Dosatron Operating Principle
The Dosatron will inject liquid additives & stock solutions at rates which are proportional to water flow - for example, a Dosatron set at a dose rate of 1% will inject 1 litre of additive for every 100 litres of water which flows through it (exact rates may depend upon physical properties of the additive, e.g. viscosity).
Dosatron operating principles are as follows:
The Hydraulic Motor
Housed in the body of the Dosatron, the motor piston is driven up and down by the flow of water through the unit - a system of valves which open and close at the top and bottom of the piston's travel allow for reciprocal movement. Each piston cycle (once up, once down) is equivalent to a fixed volume of water and the speed of the piston movement depends upon the water flow rate. The Dosatron is volumetric.
The Additive Reservoir
As the motor piston moves up, additive is drawn into the dosing stem. As the piston moves down, the non-return valve at the bottom of the dosing stem closes to prevent additive and water being forced back out of the Dosatron.
The Dosing Mechanism
Driven by the motor piston, the dosing rod enters and exits the dosing stem continuously, effectively acting like a syringe and pushing the additive into the Dosatron body where it is mixed with the water and the solution is delivered downstream. Each cycle of the piston will inject a given volume of additive and - because the Dosatron is volumetric - this results in a constant dose rate independent of fluctuations in water flow or pressure (within the operating limits of the Dosatron unit being used). Additive injection is proportional to water flow.
Dose Rate Adjustment
Dose rates can be adjusted by unlocking the blocking ring and screwing the adjusing nut up or down - because the motor piston always travels the same distance, this will result in more or less additive being injected per cycle.
Important: water flow must be stopped and pressure in the Dosatron unit allowed to drop to zero before adjustment takes place. No tools should be used to adjust the dose rate.