Working principle of the fogging machine

Working principle of the fogging machine 

The core principle of a fogger is that power generates a high-speed airflow, which splits into two streams to create "pressure-driven liquid delivery and high-speed atomization," thereby breaking the pesticide solution into micron-sized droplets that disperse into the air. The main types are pulse-type (hot foggers/smoke machines) and fan-type (backpack foggers). 

1. Principle of Pulse Fogger (Thermal Fogger)

Core: Pulse jet engine + high-temperature, high-speed airflow for particleization.

Power generation: Gasoline undergoes rapid combustion in the combustion chamber at a high frequency (approximately 60 times per second), generating high-temperature, high-speed, high-pressure gas exceeding 1000°C that is expelled backward.

Pressure-driven pesticide delivery: The engine simultaneously pressurizes the pesticide tank to create a positive pressure of 0.2–0.4 MPa, forcing the pesticide into the explosion tube.

Instantaneous atomization: High-pressure liquid pesticide enters the high-temperature, high-speed gas stream and is torn apart within 1/60 of a second into fine droplets measuring 5–50 μm, which cool upon contact with air and are ejected as smoke-like mist.

Dispersion and adhesion: The droplets are extremely light, remain suspended for long periods, and have strong penetration ability, effectively covering both the upper and lower surfaces of leaves and branches. 

Pulse Mist Blower  

II. Fan-Type Mist Blower (Backpack) Principle  

Core: Gasoline engine drives the fan → airflow splits into pressure zones → Venturi effect creates negative pressure for atomization.  

Power and Airflow: The gasoline engine drives a centrifugal fan to rotate at high speed (5,000 rpm), generating a high-speed, low-pressure airflow.  

Airflow Distribution:  

Main airflow (90%): Passes through the spray tube to the nozzle, creating a high-speed air stream.  

Secondary airflow (10%): Enters the sealed pesticide tank via a booster tube, pressurizing the liquid surface (0.05–0.1 MPa). Pesticide is then drawn through the liquid transfer tube to the nozzle.  

Venturi Atomization: At the throat of the nozzle, the airflow accelerates, creating negative pressure that draws the pesticide solution out. The liquid is then sheared and broken up by the high-speed airflow into droplets sized 10–100 μm.  

Wind-Assisted Dispersion: The mist droplets are carried by the airflow and ejected outward, dispersing and covering the crops. 

III. Key Components  

Pulse-type: fuel tank, pesticide tank, carburetor, combustion chamber, explosion tube, spray nozzle.  

Fan-type: gasoline engine, fan, pesticide tank, pressure boost tube, liquid delivery tube, misting nozzle.  

IV. Common Causes of Insufficient Power  

Fuel system: poor fuel quality, clogged carburetor, blocked fuel tank vent.  

Ignition system: carbon buildup on spark plugs / incorrect electrode gap, weak high-voltage coil output.  

Airflow system: clogged air filter, worn fan impeller, blocked spray nozzle.  

Pesticide delivery system: insufficient pressure in pesticide tank, clogged liquid delivery tube or nozzle.