Ammonia Evaporator Air Cooler

Evaporator is an important component together with other major components in a refrigeration system such as compressor, condenser and expansion device. The reason for refrigeration is to remove heat from air, water or other substance.
It is here that the liquid refrigerant is expanded and evaporated. It acts as a heat exchanger that transfers heat from the substance being cooled to a boiling temperature.
There are two types of evap.:
Forced Convection Type uses a fan or pump to force the liquid being cooled over the evap.
Natural Convection Type has the liquid being cooled flows naturally to the evap. due to the density differences of the chilled and warm liquid.

Evaporator Construction Types

There are three types of evap. construction that are commonly being used today:
Bare-Tube and Plate Surface construction have the entire surface in contact with the evaporating refrigerant inside.
Finned construction are bare-tube coils upon which fins(metal plates usually Aluminium) are being installed. A more detailed discussion on this type of design will be provided here.
Finned Evap.
The fins are added to the bare-tube to increase the heat transfer capability. They act as heat collector that pick up heat from the surrounding air and conduct it to the refrigerant inside the tube hence improving the efficiency in cooling the air of the surrounding. They are best used in the air-cooling space where the temperature is around 34°F.
Having fins mean the surface area for heat transfer has been extended. This means that the finned coils can have more compact in design compared to the bare-tube type of similar capacity.

Feature

• ammonia Evaporators systems are specially designed for medium and large industrial cold room, frozen storage ,blast freezing and fast cooling room applications.
• Artman ceiling mounted single discharge evaporators draws air across coils .

Casing

• Casing material is AlMg3 or galvanized steel depending on model and dimensions.
• All products are powder coated with RAL 9016 providing high corrosion resistance, smooth surface and decorative appearance.
• Standard hinged side coverings provide easy access to connections.

Accessories

• Hot gas defrost in coil,
• Hinged side coverings,
• Hinged or dismountable drip tray.

Sound data

• Indicated sound pressure levels comply with EN 13487.
• Sound levels are obtained from sound power levels (LwA) of the fans.
• Consult an expert for critical sound requirements.

Defrost

Hot Gas Defrost
• The standard coolers are suitable for hot gas defrost system.
• The compact evaporator coil with the small tube pitch and high heat transfer
coefficient, ensures a uniform and effective defrosting and a short defrosting time.
• Hot gas defrost with tubes positioned in drip tray is optional.
Electrical Defrost
• Electrical defrost is a standard application in coil block and optional in drip tray.
• Water Defrost
• Air Defrost

Coil

• 50 x 50 mm straight alignment,
• 15 mm AISI 304 stainless steel tubes,
• 4-7-10-12 mm of standard fin pitches. Other fin pitches are optional, Aluminum fins,
• Inlet and outlet connectors are AISI 304 stainless steel,
• Standard refrigerant connections are positioned on the right hand side of the direction of the air flow.
• Optimized circuit design,
• Test Pressure: 34 bar

In all stages of production, minimum test pressure for each coil is set at 30 bar

FANS specification

• Highly efficient axial Ziehl Abegg, EBM or equivalent fans are used in 400-450-500-630-800 mm diameters.
• Motor protection IP44 and IP54; insulation class B and F.
• Minimum working temperatures are -25 ̊C for monophase fans and -40 ̊C for triphase fans.
• Special fans should be used under operating conditions below -40 ̊C.
• Fans are arranged for standard draw through air configuration.
• 400/450 mm fans 230V 1~50 Hz; 500/630/800 mm fans 400V 3~50Hz,
• Triphase fans can work at two different speeds. Furthermore, EC fans providing speed control are optional.
• Variable fan speed regulation can be achieved using triphase fans with frequency inverter and sine filter.
• Working at low ambient temperature and high air resistance; thermistors must be used for motor protection.
• Streamers providing extra air throw distance are optional.
• Artmanreserves the right to use fans of different manufacturers. Depending on the type, the fan data may slightly vary.

Download Brochure

for more specification please download product brochure

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