Alcohol Blowtorch Combustion Tester is an essential flame retardant testing instrument for coal enterprises, primarily used to determine the flame retardant properties of polymer products used in coal mines. Its main structure consists of the following parts:

1. Blowtorch: The blowtorch should comply with MT182 requirements, with fuel supplied from a container with a graduated tube. The fuel used is a mixture of 95% ethanol (GB 394) and 5% methanol (GB 338) (V/V).

2. Combustion Test Chamber: It should have precisely machined sealed fitting holes for the entry of the blowtorch remote control device and fuel conduit. The inner surface of the chamber should be painted black (see Figure 1). The chamber should be equipped with an adjustable device to ensure the specimen is properly positioned. An exhaust hood with a fan is installed at the top of the chamber, but it must not cause changes in flame combustion; otherwise, the fan should be turned off during the test.

3.Stopwatch: The minimum division value of the stopwatch is 0.01 s.

This article mainly introduces the technical requirements and installation methods of the blowtorch in the alcohol blowtorch combustion tester, aiming to familiarize users with the equipment.

I. Technical Requirements for the Blowtorch of the Alcohol Blowtorch Combustion Tester

1.Dimensions

The specific dimensions of the burner are shown in Figure 2. Under certain environmental conditions, especially when the combustibles produce corrosive gases during combustion, the burner tube above the air intake hole may corrode, forming a conical outer surface on the burner tube's external wall. If the inner diameter and total height of the burner tube remain unchanged, this conical outer surface is considered to have no adverse effect on the normal operation of the burner. The nozzle orifice diameter of the burner (see Figure 3) should be 0.7 ± 0.04 mm.

2.Materials

The components of the burner are made from the following materials:

Burner Tube: Brass, H62 or H68 YB 146.

Base: Cast Iron; HT 200 GB 5675.

Ignition Coil Wire Mesh: Copper wire mesh or stainless steel wire mesh, 30 mesh/in.

Wire Mesh Between Burner Tube and Base: Copper wire mesh or stainless steel wire mesh, 30 mesh/in.

Valve Core: Steel, 45 GB 699.

Nozzle: Brass, H62 or H68 YB 146.

II. Blowtorch Joint Sealing

The sealing requirements for the burner joints are as follows:

Sealing Between Burner and Base: A fully enclosed sealing ring made of asbestos board, with an inner diameter of φ14 mm, outer diameter of φ22 mm, and thickness of 3 mm (sealing at the bottom thread of the burner tube does not require additional sealing with PTFE tape, as the effective sealing at this connection depends on the effective positive pressure between the steel/asbestos gasket).

Sealing Between Control Valve Core and Burner Tube: PTFE tape.

Sealing of Threads Between Burner Base and Handle: PTFE tape.

Sealing Between Nozzle and Burner Tube: PTFE tape.

III. Test Fuel for the Alcohol Blowtorch Combustion Tester

The fuel is a mixture of 95% industrial ethanol and 5% methanol by volume.

The fuel must be filtered before use.

After use, any remaining fuel in the fuel bottle must be poured back into the storage container.

IV. Fuel Bottle for the Alcohol Blowtorch Combustion Tester

The fuel bottle should have a capacity of 100 mL, with a graduated side arm marked with a minimum scale of 0.1 mL. A 6.35 mm (1/4 inch) wall-mounted single-way tap switch is installed at the bottom of the fuel bottle, connected to the burner via a transparent polyethylene plastic hose approximately 1000 mm long (with an inner diameter of φ6 mm) (see Figure 3).

V. Assembly Requirements

1. Assembly

Connect the fuel bottle to the burner using a transparent polyethylene plastic hose. The burner can be positioned at a 45° tilt or vertically. To ensure smooth testing, the fuel level must be adjusted to 600 ± 20 mm above the center of the burner nozzle. All connections of the burner must be tightly fitted.

2. Post-Assembly Inspection

After assembly, the burner must be checked for normal operation. Under stable flame combustion conditions, the burner should meet the following criteria:

a. Flame temperature: 960 ± 60°C;

b. Flame height: 150–180 mm;

c. Fuel consumption: 2.55 ± 0.15 mL/min.

When checking fuel consumption, close the fuel bottle switch so that the fuel entering the burner comes only from the graduated side arm. Measure the fuel consumption of the burner over 1 minute.