Final answer:
Dry powder extinguishers are designed for Class D fires, which involve combustible metals, and are available in both handheld and wheeled units. They work by smothering the fire and interrupting the chemical reaction.
Step-by-step explanation:
The type of portable extinguisher that comes in both handheld and wheeled units and is used for Class D fires is a dry powder extinguisher. These extinguishers are specifically designed to tackle combustible metal fires, which are categorized as Class D.
Unlike a fluorinated foam that is used to fight fires of organic liquids, dry powder extinguishers use a dry chemical agent that separates the fuel from the oxygen or removes the heat element of the fire triangle.
The agent works by smothering the fire and interrupting the chemical reaction. It's important to use the correct extinguisher for the specific class of fire to ensure efficient and safe firefighting.
The type of portable extinguisher that come in both handheld and wheeled units and are used on Class D fires are Class D extinguishers. Class D fires involve combustible metals, such as magnesium, titanium, or lithium. The extinguishers for these types of fires are specifically designed to handle such metals and prevent re-ignition.