Complete Operational Process for Measuring the Calorific Value of Coal: From Weighing the Sample to Printing the Report

After the calibration is completed, the formal measurement of coal samples can begin. The operation process and calibration are similar, but there are several precautions specific to the characteristics of coal that require additional attention.

Step 1: Sample Preparation

Coal samples must be prepared to the specified particle size (usually ≤ 0.2mm) according to national standards such as GB/T 474, and dried to an air dried state under standard conditions. Uneven particle size or insufficient drying of samples can lead to incomplete combustion and lower calorific value determination.

Step 2: Accurately weigh the sample

Weigh 0.9-1.1g of coal sample with an analytical balance, accurate to 0.0001g, and record the accurate mass. This weighing accuracy directly affects the calculation results and cannot be replaced by a regular balance.

Step 3: Install oxygen bombs

After the coal powder is loaded into the crucible, connect the ignition wire and cotton thread to ignite. Coal with high calorific value (anthracite, high-quality bituminous coal) can usually burn fully on its own; Coal with low calorific value or difficult to burn (such as brown coal) can be wrapped in mirror paper to cover the sample - the mirror paper itself has low calorific value and less ash content, which is helpful for ignition. Record the weight of the lens cleaning paper, fill in the "additive weight" column when entering the parameters, and the instrument will automatically deduct the heat of the additive.

Step 4: Oxygenation

Oxygenation for 15-45 seconds, pressure 2.8-3.2MPa. Oxygen filling should not be too fast - Excessive oxygen filling can cause oxygen to scatter the sample in the crucible or splash dust, resulting in poor contact between the sample and the ignition wire and ignition failure. Stabilize oxygenation and observe the pressure gauge slowly rising to the target value.

Step 5: Insert the inner cylinder and start the test

Place the oxygen bomb into the inner cylinder and close the instrument cover. Click on "Calorimetry Measurement" → "Calorimetry Input", enter the sample weight and number. If there are additives, enter the weight of the additives (enter 0 if there are no additives). Enter the known sulfur content and moisture data (if there are no additives, enter 0 first, and then use the data processing function to make up for it). Click back, and the instrument will automatically complete the entire testing process.

Step 6: Read the results

After the test is completed, it will automatically print information such as the heat generation of the cartridge, the high heat generation of the dry basis, the high heat generation of the analysis basis, the low heat generation of the analysis basis, the heat generation of the received basis, as well as the test number, time, etc., without the need for manual calculation.