Final Report Summary - FIRELI (Fire retardant line hoses for forestry fire-fighting applications)
The FIRELI product offering consists of two basic innovations: a novel fire-fighting hose, with increased fire retardant properties and a new coupling design for forestry applications able to provide enhanced versatility, efficiency and safety for fire-fighters.
The FIRELI hose will withstand temperatures as high as 400 ºC for more than 15 minutes (three times more time than any previous hose system), while still retaining the required properties with regard to low weight, service pressure, curvature radius, plus resistance to abrasion, chemicals, hydrocarbons and ozone.
The designed fire retardant system has been the result of a broad study on flame retardant rubber formulations with the aim to provide a durable fire resistance effect. In that sense we developed a new polymer formulation based on a polyvinyl chloride nitrile butadiene rubber (PVC/NBR) matrix using intumescent additives and fire-resistant components; as well as PVC plasticisers. The designed formulation / additives were selected to be non-toxic and have low smoke production potential. Also, these fire retardants do not volatilise easily so as to prevent detrimental effects to the mechanical, physical and other hose properties.
FIRELI hose is composed of four layers of rubber coextruded through a polyester textile wave. While the base rubber is the same in all four layers, only the outer layer is filled with fire resistant additives. This approach allows us to achieve the best compromise between fire resistance and cost.
The FIRELI hose is about to enter into industrial production and can be supplied with diameters of between 1" to 3" (25 to 75 mm) and weights of 270 and 770 grams, depending on the diameter.
The second innovation in the FIRELI product line is the new coupling. FIRELI coupling has been designed using latest technologies in computational fluid dynamics (CFD). The coupling is single piece, can be manufactured in different sizes and materials (including aluminium, stainless steel and brass) and offers significant advantages in terms of usability and reduced pressure loss at the joints. Also, the FIRELI coupling includes an optional thermal barrier coating designed to provide optimal protection to the inner rubber layer of the hose.
The problem of pressure loss will always exist as long as couplings are needed, but the particular design of the FIRELI coupling minimises these losses by offering 30 % less pressure drop per joint; as compared to the best existing design. On the other hand, the new coating protects the inner rubber layer of the hose against heat transmission through the coupling.
The smooth design of the external surface of the coupling prevents any jamming during fire forest operations, when the hose is dragged on the floor. Also, the optimised design of its mechanical fitting contributes to better usability since a simple 20 ºC turn is sufficient to securely lock the device. We also designed a new bracket aimed at combining the advantages of both internal and external hose fixing.
The FIRELI coupling offers the above improvements at a cost similar to other existing products. Also weight is 18 % lower. It can be used with both wire-wrap and ring clamps binding. The standard design is made with two lugs. However, three lugs versions can be manufactured also for specific demands. FIRELI design is hermaphrodite and, hence, the same design covers both ends of the hose. Also it is symmetrical; resulting in easier mould manufacturing and reduced production costs.
It is also noted that the standard product has been designed for a hose diameter of one inch. However, the same design is susceptible to be adapted to different diameters. FIRELI coupling can also be offered with or without coating. All these combinations will allow FIRELI manufactures to address the demand of both high end and low cost products.
The FIRELI hose will withstand temperatures as high as 400 ºC for more than 15 minutes (three times more time than any previous hose system), while still retaining the required properties with regard to low weight, service pressure, curvature radius, plus resistance to abrasion, chemicals, hydrocarbons and ozone.
The designed fire retardant system has been the result of a broad study on flame retardant rubber formulations with the aim to provide a durable fire resistance effect. In that sense we developed a new polymer formulation based on a polyvinyl chloride nitrile butadiene rubber (PVC/NBR) matrix using intumescent additives and fire-resistant components; as well as PVC plasticisers. The designed formulation / additives were selected to be non-toxic and have low smoke production potential. Also, these fire retardants do not volatilise easily so as to prevent detrimental effects to the mechanical, physical and other hose properties.
FIRELI hose is composed of four layers of rubber coextruded through a polyester textile wave. While the base rubber is the same in all four layers, only the outer layer is filled with fire resistant additives. This approach allows us to achieve the best compromise between fire resistance and cost.
The FIRELI hose is about to enter into industrial production and can be supplied with diameters of between 1" to 3" (25 to 75 mm) and weights of 270 and 770 grams, depending on the diameter.
The second innovation in the FIRELI product line is the new coupling. FIRELI coupling has been designed using latest technologies in computational fluid dynamics (CFD). The coupling is single piece, can be manufactured in different sizes and materials (including aluminium, stainless steel and brass) and offers significant advantages in terms of usability and reduced pressure loss at the joints. Also, the FIRELI coupling includes an optional thermal barrier coating designed to provide optimal protection to the inner rubber layer of the hose.
The problem of pressure loss will always exist as long as couplings are needed, but the particular design of the FIRELI coupling minimises these losses by offering 30 % less pressure drop per joint; as compared to the best existing design. On the other hand, the new coating protects the inner rubber layer of the hose against heat transmission through the coupling.
The smooth design of the external surface of the coupling prevents any jamming during fire forest operations, when the hose is dragged on the floor. Also, the optimised design of its mechanical fitting contributes to better usability since a simple 20 ºC turn is sufficient to securely lock the device. We also designed a new bracket aimed at combining the advantages of both internal and external hose fixing.
The FIRELI coupling offers the above improvements at a cost similar to other existing products. Also weight is 18 % lower. It can be used with both wire-wrap and ring clamps binding. The standard design is made with two lugs. However, three lugs versions can be manufactured also for specific demands. FIRELI design is hermaphrodite and, hence, the same design covers both ends of the hose. Also it is symmetrical; resulting in easier mould manufacturing and reduced production costs.
It is also noted that the standard product has been designed for a hose diameter of one inch. However, the same design is susceptible to be adapted to different diameters. FIRELI coupling can also be offered with or without coating. All these combinations will allow FIRELI manufactures to address the demand of both high end and low cost products.
