Hi

I am having a problem with a build-up of scale in water treatment pipes from the Clarifiers--> Semi-Treated Tanks--> Sand Filters. Now I have to replace all the pipework which is at a cost. Does anyone know of any way that I can prevent this from happening in the future?

Perhaps the scaling problems are associated with ineffective water treatment. Process engineer should be helpful in this matter. What do you mean by scales here, is it corrosion scales or deposits? If oxygen scavenging from water is not sufficient, carbon steel pipe should be corroded which shows up as scales. Deposits come from minerals in water. that;s why the water treatment/demineralisation unit should be working properly. I know about this because I installed 2 boiler chemical injection skids before. TQ

We are a beverage bottling plant and treat water before the production process. The process of water treatement is as follows:
* Municipal water comes in from outside
* This water is treated with dosed with lime, ferrous, Chlorine.
* The solution is left to settle at the clarifiers and the water is slowly pumped to a semi treated tank.
* From the semi treated tank the water is pump to the sand filters
* Then it goes through carbon filters and polishing filters before going to production


The semi-treated water does have particles in it and these collect onto the walls of the pipes. I would like to know if anyone knows how I can prevent this build thereby increasing the life of the pipes. I know of a magnetic material that is placed on the outside but I am not sure how this works.

Regards,
Ajay

If i'm in your position, maybe I will contact a water treatment company to get further advice on how to get of all the unwanted particles except healhty minerals. Another possibility is to do chemical cleaning if it's possible to shutdown the unit to get rid of the scale and if economically viable to do compared with pipe replacement. What pipe material is it, Carbon steel or HDPE? What is the piping design standard used, ANSI or national std? What is the water velocity in the pipe, is it fast enough to prevent settlement of particles under their own weights? TQ

If I were you (and I was working in a bottling plant several years) I would check lime dosing quantities. There could be some misalignement between lime dosing and settling tank capacity/ nominal flow rate on this part of process.

Moreover, galvanised steel and SS are very prone to this type of scaling. I presume you have SS, and in that case something can be done with pasivizing inner surface of pipe (not extremely cheap but much cheaper then replacing SS pipe).

Thanks DC2
I am actually from the motor industry and only in the beverage for about 2,5 years. I think your points on the flowrates is accurate valid and I am investigating it.
This could be the root cause of other issues in the water treatment area. A few questions:
1. Can excess lime dosing result in Chlorine break-throughs break-throughs after the carbon filters?
2.

2. Can excess lime/ferrous dosing result in resin breakthrough after the softners.
3. Are there any other problems that this could cause?

Thanks,
Ajay

My case, I am applying the "Scale solution"[TM](originally made by european company) using electromagnetic force and resornance.

The result is good.
Normally it need 2~3months to catch a improvement.

I attach the photos before's and after's.

scalesolution.ppt (1,116 Kb, 13 downloads) before & after