DE3634125A1 - FIRE EXTINGUISHING SOLUTION FOR THE EXTINGUISHING OF PHOSPHORUS AND METAL FIRE - Google Patents

Description

The invention relates to a fire extinguishing solution for extinguishing of phosphorus and metal fires and a process for their manufacture.

It is already known (EP 00 59 178) for deleting Fire and at the same time flaming the source of the fire to use an aqueous solution with alkali metal citrate. However, this solution is not suitable for deletion of phosphorus and metal fires.

In contrast, the invention is based on the object a fire extinguishing solution for the purpose mentioned at the beginning as a finely sprayable foam-free mixture with a very high Create network effect.

This object is achieved in that as a wetting agent Calcium chloride, magnesium chloride and as further extinguishing components Sodium metal silicate and potassium sulfate are used will. So-called are advantageously added Imitators that interrupt the fire development inhibit the molecular chains and  a buffer solution to adjust the pH. All Substances occurring in the fire extinguishing solution have multiple functions, which are necessary to the difficult Fires such as phosphor and metal fires successful to combat as well as the finest and explosive dusts, such as they z. B. occur in mining to effectively neutralize.

The invention makes a modification of the "Reinhartin brine" Use and achieved with a protective colloid frost resistance down to -40 ° C. The density of the total solution at 0 ° C is 1.83.

The sprayed acts when fighting wildfires Fire extinguishing solution as fertilizer, which the Recultivation made easier.

The fire extinguishing solution according to the invention is special for fighting red phosphorus and against metal fires suitable (fire classes A and D).  

As a result, the application of the invention Using the following in fire fighting:

• - Increase frost resistance to -30 ° C
• - High wetting ability without the addition of foam-forming Surfactants
• - High depth effect with simultaneous crystalline crust formation
• - anti-corrosive
• - nitrogen oxide formation at high temperatures (fire source)
• - Fire retardant dust control
• - Through different crystal formation - in addition to the Depth effect - a homogeneous, crystalline surface covering Crust built up
• - Chain interruption of the flammable gases with simultaneous Conversion to non-combustible substances
• - The agent works due to the high proportion of minerals in the fire fighting of forest and steppe fires long-acting fertilizer.

Description of the chemical used in the fire retardant Products:

Antifreeze components

1. Magnesium chloride MgCl₂ is readily soluble in water. When evaporating deliquescent, monoclinic crystals form. The Density of MgCl₂ is 2.316-2.33. With strong heating (Deletion process) decomposes to form Oxychloride. This oxychloride has a corrosive effect Al and chrome parts. This corroding is caused by one of the Protection group added prevented.

Mode of action

In addition to the well-known fire-extinguishing effect and the strong  Dust binding affects MgCl₂ on frost resistance positive. As its main purpose MgCl₂ in this case is used. To achieve a frost resistance of -30 ° C 25 g of MgCl₂ dissolved in 100 g of water.

2. Calcium chloride CaCl₂ is easily soluble in water. At the Heating above 200 ° C forms a porous, colorless mass. The density of CaCl₂ is 1.68.

Mode of action

As a protective group, CaCl₂ acts against corrosion MgCl₂. This eliminates the risk of corrosion.

With CaCl₂, as already described for MgCl₂, the fire extinguishing effect known. Also suitable CaCl₂ is very good for binding coal dust in mining, and thus dust explosions are treated preventively. Mainly for the fire extinguishing agent here CaCl₂ is used to the frost resistance to increase and stabilize.

To achieve a frost resistance of -50 ° C 43 g CaCl₂ dissolved in 100 g water.

Extinguishing components

1. Potassium sulfate K₂SO₄ is relatively light in water soluble. Colorless crystalline forms on evaporation Crusts.

The density of K₂SO₄ is 2.67.

Mode of action

Evaporation of the saturated K₂SO₄ solution forms  a relatively homogeneous crystalline crust that is a feed of atmospheric oxygen, or that caused by thermal effects released and until then bound oxygen of the Fire source prevented.

A sensible solution up to the saturation limit is included 100 g of water and 16.5 g of K₂SO₄, it must be a constant Temperature of 50 ° C can be maintained.

2. Sodium silicate also sodium metasilicate Na₂SIO₃ in water completely soluble with an alkaline reaction. With this one given solution is pH = 13.5. A white crystalline salt forms on evaporation.

Mode of action:

The Na₂SiO₃ is the main component of what is described here Extinguishing agent in that the solution has a strong wetting effect and thereby all dissolved salts including your own transported to the source of the fire and thus in the case of evaporation, it works deep into the source of the fire Barrier layer builds up of crystallized salts.

Intiators

Diammonium hydrogenphosphate (NH₄) ₂HPO₄ readily soluble in water. Coarse crystalline precipitate forms on evaporation.

Mode of action

The ammonium phosphates decompose when heated Formation of ammonia and polyphosphoric acid. Ammonia and polyphosphoric acid cause an interruption in the molecular chains that are required for development or Further development of a fire are significant. Thereby  this phosphate is an effective flame retardant and is suitable, especially in the given Combination, to fight forest and steppe fires. This solution also has a long-acting fertilizing effect on the treated plant area.

Buffer solution

The effect of the buffer substances is based on trapping of hydrogen or hydroxide ions to form weaker Acids or bases due to their dissociation equivalent.

The task of the buffer solution is to create the overall solution set a pH of 8. For this, a commercially available Buffer solution used that works according to NaOH. In order to adjust the pH value of 8, 46.7 ml are added Given 1000 ml of total solution.  

Recipe

By 1 l = 1000 ml = approx. 1 kg (20 ° C) fire extinguishing agent to produce, you need:

The determination of the correct solutions I-III is done using a hydrometer (DIN 12 791 sheet 1 and sheet 2 1969).

Solutions IV-V are determined by pH measurement, can also be determined with a hydrometer.

All components listed here must be in separate Mixing tanks are prepared.  

method

Due to the different mixing times and Temperatures require that for each approach a separate mixing tank is used. The solved individual components are in a central Collection container brought together and with constant stirring and by adding the buffer solution to the necessary pH adjusted from 7-8. This process takes approx. 15-20 minutes.

When producing larger quantities, it is advisable build up several lines to create a quasi-continuous one To ensure the production process.

All rooms must have good ventilation systems. The operating personnel must wear rubber gloves and safety glasses and rubber aprons.

The moving machine parts such as valves, stirrers and Pumps must be cleaned regularly with hot water become too high because of the incrustations Material wear occurs.

Apart from hot water, no solvents may be used will.

Claims (4)

1. Fire extinguishing solution to extinguish phosphorus and metal fires, whereby are dissolved in water:

• a) as antifreeze components
  Magnesium chloride (MgCl₂) and / or calcium chloride (CaCl₂)
• b) as extinguishing components
  Sodium silicate (Na₂SiO₃) and / or potassium sulfate (K₂SO₄)

and wherein a NaOH-based buffer solution for adjustment a pH of 8 is added. 2. fire extinguishing solution according to claim 1, characterized, that diammonium hydrogen phosphate ((NH₄) ₂HPO₄) as Initiator is added. 3. Process for making a fire extinguishing solution according to claims 1 and 2, characterized, that the individual components are solved separately and then are brought together with constant stirring.