Manufacturers of Cooling Towers, Cooling Systems and Air Strippers by Delta Cooling Towers, Inc.

The airflow switch is desirable when loss of airflow will have an adverse affect on system operation.  This switch will indicate loss of airflow from many causes including, but not limited to, belt slippage, belt failure, motor failure, thermal overload shutdown, media failure, etc.  The airflow switch is an on/off device that can be operated in two modes:

A. Will indicate total loss of airflow as installed at the factory, or

B.   Can indicate loss of a limited amount of airflow by varying the insertion depth of the sensing elements.

The enclosure is rated NEMA 7 and 9 as standard. The contacts have a rating of 5 amperes at 125/250 VAC and are SPDT.  It can be utilized for system shutdown, warning lights, or other functions.

The antifreeze package is supplied to provide protection against freezing of standing water in the cooling tower sump due to shutdown during winter operation.  The option is provided when draining the system during periods of prolonged shutdown is not feasible, such as during weekends, or when a separate gravity feed indoor storage tank is not part of the re-circulation system.  Resistance heating of the sump water provides protection, and this package includes the following components:

NEMA 4X Enclosure with fused disconnect, solid state printed circuit board pre-set to 45°F on/off temperature control with 5°F switching differential and built-in low level cut off, electric immersion heater, sensor probe with cord to measure both water temperature and water level and heater wiring diagram.

Immersion Heater are sized as follows:

t10 thru t25                  2000 watt

t30 & t40               4500 watt

t50 thru t150                6000 watt

T55i thru T175i           6000 watt

T200i thru T250i         9000 watt

TR-2xx812                  6000 watt

TR-3xx812                  9000 watt

TM Series                   6000 watt per cell

This option is utilized when freezing of standing water in the cooling tower sump could occur due to system shutdown during winter operation.  An electrically actuated valve will open when the pumps are not operating and the temperatures approach freezing.  The valve can be installed in the sump drain fitting of the tower (at the factory) or remotely at the piping low point (by others in the field).

Components provided are:

A)    Electrically actuated to close, spring to open, 2-way valve, 1” line size, with NEMA 4 enclosure.

B)     1” PVC tee

C)     1” PVC plug

D)    Temperature switch with bulkhead fitting

When power is removed the valve automatically reverts to the open position.  This feature ensures freeze protection even during a power outage.

Mastic coating of the blower wheel, housing and frame is desirable when additional corrosion protection is required. The mastic coating is applied directly over the standard enamel finish.

This option is recommended in areas of continuous high humidity. It also provides protection from corrosive compounds, acids, etc.

The material used is a brush on, solvent based, asphaltic film coating which is impervious to standing water and airborne spray.

Mastic coating has proven successful in prolonging the average life of a standard blower assembly.

After final assembly, the blower shaft and sheaves are coated with a special shaft coating material. This coating conforms to MIL-C-16173D, GR 1 & 4.

For best results, periodic recoating of both the wheel and housing are recommended.

Premium blower corrosion protection is desirable when the unit will be operated in highly corrosive atmospheres such as paper mills, coastal areas, chemical plants, etc.

The premium blower corrosion protection option consists of complete PVC encapsulation of the blower wheel and housing and frame. A T-304 stainless steel shaft is also included.

This option offers an extremely cost effective alternative to FRP blower assemblies. The blowers and frames are prepared at the factory with all holes and cutouts completed. The entire assembly is sandblasted, then dipped in a molten PVC solution which coats the entire surface. When dry, the PVC attains an average thickness of 30 mils and forms a complete covering of the standard frame and rousing. The blower wheel is coated in the same manner, except for the shaft bore, and is then re-balanced both statically and dynamically.

After final assembly, the shaft and sheaves are coated with a specially formulated shaft coating material which conforms to MIL-C-16173D, GR 1 & 4.

The result is a blower assembly which will give years of corrosion free service even under the most adverse conditions.

The Bottom Outlet is a convenient option when gravity draining a cooling tower.  This minimized the amount of standing water in the sump of the cooling tower. A 125lb. Flanged fitting is provided.  Provisions must be made in the mounting platform for the fitting.  The platform, indoor storage tanks and other fittings can be provided by Delta.

A control panel is required any time there are electrical devices involved in a system.  The standard features of a Delta supplied control panel are:

A)    NEMA 3R water tight enclosure

B)     Single speed motor starter

C)     110V transformer with fuses

D)    Fan Motor operating lights

E)     Fan Motor selector switches

F)      Terminal strips

G)    208V or 230V or 460V or 575V / 3Ph / 60Hz

Optional items available:

• Disconnect switch: either fused, unfused or magnetic circuit breaker type.
• Additional motor starters, selector switches and lights to interface with existing systems, remote pumps, etc.
• Any other NEMA enclosure manufactured.
• Pre-mounting of control panel and pre-wiring of skid mounted options with Liquid-Tite conduit or EMT. (Consult factory for add pricing)

Delta also can provide programmable controllers, computer interfacing, telemetry, and any other type of control system required.  Pre-mounting and pre-wiring of the control panel for a system installation are available.  This minimizes the labor required for field installation.

This option is used when the inlet water temperature entering the cooling tower will exceed 140°F.  CPVC piping would replace the standard PVC piping and can be used with water temperatures up to 160°F with standard PVC fill cooling towers and 175°F with cooling towers with High Temp fill.

This option replaces the standard float valve make up assembly to electronically maintain the water level in the cooling tower sump.  The package includes two ultrasonic level switches, solenoid valve and remote relay level controller in a NEMA 4X enclosure.

This option is desirable for multiple module installations to provide equal liquid levels in the sumps of the individual modules and allows for the installation of only one (1) water make-up line.  Delta provides the bulkhead fittings installed in the cooling towers to provide for gravity flow from one tower sump to another.  The equalizer connection is not for full flow transfer (ex: pumping from one unit to another).

The connecting piping should be field installed and is the responsibility of others.

The standard fan coating provided for the cooling tower fan ring and guards is a cross linked epoxy-phenolic with an alkaline curing agent and formulated to withstand a wide range of chemicals and for ease of handling.  This coating provides excellent chemical resistance to a wide range of acids, alkalies, solvent and water solutions.  When dry, the coating can withstand up to 400°F temperature.  The fan ring and guard steel surfaces are sand blasted and a primer is applied prior to the final application.

Also available in 304SS or 316SS for an added charge.

This option provides 150lb Schedule 80 PVC flanged connection at approximately 6” – 8” projection from the cooling tower.  Gaskets and hardware are not provided by Delta and should be provided by others with the piping companion flange.

The high sump level switch option is utilized when a potential overflow must be avoided.

Switch elevation is set below the point when the water in the sump will overflow onto the ground.

The switch can be used to illuminate a light, shut off the influent feed pump or initiate some other device or alarm.  This package consists of a NEMA 7 and 9 liquid level switch mounted in a PVC bulkhead fitting assembly with a 2” x 1” reducer bushing.

This option is used when the inlet water temperature entering the cooling tower will be greater than 160°F. High Temp Fill would replace the standard PVC fill material inside the cooling tower with polypropylene fill material.  The High Temp Fill can withstand water temperatures up to a maximum 175°F and spikes of 190°F.

The ladder assembly facilitates access to the upper section of the cooling tower for inspection and maintenance of the water distribution system and fan assembly as required.  The assembly is fabricated of aluminum for lightweight installation and has skid resistant rungs and landing platform.  The landing platform is specifically placed to maximize accessibility to the man-way located in the conical section of the tower for easy access and servicing of components.  The ladder conforms to all OSHA requirements.  In some cases the cage assembly may be required.  The unit is attached to the tower via (4) bolted connections and two base mounting bolts.

PVC coated polyester mesh screening that attaches over existing PVC louvers to prevent smaller size debris from entering the cooling tower.  Filters are weather/rot resistant and can easily be removed for cleaning.

LOW SOUND option utilizes a Wide Chord Blade Fan Prop with a belt-driven lower speed system to achieve large reductions in sound noise.  At ground levels, sound pressure levels are reduced 4-8 dB(A); Overhead, sound pressure levels are reduced 10-17dB(A). (Depending on model tower and site dynamics).  Designed to have the same very high efficiency as standard designs, utilizing premium efficient motors, resulting in the no de-rate in cooling tower capacity.

Fan Motor Space Heaters are recommended for installations where temperature variations can cause excessive condensation within the motor.  The Space Heater controls can be incorporated in our Control Panel and would be designed for automatic and manual operation.  While the motor is operating, the heater remains off.  When the motor shuts down, the heater is automatically energized during the off cycle.  The Control Panel would be designed with manual on/off control for intermittent cycles of operation.  Heaters are available for 115, 230, 460, or 550 volts, 3 phase, 60-cycle operation.

This option is desirable to prevent debris that may have entered the cooling tower sump from getting into the pump, or the rest of the cooling water system.  This option is recommended to minimize particle size that could foul chillers, heat exchangers, compressors or the cooling tower distribution laterals.

A vortex breaker pipe, which is provided as standard on pump suction applications, is included to maximize the inlet area and prevent cavitation.  The strainer is made from a vortex breaker pipe surrounded by 3/16” #2 PVC coated mesh screen.  Finer mesh screens can be overlaid to minimize particle size.  Consult Delta for add prices and availability.

The platform is beneficial in installations where a flat and level surface is not available for mounting Delta’s cooling towers.  The steel platform is also utilized for replacement installations where only “I” beams, or other forms of support exist.  This steel platform is finished in a black air-dried phenolic paint.

The platform is shipped in two separate pieces, for transportation purposes, and must be supported in the field by others.  An optional walkway can be supplied to allow for accessing the cooling tower sump, should the platform be elevated.

The platform stand option is the supporting steel legs used to raise the platform option supports the cooling tower base.   The stands are available in 10’, 12’ and 14’ heights and can also be customized to meet the applications requirements.

The pump package is offered to allow for single source responsibility of cooling tower equipment.  The size of the pump is determined by two factors:

A)    Flow rate

B)     Total dynamic head

The customer is responsible for supplying this information.  The pumps come complete closed-coupled with mechanical seals and ODP, 208/230/460V, 3 phase motor.  TEFC motors are available.

Complementary to the ladder option.  Extends above the ladder-landing platform for extra protection while accessing the top of the cooling tower. The safety cage is assembled to the ladder at the factory for ease of installation.  This assembly is attached directly to the cooling tower shell during installation.

The safety cage may or may not be required depending on OSHA specifications.  The cage assembly is manufactured of the same type of aluminum as the ladder.

These Simplex & Duplex strainers are a cost effective way for removing damage causing particulate matter from process water, protecting system components such as flow meters, pumps, and spray nozzles.   The clamp type cover is easily removed without tools, making cleaning or change outs quick and easy.  Features include a cast iron housing, hand removable cover, removable perforated stainless steel basket, Buna seals and drain plug.

This option is available on the Paragon series to replace the standard rotating sprinkler head assembly with a fixed spray nozzle system and upgraded drift eliminator.   The system is made up of a PVC lateral tree system with removable threaded spray nozzles sized for the specified flow rate and design conditions.

Stainless steel strainers are used to remove solid particles from liquid streams.  These strainers feature a stainless steel housing and fine mesh conical shaped screen.  They handle flow rates from 10 GPM to 2,000 GPM and operating pressures up to 150 psi.  Higher flow rates may be achieved by manifolding multiple filters.

Unlike traditional basket strainers, y-strainers, or bag filters, these units can be flushed while online and in service.  Settled debris is easily removed by purging through the debris flush port.  They are also available with the following options:

1. Pressure Differential Alarm Package – This alarm package continually monitors the inlet and outlet system pressure. When the filter screen becomes clogged, the pressure differential switch-gauge will trigger an audible siren and visual flashing alarm. These alarms are intended to alert maintenance personnel that the strainer screen needs to be removed and cleaned.
2. Automatic Timer Flush Package – This system will ensure that your strainer is always flushed. By using a dirty water diaphragm valve and a timer based valve controller, debris purging is automated. The timer controller is easy to use, water-resistant and can be powered with 9-volt batteries or AC power.

The strainers also operate with less than 1-PSI pressure loss at maximum flow, when clean.  This efficiency results in dependable filtration without constricting your system’s flow rate or causing unnecessary pressure loss to downstream equipment.  .

The tank is utilized when extra water capacity is required.  Potential applications are for system modulation when pumping flow rates vary, or for water storage.  A hot/cold tank arrangement may be required in those cases where the process hot water exceeds the maximum allowable inlet water temperature.  The cooling tower would flow more water than the process and the difference would be mixed with the hot water to reduce its temperature.  The tank and optional cover are fabricated of medium density polyethylene.  All fittings are Type 1 PVC.

The fan thermostat is important to minimize operating costs.  The thermostat senses water temperature and controls fan operation during cold weather service.  When cold-water temperature drops below design, the fan will shut off saving motor hp operating costs.

A single stage thermostat controls the fan on/off and is provided with a standard single speed motors.

A two-stage thermostat is required for two speed motor operation and controls the fan from ‘on’ to ‘half speed’ and then to ‘off’.  At half speed operation the motor operates at only ¼ full load BHP.  Two stage thermostats must be wired to Delta specifications.

As the cold-water temperature rises and approaches the design temperature, the thermostat signals the fan to start in order to maintain the cold water design temperature.  The thermostat has a 5°F differential in its operating range of 30°F to 130°F.  The contacts are SPDT and have a 15 Amp UL rating.  They are complete with NEMA 4 enclosures suitable for outdoor mounting.  The thermostat can be provided loose, or installed in the cooling tower sump, or an indoor storage tank.  When the thermostat is supplied with a cooling tower or storage tank provided by Delta, the package includes installation with a ¾” Schedule 80 PVC bulkhead fitting and a ¾” x ½” Schedule 40 PVC reducer bushing.  Thermostat operating range must be set in the field.  Recommended setting is approximately 70°F to 72°F, but will vary depending on the application and the installation location.

Two speed fan motors provide cold-water temperature control by means of airflow modulation, allowing for design cold-water temperature at minimum operating cost.  When provided with a two-stage thermostat, the motor can be reduced to half speed when cold water sump temperature approaches design.  The motor will shut off when the cold-water temperature falls below design.  Two-speed TEFC motors are provided for single voltage 3-phase operation only.  Single-phase dual voltage motors are not available.  NOTE: a ½ reduction in motor speed corresponds to ½ reduction airflow.  At half speed operation, only 1/8 BHP is consumed.

An optional upper safety handrail system is available to provide protection while on top of the cooling tower inspecting or working on the mechanical equipment. This option is shipped pre-fabricated for assembly in the field.

The Variable Frequency Drive Package is an energy savings device that allows speed control of the cooling towers fan motors.  The standard package includes a NEMA 1 or NEMA 3R enclosure with a VFD, electronic 3-contactor bypass, fused disconnect and 3% input line reactor.  The bypass configuration allow for isolation of the VFD for maintenance or adjustment while the cooling tower is still in operation.  The drives also include Modbus, communication protocol standard.  Other protocols are available.  Drive packages are also available with the following options:

A)    Digital Temperature Controller to automatically adjust the fan speed based upon the sump water temperature.

B)     Pump Motor Starters to control the operation of the cooling tower pump

The vibration cutout switch option is utilized to shut down the rotating mechanical fans in the event of excessive vibration.  This device helps prevent further potential damage by shutting the motor off.  It is wired in series with the motor starter coil and has dry contact rating of 10-ampere capacity at 120 VAC.

Delta provides the vibration cutout switch installed on the blower when ordered as a component of a new cooling tower or on a replacement blower assembly.