Preparation and start-up for running of vertical lime kiln system

1) Preparation and start-up for running

① Overall inspection

- Equipment: Confirm that the kiln body, burner, pipeline, valve, instrument, electrical, and transmission equipment are intact and lubricated properly. Check the condition of refractory materials.

- Safety: Confirm that all safety interlocks (gas leak alarm, pressure interlock, emergency shut-off valve) are functioning properly and effectively, and that fire-fighting facilities are complete.

- Material: Confirm that the particle size of limestone is qualified (usually 80-150mm or according to actual design requirements), and the storage capacity of the silo is sufficient.

- Energy: Confirm that the natural gas supply pressure is stable within the set range (such as 10-15 kPa), and that the power supply, compressed air, and circulating water are normal.

- Instruments: All temperature, pressure, and flow instruments have been verified to be valid and indicate accurately.

② System purge (key!)

- Close all natural gas manual valves of the burners.

- Open the combustion air valve, start the combustion air fan, and thoroughly blow the kiln, burner channel, and gas main (usually>5 minutes, or determined based on the kiln volume) to eliminate any possible combustible gases (especially for new kilns, after maintenance, or long-term shutdowns). The blowing air volume should reach the design air volume.

③ Cold kiln ignition (cold start-up)

- Start the induced draft fan and establish a slight negative pressure (-10~-50 Pa) inside the kiln.

- Start the combustion fan and set a lower air volume.

- Ignite the long flame: Insert the ignited oil soaked cotton yarn into the ignition port of the lower row burner, and at the same time, extend the cutting gun to confirm that it is fully ignited, and then probe into the lower part of the burner through the ignition port to ensure that there is a long flame in front of the lower row burner (the material level in the kiln can be adjusted appropriately according to the actual situation). Once the two constant flames are confirmed to be on, the gas burner can be gradually ignited.

- Main gas ignition: Slowly open the manual valve and regulating valve in front of the main gas regulating valve (with a small opening). Observe whether the ignition fire can ignite the main gas. Ignite one by one or in small groups, and it is strictly prohibited to ignite a large number of burners at the same time.

- Heating kiln: strictly follow the heating curve of the kiln to raise the temperature. The initial heating rate should be slow (such as<20 ° C/h), with a focus on baking the moisture in the refractory lining of the kiln. Develop curves according to the requirements of refractory material manufacturers (usually taking several days). Closely monitor the temperature at each point to avoid local overheating or excessive temperature differences.

- Gradually increase the amount of natural gas and combustion air, and maintain a reasonable air-fuel ratio (initial oxygen enriched combustion).

④ Hold kiln ignition (After a short-term shutdown of the kiln)

- Check the temperature inside the kiln (>700°C).

- Follow the "System Purge" procedure.

- Start the induced draft fan and combustion air fan first, establish negative pressure and a small amount of combustion air.

- Directly using the high temperature inside the kiln to ignite the ignition fire and main gas (usually easier). It still needs to be ignited individually or in groups.

- Quickly adjust to normal load.