Lance tube (retractable soot blower lance)

01

Match diameter, length and alloy

Jinan Yuanda Power Equipment describes a lance tube as the tubular component of a retractable sootblower that travels into and out of the combustion zone and flue gas passages, unlike a fixed element. It lists lances for retractable sootblower models in 1Cr18Ni9Ti stainless steel, 15CrMo, 30CrMoV and T91 alloy steels, with diameters of 89, 102, 108, 122 and 127 mm and lengths of 1–7 m or 1–18 m. [2]

Editorial note: give the supplier the sootblower make and model, total travel, the gas temperature zone the lance passes (furnace, superheater, economizer), and the original lance's diameter, wall, material and nozzle layout; ask for material certificates and straightness of the finished lance.

Give the supplier the sootblower make and model, lance length and travel, outer diameter and wall thickness, material grade, nozzle number, size and angle, blowing medium (steam or air) and pressure, gas temperature in the zone cleaned, straightness tolerance, and material and inspection certificates.

02

Prevent condensate erosion with preheating and correct nozzles

US patent 5,320,073 (Method and apparatus of preheating a sootblower lance) describes a long retracting sootblower with a frame outside the boiler, a carriage driven along it to extend and retract the lance, and a poppet valve that admits blowing medium only during retraction, when oppositely directed radial nozzles at the lance tip trace helical paths as the lance rotates. It explains that steam admitted into a lance still cool relative to the steam condenses, and the liquid forced out of the nozzles against boiler surfaces increases their erosion; extending the lance into the hot gas first, and dwelling if needed, preheats it so condensate does not form or re-vaporises before discharge. While steam is off, a small flow of pressurised air keeps hot combustion gases out of the lance. [1]

Editorial note: when replacing lances, keep the nozzle size and angle matched to the original design and check that the sootblower control still delays steam until the lance is hot. [1]

Field measurements show why lance pressure and nozzle placement matter. In a PEERS 2011 paper, Tran, Pophali and Bussmann of the University of Toronto, with Miikkulainen of Andritz, report force-probe trials in Swedish kraft recovery boilers: at a given distance, the force a fully expanded sootblower jet exerts on a target rises almost linearly with lance pressure; at a given pressure it falls rapidly with distance, retaining less than 10% of its original strength 1 m (3 ft) from the nozzle. Measurements were taken at 300, 750 and 1,200 mm with lance pressures of about 9–11 bar (150 psi) and 10–15 bar, and a flat target received more force than an inclined one of the same projected area. [3]

Editorial calculation: if jet force rises near-linearly with lance pressure, raising it from 10 to 15 bar gives roughly 1.5 times the force at the same distance, while the same jet loses over 90% of its strength by 1 m; nozzle size, alignment and lance travel path therefore decide what the lance can clean, not lance pressure alone. [3]

03

Match the lance to the sootblower model, travel and duty

ANDRITZ's Diamond Power sootblower page lists the long-retractable models a replacement lance tube must fit and the duties they serve. It says Diamond Power's largest retractable sootblower can travel up to 18.3 m. The IK-525 is described as its standard for online boiler cleaning, the IK-530 single rack-and-pinion design serves boilers up to 22 m in furnace width, the IK-545 is a heavy-duty utility model, and the IK-525SL inserts and retracts its lance tube without rotation. The IK-525/545EL uses an extended lance tube, mainly to remove slag and ash from superheaters, and the IKSD-E recovery-boiler sootblower is built for up to 24 operations per day, or more depending on steam conditions. Sootblowers may blow steam, air or water, and the IK-1M is a partially retractable unit whose lance tube carries an element across the boiler. [4]

Editorial calculation: 24 operations a day is one blowing cycle an hour, so a recovery-boiler lance sees about 8,760 insertions a year into the hottest gas zones; the 18.3 m maximum travel is close to the 18 m upper lance length Yuanda lists. Give the lance supplier the sootblower model (for example IK-525, IK-525SL or IK-525/545EL), the travel, whether the lance rotates, and the blowing medium, since each changes the lance length, nozzle layout and alloy. [4] [2]

04

Compare what suppliers offer

Suppliers linked to this page list soot blower lance tubes; each card links to the page reviewed.

The suppliers reviewed list replacement lances with other boiler pressure parts; ask each for the sootblower models covered, material and wall, nozzle machining, straightness, and certificates.

05

Trace the lance assembly

This is a functional reference built from the sources cited; it is not one maker's design.

06

Fill the specification fields with values for your sootblower

A lance tube quotation needs values for your sootblower. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.

07

Send the sootblower, zone and lance data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Sootblower: [make; model; travel]
Lance: [OD; wall; length]
Material: [grade]
Nozzles: [number; size; angle]
Medium: [steam or air; pressure]
Zone: [gas temperature; location]
Documents: [material certificates; straightness]

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