A single controller for managing cooling tower water: conductivity measurement, bleed-off control and dosing of antiscalant and biocide by means of two integrated pumps.
The two versions offer the same cooling tower control functions with two different dosing technologies; the choice depends on the chemical and on the performance required.
The flow rate is adjusted electronically by varying the number of revolutions per minute of the peristaltic motor (1 – 25 RPM). The stepper motor ensures optimal delivery of the product and completely silent operation. The peristaltic drive also allows dosing of substances that release gas. TPV peristaltic tube.
Conductive probeConductivity, various measuring ranges
Inductive probeConductivity, unaffected by polarisation and fouling
ManifoldSampling, dosing and bleed-off with motorised valve
Water meterPulse-output, on the make-up water
The flow rate is adjusted by varying the number of strokes per minute of the solenoid. A single flow rate and back-pressure configuration, suitable for dosing antiscalant and biocides.
Conductive probeConductivity, various measuring ranges
Inductive probeConductivity, unaffected by polarisation and fouling
ManifoldSampling, dosing and bleed-off with motorised valve
Water meterPulse-output, on the make-up water
Pump head: PVDF or PP
The WT manages the cooling tower bleed-off and the dosing of the two chemicals, antiscalant and biocide, with separate set points and independent control for each pump.
The WT continuously monitors the salt concentration in the water by means of a conductive or inductive conductivity probe. When the conductivity reaches the set value (set point), it opens the drain: the water with high salt concentration is discharged and replaced with make-up water. The drain remains open for a preset time or until the conductivity falls below the value that triggered it.
The first integrated pump doses the antiscalant: with a pulse-output water meter installed on the make-up pipe, the quantity of antiscalant dosed (mg/l) is proportional to the litres of make-up water.
Water meters →The second integrated pump doses the biocide, with timed activations or in proportion to the litres of make-up water. To preserve its effectiveness, the drain can be set to open before dosing, so as to reduce the salt concentration (pre-bleed) and increase the effectiveness of the treatment, and the drain can be inhibited for a set time after dosing, to give the biocide the necessary contact time (lockout).
The stepper motor and the control software deliver the product optimally, with completely silent operation.
The flow rate is adjusted electronically by frequency, by varying the number of revolutions per minute of the motor.
An elastomer compatible with most chemicals, which retains its elastic properties even after millions of compression cycles by the rollers.
Two tubes available, 1.6 × 1.6 mm and 4.8 × 1.6 mm, covering flow rates from 0.018 to 3 l/h.
The display colour changes according to the operating status of the WT, so that an alarm can be recognised even from a distance.
Normal operation according to the set parameters, no active alarms.
Non-blocking alarm, for example waiting for an external signal.
Blocking alarm, for example the chemical in the tank running out.
Pump stopped by an external control signal (stand-by).
The WT system supports two-way remote control: from the cloud portal, settings can be changed, operation can be checked and alarms can be received, such as product depletion; alternatively, the system can be integrated into a PLC via Modbus RTU.
Allows connection to the Nimbus cloud portal to change settings, check operation and receive alarms, such as the chemical running out.
Pump programming directly from a smartphone.
Allows connection to the Nimbus cloud portal via network cable to change settings, check operation and receive alarms.
Allows connection to the Nimbus cloud portal via the cellular network to change settings, check operation and receive alarms.
Integration into your PLC: all pump parameters can be managed from your control interface.
A single account brings together all registered installations, each with its own devices: the web portal, free of charge and with no subscription, can be accessed from PC, Mac, tablet and smartphone and allows every parameter to be both viewed and changed, with an encrypted connection and protected access.
On a single screen: probe readings, chemical levels, pump activation thresholds and active alarms, with the status of installations and devices (normal, warning, alarm, standby, not connected).
Installations appear on an interactive map with their status and open with a click; for each one, the local weather conditions and temperature are also shown.
Archive of measurements and alarms, available for consultation at any time with charts and numerical reports exportable in Excel format.
Alarm thresholds for readings, dosing, faulty probe and out-of-range readings, with notification by e-mail or SMS depending on the communication system; a warning is also issued when an installation remains disconnected beyond the set time.
Remote modification of the set points, of the dosing pump activation thresholds and of the corresponding hourly flow rate.
Status of relays, pulse outputs, digital inputs and current outputs, with the name assigned to each connection.
Tasks are scheduled by installation or by device and assigned to technicians; a reminder is sent by e-mail two days before the due date. Each task is shown as scheduled, due, overdue or completed.
The main account has full access and creates the technicians’ accounts, each enabled only for the assigned installations and devices; the last login and activity of each technician are visible.
Reports on devices, tasks and technicians, downloadable in PDF or CSV with the customer’s logo; the log keeps the history of operations and disconnections.
Logo, main colour and light or dark theme; the tiles on the main screen can be rearranged by dragging them. Two installations can be displayed side by side for comparison.
Each device is added through a guided procedure: the model is recognised automatically and associated with the installation, together with the technician to be contacted.
As an alternative to the portal, the Modbus RTU or TCP/IP port allows integration into the plant supervision system.
In the peristaltic version, performance varies with the tube diameter.
Stepper motor, 1 – 25 RPM.
| Tube (mm) | Max pressure (bar) | Flow rate (l/h) | RPM |
|---|---|---|---|
| 1.6 × 1.6 | 2 | 0.018 – 0.45 | 1 – 25 |
| 4.8 × 1.6 | 2 | 0.12 – 3 | 1 – 25 |
PVDF or PP pump head.
| Code | Max pressure (bar) | Max flow rate (l/h) |
|---|---|---|
| WT EM 0203 | 2 | 3 |
Suitable for most acids, for peroxides and for sodium hypochlorite (chlorine).
Suitable for sodium hydroxide (caustic soda).
For the complete cooling tower installation (panels, probes, corrosion and remote control) see the Cooling tower systems page.
The WT shows the function in progress and every alarm on the display; the display colour indicates immediately whether operation is normal.
Insight: the pump does not prime and does not dose →| Message | Meaning | Action |
|---|---|---|
| ALARM | An alarm is active. | From the main screen, turn the knob to the alarm status; once the cause has been removed, the WT automatically resumes the interrupted activities. |
| BLEED TIMEOUT | The bleed-off lasted longer than the maximum time set and the conductivity has not returned to the set point. | Check the bleed-off valve and the maximum bleed-off time set. |
| INHIBITOR | Antiscalant dosing in progress. | No action required. |
| BLEED | Bleed-off in progress to bring the conductivity back to the set point. | No action required. |
| PRE BLEED | Bleed-off before biocide dosing. | No action required. |
| PRE BIOCIDE 1 · 2 | Dosing of the biocide activator in progress. | No action required. |
| BIOCIDE 1 · 2 | Biocide dosing in progress. | No action required. |
| LOCKOUT 1 · 2 | Bleed-off inhibited after biocide dosing, to prevent the biocide from being discharged. | No action required. |
Green display: normal operation; yellow: warning, for example an active delay; red: alarm; white: stand-by or OFF.
Biocide and antiscalant level, flow, high or low conductivity (at a fixed threshold or linked to the set point), bleed-off time and water meter can be set as an alarm, which stops the functions, or as a warning, which only signals the condition.
In the peristaltic version the installed tube must be set: 4.8 × 1.6 mm for 0.12 – 3 l/h, 1.6 × 1.6 mm for 0.018 – 0.45 l/h. A setting that differs from the installed tube distorts the dosing.
Manual bleed-off is intended exclusively for testing and maintenance: while it is active, the automatic logic is suspended. The minimum and maximum alarms must always remain active, to avoid the risk of dangerous overdosing.
If the problem persists, contact us. Before sending the pump for servicing, empty the pump head of chemical and dry it.
The pump is supplied with low-level probes for the tanks: when a chemical runs out, it shows the alarm on the display and activates the corresponding output.
When the conductivity set point is reached, the controller opens the drain valve, with opening delay, dead band and safety timer (timeout): beyond the set time the drain closes and the alarm is triggered.
The antiscalant is dosed in proportion to the make-up water (via a water meter or at constant ppm), together with the bleed-off or for a percentage of its duration.
Before biocide dosing the controller opens the drain, on a timed basis or down to a lower conductivity value; with conductivity-based pre-bleed, the bleed-off timeout applies.
After biocide dosing the drain remains inhibited for the set time, so as to ensure the necessary contact time and prevent loss of chemical through the drain.
Controller and two dosing pumps (antiscalant and biocide) combined in a single unit, in peristaltic or solenoid version.
Separate values to control drain opening, biocide dosing and antiscalant dosing.
Electronic flow rate adjustment, independent for each pump, for dosing the correct quantity of biocide and antiscalant.
The biocide is dosed with scheduled daily or weekly activations, or in proportion to the litres of make-up water measured by the pulse-output water meter.
In the absence of flow in the probe holder (circulation pump stopped), dosing is suspended and the alarm is triggered.
Our technical department will help you select the version, probes and accessories best suited to your installation.
Call or write to us: a technician will reply with a tailored proposal of controllers, pumps, probes and accessories.