Automatic dosing in dishwashers

Whys the detergent dispenser important in dishwashers?

We remind you that to wash the dishes, in addition to a good and efficient machine, the addition of additives such as detergent and rinse aid is essential.

Although it is taken for granted that if you want to wash correctly you must use detergents, we often find that unsatisfactory washing results are due to incorrect habits, such as never changing the washing water and expecting that the detergent used in the morning may be enough for the whole day. Furthermore, the excess of detergents, like the lack of them, does not allow for a good wash.
Our dosers are of the peristaltic type; peristaltic pumps, in addition to guaranteeing constant dosing, have no priming problems after replacing an inadvertently exhausted product tank.
It is very important to know that a small amount of detergent is needed, but that it must be dosed at each wash according to the type of “dirt” (from 0.5 to 3 gr / liter approximately). The constant and regular concentration of detergent in the tank is essential.
The quantity of rinse aid to be dosed is lower than that of the detergent (from 0.2 to 0.5 gr / liter approximately); this amount is sufficient to break the water molecule, make it flow away and help the glass to dry earlier.
In this regard we must remember that no dishwasher is able to dry, (which instead is continually claimed) this occurs only by thermal shock and more or less quickly depending on the washing temperature and the external one; if the washing and / or rinsing temperature is very high it can also give rise to unsatisfactory washing results as well as damaging the glasses in a shorter time.
If the dishes are not properly cleaned they can hinder this process.
Decalcified water also allows detergents to be saved up to 50 ÷ 70%, saves electricity for water heating, improves washing and protects the dishwasher from encrustations and breakages.

How to choose the right flow rate of the dispenser

Given that a dishwasher consumes on average about 3 liters of water at each rinse and that the dispenser is commonly electrically connected in parallel to the rinse solenoid valve which works for about 16 seconds, therefore, in consideration of the dosages mentioned above, the flow rate can be calculated. dispenser with the following formula:
gr/sec. = liters of water per rinse (lt) x grams of detergent per liter of water (gr / lt) / rinsing time (sec)
Example (Specific Weight Ps: Detergent = 1.2 gr / cm3 – Rinse aid = 1 gr / cm3):
3 lt (water after rinsing) x 2 gr / lt (amount of detergent) = 6 gr: 16 sec (rinsing time) = 0.375 gr / sec
0.375 g / sec x 3600 (seconds in an hour) = 1350 g / h: 1000 (grams in kilograms) = 1.350 kg / h
1,350 kg / h: 1,2 gr / cm3 (Ps Detergent) = 1,125 lt / h
A dispenser with a minimum flow rate of 1.5 l / h is therefore sufficient

Attention: the amount of water contained in the tank is irrelevant because the tank is usually filled by the rinse solenoid valve and therefore the dosage remains proportionally correct as calculated above.