The Maintenance of Glass Furnaces

Maintenance can be explained broadly as:

 1) Scheduled Maintenance, 2) Predictive Maintenance,3) Preventive maintenance

 4) Breakdown maintenance, 5) Annual Maintenance and 6) Legal Maintenance.

 Considering above 6 types of maintenance , listing of all equipments is done and time frame of the maintenance is charted according to the equipment manual. All the parameters are noted down equipment wise. These guiding parameters will services as a reference to check the condition of the equipment. A maintenance schedule sheet is prepared for all the equipments showing limiting parameters based on their manual.

A history card must be prepared for every equipment to record any part change, alignment, breakdown with reasoning to understand behavior during major breakdown of failure.

Maintenance of plant is done to avoid any production loss due to breakdown. Maintenance department never like breakdown maintenance, other four types of maintenance are liked by them.

1.1    Scheduled Maintenance
1.1.1  What is a scheduled maintenance?
Scheduled maintenance is performed to maintain the condition of equipments as of the supplier.

Schedule maintenance is process by which one plan to perform a periodic condition check on the equipment and diagnose the condition of the equipment. It helps in timely corrective action under the preventive maintenance. To perform the schedule maintenance, it require high degree of coordination between maintenance department and the production department.

Word schedule itself describes the process. It means, user must have well in advance information for performing the maintenance of equipment. User must sign the work permit, before the maintenance team start maintenance. On completion of the maintenance, user must sign again for the handover of the equipment.

User must take trial, if the equipment was stopped to perform maintenance, else shall equipment maintenance be done in running, user must have a close look at the equipment to ensure, and equipment is good for continuous use.

Basic Task: Visual Inspection for wear and tear, lubrication and predict condition of equipment

1.2        Predictive Maintenance
1.2.1            What is a predictive maintenance?
Word “predict”, itself gives sense of explanation to type of maintenance, it is. Predictive maintenance is done with scientific approach and feed backs from regular schedule maintenance.

Example:

Let us take a case of bearing. Bearing have a life cycle which will give safe running hours or days of the bearing. The condition of bearing will further depend on the quality of material, external conditions like vibration, lubricant used, clean and ambient environment.

To ensure and predict the failure of bearing, one can take help of precise devices.  There are latest diagnostic tools like SPM (Shock Pulse meter). This SPM reading predicts it condition on the Pulse it receive and can predict the failure. There are green zone, yellow, red zone and dark red zone. Green zone is perfect condition, yellow means still better and needs lubricant or other attention like vibration etc. Once the pulse show entry to red zone, plan for replacing bearing must be taken. This is a one example of predictive maintenance.

 Key Concept

·        Data collection from Manuals

·        Combine Information

·        Analyze the equipment information from site

·        Plan for corrective action

·        Fix the schedule for the execution of plan.

·        Study the reason for possible reasons to avoid in failure in future.

·        Be Proactive.

Basic Task: Regular information collection to visualize the condition of machine. It can be thermal scanning, vibration measurement, etc to name few. Results in the preventive maintenance.

1.3        Preventive Maintenance
1.3.1            What is a preventive maintenance?
This is a process to avoid possible breakdown of the running equipment and stop or reduce production loss. Scheduled maintenance is performed to maintain the condition of equipment. Shall there be observation during schedule maintenance about bad condition of running equipment; decision is taken for either immediate repairs of equipment or shall there be a stand by equipment, a switch over is a possible way. If line equipment is without spare, a quick assessment is made for the gravity of failure. Shall it require immediate response or can be delayed couple of days, accordingly decision is taken.

 Preventive maintenance depends upon couple of feed backs. It can be Schedule maintenance result, or routine walk through around the equipment.

Basic Task: Attend the machine before failure, Find the reason for failure. And take corrective action for repetition of failure.

1.4        Breakdown Maintenance
1.4.1            What is breakdown maintenance?
Breakdown maintenance is a maintenance performed after a product producing machine fails. This is the least thing the maintenance team would like to hear.

This can happen dues some of the following reasons.

·        Lack of scheduled maintenance

·        Improper maintenance.

·        Wrong selection of equipment.

·        Overloading

·        External impact

·        Delayed maintenance schedule

This problem is not limited to the above listed; it can have many other reasons. This type of maintenance is never accepted by any management. When plant is running at optimum capacity, downtime is least recommended. Process improvement tools are implemented to reduce the down time. Continuous improvements (Kaizen) have always a room to reduce downtime. This type of maintenance can cause huge loss of production time, thus care need to be taken.

1.5        Annual Maintenance
1.5.1            What is annual maintenance?
This is a special maintenance carried out yearly on major equipments based on the maintenance manual submitted by the supplier.

Some of the equipments require major overhauling; same is done under this schedule. Some may require to replace some components or lubrication, depends upon type of equipments.

Some equipment may require belt change, pulley change, depending upon wear and tear. This doesn’t mean, if some wear or tear takes place, early, on shall not replace.

1.6        Legal Maintenance
1.6.1            What is legal maintenance?
Some equipment subjected to regulation of administration in local body or central body. The equipments coming under category are mostly hazardous in nature. To ensure the companies take proper care of maintenance of these equipments, Law and Regulation body take periodic check as required by the type of equipment. To name few as under:

·        Equipments and devices under pressure. (Steam Boiler, Pressure vessels, safety valve & Etc).

·        Installation of High and Medium Voltage ( Relays , Ct , PT, Breakers & Etc)

·        Fire prevention facilities

·        Storage tanks (LPG. Hydrogen & Etc.)