SMa – WSHi Award 2007 GE Aviation Service Operation LLP Minimize Time Needed To Clear Sludge Pit At Mechanical Clean Room
GE Aviation Service Operation LLP (GEASO) provides state-of-art jet engine component repair services, which are defect-free, delivered on time and in a boundaryless, safe, healthy and motivated work environment while complying with all government regulations and GE policies. GEASO was the first GE site in Asia to achieve Global Star Award which is equivalent to OSHA’s Voluntary Protection Program (VPP) in 1999 and was subsequently recertified in 2004. Beside the various EHS awards received from GE Engine Services, we are actively involved in Noise Control, Chemical Best Practice Award and Workplace Safety And Health Innovation Award by Ministry of Manpower.
PARTICULARS OF TEAM Facilitator : Lim Chiap Jway (Facility and EHS Leader) Leader : Chia Yeong Ming, Samon (EHS Engineer) Members : Lim Hong Kwang (Facility Engineer) Lim Tow Nan (EHS Engineer) Paul (Janitor Supervisor) Mohammed Ayub (Janitor) Raymond Choy (Waste Water Treatment Plant Technician) Lew Eng Choon (Black Belt) BACKGROUND INFORMATION OF THE TEAM Team was formed in July 2005 as it was observed that Janitor spent an average of 100.2 hours annually to manually clear the sludge in the Mechanical Clean Room where 81% of the total sludge in the plant was generated. Each sludge clearing process would require the janitor to use a hand held scoop to transfer the sludge from the pit into plastic bags which were then wheeled to the WWTP that was situated at 40 meter away. While clearing the sludge, janitor faced with the repetitive bending and stress on lower back and arms. Through brain storming and evaluating of various options, the team came up with an automated pumping system and put it into operation in February 2006.
Time Taken to Clear Sludge Annually in GEASO 81.0 % 19.4 % 6.5 % WWTP 8 hrs CCR 24 hrs MCR 100.2 hrs Area of focus PROJECT SELECTION & DEFINITION Sludge is a by-product of cleaning and polishing processes during the repair of the jet engine components. A study within the plant revealed that 81% of the total sludge produced was from the Mechanical Clean Room (MCR) with remaining 19.4% and 6.5% from the Chemical Clean Room (CCR) and Waste Water Treatment Plant (WWTP) respectively. The total time taken for clearing the sludge at MCR was averaged at 100.2hrs annually and the EHS concerns faced by the Janitor cannot be ignored.
JOB HAZARD ANALYSIS Before the automatic pumping system was implemented, Job Hazard Analysis conducted in 2003 revealed the ergonomic risks involved with the manual clearance of sludge at the MCR. Please refer to the attached JHA worksheet.
JOB HAZARD ANALYSIS • The constant removal and replacing the pit covers were the other challenges faced by the Janitor due to the weight and the possibility of pinching their fingers between the cover and the ground. • Janitor was likely to expose to noise (Hearing Protection Zone) when clearing of the sludge.
AREAS FOR IMPROVEMENT The old process are as followed; Step 3. Janitor manually removing the cover for the collection pit. Step1. Sludge produced from the tumblers and wet blast machine, flows to collection pit. Step 2. Janitor cordon surrounding area sludge collection pit Step 6. Process repeated till all sludge from pit removed and collection pit was covered. Step 5. Janitor pushes trolley with bags filled with sludge to the wastewater treatment plant, leaving pit open. Step 4. Manually removing sludge from pit using an extended scoop and placing sludge into plastic bags. NEED TO ELIMINATE THE ERGOMONIC, SAFETY & HEALTH CONCERNS AT STEP 4 AND 5.
ANALYTICAL TECHNIQUES CAUSE & EFFECT ENVIRONMENT MACHINES/ EQUIPMENT Pit is 1.2 meter deep Tumblers constantly producing waste water & residue to the collection pit Original design of collection pit Manual Clearing of Sludge Average of 80 kg of sludge produced weekly Solidification of sludge at the holding pit Single person tasked to do the job Manual Operation MAN MEASUREMENT METHODS
CORRECTION ACTIONS & IMPLEMENTATION After brainstorming, the team was able to provide two feasible solutions, i.e., to use a vacuum or automatic pumping system. Disadvantage of the vacuum equipment was costly, pit covers still required to be lifted and sludge needed to be transferred to the Waste Water Treatment Plant. In long term, the vacuum system would be difficult to maintain as well. The automatic pumping system was then chosen as it was easy to fabricate in-house, cost effective and easy to operate with minimal maintenance effort. However, the team was still faced with the pumping of solidified sludge within the pit. With further brain storming, the team decided to overcome this problem by installing a compressed air piping at the bottom of the pit to loosen the sludge. The compressed air would be activated by a level switch when the sludge reached a pre-determined level in the pit. A timer was also incorporated to start the sludge pumping process at an appropriate time. The liqufied sludge were then pumped directly to the Waste Water Treatment Plant. The automatic system was installed and tested in late November 2005 and fully commissioned and operational in February 2006. (2) Automatic pumping system. • Minimum cost to install. • Minimum alteration to existing system. • Tremendous benefits in EHS and time reductions.
BEFORE IMPROVEMENT MANUAL SLUDGE CLEARING SYSTEM TO SLUDGE TREATMENT SYS. SLUDGE INLET SLUDGE SEDIMENT PIT SLUDGE WATER PIT SLUDGE DISCHARGE PUMP AFTER IMPROVEMENT AUTO SLUDGE CLEARING SYSTEM INSTALLATION COST US$ 600 COMPRESSED INLET TO SLUDGE TREATMENT s SYS. TIMER / SOLENOID VALVE LEVEL SWITCH SLUDGE INLET DIS-USED PIT DISCHARGE PUMP COMPRESSED AIR AGITATOR
AFTER IMPLEMENTATION After implementing the automatic sludge pumping system, the manual clearing process by the janitor was eliminated, it also reduce the opportunity for janitor to be exposed to noise and chemical in MCR. PREVENTIVE MAINTENANCE & INSPECTION ARE NOW DONE ON A MONTHLY BASIS
STANDARDIZATION, DOCUMENTATION & MAINTENANCE Risk of Automatic Pumping System failing were identified and abatements incorporated. Risk Abatement Pump failure. Timer failure. Compressed air failure. Comprehensive preventive maintenance program with emphasizing on the pump, timer and compressed air system. (Refer to next slide) Training provided for designated janitor/ WWTP Technician for the automated system. Only trained janitor/ authorized person is allow to handle/operate the system. Random inspection by janitor’s supervisor, and EHS/FAC engineers to ensure works are carried out in a safe manner. Mishandling of the system. Potential injuries due to opening and closing of the pit cover during PM. Provide training for designated janitor/ GEASO CRT on how to reduce injuries. Safety risk assessment communicated to the WWTP technician and Janitor Provide barricade whenever pit cover is open.
MAINTENANCE OF NEW PROCEDURE Monthly checklist for Effluent Treatment Plant includes checking of the air tubing and timer. WWTP and Janitor continue to ensure that system is in good working condition. Facility and EHS engineers conduct random inspection at MCR to ensure that automatic pumping system is maintain and working well.
RESULTS ACHIEVED Tangible Results : Average time (Annual) saved due to automation is 92 hours. Average saving material cost is US$221 annually. Intangible Results : Elimination of Ergonomic risks Elimination of safety related issues. High morale among Janitor and employees Cost of modification : US$600 Positive air tap from existing source and additional timer installed Automatic Pumping System Innovative way to reduce the risks faced by janitor
TEAM NEXT PROJECTS • Various EHS projects are in the pipelines; • Noise reduction for Grit Blast & VTL machines. • Replacing wire ropes with pneumatic cylinders to reduce potential injuries to hand/ arm. • Eliminating ergonomic risk to arm by replacing manual operated press with hydraulic press. • Mass Hand Safety Exercise view through Video Clip from the work cells desktops to raise hand safety awareness among the workforce. CONCLUSION By using innovative engineering means, the automated pumping system eliminates the ergonomic, health and safety risks and increase the morale among both GE Employees and contractor. As a responsible organization, GE Aviation Service Operation LLP (GEASO) constantly looks into feasible and sustainable solutions to reduce and eliminate EHS concerns faced by employees and contractors working within GEASO.