Range of Services

Cor­ro­sion and ero­sion often affect pres­sure-bear­ing mate­ri­als and their metal­lic or ceram­ic pro­tec­tive lay­ers for short peri­ods of time and local­ly with extreme­ly dif­fer­ent dynam­ics (rates of wear). This can lead to unex­pect­ed and sud­den pipe leak­age which in turn results in unplanned down­time and usu­al­ly high repair costs.

01 Mea­sures accom­pa­ny­ing inspections
– boil­er inspec­tion in un-cleaned and cleaned con­di­tions allow a time­ly pre­ven­tion of damages.

Antic­i­pa­to­ry main­te­nance can pre­vent unplanned shut­downs, pro­vid­ed it includes expert inspections.

We under­take such mea­sures in both un-cleaned and cleaned con­di­tion of the boil­er. In doing so, we exam­ine all the acces­si­ble com­po­nents of the entire flue gas path. We record the spa­tial and tem­po­ral dynam­ics of cor­ro­sion and ero­sion and ulti­mate­ly gain a detailed, mean­ing­ful pic­ture of its con­di­tion. In our expe­ri­ence, a step-wise super­vi­sion leads to the best pos­si­ble result.

Step 1: Inspec­tion in un-cleaned condition
Step 2: Inspec­tion in cleaned condition
Step 3: Qual­i­ty-accom­pa­ny­ing mea­sures in the inspec­tion process

In un-cleaned con­di­tion, local anom­alies in the prop­er­ties of the foul­ing (includ­ing shape, thick­ness, colour, hard­ness, melt flow) pro­vide us with impor­tant indi­ca­tions of the spe­cial con­di­tions that are occur­ring there. From this we can deduce poten­tial cor­ro­sion and ero­sion risk areas in the boiler.

In cleaned con­di­tion, we look at all rel­e­vant heat exchang­er sur­faces and pay spe­cial atten­tion to the pre­vi­ous­ly iden­ti­fied risk areas. This assess­ment is seen through the eyes of our expe­ri­enced spe­cial­ists and is sup­port­ed by illu­mi­nat­ing the heat exchang­er sur­faces with ‘graz­ing light’, shone from a flat angle. This enables us to iden­ti­fy the areas most affect­ed by cor­ro­sion and ero­sion in the acces­si­ble areas — from spot checks to 100 per cent of a com­po­nent. We mark these areas and then eval­u­ate them by mea­sur­ing the resid­ual wall or pro­tec­tive coat­ing thicknesses.

We offer qual­i­ty-accom­pa­ny­ing mea­sures that run in par­al­lel to the supplier’s repairs and appli­ca­tion. Here we pro­vide a neu­tral, addi­tion­al impulse dur­ing the appli­ca­tion of mate­ri­als to ensure that qual­i­ty require­ments are reli­ably met. The essen­tial aspect of this is that we can derive the spe­cif­ic qual­i­ty require­ments from the assess­ment of the sub­se­quent oper­a­tional load pro­files, allow­ing to sup­port the achieve­ment of cus­tomised per­for­mance char­ac­ter­is­tics of the materials.

A cor­re­spond­ing CheMin data­base helps to archive and doc­u­ment all the data that is gen­er­at­ed. Over the course of sev­er­al revi­sions this makes the component’s devel­op­ment and its remain­ing use­ful life-time clear­ly recog­nis­able for the oper­a­tor and main­te­nance mea­sures can there­fore be timed perfectly.

This pro­ce­dure can be applied to pres­sure-bear­ing mate­ri­als and the pro­tec­tive coat­ings that are applied to them (for exam­ple cladding or ther­mal spray coatings).

Our expe­ri­ence clear­ly shows that ini­tial opti­cal obser­va­tions fol­lowed by the mark­ing of par­tic­u­lar­ly con­spic­u­ous areas based on them are clear­ly supe­ri­or to grid mea­sure­ments of the resid­ual wall or pro­tec­tive lay­er thick­ness­es. Grid mea­sure­ments do not detect local anom­alies. For exam­ple, a grid mea­sure­ment at the crown of the pipe would fail to detect pos­si­ble ero­sion on the pipe flank, sup­pos­ed­ly lead­ing to an incor­rect assess­ment of the con­di­tion of the pipe.

02 Mea­sures accom­pa­ny­ing operation
– Tests, find­ings and sen­so­ry data reveal process char­ac­ter­is­tics that make it pos­si­ble to opti­mise the suit­abil­i­ty of mate­ri­als and the per­for­mance of the entire plant.

The more com­plex and vari­able the chem­i­cal side effects of the fuels are, the high­er the demands on the prop­er­ties and qual­i­ty of the mate­ri­als used and their appli­ca­tion. This is espe­cial­ly true for the “dif­fi­cult fuels” waste, RDF, bio­mass and sewage sludge, but it also applies for fos­sil fuels and co-incineration.

It is often the case that the indi­vid­ual trades involved in the con­struc­tion of such incin­er­a­tion plants are unable to ade­quate­ly assess the sub­se­quent util­i­sa­tion require­ments. Par­tic­u­lar­ly aggres­sive fuel, the high ener­gy effi­cien­cy of the plant, long trav­el times or the need for high avail­abil­i­ty can trig­ger extreme demands that are dif­fi­cult to estimate.

Our in-ser­vice mea­sures use the real process to:

• inves­ti­gate mate­r­i­al properties
• sup­port mate­r­i­al development
• detect process char­ac­ter­is­tics and caus­es of cor­ro­sion and fouling
• deter­mine and opti­mise process properties
• detect and eval­u­ate the effects of spe­cif­ic changes (tests)

We are hap­py to coop­er­ate on a con­fi­den­tial basis with the man­u­fac­tur­ers, proces­sors and users of the mate­ri­als. We make our find­ings and indi­ca­tions avail­able for the fur­ther devel­op­ment of mate­ri­als (not only pow­er plant mate­ri­als) and their man­u­fac­tur­ing processes.

As a devel­op­ment part­ner for the improve­ment of mate­ri­als and appli­ca­tions, we pre­fer to rely on prac­ti­cal test­ing. This means that we devel­op spec­i­fied mate­r­i­al probes depend­ing on the prob­lem and the task at hand, which we then use under real and tar­get­ed con­di­tions (CheMin probes and sen­sors). This allows us to demon­strate the per­for­mance char­ac­ter­is­tics of mate­ri­als much more clear­ly than would be pos­si­ble through lab­o­ra­to­ry tests. Our expe­ri­ence shows that this pro­ce­dure is often supe­ri­or to the use of stan­dard­ised tests and cor­re­spond­ing test rigs.