Testing the Integrity of Refractory Lined Vessels using the
NDT Technique P-Response ®*
Greg Palmer
Palmer Technologies Pty Ltd., Coorparoo DC/Australien
Summary: The P-Response® system is a fast screening method for identifying suspect areas
of civil and refractory concrete, non-destructively, as opposed to visual inspection or core
drilling. The impact-echo technique (P-Impact) can be used to verify suspect areas. The PResponse
® technique has been adapted to test refractory concrete and/or brick linings in
process vessels for the cement, petroleum, petro-chemical, minerals, alumina (plus other)
industries and can be used to determine refractory lining stability and quality from the outside
of the vessel.
Introduction
Assessing refractory lined vessels in cement plants, eg cyclone roofs, is a serious issue for
maintenance managers. Assessing the condition of vessel linings has generally been carried out
visually. Visual inspection obviously cannot detect if a refractory lining has failed at the
interface allowing a section to fall while personnel are working in the vessel. Palmer
Technologies has recently carried out an assessment of refractory lined vessels using the Pimpact
and P-response® techniques.
The P-Response® system is a fast screening method for identifying suspect areas of civil and
refractory concrete, non- destructively, as opposed to visual inspection or core drilling.
The impact-echo technique (P-Impact) can be used to verify suspect areas. The advantage of
the P-response® test is that it is a fast test method and can be performed on relatively rough
surfaces. In a thin plate, like a vessel lining or concrete floor, the impact from the modal
hammer will induce a vibration (flex) over a small area which is directly related to the elastic
modulus and thickness.
The flexibility of the plate is measured by a transducer (geophone) and the frequency response
is normalized by the impact force. The mobility from one location to another is compared as
part of the assessment.
The assessment of the refractory lining condition before entry is a significant safety issue as
unstable slabs of refractory concrete can cause severe injury to personnel entering the vessel.
The P-Response® technique has been adapted to test refractory concrete and/or brick linings in
process vessels for the cement, petroleum, petro-chemical, minerals, alumina (plus other)
industries and can be used to determine refractory lining stability and quality from the outside
of the vessel.
* Methode zum Patent angemeldet * Patent pending
