The main issue is with the steam quality used for process heating. The steam quality is decrease as it reaches to the process equipment. By proper inspection and observation during the training period in swami textiles, we concluded some of the reasons behind it.
Some of the main reasons we have considered are,
1. Due to use of inefficient wood fired boiler the quality of steam is lowered at the generation so that it is getting wet near to the process equipment. Wood has lower calorific value and improper maintenance may cause of lower quality steam.
2. Decreased quality of steam may be because of lower quality insulation on the steam carrying pipes or thickness of insulation is more than the critical thickness of insulation for given condition. So improper insulation is the major factor affecting the quality of steam.
3. Improper pipeline diameters and unnecessary length of the steam carrying pipe cause the pressure drop in the pipe so the condensation of steam takes place. Sometimes it also lowers the velocity and this cause the loss of heat to the surrounding by heat transfer.
We considered these three major problems and find out the feasible solutions with the help of respected project guide Prof. U.V.Joshi and respected plant manager Mr. B.C.Suhagiya during our project hours.
We undertake the 3 of the problems consequently one after another with suitable calculated proper solutions.
Swami textile is using wood fired water tube boiler for steam generation. Steam is generated by firing of wood. Wood fired boiler has lots of its own disadvantages. Lower combustion efficiency, lower calorific value, higher moisture content, and higher ash problem, human health problem because of ash and carbon particles suspended in atmosphere.
4.2.1 Boiler Specification:
• Boiler pressure (pb) = 3-4 kg/cm2
• Boiler temperature (tb) = 150 0C
• Enthalpy of steam at boiler outlet (eb) = 2759.329 kj/kg of steam (from steam table)
• Feed Water Temperature = 80 0C
• Max. Pressure = 7 kg/cm2
• Size of the Boiler = m3
At first sight it is recommended to replace fuel of boiler like use of gas fired boiler using compressed natural gas. There are lots of advantages that affect the life of boiler and condition of boiler. Direct advantages are no or less ash deposition on the wall of boiler so less maintenance is required, less production loss, higher thermal efficiency and higher heat conduction rate to the water.
4.2.2. Cost analysis of existing boiler
? Wood fired boiler first cost = Rs.4, 50,000.
? Wood fired boiler life = 3 to 4 year depend on fuel and water condition
? Wood rate = 5 Rs./k.g.
? Per day use of wood = 200 to 300 k.g.
? Per day cost of wood = Rs.1000 to 1500
? If we consider Rs.1250 per day cost of wood, then per year cost of wood = 1250 * 365 = Rs.4,56,250/year
? Maintenance cost for cleaning boiler per year as per contact given to the agency = 25000
? Total running and maintenance cost for wood fired boiler per year = 456250 + 25000 = Rs. 4,76,250