PMTQ Cooling Tower

Principle of Operation

Warm water from the heat source is pumped to the water distribution system at the top of the tower. The water is distributed over the wet deck fill by means of large orifice nozzles. Simultaneously, air is blown through the fan section at the base of the tower and travels upward through the wet deck fill opposite the water flow. A small portion of the water is evaporated which removes the heat from the remaining water. The warm moist air is forced to the top of the cooling tower by the fan and discharged to the  atmosphere. The cooled water drains to the basin at the bottom of the tower and is returned to the heat source.

IBC Compliant

What is IBC?
   
The International Building Code requires that evaporative cooling equipment must meet the same seismic or wind load forces as the building to which they are attached.

How does it apply?
   
Based on project zip code and site design factors, calculations are made to determine the equivalent seismic "g force" and wind load on the unit.

What does EVAPCO offer?
   
Standard Structural Design:  Projects with ≤ 1.0g seismic or 2.87kPa wind loads
   
Upgraded Structural Design: Projects with > 1.0g seismic or 2.87kPa wind loads
   
The upgraded structural design package for the PMTQ is designed for 5.12g and 7kPa.

EVAPAK® Fill

The EVAPAK® fill design used in the PMTQ Cooling Tower is specially designed to induce highly turbulent mixing of the air and water for superior heat transfer. Special drainage tips allow high water loadings without excessive pressure drop. The fill is constructed of inert polyvinyl chloride, (PVC). It will not rot or decay and is formulated to withstand water temperatures of 130ºF (54,4ºC). Because of the unique way in which the crossfluted sheets are bonded together, and the bottom support of the fill section, the structural integrity of the fill is greatly enhanced, making the fill usable as a working platform. The fill selected for the Cooling Tower has excellent fire resistant qualities. Cooling Tower fill has a flame spread rating of 5 per ASTM-E84-81a. A higher temperature fill is available for water temperatures exceeding 130ºF (54,4ºC). Consult your EVAPCO representative for further details.

Easy Field Rigging

85% Fewer Fasteners. Lower Installed Cost

The PMTQ 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 fill casing section into position and set in place on the bottom fan section of the tower. In addition, the new design eliminates up to 85% of the fasteners typically used to join the tower sections in the field significantly reducing the contractor labor costs for installation.

Reduced Piping Costs

Each PMTQ Cooling Tower is furnished with one inlet and one outlet piping connection per cell. This design reduces the amount of external piping and thereby lowers the installed cost of the cooling tower. The water distribution system is pressurized and self balancing. Since field balancing is not required on the PMTQ, the need for flow balancing valves is eliminated, further reducing the cost of tower installation. The wide orifice EVAPJET nozzles with anti-sludge ring used in the PMTQ water distribution system helps prevent clogging, reducing the maintenance costs of the water distribution system.

Basin Sealing System 

Unique Seam Design–Eliminate Field Leaks

The new PMTQ features Evapco's unique panel construction design which includes a special butyl tape sealer with an integral sealing gasket. Each joint is then backed with a secondary caulking compound and encased in a double-brake flange for added strength and structural integrity. This unique sealing
system has been proven effective in both laboratory tests and years of field application.

Fast, On-Time Shipments

The PMTQ is a completely factory assembled cooling tower manufactured by a dedicated professional workforce, expert in building cooling towers. 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 PMTQ to be available WHEN THE CUSTOMER WANTS IT!

Fan Drive Accessibility

The drive components of the PMTQ 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 are located to the front of the fan section and motors are positioned on a platform base to allow for easy belt tension adjustment.

Easy Clean Sloped Basin

The PMTQ 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.

Man-Sized Access Door

Evapco offers standard “man-sized” access doors to improve access to this critical area of the unit.

Stainless Steel Strainers

The pump section connection strainer is one component subject to excessive wear and corrosion. EVAPCO provides a Type 304L stainless steel strainer on all units with pump
suction connections as standard. Strainers are positioned around a large anti-vortex hood in easily handled sections.

Superior Water Saver Drift Eliminators

The PMTQ Cooling Tower incorporates a patented* highly efficient PVC drift eliminator. The 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, PMTQ cooling towers save valuable water and water treatment chemicals. The eliminators feature a honeycomb design which offers greater structural integrity and are recessed in the top of the casing and UV protected for longer life. They are constructed of inert polyvinyl chloride (PVC) which eliminates corrosion in this critical area of the tower. The eliminators are assembled in sections for easy handling and removal for fill pack and water distribution
system inspection. *U.S. Patent No. 6,3158,0481

Pressurized Water Distribution System

The water distribution system is made of schedule 40 PVC pipe and EvapJet™ ABS plastic water diffusers for corrosion protection in this key area. The piping is easily removable for cleaning. The water diffusers have a 1 inch diameter (25mm) opening and are practically impossible to clog. They also have an anti-sludge ring extending into the headers to prevent sediment from building up in the diffuser opening. In addition, the spray branches have threaded end caps to allow easy debris removal. The spray pressure is between 1 and 6 psig (7 and 42 kPa) at the inlet header. The actual spray pressure will be shown on the certified drawings which are prepared for each unit. 

Individual Fan Drive System

Capacity Control Flexibility & Operating Redundancy

The new PMTQ 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.

Fan Motors

All PMTQ Cooling Tower models utilize heavy duty totally enclosed (T.E.F.C.) fan motors designed specifically for cooling tower applications. In addition to the standard motors offered on each cooling tower, EVAPCO offers many optional motors to meet your specific needs, including:

• Premium Efficiency Motors
• Multi-Speed Motors

Fan Shaft Bearings

The fan shaft bearings on the PMTQ cooling tower are specially selected to provide long life, minimizing costly downtime. They are rated for an L-10 life of 75,000 to 135,000 hours, making them the heaviest duty pillow block bearing in the industry used for cooling tower duty.

Five (5) Year Drive Warranty

EVAPCO provides a standard five (5) year motor and drive warranty on PMTQ Cooling Towers. This unique warranty is designed to offer the end user optimum protection against fan drive and motor failure. It is a comprehensive plan which includes the fan, fan shaft, belts, sheaves, fan bearings, driveshaft and the motor.

Self Supporting Service Platforms

Towers 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.

Screened Bottom Panels

Protective inlet screens are provided on the sides and/or end of the unit’s air intake. Screens are not provided below the fan section since most units are mounted on the roof or at ground level. It is recommended that bottom screens be added to the unit when it will be elevated. These screens can
be provided by the factory at an additional cost or added by the installing contractor.

Electric Water Level Control

Cooling towers may be ordered with an electric water level control in lieu of the standard mechanical float and make-up assembly. This package provides accurate control of water levels and does not require field adjustment.

Basin Heater Package

Electric immersion heaters are available as an option and are located in the basin of the tower. 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.

Steam or Hot Water Coils

Pan coils are available as an alternate to the electric heaters described above. Constructed of galvanized pipe installed the cooling tower basin, they are supplied less controls and are ready for piping to an external steam or hot water source. Pan water heater controls should be interlocked with the water circulating pump to prevent their operation when the pump is energized.