For more information please take a look at the product specification sheet. 

 

The following document has been formulated as a guide to answer many of the common questions which occur when you are selecting the correct system and its components and the sizing of an Electrochlorinator for a water treatment application. 

g/l = grams per litre 

g/hr = grams per hour 

l/hr = litres per hour 

Q1. How do I size an Electrochlorinator for a water treatment application? 

A1. Electrochlorinators manufacture a Sodium Hypochlorite solution, but are measured in terms of the amount of chlorine they produce. Therefore, to determine the size of the Electrochlorinator, you need to determine the amount of equivalent chlorine required to treat the water volume involved. 

Chlorine levels in the water treatment applications are measured in g/l and are called “free chlorine residual”. This is the target level you are trying to maintain in the water. 

Where the water is flowing through a pipe, the chlorine requirement can be determined by the following equation: 

WATER FLOWRATE (l/hr) x FREE CHLORINE RESIDUAL (g/l) = RATE OF CHLORINE (g/hr) 

Once the rate of chlorine required has been determined, you simply pick the Electrochlorinator from our range that has an output of chlorine greater than calculated. Therefore, if a water flow requires 175 g/hr to maintain a free chlorine residual you would select the MPX200 which is capable of delivering 200 g/hr. 

 

Q2. What happens if the water is flowing at various rates? 

A2. This is a common occurrence as water requirements can vary across the day. It is therefore important to understand the minimum, average and peak water flow rates. It is possible to size a system based either on the average water flow rate or the peak water flow rate. Sometimes it is possible that the same size Electrochlorinator fits both the average and peak requirements. 

 

Q3. What happens if the peak water flow rate is much higher than the average water flow rate? 

A3. In this situation it is important to understand how long the peak flow lasts for and whether this is a common occurrence i.e. daily. 

Where the peak flow rate requires a much larger Electrochlorinator for a short period then it is possible to install a larger product storage tank to act as a buffer for this period of high demand. 

Where peak flow rate is a common occurrence and for a sustained period then it is better to select an Electrochlorinator that can cope with this requirement and the peak water flow rate should be used to determine the size of the Electrochlorinator. 

 

Q4. What if my water has a chlorine demand? 

A4. Occasionally water will consume the chlorine and this is called Chlorine Demand. In order to reach your target chlorine residual in the water, the chlorine has to overcome a background chlorine demand. In this instance, it is necessary to factor this into the equation in Q1, to ensure that the Electrochlorinator can provide sodium hypochlorite at a rate sufficient to overcome this demand and leave enough chlorine to reach the target free chlorine residual level. 

The equation would be: 

Flow rate x (Chlorine Demand / Target Residual) = Chlorine Consumption Rate 

Where: 

Flow rate is measure in l/hr 

Chlorine Demand is measured in g/hr 

Target Residual is measured in g/hr 

Rate of chlorine consumption is measured in g/hr 

 

Q5. How do I determine the size of the Sodium Hypochlorite storage tank? 

A5. Typically the sodium hypochlorite will be stored in a tank which is sized for 24 to 48 hrs storage. The solution strength of the sodium hypochlorite will vary between 7g/l and 8 g/l depending on the system. To calculate the tank volume required use the following equation 

 

(Chlorine Consumption Rate / Hypo Strength) x Storage Time Required = Tank Volume 

Where: 

Storage Time required is measured in hours 

Chlorine Consumption Rate is measured in g/hr 

Sodium Hypochlorite Strength is measured in g/l 

 

 

 

Q6. How do I determine the size of the Sodium Hypochlorite dosing pumps required? 

A6. Dosing pumps need to be capable of supplying the correct amount of Sodium Hypochlorite to maintain the Chlorine Residual Level whilst the water is flowing between the minimum and peak water flow rates. 

Therefore you need to calculate the Sodium Hypochlorite dose rate at the minimum water flow and the peak water flow rate. Then select a pump which is capable of this variation in dose rate. 

To calculate the rate of addition of Sodium Hypochlorite, use the following equation: 

Chlorine Consumption Rate / Hypo Strength = Hypo Dose Rate 

Where: 

Chlorine Consumption Rate is measured in g/hr 

Sodium Hypochlorite Strength is measured in g/l 

Sodium Hypochlorite Dose Rate is measured in l/hr 

 

Q7. Is the water temperature important? 

A7. Yes, the water temperature entering the water softener unit within the Electrochlorinator should be maintained between 5C and 15C to avoid the formation of by-products within the process. In many countries such as the UK this is rarely a requirement, although some systems may require heating during the extreme winter months. In Middle Eastern countries it will be necessary to chill the water to maintain the maximum water temperature to the system. 

Water can be chilled using commercially available chilling systems. The ambient water and ambient air temperature will be required to determine the water chiller required. 

If the system is used at water temperatures above 15C then unwanted by-products will form in the Sodium Hypochlorite causing the reaction to lose efficiency. 

 

Q8. What is the water flow rate for each Electrochlorinator? 

A8. Please use the following table to determine the water flow rate for each system 

 

MODEL Max Water Flow Rate 

MPS50 7.5 l/hr 

MPS100 15 l/hr 

MPX200 30 l/hr 

MPX400 60 l/hr 

MPCC600 90 l/hr 

MPCC1200 180 l/hr 

MPCC2400 360 l/hr 

Q9. How much salt will I require? 

A9. Prodose Electrochlorinator systems consume between 3.5 kg and 4 kg of salt for every kg of chlorine used. Therefore you can calculate the amount of salt used in the system from 

 

Chlorine Consumption Rate x 4 = Salt Consumption Rate 

Where: 

Chlorine Consumption Rate is measured in g/hr 

Salt Consumption Rate is measured in g/hr