Comet Chemicals Ahmedabad, Gujarat

Boiler water contains suspended particles like precipitation of calcium, magnesium, silica, etc. These salts flock together and settle down at the bottom of boiler drum, low velocity areas, may adhere to boiler tubes to form a scale. To prevent the above problem, a medium molecular weight polymeric dispersant is added. This dispersant gives same ionic charges to the precipitated salts, due to which repulsion occurs among the particles. Hence all these suspended matter is kept in kinetic motion and can be removed freely through blow down.

In this program chelating agents viz., EDTA, NTA, etc., are added to feed water. These salts form water soluble complexes with calcium & magnesium and prevent them from precipitating. In case they form scales, these salts de-stabilizes the crystalline growth. This system of treatment is discouraged as the salts may carry over with steam and break into acidic components which may cause corrosion in post boiler sections. This method of treatment is implemented in boilers having operating pressure within 20Kgscm2 where soft & raw water are used as boiler feed water. The above treatment should be used in conjunction with polymeric sludge conditioners for better results. In this method of treatment precipitation of calcium & magnesium, either partially or completely, are induced by maintaining higher pH & higher alkalinity. The residual hardness, if present, should be controlled with the addition of polymeric sludge conditioners.

Boiler feed water contains dissolved gasses viz., Oxygen, Carbon dioxide and hydrozen sulphide. These gasses are removed through degasser. Oxygen in particular is removed through de-aerator. The presence of Oxygen causes pitting corrosion. The presence of CO2 causes grooving corrosion. The presence of CO2 generally occur in post boiler section where it is neutralized with the help of amines. Oxygen is removed with the addition of Hydrazine or Sulphites. Sulphites are used in boilers having operating pressure upto 600psi. Above 600psi sulphites will decompose and loose their properties. Above 600psi boilers hydrazine is used for removing oxygen. Apart from removing oxygen, hydrazine forms a magnatite film over the metal surfaces in boiler system. Also it contributes to the increase of pH. Demerits of hydrazine are: 1. It is carcinogenic. 2. It reacts very slow. To enhance the reaction rate it is supplemented with a catalyst.

This method of treatment is implemented in boilers having operating pressure within 20Kgscm2 where soft & raw water are used as boiler feed water. The above treatment should be used in conjunction with polymeric sludge conditioners for better results. In this method of treatment precipitation of calcium & magnesium, either partially or completely, are induced by maintaining higher pH & higher alkalinity. The residual hardness, if present, should be controlled with the addition of polymeric sludge conditioners.

In any cooling process water takes heat from process and cools the system. By the way it gets heated up and in turn it need to be cooled to reuse the same. It gives up the heat through a process called evaporation.There are three types of cooling systems which are in use in industry: Once through system Closed recirculating system Open recirculating system

In this program chelating agents viz., EDTA, NTA, etc., are added to feed water. These salts form water soluble complexes with calcium & magnesium and prevent them from precipitating. In case they form scales, these salts de-stabilizes the crystalline growth. This system of treatment is discouraged as the salts may carry over with steam and break into acidic components which may cause corrosion in post boiler sections.