Thrust Monitoring Alignment System
A new way of approaching the problems of roller skew and thrust control in rotary equipment.
Ideal for all rotary equipment using antifriction bearings (spherical roller bearings) on the support rollers, such as:
Dryers
Coolers
Calciners
Breakers
Crushers
Granulators
Rock washers
Debarking drums
Alignment by Thrust Monitoring System is not just another way to do alignment. It is a fundamental change, new concept. This is a revolutionary technology, where alignment is approached in a completely different way than what we have seen before. With Thrust Monitoring System bearing failures and high rates of tire and roller surface wear due to high thrust loads are a thing of the past.
Why do we focus on alignment?
Operating rotary equipment this is self evident we want to:
improve mechanical performance of the machine
Extend equipment service life
Reduce operating costs – the longer the equipment survives, your capital costs in your maintenance costs goes down in terms of dollars per ton of production.
In extending service life or improving the mechanical performance we really minimize the friction. And minimizing friction means: WE WANT TO REDUCE WEAR.
So reducing friction reduces wear. Simplifying we can think of Friction as FORCE.
The Friction is really more a resistance to a force, but nonetheless this is the force that resists rotation. So misalignment or skew makes rotation more difficult because it adds friction. And Thrust Force generated by skew is one form of our friction.
Installation of our Thrust Monitoring System allow you literally to see the friction. That friction is somehow visualized for you. Then if you can see when friction is minimized, you can make certain moves and see a move which increase a friction or a move which decrease a friction. You are able to identify a condition where a friction is minimized and find the best state of alignment possible.
In that case, Thrust Monitoring System is a REVOLUTION. Watching changes in Thrust Force (or friction) in response to bearing adjustments.
Thrust Monitoring System consist of Control Unit located next to the equipment and thrust sensors assembled to each support roller with spherical roller bearing. And that sensors becomes our window through which we can visualize friction.
We would see the change in thrust force over time. And, so the basic concept is we make a move by adjusting a bearing, either in or out, which would either add or subtract skew, and in a real time we will see the change in a thrust force over time. If we reverse the move, than we would see the opposite change in a real time on our roller.
Real-time data
Installation of real-time Thrust Monitoring System allow to extend the lifetime of components (support rollers, bearings, thrust rollers, tires etc.) by more than 10 years.
Measure force not position
Bearing position is relative; axial force is absolute.
While the best traditional methods may yield passable results, there is no immediate feedback confirming whether the set of bearing location is optimum. By measuring force in real-time, the optimum bearing position announces itself.
Bearing fail when subjected to high loads, specially high axial loads. Why not then measure those loads directly rather than assuming that a position of minimized axial load has been set without such confirming feedback?
Axial load can be changed by many reasons during equipment operation i.e.:
different operation temperature (production),
different ambient temperature (seasonal changes),
support displacement and settlement
small wear of tires and rollers running surface
different production load (feed),
tires axial run-out
In addition, even small changes at one of the support rollers has the influence over axial thrust of the all set.
Aligning the rollers based on real-time Thrust Monitoring System yields the neutral skew position of each roller within 0,05 mm with 100% reliability. Acceptable alignment usually only requires 0,1 mm resolution provided its direction is verified as positive. This method is therefore more precise than the best “measured positions” standard procedure.
How it can be said that alignment by the method of Thrust Monitoring System is more precise than standard position alignment measurement? It is simply judged by putting one method against the other. Firstly, do the best standard alignment by position measurement. Next, fit the thrust sensors to the rollers and rotate the unit. If the alignment is correct, a rotary unit requiring skew will have equal axial load on each roller that just balances gravity, which can be seen by the load on the thrust roller. If the rotary unit is horizontal, then the axial load on each roller should be near zero.
In almost three years of such testing, not a single occasion arose where further adjustment, which usually included shimming, was not required. In half of these cases, the adjustments were significant, i.e. shim and skew correction of 3 mm or more.
Advantages
1. Greatly increased accuracy
Mount on any bearing
Mount on the base
0,01 mm Sensitivity
2. Greatly increased reliability
Errors are immediately obvious (not 2 weeks later)
Alignment results are not operator skill dependent.
3. Simplified procedures.
No centerlines or offset lines
No position measurements
No levels or auto-levels
No theodolites or lasers
No optical measurement of any kind
4. Real time feedback.
With the drum in motion the simple physics of action-reaction makes changes in thrust immediately observable.
“SWEET POINT” – Perfect Alignment
Support Rolles Skewed To Thrust Dryer Uphill Until lower thrust roller turns 50% of the time
Shiny surfaces – sign of perfect alignment.
When the roller is perfectly aligned is become visually obvious, because they polish up. They have the appearance of being very shiny.
Installation of real-time thrust monitoring system allow to extend the lifetime of components (support rollers, bearings, thrust rollers, tires etc.) by more than 10 years.
Before (sign of excessive wear)
After (shiny surfaces – sign of perfect alignment)
The pernament installation
This sensors can be left in place and in that case it is not only the alignment but as permanent installation becomes complete alignment and bearing monitoring condition system which has much further benefits.
- permanently installed system comes with a display panel where each roller has an LED, whose color is indicative of alignment condition of that particular roller. Green light if the roller operates normally, a red light if there is too much uphill or downhill thrust, a yellow light – as a warning, and of course separate red light LED in a case of roller in an alarm condition. So all you need to control is a green lights.
- with this system in place you can now observe what the operating conditions are doing to your thrust generations for the skew that is there. So you see the effect of load, you see the effect of temperature. You see the effect of speed changes. And in some cases when you put different materials through the drum. So this can also be evaluated.
- this is Real-Time alignment monitoring system – so you not only have immediate notification in a field, but optionally monitor display in a control room is also available to alert the operators if something is mechanically done wrong with the support roller alignment or bearing condition.
- permanent installation is a very early warning system. The operator will notice any deviations at a very early stage, just after axial thrust will rise up, long before any damages will appear.
- with the system monitor and properly aligned rollers, adjustment do not need to be made even for several years.
- puts everyone on the same page – the alignment results are no longer as highly dependent on operator skill. The system will control the alignment by itself.
- intervals between grinding greatly increased.
CLEAN UP THE MESS – get rid of the oil
With the system installed to the equipment oiling the tires and rollers are no longer needed. Oil on the running surface is destructive – creates subsurface micro cracks. This small cracks over a period of time joins and finally create the peaces of metal falling out.
Oil on the tires is not just a housekeeping mess and safety measures, but another environmental problem. Getting rid of the oil you will become environmentally friendly.
SHIM or SKEW?
We cannot say that we have a good alignment, until we know the roller is correctly located in slope.
Following the system principle we can easily find “zero skew” position for each of rollers. But the inclination error is still unknown, because it was not measured and nothing had been done to this point to know what slope that rollers is on. So for that reason, to achieve a perfect alignment flat, cylindrical surfaces are required. This condition assures that when we finish the alignment process we are going to have minimum 70% face contact.
HAVEC Engineering deals with providing innovative solutions supporting operation of heavy duty machinery, in individual rotary kilns.
contact@havec.eu
INSPECTION OF ROTARY KILNS
Hot kiln alignment - the main area of our actions shall be to conduct mechanical inspection and to specify activities (measurements, exchanges, repairs, modifications, etc.) which should be performed to attain and maintain high effectiveness of the rotary kiln's operation.
TECHNOLOGY TRANSFER
We hold a specialist hardware and software used for professional measurements. Application of relevant tools allows for effective diagnosis and monitoring of machinery and equipment operation.
INDUSTRIAL AUTOMATICS
We developed high precision measurement systems to allow to monitor current status of equipment and to plan maintenance activities. Hence, malfunctions and breakdowns can be reduced both in respect of their intensity and frequency.
INDUSTRIAL MEASUREMENTS AND CONTROL
We provide a wide scope of measurement services addressed to many industry branches. Highly precise measurements are the starting point for analyses and regulations supporting the work of machinery and equipment.