The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (W_LC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile–butadiene rubber has the highest thermal stability in comparison to other belts.

Since there are no legally defined testing requirements for mobile positive pressure fans, they may be tested based on methods that do not correspond to their actual operating conditions. Adequate assessment of the technical and operating conditions for this type of equipment is particularly important for equipment used in rescue operations. Such units should be characterized by efficient and reliable operation. This article investigates the influence of measurement methods of the volumetric airflow rate on the performance of a power unit. The article shows that the applied measurement method, whether it is PN-EN ISO 5801 (test conditions in a pipe duct—Method A) or other methods, i.e., ANSI/AMCA 240-15 and testing of the characteristics of the velocity profile (tests in open flow—Method B), can cause differences in the power demand of fans of from 3.2% to 4.5%. The differences in the requirements of propulsion power translate into fuel consumption and emissions of harmful exhaust gases generated by the combustion drive units (4 kW). It was also observed that fans with conventional impellers (W1) show a lower power demand when applying Method B (open flow) tests, while fans with turbo impellers (W2) show a lower power demand when Method A (duct) tests are applied. Comparative analysis of the parameters of the drive unit in the test group of fans without taking into account the measurement method can cause errors of up to about 7.7%, 6.4%, and 2.4% for the power, torque, and speed, respectively.

This paper presents a review of mobile positive pressure ventilation fans for use in rescue operations available on the European market in correlation with the approval regulations of the drive units. The authors determined the approval limits for harmful compound emissions by their power units, as applicable within the European Union. The purpose of this paper is to estimate the emissions of harmful compounds from the exhausts of rescue fan power units. It was demonstrated that electric fans are not in direct competition with internal combustion fans because they are provided in different power ranges, and 74% of the electric fan market falls between 1.1 kW and 2.2 kW, whereas fans powered by combustion engines are offered in a much higher power range from 0.7 kW to 92 kW, and the most popular power range offered by manufacturers is from 3.4 kW to 6.3 kW (57% of the market). On the basis of the limits derived from approval tests it can be demonstrated that 90% of engines on the European market which are used in fans (spark ignition (SI) engine up to 19 kW) are allowed carbon monoxide (CO) emissions of 610 g/kWh and hydrocarbon and nitrogen oxide emissions (HC + NO_x) of 8 g/kWh.

The article aims to determine the influence of fan positioning parameters, i.e., its distance from a door opening (1–7 m) and the angle of inclination of the impeller axis in relation to the ground (0°–18°) on the amount of air flow pumped through a door opening. The experiment was carried out using a mock-up simulating a door opening, on which a measurement plane was located, without the cubic capacity (building structure) behind the door opening. The volumetric air flow stream was determined based on measuring (at 50 measuring points) the velocity of the air stream blown onto the surface of the door opening mock-up. Four commercial positive pressure ventilators, commonly used in rescue operations, with a power of 0.6–6.3 kW were tested. The tests showed that the value of the air flow stream at the most favourable setting (distance in the range of 3–5 m and the angle of the impeller axis to the ground in the range of 5°–12.2°) is included in the range of 18,304 ± 2460 m³/h to about 45,189 ± 4619 m³/h. Such settings cause the air stream to be aimed at the central area of the door opening. Imprecise mobile fan arrangement may reduce the flow rate from 41 to 76% in relation to the most favourable results.