Monthly Archives: February 2022

Dirty tubes on the left and clean tubes on the right after chiller condenser tube cleaning

Chiller Condenser Tube Cleaning

A nice job for our overseas engineer: to carry out chiller condenser tube cleaning in Cadiz, Spain. We have The Spanish Office near Malaga with a manager and an engineer out in the field- so our Spanish engineer assisted our overseas engineer.

Centrifugal Chiller Condenser Tube Cleaning

The factory has 4x water cooled centrifugal chillers with a combined cooling capacity of 8 MW. The chillers cool down a process involved with the production of an industrial chemical.

High Condenser Pressure

When we looked through our Tick Sheets we could see a gradual deterioration of the high side readings over a period of time. This showed us that an overhaul needed to be carried out on the condensers.

Water Tower Contaminants

We think that the fouling was due to contaminants that were carried in the air from around the factory. Each condenser has a water tower which is open to atmosphere. The condenser cooling water enters the cooling tower at the top. It runs down along plastic slats which are stacked on top of each other. In the opposite direction, air is blown up using large blowers. The air flow cools down the water, which then returns to the condenser. This process is how the contaminants from the air end up in the water.

N+1 Redundancy

This is an algebraic way of saying that there is twice as much cooling as is needed. Where N is an amount of something and +1 means another one. Redundancy is needed when a process is critical. In this instance, the factory would grind to a halt if the chillers went down. Therefore, only two of the 4 chillers run at any one time.

0161 370 7193

service@maximuschillers.com

Contact Form

Sequencer

A sequencer is available to switch between the chillers when they go into fault and to balance the compressor run hours. We decided to start work on Chiller 1 as this was a system in standby. The next chiller in standby was Chiller 2. After this chiller had been overhauled, we switched Chiller 3 off which brought Chiller 1 on. Then, when we isolated Chiller 4, the sequencer brought Chiller 3 on. Before leaving site, we temporarily lowered the setpoint for all 4 chillers to watch the sequencer bring all of the chillers on together. We then put the set point back to its usual setting, whereby Chillers 1 and 2 remained running.

Shipping for Chiller Condenser Tube Cleaning

We keep tube cleaning equipment in our stores in Jeddah, Saudi Arabia which we ship to our Middle East customers. We also have tube cleaning equipment in our stores at Head Office in Manchester, UK. We use a pallet shipping company based in Rochdale to ship parts, materials and equipment overseas. Therefore, we packed all of the necessary equipment on to a pallet, then shipped it to Cadiz. For the consumables used on the job, we have suppliers in Spain, but we usually prefer to ship these smaller things from the UK along with the equipment. This is because our engineers are more used to the brands and types of consumables that we get from our UK suppliers.

RAMS for Chiller Condenser Tube Cleaning

All of our paperwork, Tick Sheets and Risk Assessment Method Statements have been professionally translated into Spanish. Therefore, our Spanish engineer carried out a site survey to assess the risks, he then sent a report to Head Office. We decided upon the appropriate measures to control the risks, then sent the RAMS to site prior to the visit.

Permit to Work for Chiller Condenser Tube Cleaning

The onsite health and safety officer looked at our RAMS and decided how to compose his Permit to Work. Then, both of our engineers signed it at the start and at completion of the job.

Walk Round before Chiller Condenser Tube Cleaning

On completion of the paperwork, our engineers, the onsite health and safety officer and an onsite engineer had a walk round to assess the job. This was to make sure that all was okay to carry out the tube cleaning.

0161 370 7193

service@maximuschillers.com

Contact Form

Chiller Condenser Tube Cleaning Operation

Each of the 4 chillers was worked on in turn in the order as described above.

Valve Configuration

Each condenser was valved off with the configuration of the pipework changed. This was to ensure that the flow rates were correct for all 4 of the chillers. Otherwise, a catastrophic failure of the chillers could occur.

Drain Down

The condensers were then drained down and vented using a selection of fittings that were shipped out with our equipment.

End Plates

Our engineers unbolted the end plates and lifted them to the side using specialist lifting equipment.

Tube Cleaning

In Spain they just use a 220v supply for electrical equipment instead of the 110v equipment that we commonly use in the UK. As our equipment is 110v, we shipped our transformer on the pallet. Once the equipment was set up- we carried out the cleaning of each condenser tube according to standard industry guidelines.

Rebuild

The seal on the end plates is prone to leak after breaking into the system so we shipped replacements from Head Office. Our engineers found it a fiddly job as the new seals had been folded up in a different position in the packet. This meant that they kept jumping out of the grooves. When the seals eventually remained in the grooves, the end plates were bolted into position according to the correct torque setting.

Air Purge and Valve Configuration

The air was purged from the shell of the condensers and the valve configuration was returned to the original position.

Test Operation

Each of the 4 chillers was run tested in turn and the system readings were recorded on our paperwork. A dramatic increase in performance was recorded on each system. The refrigerant pressures and temperatures were a lot better and the coefficient of performance was markedly higher. This means a lower carbon footprint and lower electricity costs.

Related Articles:
Chiller Tube Cleaning Service

Chiller Condensers

Improve Chiller Efficiency

Gibraltar Chiller Maintenance

Hit the Tags at the top of the page to navigate your way to our extensive library of further reading on this subject.

Read more about Chiller Condensers on The Engineering Mindset.


Chiller maintenance service Tick Sheets showing readings

Chiller Maintenance Service

Maximus Chillers have just carried out our quarterly chiller maintenance service at a factory in the North West. We look after 6MW of cooling across 12 industrial process chillers. This was a minor visit, so no need for oil changes and checking the head gear on the reciprocating compressors. Instead, we took oil samples which we analysed in our laboratory. Read on for an insight into our engineer’s findings on each of the chillers…

News Article No.25

Chiller 1 Maintenance Service

System 1 has a compressor that had blown all three of the 200 amp centred tag fuses. On inspection with a multimeter, our engineer found a dead short to earth on the internal electric motor. We have submitted a Quote for the lift and shift, remanufacturing at our facility, then the lift back in. Several oil changes will then be carried out at planned intervals.

Chiller 2

More or less textbook readings were taken and no problems to report.

Chiller 3 Maintenance Service

Slightly poor readings were taken on the low side of all 4 of the systems. This issue has now been flagged in our system for monitoring. If it deteriorates, we will submit a Quote to take the evaporator end plates off and carry out a chiller tube cleaning operation.

0161 370 7193

service@maximuschillers.com

Contact Form

Chiller 4 Maintenance Service

Compressor 3 has had an issue that has been developing over a period of time. Occasionally, it throws the breaker, then when the electrical readings are taken- they all check out okay. The contactor condition had been inspected, the wiring and motor connectors had all been tightened up too. Shortly before the visit, our customer rang to say “Chiller 4 has gone for a Burton!” When we attended the call out, we found the contactor had blown against the inside of the panel. We have submitted a Quotation for the replacement.

Chiller 5

System 2 had a flashing sight glass in some conditions, but the other fridge readings were okay.

Chiller 6

This system had low side readings similar to Chiller 3. Again, they were not deemed to be an issue yet, but if we decide to do a chiller tube cleaning operation, we will prepare one Quote for both chillers.

Chiller 7

No problems to report.

Chiller 8

Only a short run was available due to the process load conditions, but no problems were found by our engineer.

0161 370 7193

service@maximuschillers.com

Contact Form

Chiller 9 Maintenance Service

All the way through to chiller 9 and the fault finding was easy, now this: external interlock alarm. When our engineer logged the issue with our Technical Support Desk using our real time app on his phone, he stated that to his knowledge, there were no external interlocks.

Fan Motors

Therefore, he decided to check the fan motor overload switches. All 5 fans on each system are linked together in series, so he looked for the volt feedback in the panel for System 1 and System 2- this checked out okay.

External Switch

Therefore, he decided to look for an external switch as the fault suggests. He walked along the gantry and down into the plant room below the chillers...

Pump Set Panel

There is a panel that controls the chilled water pump sets. No wire from the chiller was found to go into this panel.

Remote Monitoring Panel

This is a display that conveys the running condition of the chiller down to the plant room below. It saves a process engineer from having to go up the stairs and onto the chiller gantry. This panel is indeed connected to the chiller with electrical wiring. However, no switch was found that could have caused this fault.

Buffer Vessel

A 10,000 ltr buffer vessel is also located in the plant room. As it is open to atmosphere, our engineer looked for a low level switch which may have tripped- no switch was found.

Program Settings

Now that anything external to the chiller had been eliminated, our engineer decided that the fault must indeed be coming from inside the machine. Because the fan overloads had checked out okay, he decided to have a look at the program settings...

Extensive Library

We have an extensive library of manuals and passwords for all chillers. We also have a network of engineers around the country- one of them will know someone who will has a manual or password. When our engineer contacted our Technical Support Desk real time through his app- the manual and passwords were sent to his phone. He found the menu level and parameter for external interlocks which was found to be wrong. To our knowledge, our customer does not have the password for this chiller. The process had been off for some time due to system upgrades with contractors on site doing other work. They could have changed the setting for some reason. We don’t know- but at least the setting was corrected and the chiller came out of fault.

Chiller 10

This chiller uses belts to drive the fans. On inspection, several of them were found to be in poor condition or broken off. We have just replenished the stock of spare fan belts on site, so our engineer replaced them, then tested each fan motor in turn.

Chiller 11

This is the same make and model as Chiller 10. The same issue was found and then rectified.

Chiller 12 Maintenance Service

This chiller is in a part of the factory where the environment is very dusty. Therefore, a blocked condenser and high pressure cut outs are common place. The process engineers are aware of this issue, so they keep on top of the maintenance of the condenser. If the condenser does deteriorate- they know how to reset the fault. No problems were found with this machine.

Related Articles:
Glycol Chiller Maintenance

Planned Preventative Chiller Maintenance

Chiller Maintenance Contract

Hit the Tags at the top of the page to navigate your way to our extensive library of further reading on this subject.

Read more about buffer vessels at Fabricated Products.


Translate