Improving automatic oil return
The Witt barrel dosing pump, BDP2, is said to have many advantages for automatic oil return in refrigerant systems.
Among the advantages claimed for the BDP2 are that manual oil draining is not required; internal damping allows the use of hot gas at high pressure to be injected to activate the BDP2; it can be operated at fixed time intervals or activated when needed by the addition of a Witt supplied electronic level sensor; it’s relatively simple to install in new systems compared to a conventional manual oil drain vessel; it is adaptable to changing system requirements and has a design pressure of 40bar.
There are three different sizes, depending on the refrigerant and size of the system. UK distributor Titan Engineering will advise which is best suited for any particular application.
Don Belcher, managing director of Titan Engineering, commented: “Even with efficient oil separators there is always a small amount of oil carried over into systems, which will accumulate over time and needs to be recovered. The Witt oil recovery system incorporating the BDP2 uses existing hot gas to automatically return accumulated oil in a cost effective and energy efficient way back to the compressor via a heat exchanger and oil filter to ensure evaporation of remaining liquid refrigerant.”
One of the more common causes of poor performance and technical problems in ammonia systems is the build up of unrecovered oil as a result of poor manual oil draining technique. According to Don Belcher, the BDP2 and its accessories can automate this process: “Properly set up it can eliminate the need for the involvement of manual labour in the oil recovery process,” he said.
Unlike previous models if servicing is needed then, the BDP2 can be opened by a competent ammonia refrigeration engineer and parts can be cleaned or exchanged as needed.
