BS EN ISO 17828:2015 pdf download – Solid biofuels — Determination of bulk density
5.2.1 Balance 1 A balance shall be capable of reading to the nearest 10 g. This balance shall be used for measurements with the large container.
5.2.2 Balance 2 A balance shall be capable of reading to the nearest 1 g. This balance shall be used for measurements with the small container. 5.3 Scantlings A rigid scantling with a length exceeding the diameter of the container in 5.1.1 shall be used for levelling the material in the measuring container by lateral movements of the scantling across the rim of the measuring container.
NOTE It is advisable to use a second scantling or other device for spacing the dropping height of 150 mm between the measuring container and the wooden board in 5.4.
5.4 Wooden board A flat wooden board [e.g. oriented strand board (OSB)] with a thickness of approximately 15 mm and sufficient in size for dropping the container during shock exposure.
6 Sample preparation Sampling shall be carried out in accordance with ISO 18135. If necessary, the sample can be divided in to test portions in accordance with ISO 14780. The test portion volume shall exceed the volume of the container measures by minimum of 30 %.
NOTE Precautions should be taken to ensure that the moisture is evenly distributed within the sample.
7.1 Determination of the container volume Before use, the mass and filling volume of the container shall be determined. Weigh the empty, clean, and dry container on the balance (5.2.1 or 5.2.2). Then fill the container with water and a few drops of wetting agent (e.g. liquid soap) until maximum capacity; then weigh it again. The water should be at a temperature between 10 °C and 20 °C. Calculate the volume (V) of the container from the net weight of water and the density of the water (1 kg/dm 3 ) and record the result rounded to the nearest 0,01 l (0,000 01 m 3 ) for the large container or 0,001 l (0,000 001 m 3 ) for the small container.
NOTE 1 The effect of temperature on the density of water is negligible.
NOTE 2 The container should be cleaned regularly and its volume should be checked regularly.
7.2 Container selection The large container (5.2.1) can be used for larger materials within the scope of this International Standard. For materials with a nominal top size up to 12 mm and for pellets with a diameter equal or below 12 mm the small container (5.2.2) can be used (optional).
7.3 Measurement procedure
a) Fill the container by pouring the sample material from a height of 200 mm to 300 mm above the upper rim until a cone of maximum possible height is formed. NOTE Make sure that the container is dry and clean before being (re)filled.
b) The filled container is then shock exposed to allow settling. This shall be done by dropping it freely from 150 mm height onto a wooden board (5.4). Before shock exposure, remove particles from the wooden board within the dropping area. Make sure that the container hits the board in a vertical position. Repeat the shock exposure two more times to apply a total of three shock exposures. Then refill the resulting empty space at the top of the container in accordance with 7.3 a). NOTE The second scantling or device referred to in 5.3 can be used for spacing of the distance between the measuring container and the wooden board before dropping. Also, other mechanisms to create a comparable shock impact can be suitable.
c) Remove surplus material by using a scantling (5.3), which is shuffled over the container’s edge in oscillating movements. When the test portion contains coarse material, all particles preventing the free passage of the scantling have to be removed by hand. If the removal of larger particles tears bigger holes into the leveled surface, the cavities shall be refilled and the removal procedure is repeated.
d) Weigh the container with the remaining sample material.
e) Unify the used sample material with the unused sample material and repeat the procedure from 7.3 a) to 7.3 d) at least once in order to get duplicate determinations.
f) Determine moisture content of the test sample material as received according to ISO 18134-1 or ISO 18134-2 immediately after bulk density determination.BS EN ISO 17828 pdf download.