Flame safety lamp fsl

used in underground coal mines

1. FLAME SAFETY LAMP By M.SATHWIK

2. It works on the principle of WIRE GAUZE J.K.DEY& sons introduced flame safety lamps with trade name VELOX. GL-50 is permitted by DGMS for gas testing in degree-1&2 mines gassy coal mines. Gl-60 is permitted for all degree gassy mines Principle of flame safety lamp

3. BONNET:- It protects the wire gauge from damage due to external hit. It also guards the flame againist high air velocity.

4. OUTER GAUGE:- The function of outer gauze is to prevent the passage of flame from outer gauze . While hot combustion gases passes heat is absorbed by gauzes which then dissipiate by way of radiation.

5. INNER GAUGE:- The function of gauzes is to prevent the passage of flame from interior to exterior of lamp. The gauzes are made of COPPER Wire of 28 mesh.

6. FUEL VESSEL:- Kerosene oil and ESSO- SOLVENT NO.1425,SOLVENT are used in lamps. More volatile fuels like Mineral colza, paraffin & naptha are used.

7. A Set of fiver pillars to protect the Glass from external hit. The bonnet rests on pillars over the oil vessel. Angle between two pillars is 72 degrees PILLARS:-

8. Two asbestos rings are fixed at top and bottom of glass are to prevent the gases to come outside. Magnetic lock:- Safety lamp should be kept securely locked. Magnetic lock is used to locking or unlocking the safety lamp . The magnetic lock prevents the lamp from opening underground for any purpose. Asbestos rings:-

9. It should be tough quality glass and of sufficient thickness so as to withstand the shock pressure should an explosion occurs inside the lamp. Glass cylinder should be 4-5mm thick. GLASS:-

10. WICK adjuster is to adjust lower or higher the flame. The wick passes through the wick holder. Wick may be either flat or round one ,flat wick is generally wider than round one. Wider the wick, longer is the cap. WICK &WICK ADJUSTER:-

11. Sharp detection of methane gas . Detect the shortage of oxygen gas. Detect the presence of carbondioxide gas. Magnetically locked equipment . Top feed device for testing methane gas close to roof. Safety lamp is used for detecting or estimating of firedamp by ACCUMULATION TEST& PERCENTAGE TEST. Weight of safety lamp is 1.7 kg. The whole lamp is made of such metals as to make it robust for underground use . All the metallic components also help in dissipiating heat of lamp. USES:-

12. Flame safety lamp gives a good warning againist oxygen deficiency in air. For each 1% oxygen deficiency from the normal concentration the light output decreases by (30%). Below 17%-17.5% Oxygen ,the lamp will be extinguished. In Accumulation test spiring (or) jumping of flame gives the positive response indicating an accumulation of gas not less than 3%. If accumulation test shows positive response then it is not wise to go for more precise PERCENTAGE test.

13. If safety lamp gives negative response the percentage test is carried out because it may contain gas not less than 3% in air. Percentage test is carried out to estimate concentration more (or) less accurately. Below 1.5% methane the gas can be hardly identified. The percentage test is carried out with a range of 1.5%to4% methane with an accuracy of 0.25%. Above 4.0% methane tip of flame is generally not visible as it becomes longer than glass height.

14. During percentage test the gas cap is first noticeable at a concentration of 1.5%. At 1.5% gas cap is not fully developed but it appears as a truncated cone with concave(or) rounded tip. The height of cap is 4mm. At 2.0% methane the cap is fully formed but with a rounded tip. The height is of 6mm. At 2.5% methane ,a first triangular cap with sharp apex is first formed at a height of 8mm. At 3.0% methane , a triangular cap with sharp apex is formed with a height of 12mm. At 3.5% methane , at triangular cap is formed with a height of 18mm. At 4.0% methane ,a triangular cap is formed with a height of 28mm but it is generally not visible because it is high than glass height. THE END. PERCENTAGE TEST :-