Water Powered Smoke Ejector

Fires in underground structures are a nightmare for firefighters. In places such as subway systems, underground shopping malls, and civil defense shelters, a fire creates a critical dilemma: smoke cannot be vented out, and rescue personnel cannot enter. Addressing the unique characteristics of underground spaces, Taizhou Mingxin Firefighting Technology Co., Ltd. has developed this high-capacity, water-driven smoke extraction fan-specifically designed to solve the challenging problem of "trapped smoke" in subterranean environments.

We have dubbed this YYS1.2/7.9-70 water-driven smoke extraction fan the "Earth Dragon." It boasts an astonishing smoke extraction capacity of 70,386 m³/h, earning it the title of the "King of Smoke Extraction" among all our models. What does this mean in practical terms? It is equivalent to completely exchanging the air within a standard basketball court in just one minute. No matter how vast the underground space, with this device on the scene, smoke simply cannot accumulate.

In 2023, a subway station in a certain city conducted a live-action drill. The scenario simulated a fire on the platform level, with dense smoke billowing up the stairwells until visibility on the entire station hall level dropped to zero. The rescue team carried the "Earth Dragon" down to the station hall level, connected an 80mm fire hose, and opened the valve; the unit operated at a working pressure of 1.2 MPa with a water flow rate of 23 L/s. Once activated, the machine unleashed a powerful gale-laden with a fine water mist-that blasted directly into the stairwell. Ten minutes later, visibility on the station hall level had recovered to over 10 meters, allowing rescue personnel to safely descend to the platform level and extinguish the simulated fire.

Mingxin's engineers invested considerable effort into refining the mobility of this machine. Underground passages are often narrow and stairwells steep, making it impossible to maneuver the unit using standard wheels alone. Consequently, we equipped this machine with a hybrid wheel system featuring a combination of universal casters and star-shaped stair-climbing wheels. On flat ground, the universal casters allow for effortless, omnidirectional movement; for ascending or descending stairs, the star-shaped wheels engage, enabling the unit to "climb" step-by-step without requiring personnel to physically carry it.

The fan impeller measures 790 ± 20 mm in diameter-making it the largest component among all Mingxin products. Why make it so large? Because airflow volume is directly proportional to the square of the impeller's diameter; the larger the diameter, the greater the airflow. To achieve a smoke extraction capacity exceeding 70,000 m³/h, the use of a large-diameter impeller was absolutely essential. Despite its substantial size, the unit's weight has been well-managed, with the entire assembly weighing in at 55 kg. Equipped with two sets of wheels, it can be easily maneuvered by just two people.

The operating pressure range spans from 0.6 to 1.6 MPa. This wide range implies that the unit places minimal demands on the water source; it can be supplied by a fire truck, a municipal fire hydrant, or even a high-pressure water pump. As long as there is water flow, the unit operates-and where there is operation, there is airflow.