waterhardness-140802091619-phpapp01.pptx

Slide 1

Water Hardness

Name : MAZADUL HASAN SHESHIRID: 2010000400008Batch: 13th Batch (Session 2009-2013)Department: Wet Processing Technology Email: [email protected]: www. Textilelab.blogspot.com Southeast UniversityDepartment of Textile EngineeringPREPARED BY right

Generally soaps create foam in water, but in present of some materials the foam creation is reduced and need more soap for producing foam, and this condition of water is called water hardness.

The presence ofCalcium,Magnesium salti.e. bicarbonates, sulphates, chloride in water is called causes of hardness of water. The water which contains these salts is called hard water. Hard water does not easily form lather with soap as the salt of Calcium and Magnesium react with soap to form insoluble organic salts.

CaSO4 + 2RCOONa (RCOO)2Ca + Na2SO4MgSO4 + 2RCOONa (RCOO)2Mg + Na2SO4WATER HARDNESSWATERThe major concern for any kind of wet process industry is Water because it is the quality of water which determines the quality of dyeing. Water quality generally vary in different areas, also depends on the level or height of water level beneath the ground. In Narayangonj water level is around 130-140 ft but Knit Concern dyeing water is lifted from about 600 ft deep by submergible pumps.

Quality of Water found in the raw water here total Hardness 250-300 ppmpH 8-9TDS 2000-3000 ppmSECTIONHARDNESS IRON CONTENT TDS pHKnit dyeing - (R-COO)2Mg + Na2SO4

Reaction with DyestuffThe reactive groups present in dyes, react with Na, Ca, Mg, Fe of hard water. This causes wastages of dye, produces duller shade and faulty dyeing. Sequestering agent is added to prevent it.

Deposition on Textile MaterialSoap reacts with hard water and produces insoluble salts which deposit on the fabric during scouring. These salts do hard and un-flexible the fabric.

Corrosion of BoilerIn boiler, CO2 reacts with the iron (in presence of dissolved O2), forming FeCO3 which hydrolyses to Fe(OH)2.FeCO3 + H2 ------> Fe + H2O + CO2 Fe(OH)2 +CO2------->FeCO3 + H2O

Heat Loss Due to scale in the pipe, fuel consumption increases, thus heat loss is occurred. Again scale formation reduces thermal conductivity. Local overheating under the scale causes softening and ultimate tube failure.