Photo Cells, also known as flame sensors or flame detectors, are devices used in burners to detect the presence or absence of a flame during the combustion process. They play a critical role in ensuring the safety and efficiency of the burner system. Here are key points about photocells used in burners:

1. Function: Photocells are designed to detect the light emitted by the flame during combustion. When the burner is operating correctly, the flame emits light, and the photocell senses this light signal. If the flame goes out or becomes unstable, the photocell detects the absence or change in light and sends a signal to the burner control system.

2. Safety Feature: The presence of a functioning flame is essential for safe and efficient combustion. Photocells act as a safety feature by shutting down the burner if they detect a loss of flame. This helps prevent the release of unburned fuel into the environment.

3. Types of Photocells:

   • Ultraviolet (UV) Photocells: These photocells detect ultraviolet light emitted by the flame. UV photocells are commonly used in oil and gas burners.
   • Infrared (IR) Photocells: These photocells detect infrared radiation produced by the flame. IR photocells are often used in gas burners.

4. Installation: Photocells are typically installed close to the flame, allowing them to receive the maximum amount of light emitted by the combustion process.

5. Cleaning and Maintenance: Regular cleaning and maintenance of photocells are important to ensure their proper functioning. Accumulation of dirt or soot on the photocell surface can interfere with its ability to detect the flame.

6. Integration with Burner Controls: Photocells are connected to the burner control system. If the photocell detects an issue with the flame, it sends a signal to the control system, which, in turn, takes appropriate action, such as shutting down the burner.

7. Reliability: Photocells are designed to be reliable and durable, but they can be affected by environmental factors such as dirt, moisture, or changes in ambient light. Regular inspection and testing are essential to ensure their reliability.

8. Manufacturers: Various manufacturers produce photocells for burners, including Ecee, Siemens, and Riello, among others. The choice of photocell may depend on the specific requirements of the burner system.

In summary, photocells are critical components in burner systems, providing a safety mechanism to monitor the presence of a flame and ensure the proper functioning of the combustion process. Regular inspection, cleaning, and maintenance are key to their reliability and effectiveness.