- One central vessel (accumulator) for all evaporators on a common suction system.
Provides liquid slop-over protection for system compressor(s).
Provides increased, efficient utilization of evaporator's internal coil surface for heat transfer.
Liquid refrigerant feed to the evaporator(s) is insensitive to floating head pressure.
Starcore Refrigeration Ltd. offers Horizontal low pressure pumped factory assembled pumped packages both for ammonia and halocarbon refrigerants. These packages are factory assembled, pre-wired and pre-piped on a common structural steel base complete with:
Accumulator : Suitably sized for given design criteria to maintain adequate separation velocity and dry gas velocity for compressor suction return. Vessels are ASME code designed
Pumps : Suitably sized to meet given system flow requirements as a function of required BTU removal required bypass flow to meet minimum pump flow requirements and system head at liquid specific gravity. Centrifugal pumps are dual mounted with one serving as a standby. Pumps are hermetically sealed, suction service valves, discharge stop/check service valves, bypass hand regulator valves and relief regulators, and volute vent valves.
Interconnecting Pipe, Valves and Fittings : Starcore Refrigeration Ltd. LP packages are furnished with the required interconnecting refrigerant pipe, valves and fittings, including pump vent lines, volute vent lines, pump bypass lines, gauges, and gauge valves. Valves are low temperature steel construction. Pipe 2 and smaller is schedule 80. Pipe 2-1/2 through 10 is schedule 40. Pipe for applications 20°F and above is ASTM A106 GRADE B. For applications below 20°F, ASTM 333 GRADE 6 carbon steel pipe is used. Pipe joints 1-1/2 and smaller are socket welded with 3000# class, socket weld fittings. Pipe joints 2 and larger are butt welded with fittings compatible with the wall thickness of the pipe.
Level Control : It incorporates isolation valves with flanged unions, electronic probe, high liquid level float switch, and drain valve. For operating level control level float switch with solenoid valve is incorporated. For low level a float switch is provided to cut off the ammonia recirculator to prevent damage during dry run.
Oil Pot : a 300-psi ASME CODE oil pot is provided with a relief valve, return service valve, vent service valve, oil drain service valve, and a spring return oil drain valve.
Control Panel : A NEMA 12 (460v power/120v control, 60 Hertz) pre-wired control panel is provided complete with the following:
Pump starters, Individual pump motor amperage monitor/display
Differential pressure switch
Control voltage with interlock for all Controls
Main power disconnect
Individual pump PROOF RUN indicators
High and low level indicators with alarm
Operating liquid level indicator
Low level reset
Mechanically pumped liquid refrigerant overfeed systems are very prevalent in industrial ammonia refrigeration applications. These systems function through the use of a mechanical pump that circulates liquid refrigerant through the evaporator(s). The two-phase (liquid/vapor mixture) is then returned to and separated in a central low-pressure
receiver (accumulator) with the dry vapor directed back to the compressor(s). An operating liquid refrigerant level is maintained (by liquid makeup) in the low-pressure receiver to replace liquid refrigerant that evaporated in the evaporator(s) by means of either electro-mechanical or electronic control devices.
In some cases, the system may witness a greater liquid refrigerant flow rate than the load requires, consequently producing disproportionate two-phase flow (added pressure drop) in the liquid/vapor return line to the low-pressure receiver.
iquid Make-up Control (Sub-assembled or Shipped Loose)