In many processes dosing is effected periodically or is initiated by external events. In almost any case collateral actions must be triggered in advance or with delay such as the powering of a mixer before starting metering. Or a metering station is to be added to an existing process and shall operate as an autonomous unit.
The Process-Timer was designed especially for these tasks, that so far could only be realised with programmable logic controllers. The feed rate (stroke frequency) as well as the mode of operation of the pump can be adjusted or changed via the Process-Timer. Additionally, both optional relays can be integrated into the programm for controlling peripheral devices. As this is effected entirely independently from the adjusted dosing times, beside the examples listed above, monitoring tasks (e.g. alarm, if no control contact is ascertained within a defined time period) can be solved by means of the Process-Timer.
Modes of Operation
Time-controlled operation of the pump will have the Timer work every hour, daily, on weekdays only, on weekends, weekly or bi-weekly as per your demand. Beside the starting and stopping of the pump, the operation mode can be changed and one or two of the relays (supplied on demand) can be controlled. Thus, for instance, it will be possible to switch on the mixer before starting dosing and - if required - even let it run after the pump has stopped
Entirely new perspectives are granted with the event-controlled Timer Version. Here, a program is started after an external start-contact or at a point in time defined in advance. This program can consist of up to 80 different points such as pump start/stop, switch to external contact operation for a defined time period etc. Here, too, relays can be integrated into the program.
With the overlapping of the two versions almost no limits are set to the application possibilities. The integrated timer can completely replace program controls that operate with conventional timer-clocks. Beside cost-savings above all the space saving is an advantage - and this all at protection class IP 65!
Application Example 1: Shockdosing of Biocides in the Cooling Circuit
In the cooling circuit shock dosing of biocides is effected periodically in order to avoid the generation of bacteria and algae. During the dosing until the complete distribution of the biocide, the guide value of the cooling water can increase to such a level that automatic desalination is initiated. To avoid that, it must be deactivated from the point of dosing on and for several hours. In some cases, before shock dosing, principally a forced desalination is effected. The time period to the next controlled desalination as per guide value will thus be enlarged and the effectivity of the biocide dosing be increased. A metering pump type gamma/L or Sigma with Process-Timer and two relays will be used, additional control devices are not necessary.
Application example 2: Spraying of Carbon-Resolving Substances in the Exhaust Fumes of Ships
In intervals of 4 to 6 hours carbon-resolving chemicals are added to the diesel exhaust fumes. Thus sedimentations on the heat exchangers integrated into the ship chimneys are prevented. For covering a large efficient surface, the chemical is sprayed with air. Metering pumps type gamma/L with Process-Timer will simultaneously open the solenoid valve for the spraying air via the integrated relay when starting dosing. After adding the required dosing amount, the solenoid valve will keep open for a minute to puff the chemical from the injector and thus to avoid plugging.
Application example 3: Automatic Ventilation after longer Downtimes of the Pump
Metering of outgasing media after longer downtimes of the pump often brings about gas formation in the suction line. When restarting the pump this can lead to a breakdown of the dosing. Here, the dosing monitor "Flow-Control" is used, that reports every single dosing stroke. If no report comes about within a defined time period, the pump will be switched to maximum frequency in order to free the liquid end as quickly as possible from air. If, after a further interval, that can equally be adjusted to your requests, still no dosing stroke is reported from the Flow-Control, the Process-Timer stops the pump and an error message is given via the relay.
Dosage against a high counter-pressure do not allow suction against pressure or dosing gas from the liquid end into the pressure line. Here, a discharge possibility via a bypass line from the pressure side of the pump back into the container, where a solenoid valve is installed, is recommended. The discharge is effected periodically, whereas the Process-Timer switches the pump on maximum frequency and simultaneously opens the solenoid valve in the bypass line.
Programming Software for comprehensive Program Sequences
All possibilities of the Timer can be reached and used via the keyboard of the pump. As the Timer even allows very comprehensive program sequence realisations, a programming kit is offered, that gives the possibility to enter the parameters per PC or Laptop. The finished program will than be transmitted to the pump via USB adapter.
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