LY/T 3243-2020Methods for the determination of broken-resistance and proximate analysis of solidified biofuels (English PDF)

4.1 Method summary

Weigh a certain quality of biomass fuel sample, put it into the test box, and make the test box rotate around the fixed shaft at a certain speed to make A certain degree of collision occurs between the test samples and between the sample and the vessel wall. Then separate the worn out fine particles, according to the remaining Calculate the shatter resistance of the sample mass.

4.2 Equipment

4.2.1 Testing machine

The testing machine consists of a test box with a rotating shaft and a rotating device. (see picture 1) the test box has a rectangular parallelepiped structure and is made of hard materials (steel, aluminum or plexiglass). Length 300mm, width 125mm, height 300mm, the wall thickness is not less than 6mm. A baffle is installed in the box, the length of the baffle is 230mm, and it is installed along the diagonal line of the plane of 300mm×300mm.

The location and specific dimensions are shown in Figure 2, and the unit is mm. Two identical test boxes are connected together by a rotating shaft. Axis of rotation the line and the center axis of the 300mm×300mm side of the test box should be consistent, so that the test box can rotate at a constant speed along with the rotating shaft.

4.2.2 Test sieve

According to the diameter of the measured biomass briquette, select a suitable test sieve in accordance with ISO 3310-1.The aperture of the sieve is approximately equal to that of the briquette fuel.

2/3 of the diameter (or diagonal), but not more than 45mm.

For pellet fuel, a round-hole sieve with an aperture of 3.15mm is selected.

4.2.3 Balance

Sense amount 0.1g.

4.3 Sample preparation

The samples used to determine the shatter resistance shall be sampled according to the requirements of GB/T 35820, and the samples shall be stored in a closed container to prevent moisture absorption.

During the test, the sample should be at room temperature.

4.4 Test procedure

4.4.1 Weigh a sample of 1000g±10g, divide it into two evenly and put them into two test boxes respectively. For the molded fuel with a particle size greater than 12mm the material sample can be weighed 1000g±50g.

4.4.2 Turn on the rotating device, make the test box rotate 500±1 revolutions at a speed of 40r/min±1r/min, then close the rotating device, and set the sample Take it out of the two test boxes.

4.4.3 Select the test sieve in accordance with the provisions of 4.2.2, place the sample on the test sieve, and screen through mechanical vibration or artificial vibration to ensure the powder and crumbs are completely separated from the sample.

4.5 Result calculation

Calculate the shatter resistance of biomass briquettes according to formula (1).

4.6 Precision of determination of shatter resistance

The reproducibility limit and reproducibility critical difference of the determination of the shatter resistance of biomass briquettes are as specified in Table 1.

5.1 Method A (Nitrogen Drying Method)

5.1.1 Method summary

Weigh a certain amount of biomass briquettes for general analysis samples, put them into a drying oven at 105°C±1°C and vented with nitrogen, and keep it dry.

After drying until the mass is constant, calculate the mass percentage of moisture based on the mass loss of the sample.

5.1.2 Reagents and equipment

5.1.2.1 Nitrogen. the purity is 99.9%, and the oxygen content is less than 0.01%.

5.1.2.2 Color-changing silica gel.

5.1.2.3 Drying box. the box body is tight, has a certain gas flow space and gas inlet and outlet, and is equipped with an automatic temperature control device, which can the internal temperature is controlled within the range of 105°C±1°C.

5.1.2.4 Glass weighing bottle. diameter 40mm, height 25mm, equipped with a tightly ground bottle cap (see Figure 3, unit is mm).

Figure 3 Glass weighing bottle

5.1.2.5 Dryer. built-in color-changing silica gel.

5.1.2.6 Flow meter. the range is 100mL/min~1000mL/min.

5.1.2.7 Analytical balance. Sensitivity 0.1mg.

5.1.3 Test procedure

5.1.3.1 Use the pre-dried weighing bottle to weigh 0.5g ± 0.05g of the general analysis sample of biomass briquettes, weigh to 0.0001g, lightly Vibrate the weighing bottle to spread the sample evenly on the bottom.

5.1.3.2 Put the open weighing bottle and bottle cap into a drying oven that has been pre-filled with nitrogen and heated to 105°C ± 1°C, and dried for 2 hours. Weighing Nitrogen gas was started 10 minutes before the bottle was placed in the drying oven, and the nitrogen flow rate was based on 15 air changes per hour.

5.1.3.3 Take out the weighing bottle from the drying box, quickly close the bottle cap, and immediately put it into a desiccator with color-changing silica gel to cool to room temperature (approximately 15 min) after weighing.

5.1.3.4 Perform check drying, put the weighing bottle back in the drying oven for 30 minutes, take it out and weigh it, until it has dried twice before and after.

The decrease in the mass of the sample does not exceed 0.0010g or until the mass increases. In the latter case, the previous mass of the increased sample mass is used as a basis for calculation.

5.2 Method B (air drying method)

5.2.1 Method summary

Weigh a certain amount of biomass briquettes for general analysis samples, put them in a drying oven at 105°C±1°C, and dry them in the air to mass Constant, calculate the mass percentage of moisture based on the mass lost by the sample.

5.2.2 Instruments

5.2.2.1 Electric heating blast drying oven. equipped with automatic temperature control device, which can control the temperature in the oven within the range of 105°C±1°C.

5.2.2.2 Glass weighing bottle. same as 5.1.2.4.

5.2.2.3 Dryer. same as 5.1.2.5.

5.2.2.4 Analytical balance. same as 5.1.2.7.

5.2.3 Test procedure

5.2.3.1 Use the pre-dried weighing bottle to weigh 0.5g ± 0.05g of the general analysis sample of biomass fuel, and weigh it to 0.0001g gently.

Vibrate the weighing bottle to spread the sample evenly on the bottom.

5.2.3.2 Put the open weighing bottle together with the bottle cap into the pre-blasted drying box which has been heated to 105°C±1°C, and dry for 2h.

5.2.3.3 Take out the weighing bottle from the drying box, quickly close the bottle cap, and immediately put it into a desiccator equipped with color-changing silica gel to cool to room temperature (about 15 min) after weighing.

5.2.3.4 Carry out inspection drying for 30 minutes each time, until the mass reduction of the sample after two consecutive dryings does not exceed 0.0010g or the mass Until the increase. In the latter case, the previous mass of the sample mass increase is used as the basis for calculation.

5.3 Calculation of results

Calculate the moisture content of the biomass fuel sample according to formula (2).

5.4 Precision of moisture determination

The repeatability limit of the moisture determination of the biomass briquette sample is 0.15%.

6.1 Method summary

Weigh a certain amount of biomass briquettes for general analysis samples, put them into the muffle furnace, and heat them to 550°C± at a certain heating rate.

At 10°C, burn the sample in the air to a constant mass, and take the percentage of the mass of the residue to the initial mass of the sample as the ash content of the sample.

6.2 Instruments and equipment

6.2.1 Muffle furnace. It can heat up at a rate of 5°C/min and can maintain the temperature in the furnace at 550°C ± 10°C. The ventilation conditions in the furnace can guarantee the test During the combustion process, the amount of oxygen is sufficient.

The constant temperature zone of the muffle furnace should be measured with the furnace door closed at least once a year. Temperature control instruments (including thermocouples and secondary display instruments) Calibrate at least once a year.

6.2.2 Ash dish. porcelain, rectangular, bottom length 45 mm, bottom width 22 mm, and height 14 mm (see Figure 4, the unit is mm).

6.2.3 Dryer. same as 5.1.2.5.

6.2.4 Analytical balance. same as 5.1.2.7.

6.2.5 Ash dish holder. It is made of nickel-chromium wire or other heat-resistant metal wire, and its specifications and dimensions should be such that all ash dishes are located in the constant temperature zone of the muffle furnace.

And the bottom of the ash pan is immediately above the hot junction of the thermocouple (see Figure 5, the unit is mm).

6.2.6 Ash dish holder clamp (see Figure 6).

6.3 Test procedure

6.3.1 Weigh 0.5g ± 0.05g of the general analysis sample of biomass briquettes in an ash dish that has been burned to a constant mass, and weigh to 0.0001g.

Gently shake the ash dish to make the sample evenly spread on the bottom of the ash dish.

6.3.2 Put the ashtray on the ashtray rack, use the ashtray rack clamp to send the ashtray rack into the constant temperature zone of the muffle furnace, close the furnace door and leave the furnace door the gap is about 15mm. Raise the furnace temperature to 250 °C ± 10 °C in not less than 50 min, and keep it at this temperature for 60 min. Of course