what is the working principle of CRB ? 

The principle of working behind CRB (Counter Rotating Brushes) in carpet cleaning services involves the use of two brushes that rotate in opposite directions to enhance the cleaning efficiency. Here's how it works:

1. **Dual Brush System**: The CRB system typically consists of two brushes positioned close to each other. One brush rotates clockwise, while the other rotates counterclockwise.

2. **Agitation and Loosening Dirt**: As the brushes rotate in opposite directions, they create a scrubbing action that agitates the carpet fibers. This agitation helps to loosen embedded dirt, dust, and debris from deep within the carpet pile.

3. **Improved Soil Removal**: The counter-rotating motion ensures that the brushes work against each other, which enhances the mechanical action needed to dislodge stubborn soil particles. This is particularly effective for removing ground-in dirt and pet hair.

4. **Enhanced Cleaning Solution Penetration**: The scrubbing action also helps to work the cleaning solution deeper into the carpet fibers, ensuring that it reaches the dirt and stains more effectively.

5. **Efficient Pickup**: After the brushes have loosened the dirt and the cleaning solution has done its job, a vacuum system typically follows to pick up the dislodged dirt and the cleaning solution, leaving the carpet cleaner.

6. **Uniform Cleaning**: The opposing rotation of the brushes ensures that the entire carpet surface is evenly cleaned, reducing the likelihood of streaks or missed spots.

Overall, the CRB system is designed to provide a thorough and deep clean by maximizing the mechanical action needed to remove dirt and stains from carpets, making it a popular choice in professional carpet cleaning services.