Softener under performing 1

[vij36]

Dear All,

We have installed a brand new water softener with two units each of 1000 liters resin capacity.
Our hardness of water is 250 ppm. So for a 50 ppm outlet hardness we expect the OBR need to be at least 2,00,000 liters for each unit.

After filling brine (150 kg each unit) and after a water flow of about 70,000 liters (each unit) hardness showed 6 ppm which is up to the mark. After flow of another 25,000 liters (total flow through softener is 70,000 + 25,000) the softener hardness is measured 180 ppm. For 95,000 liters flow itself the hardness is increased to 180 ppm from 6 ppm.

For 1000 liter resin tank when 900 liters actual capacity is considered the softener supposed to perform up to 2,00,000 liters of inflow.

Vendor says the water may not be passing through all over the resin tank area which may be one of the reason.

Could throw some light what may be the other reasons.

Thanks,

 

[vij36]

Dear Sirs,
Apologies for the delay in response to your advices since the campus is shut down due to Covid restrictions and delay in some safely mechanisms implementation.

I have redesigned the system after studying the inputs here and they are below.

1) Ensuring Constant flow of 30 to 35 gpm (1.9 to 2.2 LPS)at a pressure of 3.5 bar at each softener tank.

Still didn't get success in maximizing the performance. Each softener capacity is supposed to be 53,000 gallons (approx. 200,000 liters)considering a hardness of 250 ppm of raw water. However after 22,000 gallons (83,000 literature approach.) of flow only softener output shows 175 ppm.

The vendor is still arguing on his old assumption that back pressure from 15 m overhead tank is the culprit.

One more angle i am feeling, is there any flaw in brine tank design. Because the full 150 kg salt required for regeneration has not been taken by softener tank but still 4 to 6 inches of salt still exists in brine tank without being melted. Can this lead to the assumption that softener tank didnt recharged fully while doing regeneration?

The brine tank is 500 liters (130 gallons) with float valve kept at 85% level. Salt filled is 150 kg.

Where the system might be going wrong. Kindly advice.

 

[bimr]

Don't understand the method that you are using for the brine tank. Usually the brine tank is filled to the top with salt. Salt is not added for each regeneration cycle. The maximum brine concentration is approximately 26% so all of the salt will not dissolve. See the link.

Link

Are you using the correct type of salt? Should be 100% sodium chloride salt? Is the brine step in minutes the correct length?

I don't understand the overhead tank issue. If you have a flow meter, you can observe the water moving downstream. The check valves on you flow diagram will prevent backflow.

 

[vij36]

Dear Sir,
In a 500 liters tank we added 150 Kg of rock salt. As you advised verifying the quality of salt if it has any impact on performance.

Could you clarify the below sentence. I didn't understand.

Is the brine step in minutes the correct length?[/b]

 

[bimr]

The brine step should be specified in the instructions as a time period. Time can vary from 30 minutes to maybe 100 minutes.

 

[vij36]

Dear Sirs,

Covid created havoc upon our lives and there is a long delay.

The Softener does not showing any mercy in terms of its efficiency.
In a separate thread below 2 days back I have verified the brine tank and brine quantity also.
Brine tank capacity

I do have another query regarding brine tank.
The tank is 500 liter in which about 350 liter water, 150 Kg of salt is filled for one regeneration.
This combination yields only 75,000 liters softened water. After that the hardness ppm goes beyond 150 ppm.
Expected softened water quantity per regeneration is about 200,000 liters.

Should the salt be refilled for every regeneration ? Current regeneration process takes about 2 hours )with 1.5 hr brine charging which takes 300 liters of salt water ) and then half an hour for backwash and rinsing.

 

[bimr]

The brine tank should generally have enough salt for at least 3-5 regeneration cycles. It is not common to have a salt capacity of a single regeneration.