(334). Start a Bleaching Powder Making Plant
Bleach is a chemical compound derived from natural sources used to whiten fabrics. Bleach works by the process of oxidation, or the alteration of a compound by the introduction of oxygen molecules. A stain is essentially a chemical compound, and the addition of bleach breaks down the molecules into smaller elements so that it separates from the fabric. Detergent and the agitation of the washing machine speed up the cleaning process. The disinfecting properties of bleach work in the same mannererms are broken down and rendered harmless by the introduction of oxygen. In industry, different forms of bleach are used to whiten materials such as paper and wood, though most bleach is used to launder textiles.Bleaching powder or “chlorinated lime” is a pale white powder of pungent odor slightly different from that of chlorine. The powder is unstable and rapidly deteriorates in hot tropical climates. It is mainly used for bleaching cotton yarn, textiles and paper pulp. It is also used as a disinfectant, especially for sterilizing wounds, surgical dressings, etc. and in water purification and sanitation. Some times it is also used as a source of chlorine in the preparation of chloroform.
The two big textile mills located in the Amhara Region produce about 4000 tons of yarn and their combined annual fabrics production capacity is more than 30 million m2. Part of the yarn and fabrics production needs bleaching powder for whitening purposes. The urban water supply systems, the health care facilities and the various sanitation works of the Region all need bleaching powder. Since the main raw material for bleaching powder (which is lime) is found in the Region, it makes economic sense to promote a project which will produce bleaching powder for the Region and also for other parts of the country.
Historycommonly used until around World War I, when liquid chlorine and sodium hypochlorite solutionshe forerunners of modern household bleachere introduced. About this time, researchers found that injecting salt water with electrical current broke down the salt (sodium chloride) molecules and produced a compound called sodium hypochlorite. This discovery enabled the mass production of sodium hypochlorite, or chlorine, bleach.
Types of BleachMarket Potential: The requirement of the Region for this product and the potential of exporting the product to other parts of the country will justify the establishment of a small plant which will produce bleaching powder. If the plant is established in the western part of the Region, it will be possible to export the product to the neighboring country.
Uses of Bleaching Powder
Referred to by chemists as calcium chlorohypochlorite, a salt mixture comprised of hydrochloric acid and hypochlorous acid, bleaching powder has many uses. Bleach powders take time to dissolve in water and longer to work but have a longer shelf life in comparison to liquid bleaches and can be used on items like upholstery, carpet and some delicate fabrics. However, bleaching powder should never be combined with ammonia or used on colored fabrics as it will cause fading.
Process and Technology:
There are two main processes for producing bleaching powder-these are Krebbs Beckman Towers Process and Hasen Clever Process. In the Hasen Clever Process, there are cast iron cylinders operating in series with hydrated lime and chlorine being fed counter current to each other. The cylinders are provided with rotating blades and are arranged horizontally one above the other. The blades act both as mixers and conveyors of the inside mass. Hydrated lime is charged at one end of the top most cylinders while chlorine is introduced at the other end of the bottom must cylinder. With the rotation of the blades there is a through mixing of the chlorine and lime. The chlorinated lime is discharged from the bottom cylinder and the unreacted chlorine is recovered from the top cylinder and recycled along with fresh chlorine. Machinery needed for the plant include cast iron cylinders, feed hopper, chlorine cylinders, lime storage tanks, piping instrumentation accessories, laboratory equipment.
The Manufacturing Process
Preparing the components
The chemical reaction
Cooling and purifying
Special Considerations in Packaging
The major equipment required by the unit for manufacturing bleaching powder are as follows:
Chlorinator with separator, agitator : 2 Nos.
Reduction gear box : 2 Nos.
Slip ring motor : 2 Nos.
Chain & pulley block : 1 No.
Lime storage tank : 1 No.
Water pump : 2 Nos.
Vacuum pump with motor : 2 Nos.
List of Machinery Suppliers:
1. M/s (Alum.) Mars Design Pvt.Ltd.
P-142, Lake Road,
Kolkata – 700 029
2. M/s The Dharamsi Morarji Chemicals Co.Ltd.
Regent Chamber, (8th Floor)
208, Nariman Point, Mumbai – 400 021
List of Raw Materials Suppliers:
1. M/s Indo Chem. Pharma Inc.
2nd Floor, Kumpta Street,
Baliard Estte, Mumbai – 400 001
2. M/s Kotak Chemicals Pvt. Ltd.
240 Dr. D.N. Road, Mumbai – 400 001
3. M/s DCm Chemicals Works,
P.B. No. 1211, Najafgarh Road,
New Delhi – 110 015