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CCT TowerCCT Towers - InstallationCCT Towers - InstallationCCT Towers - InstallationClosed circuit operation diagramNozzleDrift eliminatorsCirculation pumpThermal exchange pipesThermal exchange pipesFan unitCollecting basin treatment with three fiberglass layers

CCT CLOSED CIRCUIT COOLERS

The CCT SERIES is dedicated to every industrial sector with a modular conception. These models are characterized by well-defined standards and are supplied with a preassembled structure, reducing to zero the assembly costs (to consider only positioning on site). DURABOND/HYB/CCT protection surface treatment of metallic parts is different from area to area, for the tower body and the basin exterior is composed of a furnace polymerized plastic anti-corrosion cycle, meanwhile for the basin internal surfaces (then the ones more exposed to corrosion) of three layers of fiberglass modeled directly on blasted surfaces. CCT coolers have dimensions compatible with road and container transport. The ordinary maintenance and sometimes even the extraordinary one is ensured by oversized inspection doors placed on every cell/fan unit. The fan units are planned for a long life and with components of utmost quality; the maintenance program is very easy since there aren’t any transmission organs. The most important feature that distinguishes the closed circuit towers from the open circuit ones consists in the fact that  the flow (and then the heat exchange) of the primary circuit circulating inside the cooling internal circuit is separated from the secondary spraying circuit. Through the spraying water of the secondary circuit, the water is pulverized on the primary circuit pipes and, in this way, together with the air crossing the tower in countercurrent, the heat exchange occurs. The most important aspect to underline is that the water circulation in the primary circuit and then the process water, is not contaminated by the one circulating on the secondary circuit; therefore it is possible to prevent any possible corrosions since the air, being outside the pipes, is not in contact. 

Heat Exchange Principle

  • - The thermal charge inside the pipes bundle, is dispersed by the evaporation phenomenon triggered by the fresh water pulverized on the pipes, by using the latent heat.
  • - The effect of the forced ventilation, on the water film present on the pipes, produced by the spraying of the secondary circuit,  favors the evaporation by ejecting the heat into the external environment.
  • - Spraying water is cooled by the air coming (sucked) from the aspiration windows below called “louvers”;
  • - Providing a lower condensing temperature, with less energy and water consumptions, the closed circuit coolers are more compact compared with traditional air coolers, which don’t use spraying water (then with a lower performance);
  • -For the various needs and requests, we can select exactly in the required working point, the right balance between spray water and air flow in countercurrent, with different shapes and materials tubes.

 

FAN UNIT

For CCT SERIES of classic induced execution towers, the choice regarding the type of fan is almost obliged. The electric motor is placed inside the air flow, the motor foreseen for utilization in saturated ambient is asynchronous three-phase TEFC with oiled watertight IP54 bearings, which ensure durability. On the drive shaft an axial fan in aluminum alloy is placed. 

Electric motors: are planned for severe conditions with continuous working S1 type and are asynchronous three-phase TEFC, equipped with oiled watertight IP54 bearings. They are placed inside the flow crossing the cone trunk stacks for a better fluo-dynamic distribution. The electric motors frames are designed to transfer the dynamic loads to the cooling tower structure, minimizing vibrations and allowing an easy and intuitive maintenance. All the rotating parts outside the stack are protected against accidental interferences in accordance with the most updated safety standards.

 

STACKS

All the mechanical groups in each cooling tower cell has an high thickness steel stack with DURABOND/HYB/CCT protection. Each stack has a circular inlet junction and a pyramidal section, the outlet section is designed to reduce pressure by obtaining an high efficiency of the axial fan. The stacks are fixed to the structure through dedicated bolts by securing them to the tower planking level.

 

WATER DISTRIBUTION SYSTEM

Inside the cooling tower upper section is placed the distribution system of “gravity” type. It is composed by a PVC main channel connected to the PVC secondary ones whereon the ABS spray nozzles are placed in order to ensure a water uniform distribution upon the whole dispersion section.

The a.m. nozzles are of three-stage type. This innovative spray nozzle has been designed to reach the following main goals:

  • - Large water distribution (approximately 1 m2) in order to avoid any possible overlapping  of the nozzles flows on the same dispersion surface.
  • - Uniform hydraulic load in order to avoid any air bypass  where the same is lower and not equally distributed.
  • - Lower distance between nozzle and filling  (600mm) in order to reduce the pumping elevation.
  • - Low operating pressure in order to reduce the pumping elevation.
  • - Self-cleaning surface.
  • - Anti clogging.

 

DRIFT ELIMINATORS

The drift eliminators are located below the fan unit in order to reduce the quantity of water entrained and dispersed into the external environment. The available materials are PVC, PP and CPVC with cellular technology and superlative performances (the water drift rate is less than 0.002% of the volume circulating on the secondary circuit). The maintenance is very easy, due to the light weight of the elements and the possibility to be shaped to size in case of revamping.

 

HEAT EXCHANGE TUBES

The tubes forming the internal dispersion are designed on the specific project for the best performances and efficiency. They are available in different materials like hot galvanized steel, stainless steel 304/316, all with 12 passages. The maximum pressure limit for the standard execution is fixed from 1,6 to 3 MPa with a loss of pressure of 0,06 MPa.

 

CIRCULATING PUMPS OF THE SECONDARY CIRCUIT

These pumps are dedicated to the secondary spraying circuit, pumping the water from the basin of the cooling tower to the spraying upper circuit in continuous. The frame is of “Flange to Flange” type to optimize the spaces and for a simple maintenance and assembly. The execution is “close-coupled”, with a single impeller of centrifugal type; the electric motor is equipped with an extended shaft directly connected to the pump. The pump casing is characterized by a suction and delivery flange with the same diameter that are in line (on the same axis) in order to improve the plant entry of the same.

 

WATER COLLECTING BASIN

The water collecting basin is supplied with a preassembled structure made up of bolted and sealed sheet panels treated with our DURABOND/HYB/CCT-F cycle, that is an hybrid protective treatment effected on rough blasted carpentry, made up of three layers of fiberglass modeled directly on the internal surfaces; on the basin external surfaces with the anti-corrosion DURABOND/HYB/CCT cycle, a furnace polymerized plastic anti-corrosion cycle. Optionally it is possible to ask for the deicing SCAM/RS resistances, the make-up valve SCAM/VL and the level control system through SCAM/LV420 sensor already assembled on water-collecting basin.