HU195120B - Method for utilizing waste extinguishing powder - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to a method of fire extinguishing powder utilization. The essence of the procedure is that the waste is a fire-fighting powder from the coarse contaminants cleaned and then 5-15 wt.% water adsorbent is added. Then, 30-70% by weight of the powder mixture in a quantity of material that is at least 40% by weight of inorganic oxide and alkali metal, earth metal, carbonate, hydrogen carbonate or hydrogen phosphate.

Description

The present invention relates to a process for the utilization of waste extinguishing powder. Our process solves the recovery of maintenance waste material. In addition to protecting our environment, this resource replaces imported material in one of the peripheral areas of the industry for fire extinguisher production.

It is known that the servicing of hand and vehicle dust extinguishers generates significant amounts of waste extinguishing powder. Namely, the dust extinguishers must be periodically renovated and repaired according to official regulations. There is a known risk of fire extinguishing powder being damaged when standing in the appliances; it is expected to reduce its ejection and fire extinguishing capacity, which may impair the effectiveness of the application.

The cause of a harmful change in fire extinguishing powder may be various; in particular, the moisture content is increased due to the slow chemical processes in the powder which also produce water vapor.

In general, widespread extinguishing powders contain the acid salts of alkali metals. For example, the decomposition of sodium bicarbonate in standing powder in the most used sodium bicarbonate active ingredient

2NaHCO ₃ = produces water vapor and carbon dioxide by reaction with Na ₂ CO ₃ + H ₂ O + CO ₂ . An increase in moisture content, either as a result of the decomposition reaction of the active ingredient or a local increase in moisture content, for example due to cooling, increases the likelihood of dust adhering and thus causes the aforementioned adverse quality changes.

The formation of larger particles, also referred to as powder aging, has been studied in detail. During this process, the mechanism of aging of NaHCO ₃ drug-based powders has also been shown to lead to a decrease in the specific surface area through the decomposition of hydrogen carbonate. If the powder is stored in an airtight container, such as a hand fire extinguisher, equilibrium pressures of CO ₂ and water vapor will develop over time in a closed atmosphere. This means that the reaction is now reversed at the same rate as the decomposition. BACKGROUND OF THE INVENTION Hydrogen carbonate formed in the reverse reaction is formed on the surface of larger crystals for thermodynamic reasons, while decomposition occurs for similar reasons predominantly on the surface of smaller crystals, thereby crystallizing over time. As a result, the average particle size is shifted towards larger particles, which results in a decrease in grafting efficiency due to surface reduction.

During periodic refurbishments of dust extinguishers, a considerable amount of waste dust is generated, which in any case is a problem of environmental contamination due to the composition of the extinguishing powder, since it is practically impossible to neutralize the active substances; any chemical process provides another 2 pollutant products, for example, the neutralization of sodium bicarbonate with a waste acid yields the appropriate amount of sodium salt. On the other hand, the vaccine powder removed from the device is of considerable value.

Our investigations revealed that the damage of fire extinguishers stored in the appliances depends largely on their moisture content. It also causes a decrease in their ejection capacity and a decrease in their flame extinguishing ability.

A detailed explanation of the above can be found in HM Schreiber - P. Prost: Löschmit ₁₅ tel, Berlin (Staatsverlag dér DDR, 1972) and in Fábián S .: Fire extinguishers (Táncsics, 1978).

It is known that the effectiveness of fire extinguishing powders is based on the anti-catalytic, flame retardant effect of their surface. On the surface, the chain members of the combustion chains are removed from the gas space by adsorption or simple collision, thereby interfering with the combustion mechanism. Therefore, it is advisable to select a large surface area for the fire extinguishing powder using the appropriate particle size. This aspiration is limited by the additional dust requirements; whereby good kilövellhetőség and granules ₃₀ while avoiding sticking of the powder should not be too small average particle size.

In order to simultaneously satisfy the two contradictory requirements mixed with rolling for ³⁵ helper antiblocking lubricants for dusts. Publications and published patents designate colloidal silica gel (aerosil), zeolite (aluminum silicate) as a lubricant. ⁴⁰ Hungarian health and safety regulations do not allow the use of SiO _2- containing powder as a cause of silicosis.

It is an object of the present invention to provide a process for utilizing waste extinguishing powder which makes it possible to utilize a secondary extinguishing powder which has become worthless as a result of replacement.

The object of the present invention is achieved by a process which is characterized in that it is purified from coarse impurities and then premixed with 5-15%, preferably 10% by weight of water-binding adsorbent having a particle diameter of 20-30 µm, preferably with active alumina. while producing a relative humidity below 60% above the powder blend. To this mixture is added an amount of 30-70% by weight, preferably 50% by weight, of a mixture of at least 40% by weight, preferably 65% by weight, of an inorganic oxide having a particle size of 30-60 µm, preferably a water particle of less than 20 µm. at least one of hydrogen carbonates, carbonates, hydrogen phosphates, or phosphates

Includes -2195120. The resulting mixture is homogenized by further mixing.

Preferably, in terms of flame retardancy, a waste extinguishing powder containing inert carrier material in excess of 20% by weight is used.

Preferably, the waste extinguishing powder is admixed with the necessary additives in the form of a known active extinguishing powder containing an adsorbent.

Thus, the recognition of the use of an approved fire extinguishing powder type and its additive as a suitable additive for the purpose provides confidence-building benefits.

The importance of moisture content is already 171,098 lj. it became very clear from the Hungarian patent specification; as a practical consequence, the presently manufactured fire extinguishing powder contains activated alumina and alumina hydrate (also known as gamma-earth) as an inert carrier material. The role of the carrier, according to this patent, is to provide a good ejection of the active ingredient at a low average particle size, which in turn is advantageous in terms of flame retardancy. The adsorbent used as a carrier controls the free moisture content of the extinguishing powder mixture, which is relevant for said damage, according to its adjustable own moisture content. For the purposes of this specification, the relative humidity at 24 hours above the dust should be below 60%.

Reuse or regeneration of the powder discharged from the device during powder exchange may be accomplished by mixing the powder with a pre-selected ceramic adsorbent or fresh fire extinguishing powder containing greater than 15% by weight of the adsorbent after appropriate pre-treatment and homogenizing the mixture. In this respect, it does not matter whether the waste material contains more than 90% NaHCO ₃ or other active ingredient, or it already contains an adsorbent or other carrier material (for example, fire-extinguishing powder manufactured according to U.S. Patent No. 171,098). An essential feature of the process is to adjust the moisture content of the mixture to a favorable value and to the requirements of the inoculated powder produced by said patent with the aid of a pure adsorbent or adsorbent used in fresh extinguishing powder.

For example, waste material can be processed in the following way.

Example 1

The incoming waste material is cleaned from the mechanical coarse contaminants by sieving to clean the incoming waste. The cleaned waste is transported to closed mechanical or pneumatic systems. From the containers, the tested and certified material, determined by its water-soluble and non-water-soluble contents, is transported to homogenizing mills. The same mills are fed with the required amount of active alumina (gamma-earth) adsorbent material, as well as other excipients, which are intended to promote fluidity and slackness of the mixture. The homogenizing mills do not contain a grinding body and mix the waste material and said components without crushing. The duration of homogenization is a shift, which includes dispatch and emptying. According to our experiments homogenization time of 6000 kg material min. 2 hours, twice safe, several times not technologically disadvantageous. The homogenate alone satisfies and meets the technical requirements for extinguishing powder, including flame retardancy.

The detailed description and formula of this operation are as follows:

Recipe for Example 1 (the text describes the general session):

The incoming waste material contains 57.5% of water-insoluble matter (carrier material) (after sieving and cleaning), and 42.5% of sodium bicarbonate and 1% of sodium carbonate. Above the rel. humidity 72%. To 4000 kg of such material is added 250 kg of activated alumina and homogenized for 2 hours. The rel is then measured above the homogenate. moisture. If it is less than 50% then 2000 kg of AP 100 extinguishing powder is added; After 2 hours of homogenization, regeneration is complete. If the material homogenized with alumina is rel. above 50% humidity, add another 100 kg of activated alumina, homogenize for another 2 hours, and then proceed with the addition of 2000 kg of AP 100 extinguishing powder as above.

Activated alumina has water-binding properties:

10% rel. sap. 5 m% H ₂ O in air (based on its own weight)

60% rel. sap. binds 15m% H ₂ O from air (based on its own weight)

90% rel. sap. 30 m% H ₂ O from air (based on its own weight)

Example 2

the. A quantity of 1 kg of waste powder passing through a sieve with a 0.5 mm mesh size was placed in a 5 liter oxicator in the presence of a hygrometer. The relative humidity above the powder was 46%, and after 1 hour the relative humidity. humidity increases to 75%, which indicates that desiccant is required. After mixing 100 g of adsorbent (gamma soil K 31), rel. humidity, which decreases to 48% after 1 hour.

b. The water-insoluble amount of the waste extinguishing powder is determined by a known dissolution method, which is 56% by weight.

-3195120

c. In a 10,000 liter mixing mill, 2,500 kg of feed material, then 250 kg of gamma-earth, are weighed and 3250 kg of an antipyro-100 type fire extinguisher are added. After two hours of homogenization, we qualify the product and find it meets the specifications - a commercially available extinguishing powder.

Example 3

the. Waste to be recovered using the extinguishing powder tested by the method described in Example 2. moisture content 65%. The water-insoluble component is 10% by weight. In practice, this is largely a mixture of Pyrematt and to a lesser extent Antipyro fire extinguishing powder. The water solubility of 50% by weight when NaHCO _third

b. The AP-100 type powder to be produced should contain max. 55% active ingredient, relative humidity below 60%.

c. The freshly prepared fire extinguishing powder, when measured, contains 40% by weight of the active ingredient, with a relative humidity of 42%.

d. Using the mathematical method of intermediate level, calculate the required composition. Prior to finalization, weigh in a 2 kg laboratory homogenizer and adjust as necessary for final dispatch;

c. 1500 kg of consumables

4500 kg of freshly manufactured antipyros powder

After 6000 kg of homogenization for 2 hours, it contains 52% by weight of baking soda and 47% relative humidity. Other technical characteristics are measured by known methods.

EXAMPLE 4 A wt% AP-100 fire extinguishing powder (according to Examples 1-3) (ex. Patent No. 171,098) is subjected to factory fire testing after production testing.

Based on many years of experience, the extinguishing powder produced from the materials used in the above examples is completely equivalent to the currently produced extinguishing powder in terms of fire extinguishing ability, sputtering and storage.

Because this product is a "trust article" that can be used in practice, its research and development results were preceded by years of work, while ensuring that no publication was made.

Claims (3)

PATIENT INDIVIDUAL POINTS A method for treating a waste dust of waste, comprising purifying it from coarse dirt, and then mixing 5 to 15 m, preferably 10 m%, of 20-30 µm diameter water absorbent adsorbent, preferably active aluminum oxide, until the powder mixture is mixed. no more than 60% relative humidity above 60%, then a mixture of 30% to 70%, preferably 50%, is added to this mixture at least 40% by weight, preferably 65% by weight, of 30 to 60 [mu] m particles, preferably water-absorbing inorganic oxide, and alkali metal, earth metal, hydrogen carbonates, carbonates, hydrogen phosphates, or phosphates having a particle size less than 20 [mu] m, and the mixture thus obtained homogenizing with further stirring. Method according to claim 1, characterized in that a fire extinguishing powder having an incremental carrier above 20 m% is used as a flame retardant. Method according to claim 1 or 2, characterized in that the active fire-extinguishing powder, which is known per se and which also contains the required adsorbent, is mixed with the waste extinguishing powder. Without drawing Published by: National Office of Invention, Budapest Responsible for release: Zoltán Himer Head of Department Ns 2598. Printing company, Uggorod