Pengaruh Jenis Bed Material Terhadap Laju Abrasi Wall Tube Boiler pada PLTU Circulating Fluidized Bed (CFB)
Andi Setyawan, Ir.Fauzun, S.T., M.T., Ph.D., IPM, ASEAN Eng. ; Ir.Muslim Mahardika, S.T., M.Eng., Ph.D., IPM, ASEAN Eng.
2026 | Tesis | S2 Teknik Mesin
Penelitian ini
bertujuan untuk menganalisis pengaruh jenis bed material terhadap laju abrasi
(erosion rate) pada wall tube boiler tipe Circulating Fluidized Bed (CFB).
Masalah abrasi pada wall tube menjadi penyebab utama kebocoran dan penurunan
efisiensi operasi pada PLTU CFB di lingkungan PT PLN Nusantara Power. Dua jenis bed material yang diuji
adalah aluminium oxide (Al?O?) dan silika (garnet), dengan variasi waktu
sandblasting 2, 4, 6, 8, dan 10 menit, serta tekanan operasi 5–7 bar dan sudut
nozzle 45°.
Sampel uji
berupa potongan water wall tube baja SA210 Grade A diambil dari PLTU Punagaya.
Pengujian dilakukan meliputi pengukuran massa, ketebalan, kekerasan (Vickers),
microstructure (mikroskop optik dan SEM-EDX), serta kekasaran permukaan. Hasil
pengujian menunjukkan bahwa penggunaan pasir silika menghasilkan laju
pengurangan massa dan ketebalan yang lebih besar dibanding aluminium oxide,
menandakan tingkat abrasi yang lebih tinggi. Sebaliknya, aluminium oxide cenderung meningkatkan kekerasan permukaan
akibat fenomena work hardening dari tumbukan partikel abrasif.
Secara umum,
peningkatan durasi sandblasting berbanding lurus dengan laju kehilangan massa
dan penurunan ketebalan material. Analisis mikrostruktur menunjukkan terjadinya
deformasi plastis dan perubahan butiran akibat energi tumbukan partikel
abrasif. Hasil penelitian ini memberikan pemahaman mengenai mekanisme abrasi
pada CFB boiler serta rekomendasi teknis pemilihan bed material yang dapat
memperpanjang umur pakai wall tube dan meningkatkan keandalan operasi
pembangkit.
This research aims to analyze the effect
of different types of bed material
on the abrasion rate (erosion rate)
in the wall tube of a Circulating Fluidized Bed (CFB) boiler. The
abrasion issue in wall tubes is the main cause of leaks and reduced
operational efficiency in CFB power plants managed by PT PLN Nusantara Power.
Two types of bed material tested are aluminium oxide (Al?O?) and silica (garnet), with
variations of sandblasting time of 2, 4, 6, 8,
and 10 minutes, an operational pressure of 5–7 bar, and a nozzle angle of 45°.
The test samples consist of sections of
SA210 Grade A steel water wall tube
taken from the Punagaya power plant. The tests include measurements of mass,
thickness, hardness (Vickers),
microstructure (optical microscope and SEM-EDX), and surface roughness. The
test results indicate that the use of silica sand results in a greater rate of
mass and thickness reduction compared to aluminium
oxide, signifying a higher level of abrasion. Conversely, aluminium oxide tends to increase surface hardness due
to the work hardening phenomenon resulting from the impact of abrasive
particles.
In general, an increase in the duration
of sandblasting is directly proportional to the rate of
mass loss and reduction in material thickness. Microstructure analysis shows
the occurrence of plastic deformation and grain change due to the energy of
impact from abrasive particles. The results of this study provide an
understanding of the abrasion mechanism in CFB boilers, as well as
technical recommendations for the selection of bed
material that can extend the lifespan of wall tubes and
improve the operational reliability of the power plant.
Kata Kunci : CFB boiler, abrasi, wall tube, aluminium oxide, silika, sandblasting, PLN Nusantara Power
