Electronics. Dental. Nuclear. Enamel coatings

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Figure 1: MUFFLE FURNACE

BOMB CALORIMETER A bomb calorimeter is a type of constant-volume calorimeter used in measuring the heat of combustion of a particular reaction. Bomb calorimeters have to withstand the large pressure within the calorimeter as the reaction is being measured. Electrical energy is used to ignite the fuel; as the fuel is burning, it will heat up the surrounding air, which expands and escapes through a tube that leads the air out of the calorimeter. When the air is escaping through the copper tube it will also heat up the water outside the tube. The change in temperature of the water allows for calculating calorie content of the fuel.

CONSTRUCTION: The bomb calorimeter consist primarily of the sample, oxygen, the stainless steel bomb, and water. The bomb (not related to a military weapon) is a container designed to withstand high pressure, and is equipped with valves for adding gases and electrical contacts for initiating combustion reactions. The bomb is pressurized with excess pure oxygen and containing a weighed mass of sample. Electricity is used to ignite the fuel and when the fuel ignites, energy is released by the combustion and heat flow from this crosses the stainless steel wall, thus raising the temperature of the steel bomb .The water jacket prevents heat flow from the calorimeter to the rest of the universe. 6

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Figure 2: BOMB CALORIMETER

WORKING PRINCIPLE: The basic principle is the simple: A chemical reaction heats a quantity of water in an insulated container. In this case, however, the reaction takes place inside a sealed container, or bomb. The bomb contains the chemical to be analyzed and enough oxygen to make sure the sample burns completely. The bomb sits submerged in a container of water, and ignition wires start the combustion. Because the reaction takes place in a rigid, sealed container, no pressurevolume work is done by the reaction; all the energy will be released as heat, and none as work. There are two electrodes as shown in the given figure. There is a platinum wire, which is dipped in the fuel sample and its two ends are attached with the two electrodes. For the ignition of the fuel, electric current is supplied and a spark is produced. A stirrer is used for the uniform distribution of temperature.

APPLICATIONS: A bomb calorimeter measures:    

Heat of combustion produced in a chemical reaction. Reaction enthalpy. Heats involved in formation. Heats involved in the reaction. 7

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    

Change in enthalpy throughout the reaction. Calorific value of solid and liquid fuels, which are traded based on that value. The calorie content of a products such as food. Heat of detonation of propellants and explosives. Whether the hazardous waste fuel is safe and appropriate for use.

PENSKY MARTENS APPARATUS Pensky martens apparatus is used to determine the flash point of fuel oils and lubricating oils. Flashing above 490C. It consists of an oil cup with a circular marking for oil level indication. A lid to cover the oil cup with sliding shutters with ports, oil stirring mechanism and dipping wick holder, cast iron oil cup holder (air bath), electric heater with control.

CONSTRUCTION: A Pensky Martin apparatus consists of the following parts:

SAMPLE CUP: Sample cup is a cylindrical vessel, made of brass with a filling mark grooved inside near the top. It is provided with a lid.

LID: The lid is equipped with the following parts:

STIRRER: The stirring device consists of a vertical steel shaft mounted in the center of the cup and carrying two-bladed brass propellers.

COVER: It has four opening, one for thermometer and the rest for the oxygen entry and exposure of vapors to test flame.

SHUTTER: The lid is equipped with a brass shutter operating on the plane of the upper surface of the cover. The shutter is so shaped and mounted on the lid that when in one position, the holes are completely closed and when in the other, these orifices are completely opened.

FLAME EXPOSURE DEVICE: The lid is equipped with a pilot lamp with such a mechanism that its flame operates simultaneously with the shutter. 8

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When the shutter is in the ‘open’ position, the tip is lowered down in the center of the central orifice.

HEATER: The cup is heated by means of burner or it is electrically heated. The air bath has cylindrical interior about 4 cm. deep and can be heated by a direct flame or an electric resistance element. The top-plate is also made of metal and mounted with an air gap between it and the air bath.

Figure 3: PENSKY MARTENS APPARATUS

WORKING PRINCIPLE: In the Pensky Marten’s closed cup flash point test, a brass test cup is filled with a test specimen and fitted with a cover. The sample is heated and stirred at specified rates depending on what it is that's being tested. An ignition source is directed into the cup at regular intervals with simultaneous interruption of stirring until a flash that spreads throughout the inside of the cup is seen. The corresponding temperature is its flash point. Pensky Martens closed cup is sealed with a lid through which the ignition source can be introduced periodically. The vapor above the liquid is assumed to be in reasonable equilibrium with the liquid.

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APPLICATIONS: Pensky marten’s apparatus is used for:      

Measuring the flash point of fuel. Measuring the fire point. Determining whether the waste containing any type of liquid fuel is safe to dispose of. Determining the quality of the fuel. Determining the conditions for the transportation of fuel. Determining whether it is transportable at normal temperatures or not.

REDWOOD VISCOMETER CONSTRUCTION: Redwood viscometer Consists of a cylindrical oil cup furnished with a gauge point, a gate/ metallic Orifice jet at the bottom having a concave depression from inside to facilitate a ball with stiff wire to act as a valve to start or stop oil flow. The outer side of the orifice jet is convex, so that the oil under test does not creep over the lower face of the oil cup. The oil cup is surrounded by a water bath with a circular electrical immersion heater and a stirring device. Two thermometers are provided to measure water bath temp. & oil temperature under test. A round flat-bottomed flask of 50ml marking, to measure 50 ml of oil flow against time. The water bath with oil cup is supported on a tripod stand with leveling screws.

Figure 4: REDWOOD VISCOMETER

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WORKING PRINCIPLE: Red wood viscometer is based on the principle of laminar flow through the capillary tube of standard dimension under falling head. The viscometer consists of vertical cylinder with an orifice at the center of the base of inner cylinder. The cylinder is surrounded by a water bath, which can maintain temperature of the liquid to be tested at required temperature. The water bath is heated by electric heater. Cylinder which is filled up to a fixed height with liquid whose viscosity is to be determined is heated by water bath to the desired temperature. Then orifice is opened and the time required to pass the 50cc of oil is noted. With this arrangement variation of viscosity with temperature can be studied.

APPLICATIONS: Redwood viscometer is used for measuring kinematic viscosity of petroleum products in:     

Petroleum industries. Oil refineries. Industries. Educational institutions. Research organizations.

SAYBOLY VISCOMETER CONSTRUCTION: The apparatus mainly consists of a standard cylindrical oil cup surrounded with a water bath with an immersion heater and a stirring device. The apparatus is supplied with two S.S. Orifice jets namely Universal jet & Furol jet, which can be fitted at the bottom of the oil cup as per our requirement. A rubber cork stopper arrangement is provided also at the bottom to facilitate start and stop the oil flow from the Viscometer. Two thermometers are provided to measure water bath temperature a...