Mechanisms for the removal of calcium phosphate deposits in turbulent flow

Felicia Littlejohn, Christine S. Grant, Avelino E Saez

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

This work investigates the mechanisms for the removal of calcium phosphate deposits from stainless steel tubing in turbulent flows. Two types of deposits were analyzed: brushite (dicalcium phosphate dihydrate, DCPD) and a mixture of DCPD/hydroxyapatite (HAP). Cleaning studies were carried out at pHs ranging from 2.85 to 10. The data were analyzed by means of a mathematical model that incorporates the effects of interfacial dissolution and mass transfer. The results show that the HAP/DCPD cleaning rate is influenced both by the kinetics of the interfacial dissolution and by mass transfer. Within the same range of experimental conditions, the rate-limiting mechanism for DCPD removal was the abrasion of the solid by shear stresses. In this case, the interfacial dissolution process plays the role of decreasing the structural integrity of the deposit. These findings show that the removal mechanism of the HAP/DCPD mixture differs significantly from the behavior of individual components.

Original languageEnglish (US)
Pages (from-to)933-942
Number of pages10
JournalIndustrial and Engineering Chemistry Research
Volume39
Issue number4
StatePublished - 2000

Fingerprint

Phosphate deposits
Calcium phosphate
turbulent flow
Turbulent flow
Phosphates
Deposits
calcium
phosphate
Hydroxyapatite
Durapatite
Dissolution
dissolution
mass transfer
Cleaning
Mass transfer
Structural integrity
Tubing
abrasion
Abrasion
Stainless Steel

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Environmental Science(all)
  • Polymers and Plastics

Cite this

Mechanisms for the removal of calcium phosphate deposits in turbulent flow. / Littlejohn, Felicia; Grant, Christine S.; Saez, Avelino E.

In: Industrial and Engineering Chemistry Research, Vol. 39, No. 4, 2000, p. 933-942.

Research output: Contribution to journalArticle

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