Category Archives: Industrial Refrigeration

Industrial Refrigeration Ammonia Service Cat Ladder

Industrial Refrigeration Ammonia Service

Industrial Refrigeration Ammonia Service Visit

The industrial refrigeration ammonia service visit was in Aberystwyth. We look after 2 ammonia chillers on site. They are 10 year old chillers that have been designed to need ongoing service. Quite easy job as the faults they go into are reoccurring round in a circle. They have previously had the same problems

Shaft Seal for Industrial Refrigeration Ammonia Service

The industrial refrigeration shaft seal had started to leak so ammonia service was arranged. It was fitted by removing the shaft seal cover, splitting the coupling and sliding the shaft seal over the shaft. After removing the non condensables, we reintroduced the ammonia back into the compressor. The 'o' rings leaked

Ammonia Service of Leaking Industrial Refrigeration 'O' Rings

The ammonia service of industrial refrigeration ‘o’ rings occurs because they become flattened and plastic like. This is caused by heat around the high side of the screw compressor. When there is pressure in the system- the oil if forced against the gap- making a seal. After the ammonia refrigerant had been handled- the oil ran away- causing the leak when the ammonia was reintroduced

0161 370 7193

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Lift and Shift for Ammonia Service Visit

Before the ammonia service visit, the compressor had been removed of it’s pipework and ancillaries. The lift and shift guys arrived and set up their lifting equipment. They raised the compressor and manoeuvred it on to a trolley. They used a stair walker to get it up and down the steps. They used a winch to get the compressor, end on- down a cat ladder

Tear Down if the Ammonia Screw Compressor

It is always better to tear down this kind of compressor in a workshop- on a bench with compressed air and all the tools nearby. We unbolted the castings and slid the screw out. The various castings being laid out in a line. We replaced the ‘o’ rings for new the rebuilt the compressor

Ammonia Refrigerant Charging
Ammonia Refrigerant Charging

Ammonia Refrigerant Service Charge

Part of the ammonia refrigerant had been handled during the service visit. This left the compressor pipework, compressor and the oil separator open to atmosphere. The non condensables were evacuated. In the photo we are lifting the cylinder up a cat ladder into the plant room. From there it needed to be man handled up some steps, down some steps and out onto the roof. We charged the ammonia plant with liquid ammonia until the superheat and subcooling values were within industry known limits. The sight glass levels and condition were monitored too

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Industrial Refrigeration Oil Service

Industrial Refrigeration Oil Service

Industrial Refrigeration Oil Service

An industrial refrigeration oil service visit was arranged because of an oil return issue. Several fans had been down on the air cooled chilled water system. This causes the chilled water system to unload so as to prevent a fault occurring. The lower mass flow rate of the refrigerant caused oil to migrate to the low side of the system. Several vessels are available with various forms oil return control. These vessels were valved off. A two man team with the correct ammonia PPE and breathing apparatus carried out the job

Not Enough Oil Recovered During Service to the Industrial Refrigeration Plant

Only some of the oil was recovered using during the industrial refrigeration service of the plant. Therefore, the engineers decided to add new oil to get the chilled water system running. The only problem with doing this is that once running the machine, the oil has to be got back out. Therefore, the industrial refrigeration oil service had to be carried out a second time to resolve the oil return issue

0161 370 7193

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Industrial Refrigeration Service by Fitting Fan Decks

For this industrial refrigeration service visit, scaffolding had been erected in accordance with the Risk Assessment. The old fan decks were lifted out by the two man team. A really good team was sent out: one of the men was more technical and the other more mechanical- complementing each other with their different skill sets. The new fans were an updated version and the wiring was different. The fault link had to be adapted but the 0-10v input from the controller was the same. The controller reads the pressure from a transducer, then sends out a voltage which the fan turns into the corresponding speed

Service Testing of the Industrial Refrigeration System

The fault link had been correctly modified, so service testing of the industrial refrigeration system was carried out. The machine loaded up to 62% and monitoring continued during the rest of the visit

Read More about International Institute of Ammonia Refrigeration Technology and Standards

 


Service to Industrial Refrigeration Controller

Industrial Refrigeration Service Visit

Tick Sheet for the Industrial Refrigeration Service Visit

The industrial refrigeration service visit is carried out inside a walk in room so some of the machine can be serviced in the dry. Good job because it is a bit of a rainy day- don't want to get the tick sheet wet!

Chiller Controller

The controller for the plant has been problematic from when the chiller was first lifted in. It faults out regularly: reoccurring known faults known to the customer. Part of the problem are low load conditions. This causes the chiller to go into various alerts then it eventually trips out

Over Complicated Program for the PLC

Another part of the problem are over complicated controls. I often think about the same machine in a critical process environment. This machine is bespoke so there will be a bog standard version as well. The controls on this version have too many sensors, generating too many faults. There is always something which trips it out when no fault as such is present. The controls themselves are a fault if they are problematic. Factory Managers don't like too many industrial refrigeration service visits because of spurious trip outs- they just want the plant to just run seamlessly. This customer, however, has to pay for more parts and more industrial refrigeration service is to keep it running

0161 370 7193

service@maximuschillers.com

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Trim the Ammonia Refrigerant

The chiller has a low refrigerant charge so an industrial refrigeration service visit has been arranged to trim the ammonia refrigerant. We have state of the art ammonia refrigerant recovery units Read More but these are used when handling tonnes of ammonia refrigerant. This is just a small 200kw industrial refrigeration plant so we will be using a smaller ammonia refrigerant recovery method

Oil Return During the Industrial Refrigeration Service Visit

Low refrigerant charge diagnosed during the industrial refrigeration service visit causing the oil to migrate to the low side of the system. The oil will need to be manually recovered from various vessels following the ammonia oil recovery procedure

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Service Welding for Industrial Refrigeration

Industrial Refrigeration Service Welding

Industrial Refrigeration Service Welding of the Pipework

The ammonia had been removed to perform industrial refrigeration service welding. This was carried out using the zero-zero breaking in procedure. This visit was to replace rusted pipework. The welder got strait to it: grinding out the components ready for the welding. After the welding was completed, the vessel was leak tested and pressure tested. Another part of the system which contained liquid required works so:

Ammonia Refrigerant Transfer Pump

The ammonia refrigerant transfer pump failed during the recovery of 6 tonnes of anhydrous ammonia. There was a tight schedule as delays would mean less time for the upgrade during factory shutdown. Our engineer quickly took the side covers off the ammonia refrigerant transfer pump. He found that the coupling had come loose. Luckily, he found it to be not damaged more than scratches. Therefore, he bolted it together again and tested it: back in production

0161 370 7193

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Shell and Tube Service

After the above was carried out- the plant was inspected. The condenser had failed on the industrial refrigeration plant. Ammonia had been leaking into the water system causing the ammonia warning alarm being triggered with plant shut down

Burst Tubes

Our shell and tube technician identified the tubes. Then, industrial refrigeration service welding was carried out on the burst ones. Dehydration was easy as the ammonia refrigerant had been leaking out with not much water getting in. Also, the water system was drained prior to removing the refrigerant

Run Testing

The customer signed off the paperwork for the job. The readings were monitored for some time to look for any abnormalities. All readings were okay- another happy customer!

Are you a factory manager or facility manager? Have you got service issues with your industrial refrigeration plant? Bills too high? For service: Maximus Chillers can help Click Here

For the International Institute of Ammonia Refrigeration (IIAR) Click Here


Float valve on an industrial refrigeration machine

Industrial Refrigeration Maintenance

Industrial Refrigeration Maintenance of Float Valve

On a recent visit to a site in the South East, the industrial refrigeration maintenance of float valve was carried out. It was an easy job as the electronic part can be easily removed and replaced without breaking into the system. It works by detecting a level in the float chamber and operating the expansion valve solenoid coil

High Head Pressure

The call out had been to investigate a high head pressure issue. Our engineer arrived on site about 9 o clock and started to investigate the industrial refrigeration fault- a cup of coffee in hand. The machine started to load up and at around 70% it backed off with high lift warnings on the display. There was a low temperature drop on the liquid line between the float valve and the expansion valve- float valve failure. The float valve is stand alone as it will let anhydrous ammonia liquid through when it builds up- that is if it works of course

0161 370 7193

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Industrial Refrigeration Maintenance of Electronic Parts

Industrial refrigeration maintenance was carried out to the electronic parts with a straight swap

Slide Valve Sensor

A common kind of slide valve sensor on an industrial refrigeration system works by converting the length of the slide arm into 4-20mA. 4 being closed and 20 being open. To get it to work you have to set the minimum position on the slide arm with a lock nut- then set that to 0 in the program

Failed Slide Arm Electronics

A common fault is when the slide arm electronics fail, giving a stuck reading on the display. The chiller controls notice the abnormality and shut down the plant

Calibration

If the slide arm is okay, calibration can sort out the problem. In the program, the minimum and maximum positions can be set to ensure the smooth running of the plant, therefore maintenance can be kept to a minimum

Are you concerned with high maintenance costs and a tight budget? Maximus Chillers can relieve the stress- Click Here

Visit the Institute of Refrigeration for industry publication resource


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