Industrial Refrigeration Sludge

Industrial Refrigeration Sludge

Industrial Refrigeration Sludge

This industrial refrigeration visit is to remove sludge from the system. There had been a long period of neglect prior to Maximus Chillers attending site, so regular oil changes had not been carried out. Two oil changes have now been carried out and still a small amount of sludge still remains in the system

Industrial Refrigeration Sludge

Due to previous industrial refrigeration sludge removal, the plant was down to about half of its 60kg charge of refrigerant. It was starting to show signs of refrigerant shortage as the machine was preventing loading up. An ammonia suitable pump out unit was used to decant the remaining refrigerant into a cylinder for disposal

Pressure and Temperature

Once this had been carried out, any residual refrigerant in the oil and liquid on the low side of the plant was carefully handled until the plant was at the same pressure and temperature of the surrounding environment. See picture of some remaining liquid boiling off in an oil return vessel on the bottom of the flooded evaporator

0161 370 7193

service@maximuschillers.com

Contact Form

Industrial Refrigeration Sludge Oil

Once the pressure and temperatures equalized, our engineer drained the oil in the system from four different vessels. The oil was then removed from site for recycling. Usually, pressure helps with the process, but as the system was empty, gravity was sufficient for most parts of the plant. Nitrogen being introduced to the oil supply pipe to push it back to the oil separator

Flushing Agent

A flushing agent specially formulated for use in ammonia systems was used to aid the removal of sludge and oil from the pipework around the chiller

Evacuation

After a pressure test, the evacuation process was started. This was to boil off any remaining flushing agent, to remove non condensables and remove any moisture. A near perfect vacuum was achieved

Run up

New refrigeration grade anhydrous ammonia was charged into the system, a little at first to check for any leaks. Then, the plant was checked for effective running conditions. All readings were okay with the compressor loading up to 100% before backing off to match the load

Read more about oil analysis and testing at the Institute of Refrigeration | Click Here


Industrial Refrigeration Ammonia Cat Ladder

Industrial Refrigeration Ammonia

The industrial refrigeration ammonia 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 attention. Quite easy job as the faults they go into are reoccurring round in a circle. They have previously had the same problems

Ammonia Shaft Seal for Industrial Refrigeration

The industrial refrigeration shaft seal had started to leak ammonia. It was replaced 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

Leaking Industrial Refrigeration Ammonia 'O' Rings

Ammonia leaks 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

service@maximuschillers.com

Contact Form

Lift and Shift for Ammonia Visit

The pipework and ancillaries had been removed from the compressor prior to the ammonia visit. Our lift and shift guys arrived and set up their lifting equipment. They raised the compressor and manoeuvred it on across the roof. They then manoeuvred it up then down some steps. They used lifting equipment to get the compressor, end on- down a cat ladder

Tear Down of 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 Charge

Part of the ammonia refrigerant had been handled during the 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

If you would like to buy an introduction to ammonia refrigeration from the iiar Click Here


Industrial Refrigeration Oil

Industrial Refrigeration Oil

An industrial refrigeration oil visit was arranged because of an oil return issue. Several fans had been down on the air cooled system. This causes the 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 from the Industrial Refrigeration Plant

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

0161 370 7193

service@maximuschillers.com

Contact Form

Fan Decks

For this 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

Testing of the Industrial Refrigeration System

The fault link had been correctly modified, so 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

 


Translate