AIT DRIVEX is specialized in the development, commercialization and control of the application of chemical treatment and cleaning processes for the treatment of fouling (fire side) of industrial boilers using heavy or residual fuels, coals , Wood, industrial waste or household waste as fuel.
AIT DRIVEX offers its services, products and materials for:
To Preventive Treatment of Pollution.
To the Curative Treatment and to the neutralization of the acidity.
Mechanical cleaning of smoke tube boilers.
In all of these areas, DRIVEX assists its customers in assessing their needs and determines the most suitable solutions to improve the efficiency and durability of their heat generators
THE INTEREST OF PREVENTIVE CHEMICAL TREATMENT
The combustion of heavy fuels, coal, wood, household refuse and special waste generates incombustible ash and / or carbon monoxides which contribute to the fouling of the heat exchanger exchange surfaces: hot water boilers or Steam, recovery and other fluid reheating furnaces.
Similarly, the lubricating oil that escapes from gas or oil engines in cogeneration plants is attached to exchangers intended to produce hot water or steam.
To remove these deposits, use the running cleaning systems, if any, or stop the boilers periodically to clean them. These operations are costly: wasted energy (steam, compressed air), shot, maintenance of chimney sweepers, replacement of eroded tubes but also in production losses following scheduled or unplanned cleaning stops.
Preventive Chemical Treatment is therefore the only way:
To compensate for the shortcomings, the failures or even the absence of the cleaning systems in operation,
To slow the fouling,
To facilitate periodic cleaning, Neutralize the acidity of the deposits.
the fouling of the heat exchange surfaces (côté feu)
The causes are many :
The composition of combustibles
The composition of liquid fuels marketed in France, among others, has evolved considerably over the past 25 years. The raw petroleum refining processes have undergone numerous improvements designed to extract the maximum amount of white products for which demand has increased considerably.
Sources of supply have been diversified: the crude used does not all have the same chemical characteristics: contents of asphaltenes, sulfur or vanadium and sodium can vary from one crude to another.
In order to market black products that have become too abundant, they have been mixed with other lighter products.
Despite the precautions taken, these products are more messy than before. They can sediment into tanks as a result of reheating, asphaltenes fouling filters and burner noses, vanadium deposits clogging gas passages in superheaters, etc.
The origin of the coals
Supply sources are no longer French but global. For comparable elementary compositions, the fire behavior of these coals can generate problems of fouling which must be controlled. This may take time; During this time, the exchange surfaces become dirty.
Obsolescence and aging of heating equipment
In 1995, a very serious survey published by one of the main bodies responsible for controlling pressure vessels indicated that 60% of the French boiler stock was more than 20 years old. Even if well maintained, the heating equipment: fuels preparation group, burners, charcoal grills, running sweeping systems are less efficient than when they were built. The fouling of the exchange surfaces becomes faster, the cleanings less effective.
The over-dimensioning of the means of energy production
Before driving operators to consider other forms of energy production, reducing energy requirements in recent decades has led them to reduce the load on boilers. However, the person skilled in the art knows that the efficiency of a generator is less good at 50% of the nominal than at 80%; So fouling became more important and faster.
La technologie de certains générateurs.
A quelques exceptions près, il est rare de trouver des chaudières à tubes de fumée fonctionnant au fuel lourd ou au charbon ou des chaudières de récupération équipées de ramoneurs à vapeur ou à air comprimé.
Seules les installations de cogénération de grande puissance équipées de chaudières produisant de la vapeur à haute pression peuvent utiliser des ramoneurs à vapeur à condition de disposer d'une quantité suffisante.
Les installations qui ne produisent que de l'eau chaude ne sont équipées d'aucun système de nettoyage en marche ; les récupérateurs de chaleur doivent être nettoyés à l'arrêt dans des conditions très difficiles
Les causes accidentelles
They are very frequently associated with transient mechanical failures: wear of burner pellets, coke in the nose of burners, blockage of air regulators, combustion control systems, chimney sweepers, etc.
Frequent and large amplitude variations in load are more often the main cause of rapid fouling.
Repeated wet cleaning can also contribute to the formation of very hard, often acidic, deposits that gradually obstruct the passage of gas.
Finally, in cogeneration installations equipped with gas or oil-fired engines, it is very often the excessive consumption of lubricant which causes the fouling of the exchangers.