Will a dry powder fire extinguisher that has not been used for a long time cause the dry powder to agglomerate

Basic structure and fire extinguishing principle of dry powder fire extinguisher
Dry powder fire extinguisher is a common portable fire extinguishing equipment, widely used in factories, shopping malls, office buildings, parking lots, residential areas and other places. It is filled with dry powder fire extinguishing agent and driving gas, generally nitrogen or compressed air.
The main components of dry powder fire extinguishing agent include sodium bicarbonate (BC dry powder), ammonium phosphate (ABC dry powder), etc. These powders are sprayed to the fire source through gas pressure, covering the surface of combustibles, isolating oxygen, and inhibiting the combustion reaction chain, thereby quickly extinguishing the fire.

Physical changes of dry powder fire extinguishers when they are not used for a long time
If dry powder fire extinguishers are not used for a long time and lack regular maintenance, the fire extinguishing agent is prone to agglomeration. Agglomeration will lead to poor spraying and the fire extinguishing agent cannot be sprayed smoothly, so that the fire cannot be extinguished normally at critical moments.
Agglomeration is mainly manifested as the fire extinguishing agent changing from the original loose powder to agglomeration, compaction or compacted block objects. This change will seriously affect the spraying performance and fire extinguishing effect of the fire extinguisher, and may even cause the fire extinguisher to fail completely.

The main reasons for dry powder agglomeration
Humidity intrusion: Although the dry powder fire extinguisher has a closed structure, if it is not tightly sealed or stored in a high humidity environment for a long time, the moisture in the air may penetrate into the fire extinguishing agent through the leakage point, causing the dry powder to absorb moisture and agglomerate.
Standing time is too long: The dry powder fire extinguisher has been standing for many years without vibration, and the internal powder naturally settles and compacts, which is easy to form agglomeration. Especially when the ambient temperature changes greatly, the risk of compaction and agglomeration is higher.
Frequent temperature fluctuations: If the fire extinguisher is stored in a space with a large temperature difference between day and night and alternating hot and cold seasons, the internal water vapor condensation and evaporation cycle will aggravate the dry powder moisture absorption process and increase the probability of agglomeration.
Poor quality dry powder material: Some poor quality dry powder fire extinguishers use unqualified fire extinguishing agents, with uneven particle size and poor anti-caking performance, which are more prone to moisture absorption, compaction, and agglomeration.
Long-term lack of maintenance inspection: If the dry powder fire extinguisher lacks regular flipping, shaking, testing and other maintenance measures, the internal powder will not flow for a long time, which is very easy to form agglomeration.

Effect of dry powder agglomeration on fire extinguisher performance
Spray blockage: agglomerated dry powder particles become larger or stick together, making it difficult to pass through the nozzle, resulting in a weakened spray force or even failure to spray dry powder.
Decrease in fire extinguishing effect: the spray range of dry powder becomes smaller and the speed becomes slower, making it difficult to cover the burning area, and the fire extinguishing efficiency is significantly reduced.
Risk of equipment scrapping: once the internal dry powder is severely hardened, the fire extinguisher needs to be opened for cleaning or replacement, increasing maintenance costs or even directly scrapped.
Delay in fire extinguishing: in the event of a sudden fire, the fire extinguisher cannot be used normally, which will delay the initial rescue and cause greater losses.

How to determine whether the dry powder fire extinguisher is agglomerated
Weighing check: after the dry powder is agglomerated, the mass of the fire extinguisher may be abnormally heavy and exceed the rated range, which can be judged by weighing.
Shake and listen: shake the fire extinguisher gently. If there is no sound of loose powder shaking, there may be internal hardening.
Regular flipping: by regularly inverting and gently shaking the fire extinguisher, feel whether the dry powder flows smoothly and judge its looseness.
Use professional testing tools: Some units can use special testing equipment to evaluate the internal dry powder status to ensure the reliability of the equipment.

Effective measures to prevent dry powder agglomeration
Regular maintenance: Shake and turn the fire extinguisher at least once a quarter to prevent powder sedimentation and compaction.
Control the storage environment: Store the fire extinguisher in a dry, ventilated, and temperature-stable environment to avoid moisture and temperature fluctuations.
Seal inspection: Regularly check the sealing of the fire extinguisher bottle to ensure that there is no leakage in the safety valve and valve parts.
Use qualified products: Purchase regular brand fire extinguishers with national certification, and the dry powder formula has stronger anti-caking ability.
Regular annual inspection and replacement: According to national standards (such as GB 4351), a comprehensive inspection of the fire extinguisher is carried out every year. It is recommended to replace the dry powder or the entire bottle every 5 years.