THE RESULTS OF EXPERIMENTAL STUDIES ON THE EFFECTIVENESS OF THE FIRE PUMP AND HOSE SYSTEM WITH A SUCTION LINE FOR WINTER CONDITIONS

This article is a continuation of a publication published in the journal "Technosphere Safety" (No. 3 (44), 2024). We discussed how the performance and reliability of fire pumping and hose systems are significantly reduced during autumn and winter. This increases firefighting time and fire losses. Domestic specialized units and their systems are not adequately adapted to low-temperature operating conditions. Therefore, any new developments that improve the adaptability of units, fire pumping and hose systems, and fire-fighting equipment to low temperatures are important.
To improve the operational reliability of fire pumps and their suction systems, several interesting prototypes were considered during the patent search. Among these, the most promising technical solution — Patent No. 2183975, "Method for Heating Water Supplied through Fire Hose Lines" — was identified asthe most cost-effective, energy-independent, and compact device for minimizing the rate of ice formation in the suction hose line of a fire pump, including its suction nozzle.
The proposed hose insert in the suction line of a fire pump is used in the second stage of the heating process for water supplied from an open water source to a dedicated unit. This positive effect is achieved initially due to the relatively low efficiency of a centrifugal fire pump (i.e., selfheating of water by throttling in the dedicated unit), and then due to the insert's design features, which allow for a slight reduction in the vacuum in the suction hose line and, consequently, a slower rate of ice formation on its walls. 
The results of pre-commissioning tests of the hose insert in the suction line of the fire pump of the proposed design, conducted in January 2025 during the Interdepartmental experimental research exercise "Safe Arctic — 2025", demonstrate its effectiveness.