Lime dosing 5

[topgun67]

My customer is local water authority and on the sewage treatment side is dosing lime into slurry to achieve better "caking" However they run the lime through a slaker which is causing a great deal of health and safety issues. Does any body succesfully dose lime into slurry. If any further information is required please let me know.
Many thanks

 

[orenda1168]

Topgun67:

Your customer might do well to contact a slaked lime slurry supplier rather than doing this himself. Lime slaking is a highly exothermic process that can lead to safety and handling issues, and is probably bestleft to those who do it for a living....Chemical Lime is one company country-wide who should be contacted.

Orenda

 

[topgun67]

Thanks for the advice. The water authority had a system installed by a specialist lime slaking company who have done a bad job. They have given enough thought to the exothermic reaction. ( lime boiling over, pipes blocking up etc }At present the lime dosing plant is not running because H&S have deemed it unsafe. They are now actually putting bags of lime directly into the slurry.
this is unacceptable long term hence my question!

 

[25362]

Could visitingthe following site be of any help ?

http://www.cleevemh.co.uk/pdf/eurosource-lime-slurry-plant.pdf

 

[topgun67]

Thank you 25362,

Have just spoken to your company and they in the process of trying to help? Any other comments would be most usefull

Many thanks

 

[orenda1168]

Topgun67:

Another thought......has your customer considered moving over to a pre-made magnesium hydroxide slurry rather than fighting the calcium oxide slaking process?

Orenda

 

[bimr]

Many users will use hydrated lime rather than quicklime because it is difficult to get lime slakers to work properly.

Quicklime is generally only used for large volume useres because the cost of quicklime is a little less than the cost of hydrated lime. If you can get by with bags, it doesn't appear that you are a high volume user.

Hydrated lime is much easier to mix into solution so it may be the way to go.

 

[cub3bead]

You can also receive bulk delivery of dry hydrated lime up to 25 tons.

Along the Texas Gulf Coast we normally use a 40% hydrated lime slurry because of plugging problems associated with with either dry lime product. The dry stuff turns into a solid rock in the storage silos from the ambient moisture. Operators and maintenance personnel just love clearing them out. {cannon]

 

[ch81pc]

I carried out my Masters research on effect of dosing Aqualime (calcium hydroxide slurry)on the dewaterability of primary and secondary sewage sludges. I found optimum improvemnt in dewaterability and cake quality to occur with a 20% (w/w dry lime equivilant) dose of aqualime with a 2 hour contact time.
I have also worked on a plant that doses lime solids directly to freshly centrifuged cake. The exothermic reaction that occured in the storage pile resulted in a further decrease in water content and improvment in cake structure.

I hope this is usefull.