ASTM E711 PDF
Find the most up-to-date version of ASTM E at Engineering ASTM E() [ Withdrawn ]. Standard Test Method for Gross Calorific Value of Refuse-Derived Fuel by the Bomb Calorimeter. Designation: E – 87 (Reapproved ) Standard Test Method for. Gross Calorific Value of Refuse-Derived Fuel by the Bomb Calorimeter1 This standard.
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This test method covers the determination of the gross calorific value of prepared analysis sample of solid forms of refuse-derived RDF by the bomb calorimeter method. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Calorific Value – the heat of combustion of a unit quantity of a substance. Gross Calorific Value – the heat produced by combustion of a unit quantity of solid fuel, at constant volume, in an oxygen bomb calorimeter under specified conditions such that all water in the products remain in liquid axtm. Net Calorific Value – a lower value calculated from the gross calorific value.
It is equivalent to the heat produced by combustion of a unit quantity of solid fuel at a constant pressure of one w711, under the assumption that all water in the products remains in the form of vapor.
Calorimeter – describes the bomb, the vessel with stirrer, and the water in which the bomb is immersed. This is the number that is multiplied by the corrected temperature rise in degrees and divided by the sample weight in grams to give the gross calorific value after thermochemical corrections have been applied. Wastes used as fuel in as-discarded form with only bulky wastes removed. Wastes processed to coarse particle size with or without ferrous metal separation. Combustible waste fraction densified compressed aastm the form of pellets, sligs, cubettes, or briquettes.
Calorific value is determined in this method by burning a weighed analysis sample in an oxygen aetm calorimeter under controlled conditions. The calorific value is computed from temperature observations made before and after combustion, taking proper allowance for thermometer and thermochemical corrections. Either isothermal or adiabatic calorimeter jackets may be used. The calorific value, or heat of combustion, is a measure of the energy available from the fuel. Knowledge of this value is essential in assessing the commercial worth of the fuel and to provide the basis of contact between producer and user.
Test Room – The apparatus should be operated in a room or area free of drafts that can be kept at a reasonably uniform temperature and humidity for the time required for the determination.
The apparatus should be shielded from direct sunlight and radiation from asmt sources. Controlled room temperature and humidity are desirable. Oxygen Bomb – constructed of material that are not affected by the combustion process or products sufficiently to introduce measurable heat input or alteration of end products. If the bomb is lined with platinum or gold, all openings shall be sealed to prevent combustion products from reaching the base metal.
The bomb shall be designed so that all liquid combustion products can be completely recovered by washing the inner surfaces.
There shall be no gas leakage during a test. The bomb shall be capable of withstanding a hydrostatic pressure test of 21 MPa psig at room temperature without stressing any part beyond its elastic limit. Calorimeter – made of metal preferably copper or brass with a tarnish-resistant coating and with all outer surfaces highly polished.
Its size shall be such that the bomb will be completely immersed astmm water when the calorimeter is assembled. It shall e71 a device for stirring the water thoroughly and at a uniform rate, but with minimum heat input.
Continuous stirring for 10 min shall not raise the calorimeter temperature more than 0. The immersed portion of the stirrer shall be coupled to the outside through a material of low heat conductivity.
Jacket – The calorimeter shall be completely enclosed within a stirred water jacket and supported so that its sides, top, and bottom are approximately 10mm from the jacket walls. The jacket may be arranged so as to remain at constant temperature or with provisions for rapidly adjusting the jacket temperature to equal that of the calorimeter for adiabatic operation.
It shall be constructed so that any water evaporating from the jacket will condense on the calorimeter. Thermometers – Temperatures in the calorimeter and jacket shall be measured with the following thermometer or combinations thereof:. Other thermometers of equal or better accuracy are satisfactory. These thermometers shall be tested for accuracy against a known standard preferably by the National Bureau of Standards at intervals no greater than 2.
The maximum difference in correction between any two test points shall not be more than 0. The maximum astk between any two test points shall not be more than 0. Calorimetric-Type Platinum Resistance Thermometer,tested for accuracy against a known standard. Thermometer Accessories – A magnifier is required for reading mercury-in-glass thermometers to one tenth of the smallest scale division. This shall have a lens and holder designed so as to introduce no significant errors due to parallax.
ASTM E711 – 87 Gross Calorific Calorimeter
A Wheatstone bridge and galvanometer capable of measuring resistance to 0. Sample Holder – Samples shall be burned in an open crucible of platinum, quartz, or acceptable base-metal alloy.
Base metal alloy crucibles are acceptable if after a few preliminary firings the weight does not change significantly between tasks. Firing wire shall be mm of No. Equivalent platinum of palladium wire may be used provided constant ignition energy is supplied, or measured, and appropriate corrections made. Firing Circuit – A 6 to 16V alternating or direct current is required for ignition purposes with an ammeter or pilot light in the circuit to indicate when current is flowing. A step-down transformer connected to an alternating current lighting circuit or batteries may be used.
Caution – The ignition circuit switch shall be of momentary double-contact type, normally open, except when held closed by the operator. The switch should be depressed only long enough to fire the bomb. Purity of Reagents – Reagent grade chemicals shall be used in all tests.
ASTM E (Re-approved ) – International Standards
Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
Purity of Water – Unless otherwise indicated, references to water shall be understood to mean reagent water. The crystals shall be pelleted before use. Commercially prepared pellets may be used provided they are made from National Bureau of Standards benzoic acid. The value of heat of combustion of benzoic acid, for use in the calibration calculations, shall be in accordance with the value listed in the National Bureau of Standards certificate issued with the standard.
The indicator selected shall be used consistently in both calibrations and calorific determinations. Oxygen – free of combustible matter. Oxygen manufactured from liquid air, guaranteed to be greater than Oxygen made by the electrolytic process may contain a small amount of hydrogen rendering it unfit without purification. Sodium Carbonate, Standard Solution 0. The buret used for the HNO3 titration shall be of such accuracy that estimations to 0.
A more diluted standard solution may be used for higher sensitivity. Due to the origins of RDF in municipal waste, common sense indicates that some precautions should be observed when conducting tests on the samples. Recommended hygienic practices include use of gloves when handling RDF and washing hands before eating or smoking.
RDF products are frequently non-homogeneous. For this reason significant care should be exercised to obtain a representative laboratory sample for the RDF lot to be characterized. The sampling method for this procedure should be based on agreement between the involved parties. The laboratory sample must be air-dried and particle size reduced to pass a 0. Determine the energy equivalent of the calorimeter as the average of a series of ten individual runs, made over a period of not less than 3 days or more than 5 days.
To be acceptable, the standard deviation of the series shall be 6. For this purpose, any individual run may be discarded only if there is evidence indicating incomplete combustion. If this limit is not met, repeat the entire series until a series is obtained with a standard deviation below the acceptable limit.
The weight of the pellets of benzoic acid in each series should be regulated to yield the same temperature rise as that obtained with the various samples tested in the individual laboratories. The usual range of weight is 0. Make each determination in accordance with the procedure described in Section 11, and compute the corrected temperature rise. Determine the correction for HNO3, and firing wire.
Standardization tests should be repeated after changing any part of the calorimeter and occasionally as a check on both calorimeter an operating technique. Weight of sample – Thoroughly mix the analysis sample of solid fuel in the sample bottle, taking care that the heavies and lights fluff are distributed in the sample.
Carefully weigh approximately 1g of the sample directly into the crucible in which it is to be burned or into a tared weighing scoop which the sample is transferred to the crucible. Weigh the sample to the nearest 0. Some form of compaction may be necessary to ensure satisfactory ignition and complete combustion. Water in Bomb – Add 1. Before adding this water, rinse the bomb, and drain the excess water, and leave undried.
Firing Wire – Connect a measured length of firing wire to the ignition terminals with enough slack to allow the firing wire to maintain contact with the sample. Oxygen – Charge the bomb with oxygen to a consistent pressure between 20 and 30 atm 2.
This pressure must remain the same for each calibration and for each calorific determination. If, by accident, the oxygen introduced into the bomb should exceed the specified pressure, do not proceed with the combustion. Detach the filling connection and exhaust the bomb in the usual manner. Calorimeter Water – It is recommended that calorimeter water be adjusted before weighing as follows: Isothermal Jacket Method 1. Observations, Isothermal Jacket Method – Assemble the calorimeter in the jacket and start the stirrer.
Allow 5 min for attainment of equilibrium; then record the calorimeter temperatures at 1min intervals for 5 min. Fire the charge at the start of the sixth minute and record the time and temperature. After the rapid-rise period about 4 to 5 minrecord temperatures at 1 min intervals on the minute until the difference between successive readings has been constant for 5 min.
Observations, Adiabatic Jacket Method – Assemble the calorimeter in the jacket and start the stirrer. Adjust the jacket temperature to be equal to or slightly lower than the calorimeter, and run for 5 min to obtain equilibrium.
Record the initial temperature and fire the charge.