IESL Part III case studies

IESL Part III · Put your knowledge to work in context.

The Institution of Engineers, Sri Lanka (IESL) is the apex body of engineering professionals in Sri Lanka, incorporated in 1968 by Parliament Act No. 17, and it awards credentials such as Chartered Engineer - CEng (SL) and AMIE (SL) that enable a person to practise as a licensed engineer in the country. The IESL Part III case studies are 5 cases and about 5,432 words.

Drip Block Losing Emission Uniformity: Iron, Filters and Pressure-Compensating Emitters

A 12 ha banana plantation in the dry zone is irrigated by a drip system fed from a 60 m deep borehole. Design data: 2.0 bar at the sand-filter outlet, 4.0 L/h pressure-compensating emitters on 30 m laterals, emitter regulation range 1.0 to 3.5 bar.

1,158 words, about 6 min 2

Low Delta-T Syndrome in a Hotel Chiller Plant with Remote DP Control

A 320-room hotel tower has a chilled water plant of two nominal 500 TR centrifugal chillers with variable-speed drives, primary/secondary pumping and a common header, serving AHUs on 14 floors. Design conditions are 6.5/12.5 degrees C (delta-T 6 K) and 160 kPa differential at the most remote AHU, where the secondary loop differential-pressure sensor is installed.

1,027 words, about 5 min 3

Strutted Excavation Exceeding the Action Level Next to a 1930s Masonry Building

A 7.2 m deep, 40 m by 25 m basement is being excavated in firm to soft marine clay using a contiguous bored pile wall (600 mm diameter at 750 mm centres) with three levels of steel struts. A four-storey load-bearing masonry building from the 1930s sits 5.5 m from the wall face on shallow footings.

1,063 words, about 5 min 4

Solvent Recovery Column with Rising Pressure Drop and Falling Purity

A solvent recovery column separates methanol from water. It has 24 valve trays on 450 mm spacing, a thermosiphon reboiler on 6 bar steam and a shell-and-tube overhead condenser on cooling water.

1,093 words, about 5 min 5

Capacitor Bank Failures and Harmonic Resonance on a VFD-Loaded 630 kVA Supply

A factory is fed by a dedicated 630 kVA, 11/0.433 kV Dyn11 transformer with 5.5% impedance. The main LV board supplies six 75 kW 6-pulse variable-frequency drives on pump and fan duty, plus about 300 kVA of single-phase load consisting of LED lighting, switch-mode chargers and office IT, on the same board.

1,091 words, about 5 min