PMC-E Evaporative Condenser

Principle of Operation

The refrigerant is circulated through the coil of the evaporative condenser. Heat from the refrigerant is dissipated through the coil tubes to the water cascading downward over the tubes. Simultaneously, air is forced in through the two stage vane axial fans at the base of the condenser and travels upward over the coil opposite the water flow. A small portion of the water is evaporated which removes the heat. The warm moist air is forced to the top of the evaporative condenser by the fan and is discharged to the atmosphere. The remaining water falls to the sump at the bottom of the condenser where it is recirculated by the pump up through the water distribution system and back down over the coils.
 Duty Automotive Duty and Many More, Consult the Factory

Patented Thermal-Pak® Coil

EVAPCO's Thermal-Pak II coils is designed to assure maximum cooling capacity. The airflow through the coil is counterflow to the fluid flow, providing the most efficient heat transfer process. A special coil design is utilized to reduce the air pressure drop through the unit while maximizing tube surface area and increasing its heat transfer capabilities. The uniquely shaped tubes of the coil are staggered in the direction of airflow to obtain a high film coefficient.

The coils are manufactured from high quality steel tubing following the most stringent quality control procedures. Each circuit is inspected to assure the material quality and then tested before being assembled into a coil. Finally, the assembled coil is pneumatically tested at 400 psig (2758 kPa) under water to ensure it is leak free.

To protect the coil against corrosion, it is placed in a heavy steel frame and then the entire assembly is dipped in molten zinc (hot-dip galvanized) at a temperature of approximately 800°F (427º).

Efficient Drift Eliminators

The PMC-E Evaporative Condenser utilizes a NEW patented highly efficient PVC drift eliminator design. The drift eliminator removes entrained water droplets from the air stream to limit the drift rate to less than 0.001% of the recirculating water rate. With a low drift rate, the PMC-E Evaporative Condenser saves valuable water and water treatment chemicals. The PMC-E Evaporative Condenser can be located in areas where minimum water carryover is critical.

The drift eliminators are constructed of an inert polyvinyl chloride (PVC) plastic material which effectively eliminates corrosion of these vital components. They are assembled in sections to facilitate easy removal for inspection of the water distribution system. Eliminators incorporate UV inhibitors to resist cracking and degradation due to sunlight.

Unique Rigging Design

• 85% Fewer Fasteners
• Lower Installed Cost

The PMC-E features a new field seam design which ensures easier assembly and fewer field seam leaks. The field seam incorporates new self-guiding channels to guide the coil casing section into position and set in place on the bottom fan section of the condenser. In addition, the new design eliminates up to 85% of the fasteners typically used to join the condenser sections in the field significantly reducing the contractor labor costs for installation.
 

Pressurized Water Distribution System

PMC-E condensers are equipped with heavy-duty precision molded EvapJet™ spray nozzles with large orifice to eliminate clogging. EvapJet nozzles unique design ensures complete and even water coverage, resulting in maximum thermal performance.

The fluidic geometry of the EvapJet nozzle breaks the fluid into two separate paths. Typically when the two fluids meet head on they will create a planar water stream however, the EvapJet nozzle is designed such that the streams meet at an angled approach. This design results in an oscillatory motion characteristic of fluidic nozzles.

The sweeping oscillations from EvapJet's colliding water streams provide complete coil coverage. Traditional nozzle designs can create uneven water distribution that can result in "dry spots" or heat transfer surfaces not covered by water, thereby reducing thermal performance. Also, the EvapJet nozzle design incorporates a dispersion bar at the nozzle orifice to further ensure even water distribution over the heat transfer surface.

The EvapJet spray nozzles are threaded into spray branches for ease of removal and positive positioning. The spray branches shall be constructed of Schedule 40, PVC pipe for corrosion resistance. All spray branches are removable and include a threaded end plug for ease of cleaning. The water distribution is designed to provide a minimum 6 GPM over each square foot (4 liters per second over each square

Fast, On-Time Shipments

The PMC-E is a completely factory assembled evaporative condenser manufactured by a dedicated professional workforce, expert in building evaporative condensers. Factory trained mechanics and EVAPCO's strict quality control and inspection procedures guarantee the quality of every unit shipped.

EVAPCO's controlled factory environment ensures fast on-time shipments, allowing the PMC-E to be available WHEN THE CUSTOMER WANTS IT!

Easy Access

Drive components of the PMC-E are easily accessed for routine maintenance from the front of the unit. Bearing grease fittings are extended to the outside of the unit for ease of lubrication. All drive sheaves have been relocated to the front of the fan section and motors are positioned on a platform base to allow for easy belt tension adjustment.

Most PMC-E models* are equipped with horizontally mounted pumps which reduce water weight and improve pump operation. The simplified pump piping also allow for easier basin access.
* Check engineering data for availability

Stainless Steel Strainers

One component of evaporative cooling equipment which is subject to excessive wear and corrosion is the suction strainer. EVAPCO provides a lasting Type 304 stainless steel strainer on all units (except remote sump applications) as standard. Strainers are positioned around a large anti-vortex hood in easily handled sections.
 

Thermal-Pak II® Coil

EVAPCO's Thermal-Pak II ® coils feature a patented design which assures maximum cooling capacity. The airflow through the coil is counterflow to the fluid flow, providing the most efficient heat transfer process. A special coil design is utilized to reduce the air pressure drop through the unit while maximizing tube surface area and increasing its heat transfer capabilities. The uniquely shaped tubes of the coil are staggered in the direction of airflow to obtain a high film coefficient.

The coils are manufactured from high quality steel tubing following the most stringent quality control procedures. Each circuit is inspected to assure the material quality and then tested before being assembled into a coil. Finally, the assembled coil is pneumatically tested at 400 psig (2758 kPa) under water to ensure it is leak free.

EVAPCOAT Construction

G-235 Hot-Dip Galvanized Steel Construction

The standard material of construction for evaporative cooling equipment for many years has been hot-dip galvanized steel. The purpose of galvanizing is to protect the base metal from corrosion, and the thickness of the galvanized layer directly affects the equipment life.

EVAPCO has been instrumental in the development of corrosion protection technology and was the first manufacturer to use G-235 (Z600-Europe) galvanized steel construction. The G-235 (Z600-Eurpe) designation equates to a minimum of 2.35 ounces of zinc per square foot (600 grams per square meter) of surface area.

The EVAPCOAT Corrosion Protection System is the heaviest galvanized coating available for extended corrosion protection eliminating the need for costly, unreliable epoxy paint finishes.

Fan & Drive System

Energy Efficient for Lowest Operating Cost

The new fan drive system of the PMC-E utilizes larger diameter vane-axial fans in a two stage arrangement to provide more efficient air flow and reduced power consumption. When compared to the traditional centrifugal fan condenser models, the vane-axial fan design can offer up to a 50% reduction in energy consumption. And, with the new PMC-E model selections even more low horsepower options are available to obtain greater energy savings.

Capacity Control Flexibility & Operating Redundancy

The new PMC-E fan drive system provides individual motor to fan configuration as standard equipment on all models. The dedicated fan to motor arrangement ensures less “wear & tear” on the drive system versus tandem fan motor drive arrangements resulting in less maintenance. The individual motor to fan design offers greater capacity control flexibility to match the system load requirements. In addition, all Evapco condensers are equipped with an internal baffle system which extends from the pan bottom vertically through the coil bundle.  This unique design allows the user to cycle fan motors independently without harmful effects of air by-pass inside the unit. The individual motor to fan design ensures maximum operating redundancy in the condenser fan system when critical operation is necessary.

Sloped Pan Bottom  

 The PMC-E drain pan is designed to improve maintenance access and make it easier for operating technicians to clean. The bottom of the pan is sloped to the unit drain to ensure that the basin will completely drain and allow sediment and debris that may collect in the basin to be easily flushed from the unit. The design helps to prevent buildup of sedimentary deposits, biological films and standing water. In addition, Evapco offers a special “man-sized” access door option to improve access to this critical area of the unit.

Fan and Drive System

Capacity Control Flexibility & Operating Redundancy

The new PMC-E fan drive system provides individual motor to fan configuration as standard equipment on all models. The dedicated fan to motor arrangement ensures less "wear & tear" on the drive system versus tandem fan motor drive arrangements resulting in less maintenance. The individual motor to fan design offers greater capacity control flexibility to match the system load requirements. In addition, all Evapco condensers are equipped with an internal baffle system which extends from the pan bottom vertically through the coil bundle. This unique design allows the user to cycle fan motors independently without harmful effects of air by-pass inside the unit. The individual motor to fan design ensures maximum operating redundancy in the condenser fan system when critical operation is necessary.  

Vane Axial Fan Assembly

The new fan drive system of the PMC-E utilizes larger diameter vane-axial fans in a two stage arrangement to provide more efficient air flow and reduced power consumption. When compared to the traditional centrifugal fan condenser models, the vane-axial fan design can offer up to 50% reduction in energy consumption. And, with the new PMC-E model selections, even more low horsepower options are available to obtain greater energy savings.

Power-Band Belt Drive

The Power-Band drive is a solid backed belt system that has high lateral rigidity. This eliminates the problem of mismatched belts and prevents belts from jumping sheaves, a common problem with other designs.

Internal Baffles

As a standard feature, all Evapco condensers with multiple motors are provided with an internal baffle system which extends from the pan bottom vertically through the coil bundle. This allows the user to cycle fan motors independently to match system load without the harmful effects of air by-pass.

Bearing Lubrication

Lubrication lines are extended to the outside of the unit for easy access.

304 Stainless Steel Coil

The EVAPCO manufactured Stainless Steel Coil is an elliptical tube, continuous return bend, 304 stainless steel coil. It is available in both the Thermal Pak Coil design used on AT, UB, LR and LS coolers and condensers and in the patent pending SensiCoil design used in the ESWA.

This option has superior corrosion resistance for Open Systems and Hostile Environments and is available with the Standard Evapco Lead Time! For more detail on the corrosion resistant properties of 304 stainless steel, see Evapco's Maintenance Instruction Bulletin, 112AA.

The Evapco 304 SST coil option can be manufactured as an ASME coil and is CTI certified on the ESWA closed circuit cooler.
 

Access Ladders

Vertical access ladders are available on all PMC-E models. The EVAPCO designed access ladder features a ladder arrangement which provides fast and easy access to the water distribution system. The ladder(s) will ship loose and must be field mounted. The ladder meets all applicable OSHA requirements.

Stainless Steel Water Touch Basin

The basin area of the condenser experiences turbulent mixing of air and water, in addition to silt build-up. In conjunction with the EVAPCOAT Corrosion Protection System, EVAPCO offers an optional Stainless Steel Water Touch Basin.  The basin section provides the structural support for the unit and is a critical part of the condenser. The Stainless Steel Water Touch Basin provides maximum corrosion protection.

Extended Surface Coil

Condensers can be provided with spiral fins on the heat exchanger coil to increase the dry performance of the unit. Dry performance is accomplished by rejecting heat to the atmosphere without the use of the spray pump and the evaporation process. Dry operation can be practical in cold climates and/or when reduced winter loads exist. The number of fins per inch and and quantity of rows finned can be varied to obtain different dry performances.

Electric Heaters

Electric immersion heaters are available as an option and are located in the basin of the condenser. They are sized to maintain a +40° F (4,4º C) pan water temperature at 0°F (-18º C) ambient with the fans off *. They are furnished with a thermostat and low water protection device to cycle the heater on when required and to prevent the heater elements from energizing unless they are completely submerged. All components are enclosed in rugged, weather proof enclosures for outdoor use. Heater control packages that include contactor, transformer or disconnects are available.

(*) - Electric heater selection based on 0°F (-18º C) ambient temperature. For alternate low ambient heater selections consult the factory.
 

Electric Water Level Control 

EVAPCO evaporative condensers are available with an optional electric water level control system in place of the standard mechanical makeup valve and float assembly. This package provides very accurate control for the basin water level and does not require field adjustment, even under varying operating conditions.

The control was designed by EVAPCO and is manufactured exclusively for EVAPCO. It consists of multiple heavy duty stainless steel electrodes. These electrodes are mounted external to the unit in a vertical stand pipe. For winter operation, the stand pipe must be wrapped with electric heating cable and insulated to protect it from freezing.

The weather protected slow closing solenoid valve(s) for the makeup water connection is factory supplied and is ready for piping to a water supply with a pressure between 25 and 50 psig (138 kPa and 345 kPa).

Oversized Access Doors

For enhanced basin accessibility, the Oversized Access Door option enables maintenance personnel to quickly and easily enter the basin for float valve adjustment and unit inspection.

Self Supporting Service Platforms

Condensers are available with self-supporting service platforms that include access ladders which are designed for easy field installation. This option offers significant savings in comparison to field constructed, externally supported catwalks. The EVAPCO service platform option may be installed on either side, or the end opposite the connections.

Remote Sump Configuration

For units operating in areas where temperatures may be very low, or where low temperatures may occur during periods when the unit is not operating, a sump located inside the building is the preferred means of ensuring that the basin water will not freeze.  For these applications, the condenser will be supplied without the spray pump, suction strainers and all associated piping, but with an oversize bottom outlet.

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