How is the foam solution discharged in a foam blower system?

In a foam blower system, the foam solution is discharged as a fine spray onto screens. This method is effective because it allows for maximum surface area exposure of the foam solution to the fire or hazard, promoting better foam expansion and effectiveness. By creating a fine spray, the foam can more easily form an insulating blanket over flammable liquids and effectively smother flames. The screens help in distributing the foam evenly, enhancing the coverage and allowing for proper application on the targeted surfaces.

The other methods do not align with the operational principles of foam systems. A concentrated jet through a nozzle would not adequately disperse the foam for effective application, while a dense fog without screens might not ensure the necessary coverage or stability of the foam. Discharging a solid stream directly onto surfaces would lack the necessary spread and could lead to improper application, making a fine spray the most suitable method in this context.