دراسة تأثير نوع حبيبات وسط مسامي على تحسين انتقال الحرارة للمبادل الحراري ذي الأنبوب المزدوج

Abstract EN

The current research aims to evaluate the efficiency of tube settlers in removing lowturbidity of Tigris River water in Mosul city, then comparing the results with theconventional settler.

Laboratory model for tube settler is designed and manufactured forconducting the experiments.

The model consists of a coagulation and flocculation basincontaining a mixer.

This basin is connected with water fixing level basin which is used toobtain a uniform flow in the model.

This basin is followed by another one which is calledpre-tube settler basin.

After that came the tube settler unit.

It consists from 4 tubes of squaresection and 4 x 4 cm2 in dimension and manufactured at five levels of inclination angle: 30, 40, 50, 60 and 70 degrees.

These tubes are manufactured at 40 cm in length and theirlength can be increased by connecting additional pieces with a length of 20 cm to obtainthe studied length levels: 60, 80, 100 and 120 cm.

Alum is added as a coagulant with sixlevels at 0, 5, 10, 15, 20 and 25mg/L.

At the same time, another model was designed andmanufactured for conventional settler from glass for making experiments parallel to thetube settler and compare the results between them.

The initial turbidity of raw water rangedfrom 20-29 NTU during the study period.

Turbidity removal percent was used as anindicator of tube settler efficiency.

The highest turbidity removal percent reached 80.53% with an effluent turbidity of 5.1 NTU at 120 cm length, 15 mg/L alum dose and 60°inclination angle.

The results showed an increase in turbidity removal percent withincreasing the tube length at all levels of the inclination angle and alum dose.

The tubesettler exceeds the conventional one by 20-30% in removing percent of low turbidity withinthe range of 20-29 NTU of the Tigris River water.

Additionally, the short detention time oftube settlers compared with the conventional one can be utilized to increase the productionof the plant.

This can be achieved by installing modular tube settler units in thesedimentation tanks of the old water treatment plants.