High Pressure Receiver (Liquid Receiver)
The high-pressure receiver also called liquid receiver is generally needed in a refrigeration system when operating less than its full nominal capacity. Liquid receivers are generally installed close to the condenser outlet. High pressure liquid receivers permit also to maintain a sufficient head pressure during low ambient temperature. The high-pressure receiver permits to hold excess refrigerant which is not in circulation due to lower capacity needs. It’s a storage pressure vessel which is generally sized for 80 % to 100 % of the full refrigeration system charge.
SURGE DRUM & ACCUMULATOR
A flooded refrigerant surge drum permits to separate vapor from liquid phasis of the refrigerant coming out of the evaporator in order to protect the compressor against liquid hammering. Surge drum permits also to absorb excessive surge due to variation of the refrigeration system load.
Oil Pot
In a refrigeration system, oil accumulation in heat exchangers shall be avoided to maintain a good efficiency. Indeed, too much oil presence in evaporator or condenser affects negatively their efficiency since the oil will act as a thermal barrier in those heat. Oil pot collects the mixture of refrigerant and oil that typically accumulate in the bottom of pressure vessels. Moreover, the oil pot allows to isolate most of the oil at a single location to easily drain it from the system during maintenance.
INTERCOOLER
When multistage compression is used in a refrigeration system, cooling refrigerant vapor between the several stages of compression is needed. Cooling is achieved by an Intercooler which desuperheat booster compressor discharge vapor before the high stage compression. There are two types: open type intercool, also called flash type intercooler and a closed type intercooler also called a shell-and-coil intercooler. The sub-cooled liquid leaving the intercooler lowers the inlet vapor quality, thus reducing the mass flow rate through the evaporator as well as diminishing the sizing of the low-stage compressor required for a certain system capacity.
TRANSFER DRUM & DRUMP TRAP
Drum traps are designed to collect by gravity the overfed liquid refrigerant from the low-pressure receiver. Drum traps also called transfer drums return the excess liquid to the controlled pressure receiver (CPR) using the pumping power of the discharge gas pressure. Docal drum trap are ASME certified (U stamp our UM stamp) and can also bear Canadian registered number (CRN) from CSA B51 for Canada or with National Board for USA. Post-weld Heat treatment and corrosion allowance are available as options.
CONTROL PRESSURE RECEIVER
Controlled Pressure Receivers (CPR), mostly seen in industrial ammonia refrigeration systems, permits to avoid recirculation pumps. A controlled pressure receiver mixes saturated and return liquid lines and feds evaporator with partially subcooled liquid. With properly adjusted liquid feed rates and set pressure regulators, CPR liquid overfeed systems often represent the most efficient option in system design. Some of the advantages of a controlled pressure receiver systems are the elimination of pumps, excellent evaporator heat transfer and the possibility of back-regulating evaporators.
THERMOSIPHON
Thermosiphon receivers are required in industrial refrigeration systems when cooling the oil for the screw compressors. Thermosiphon use boiling refrigerant at condensing temperature as the cooling medium. Essentially the flow is generated by gravitational forces (thus the importance of an elevated installation) and variations in fluid densities in the coil coolers, rather than mechanical pumps. Custom designed and built to any size and configuration, the Docal Thermosiphon receivers are certified according to the latest ASME standards and available with National Board (USA) or CRN (Canada) certifications. Post-weld heat treatment and corrosion allowance available as options.