In 1991 the "User Group" methodology wasintroduced for the textile industries in The Netherlands. The Netherlands textile industry was able to achieve 8% energy consumption reduction nationwide. "User Group" is a methodology where companies with comparableprocesses collectively discuss problems and identify solutions.
Recently with the support of The Netherlands based NGO Solidaridad,CREM a consultation organization & TNO a Dutch researchorganization we, at conquest launched the User Group project here in Tirupurfor the textile wet processing industries focusing on energy conservation &management in the steam generation and distribution systems. Ten Companiesvolunteered to participate in the project. After initial discussions anddeliberations on energy saving opportunities the team decided to focus on steamgeneration & distribution areas. From the literature research and basicevaluation our team identified to focus on improving boiler efficiency,insulation & steam trap maintenance where opportunities exists for a lowcost short-term effective benefits. This article is focused on steam traps as wefound out during the initial stages of evaluation it has enough potential andcontribution towards energy savings. The regular industrial practice is toadapt break down maintenance for failed traps once they have observed thechange in heating cycle timings in the process of coloration and no activesteam trap maintenance schedules are followed.
Thomas K Lago in PM Engineer magazine once wrote, "Lackof Steam Trap Knowledge Is the Weakest Link". Yes! It is true, whenconsidering the steam distribution systems in the process; the steam trap isthe least understood equipment. The foremost reason for this is the lack offundamental knowledge about the trap. Before discussing further let usunderstand the working of the trap.
Dyeing requires steam to heat the liquor to the requiredtemperature and maintain the temperature for a specific period of time. In suchprocess the latent heat of steam is used, hence the vapor is condensed as itgives up its heat content. In order to have continuous steam heat, one mustcontinuously remove the condensate formed. Steam trap is a device used in thesteam distribution line to drain the condensate alone without letting the steamto leak. These traps act as a valve. Three different types of traps areavailable namely, thermo dynamic, float & bucket type. Each one of them isused depending on the field of application.
The failure of these traps will result in steam leakages andsuch losses increase the operating cost of the process, increase the processtime and this means more use of energy and costs. The failure of the trap canbe categorized as leaking, blowing, rapid cycling & clogging. From thevarious literatures and the energy conservation manuals it has been observedthat about 15 to 30% of traps in the steam systems would fail if they are notmaintained. Further 50% of the traps may fail in the plant with no active steamtrap testing and repair program. With regular maintenance plan this figure canbe reduced to lesser than 3%.
The functionality of traps is evaluated by various methods(visual, temperature and ultra sonic detection methods). The observations oftraps by using ultrasonic equipments are limited due to their high costs. Yetthere is a scope for evaluating the steam trap in a much easier manner. In thisproject, based on the less widely used Masoneilan & Napier formula (Obtainedfrom the project report submitted to UNFCCC- AM0017/Version 02); theperformances of the traps are evaluated. For the evaluation we suggested theindustries to measure the input and output temperatures in the steam trap; theperformance of the trap can be determined by evaluating the temperaturedifferences. If the output temperature at the trap in the condensate line ismore than 95C; it means steam is leaking through it, then the trap can betermed as faulty, depending on the condition of the trap, it can be furtherlisted under any one of the before mentioned four faults namely blowing,leaking, rapid-cycling & clogging. From the observations and survey, thefacts came into light that, about 25% of traps were found malfunctioning.
With the survey of steam trap performance for the group companies following were observed. The achievable energy savings out of carrying proper maintenance for the combined capacity of 300 traps is about 17, 00,000 INR, fuel savings for the same is about 700 tonnes per annum; In a nutshell, if a company with a steam trap capacity of 100 is adapting proper maintenance plan for the steam traps means they could save approximately 8-10 lakhs of rupees and further 400 tonnes of fuel per annum. Does this figure give us enough evidence to adapt the maintenance plan for traps?
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The authors; Mr. Raman Azhahia Manavalan holds an M. tech in Textiles & B. N. Sandeep holds B. Tech., PDT (Textiles) and they are associated with Conquest Quality Systems Services Pvt Ltd.
Conquest provides service to the textile industries on various process improvement projects. Conquest has 12 years experience in providing consultancy for various certification processes for the textile industries, which includes ISO, WRAP, GOTS, OE, EU-ECOLABLE, ICE, and factory audit and code of conduct.
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