What are factors you have to control when using gas fired kiln?
The process of firing ceramic workpieces is one of the key ceramic manufacturing process. Originally, we used wood and oil as fuel because it is plenty and cheap but when the price of such fuel moved higher, today's ceramic kilns are increasingly turning to gas and natural gas fuels.
Let's take a look if you want to use this type of fuel. What potters need to know on how to control this type of kiln in order to be able to use it safely and suitably?
Kiln Temperature Control >>> Generally, it measures by using Thermo-Couple and compared it with the set point value in the period of firing each time according to the firing table whether it is stable or not. It should not be measured from the temperature or gas pressure used only. The constant firing temperature control depends on the following:
1) Positioning of the workpiece on the fixed firing car
2) Constant heating system according to the original graph
3) Thermo-Couple used to measure temperature in the kiln is working properly. They must be calibrated annually.
4) The Thermo-Couple should not be positioned near the nozzle or embedded in the insulation. It must protrude 3 inches from the wall or roof of the kiln.
Understanding Kiln Atmostphere Control >>> Each kiln should be equipped with a valve to measure the fuel consumption of the kiln to calculate the optimal ratio of fuel to air. If there is too much air, the heat will be less but if the excess air is too little, the coating will not be shiny. The data of the fuel-air ratio will be used to adjust the ratio at the nozzle making the appropriateness between thermal energy supplied to the excess residual air or oxygen levels inside the kiln
Understanding Kiln Pressure Control >>> A 'liquid manometer' is a device for measuring the pressure in a kiln which is convenient to use and cheap. It should be used in the pressure measurement range between 2-3 mm. of water (Wg) and the pressure measurement position of the kiln should be at the lowest pressure point, such as the center of the kiln door just below the top of the car kiln a little or around the joint of the roller bar in a roller kiln that has been fired for 24 hours, or use the same channel as the oxygen meter, etc.