Sprinkler-1 Fire Protection Ltd.
2120 Dunakeszi, Pf. 37.
Phone/Fax: +36 1 236-0772
E-mail: info@sprinkler-1.hu

Production and Sale of Tools of Fire Protection Equipment

Design aid

DESIGN AID

After having received your written inquiry, you will be contacted by our colleague, with whom you can discuss the design task, also in the light of historical documentation materials and identify the character and content of the work. For confidential treatment, we hand over the relevant design aid chapter to our partner who is qualified to produce designs.

FOAM BASIC NOTIONS

Extinguishing foam:
Dispersal fluid consisting of foam solution bubbles

Heavy foam:
Foam with a foam expansion ratio of 2 to 20 (l/l) is included in this category.

Medium foam:
Foam with a foam expansion ratio of 20 to 160 (l/l)

Light foam:
Foam with a foam expansion ratio above 160 l/l is included in this category. Foam with a foam expansion ratio of as high as 1,200 (l/l) is used in fire-fighting installations and devices.

Foam mixers:
Foam solutions are produced by continuous, “stationary type” adding and mixing of foam concentrate to and with the fire-fighting water. To achieve this, a device operating on hydro-dynamic principles, e. g. Venturi mixer, injector type mixer, is used; in other cases, a mechanically-driven, i. e. water-motor driven foam pump or foam concentrate pump is used, or a hydro-static pressurised tank, a so-called bladder tank. The objective is to achieve a mixture of suitable proportions, which is absolutely safe for use.

Pipe type air foam nozzle:
Foam solution drops streaming, under pressure, at a high speed out of the nozzle are pulverised due to the effect of turbulence, and then, inside the pipe, become foam. This is nothing more than an injector driven by a foam solution, in which both phases, i. e. the foam solution and the air – are transformed into foam, constituting an integrated dispersal system. The pipe nozzle is mainly used in producing medium and heavy foam.

Semi-stationary foam extinguisher:
An integrated fire-extinguishing installation, in which the foam concentrate and the foam adding-mixing equipment required for extinguishing the fire are taken to the site by the fire-fighters deployed. Pipe-type air foam nozzles and their related piping are mounted on the facility to be protected from fire and extinguishing is carried out manually by the fire-fighters deployed.

Stationary foam extinguisher:
On the facility to be protected, all the conditions required for fire-extinguishing are provided; the extinguishing operation can be launched by depressing the control button or by opening a valve, or it starts automatically at the signal emitted by the fire alarm device.

Foam generator:
It operates on the same principle as the pipe-type air foam nozzle with the only difference that the proportion of added-mixed air (i. e. the foam expansion ratio) is higher than that by orders of magnitude. There are foam generators that pulverise the foam solution into the air flow of electrically- or water-motor-driven fans, which they also blow through a perforated plate, but there are also machines operating on hydrodynamic principles, such as the pipe-type air foam nozzle.

Foam monitor or foam gun:
This is a foam solution jet nozzle that scatters the foam solution, as a rule, with the option of adjusting its scatter pattern (focused or spread).

Foam intensity:
A value typical of the efficiency of extinguishing, i. e. the specific (per/sq. m) volumetric flow (l/min) of the foam solution transferred onto the protected surface under threat, of which foam is generated.

Foam concentrate:
A water-soluble substance that diminishes the surface tension of the water (makes the water softer, thus it makes the foam better, see also washing with detergent in rainwater). In addition to generating bubbles, the fire-extinguishing capability of the foam substances makes use of their aptness to generate a film layer – see below (AFFF, AFFF/AR). AT PRESENT, the long-term environmental impact of foam concentrates is being examined and there is an international ban on substances that might pose a threat to the environment.

Foam solution:
The solution of water and concentrate, which is used in different degrees of concentration (as a rule, in a concentration of 0.1 to 6%), generates, if air or gas is added to and mixed with it, a long-lasting foam; with certain types, 1 or 2 fire-preventive film layers are generated on the surface of the liquid to be extinguished (AFFF).

AFFF foam:
Foam that is able to generate layers of film; also suitable for extinguishing foam-destroying liquids, and its ability to generate layers of film synergically multiplies the extinguishing capability of foam, thereby resulting in a more efficient extinction of the fire.

Foam featuring a double layer of film:
The AFFF/AR foams that generate a double layer of film can also be effectively deployed against such foam-destroying liquids as alcohol or acetone. They are also called alcohol-resistant foams. The point of a double film-layer is that the foam solution - also generates a surface film with the liquid to be extinguished (which we can imagine as if we dripped some thin spindle oil on a surface of water in a washing bowl and the oil-drop covers the whole surface with an oil-film), the substance of which is constituted by the mixture of the flammable liquid and of the foam solution, and - the foam solution generates another film too, with the foam solution of the extinguishing foam, the foam substance of which is constituted by the mixture of the foam solution and of the foam-generating substance (this we can imagine, continuing the above image, as if we let a water-film disperse on the surface of the spindle oil-film and the extinguishing foam itself were positioned above it).

 

Sitemap
Back to main page

 

 

Deutsch English Back to main page Magyar