ISO/TR 23437 pdf free download
ISO/TR 23437-2020 pdf free download.Solid biofuels一Bridging behaviour of bulk biofuels.
4.6 Calculation
The measured bridging behaviour for a sample is calculated as the arithmetic mean and standard deviation from the total of ten repeated measurements of the same sample (five for pellets or seeds) of the slot opening width “1” as determined in 4.5.
The above average is useful information in order to compare biofuels. For the design of installations, the maximum value for the ten (or five) tests is of importance.
4.7 Precision and bias
Because of the varying nature of solid biofuels covered by this document, it is not possible at this time to give a precision statement (repeatability or reproducibility) for this test method.
Precision of measurement was proven to be highly fuel dependent. This is also evidenced by the results given in 6.1.
4.8 Test reporting
The test report includes at least the following information:
a) an identification of the laboratory performing the test and the date ot the rest;
b) an identification of product (or sample) tested;
c) a fuel characterization in accordance with ISO 172251:_1). Table 1 (origin and source), Table 2 (traded form) and the relevant table for that fuel (choose from Tables 3 to 15);
NOTE A detailed fuel description (e.g. type of raw material, method of comminution, storage history, photos with metric ruler) Is highly recommended to allow sound data evaluation and interpretation of measured results.
d) a reference to this document, i.e. ISO/TR 23437;
e) the individual results of the bridging test(s) as well as the maximum value, average and standard deviation of the calculated average;
f) the average result from the moisture content determinations;
g) the result of the particle size classification, if performed;
h) the result of the bulk density determination, if performed;
i) any unusual features noted during the determination that could affect the result;
j) any deviation from this document, or operations regarded as optional;
k) the date of the test.
5 Part II: Implementing the measuring principle
5.1 Review of apparatus construction
The idea for the principle was conceived during a research project conducted by Mattssonl1l in the late 1980s. A test bench was designed where the bridging test apparatus had a hanging bottom, sustained by steel cables, and the opening was performed via two hand-operated rollers on which the bottom rubber mat was rolled. This is referred to as “Mark 1 apparatus”.
In a later version in the 1990s, the manual operation was replaced by two electrical step motors. These allowed a more gradual opening of the slot as well as automated reading of the width of the slot opening I. Another good feature of this version was that the slot could be opened very quickly after the reading had been completed. This saved a lot of time during the measurement cycle. This machine is referred to as ‘Mark 2 apparatus”.
In the method revision within the Bionorm 2 project, the overall dimensions of previous machine were retained but several changes were introduced. The bottom was kept completely flat, a smooth opening drive was applied and the previously large roller radius, which formed the opening slot, was replaced by a slim deflection edge of only about 32 mm radius at the slot opening (see radius r in Figure 3). This machine is referred to as “Mark 3 apparatus”.
The defined measuring principle as described in Part I was accomplished in an apparatus construction as shown in Figure 5. This equipment implements the required split floor design, which is fully simultaneously movable to both sides. Both halves of the floor are mounted on an undercarriage, which travels on wheels. The opening mechanism ensures a fully parallel movement to both sides. The opening process is propelled by a crank handle. An alternative apparatus version with an electric motor (with
1) Under preparation. Stage at the time of publication: ISO/DIS 17225-1:2020.
© ISO 2020— All rights reserved 7
ISO/TR 23437:2020(E)
adjustable speed) was also successfully tested. It accelerates testing, e.g. by enabling a quick floor closure after testing. In Eigure.6, further details of the construction are shown with view from the bottom.
The recommendation is that any future machines are equipped with electric drive. The additional cost of the electrification is easily gained back by the reduced time during testing and a more homogeneous movement between tests is guaranteed.ISO/TR 23437 pdf download.
