(1) When using a portable dry powder fire extinguisher, the fire extinguisher can be carried to the fire site, if used outdoors, it should be selected in the upwind direction of the flame, in the combustible place that people can approach, pull out the fire extinguisher safety pin, hold the spray hose with one hand, grasp the pressure handle with the other hand, and open the fire extinguisher to spray the fire extinguishing agent. If the fire extinguisher does not have a spray hose, you can hold the bottom of the fire extinguisher with one hand and grasp the pressure handle with the other hand to open the fire extinguisher to spray the fire extinguishing agent, but do not make the fire extinguisher rotate sideways. The pressure handle can be continuously opened or closed when needed, and the extinguishing agent can be sprayed intermittently.
2) When using a cart-type dry powder fire extinguisher, the fire extinguisher can be pushed (or pulled) to the fire site, and the spray hose can be unfolded at the place where people can get close to the combustible, and then, hold the spray gun with one hand, pull out the safety pin with the other hand, open the head valve, and then hold the spray gun with both hands, unfold the spray hose, open the spray gun valve, and spray the fire extinguishing agent. The lance valve can be continuously opened or closed when required, and the extinguishing agent can be sprayed intermittently.
3) When using ABC dry powder fire extinguisher to extinguish the fire of solid combustibles, the fire extinguishing agent is aimed at the burning materials from near to far and sprayed left and right, if conditions permit, the user can carry the fire extinguisher along the perimeter of the burning materials to spray the fire extinguishing agent completely on the combustibles until the flames are all extinguished.
4) When using a dry powder fire extinguisher to extinguish a liquid fire that is flowing and burning, aim at the root of the flame from near to far and sweep left and right, and at the same time, the user and the fire extinguisher should quickly move forward until the flame is completely extinguished.
5) When using a dry powder fire extinguisher to extinguish the flammable liquid burning in the container, the user should aim at the root of the flame and shake it left and right to sweep so that the sprayed dry powder stream covers the entire open surface of the container. When the flame is driven to the edge of the container, the user should continue to spray until the flame is completely extinguished. It should be avoided to spray directly at the liquid level to prevent the impact of the jet from splashing out the combustible liquid and expanding the fire, resulting in difficulty in extinguishing the fire. If the combustible liquid burns in the metal container for too long, the wall temperature of the container is higher than the spontaneous ignition point of the flammable liquid to be extinguished, it is easy to cause the phenomenon of re-ignition after extinguishing the fire.
Precautions. (1) The powder mist of dry powder has an irritating effect on the human respiratory tract, and even has a strong suffocating effect.
2) Dry powder fire extinguishers are not suitable for use in places with precision instruments and equipment or museums, because the residual dry powder is not easy to remove and is corrosive.
3) The dry powder particles are very lipophilic, and when fighting oil fires, the powder particles will be wetted by the oil as soon as they fall to the oil surface and sink into the oil. Once the dry powder is sprayed, even a small residual fire can ignite the entire oil surface. Therefore, the re-ignition resistance of dry chemical fire extinguishers is poor, and after extinguishing oil fires, the presence of fires around should be avoided.
4) BC dry powder fire extinguisher cannot extinguish the fire of solid organic matter.