Dear Colleagues,

I am searching for a SIMPLE & robust current-less drip-feed or batch flocculant dosing system for raw sewage, a dosing system without external power needs or electronic gadgets.

I know from drinking water treatment plants and in irrigation systems such currentless & simple dosing systems for flocculant or chlorine exist or..., proportional systems for clear water like this example:

This system can not be used for raw sewage as it would block very soon.

In textbook "water, wastes and health in hot climates" by Mara, Mc Garry, Feachem, 1977 (ISBN 0 471 99709 9) page 187 is shown a nice sketch, see c) of a system with a ball float on a pivoted arm for a drip feeding device controlled by water flow regardless clear water or raw sewage, seams to me promising:

I would appreciate any hints and experiences made.
Thanks.

Regards,
Detlef