Perancangan Unit Venturi Self-induced Scrubber Untuk Penurunan Suhu dan Pengendalian Emisi Asap Penyangraian Biji Kopi

Abstract

Penyangraian biji kopi menghasilkan gas buang bersuhu tinggi yang mengandung CO, VOC, partikulat, tar, dan aerosol minyak sehingga memerlukan pengendalian sebelum dilepaskan ke lingkungan. Tugas akhir ini bertujuan merancang dan mengevaluasi venturi self-induced scrubber sebagai unit prapengolahan emisi tanpa sistem penyemprotan. Perancangan dilakukan menggunakan metode desain keteknikan melalui tahap eksplorasi, pendefinisian masalah, ideasi, pengembangan prototipe, dan validasi. Unit dirancang untuk kapasitas 5 kg/batch dengan dimensi 600 × 300 × 1.200 mm, delapan sekat pengarah, adjustable throat 1-20 mm, dan volume air 42,5 L. Pengujian dilakukan pada kapasitas 500 g dan 1.250 g dengan pengukuran CO dan VOC menggunakan ALTAIR 5X Multigas Detector. Hasil pengujian menunjukkan penurunan suhu gas dari sekitar 179 °C menjadi 32 °C. Efisiensi penyisihan CO mencapai 89% dan 78%, sedangkan VOC mencapai 90% dan 76%. Hasil tersebut menunjukkan bahwa venturi self-induced scrubber efektif menurunkan suhu dan konsentrasi emisi pada kapasitas pengujian.

Coffee bean roasting generates high-temperature exhaust gases containing carbon monoxide (CO), volatile organic compounds (VOCs), particulate matter, tar, and oil aerosols, requiring appropriate treatment before being released into the environment. This project aimed to design and evaluate a Venturi self-induced scrubber as an emission pretreatment unit operating without a spray system. The design process followed an engineering design method consisting of exploration, problem definition, ideation, prototype development, and validation. The unit was designed for a capacity of 5 kg/batch, with dimensions of 600 × 300 × 1,200 mm, eight flow-guiding baffles, an adjustable throat of 1–20 mm, and an operating water volume of 42.5 L. Prototype testing was conducted at roasting capacities of 500 g and 1,250 g, with CO and VOC concentrations measured using an ALTAIR 5X Multigas Detector. The results showed that the gas temperature decreased from approximately 179 °C to 32 °C. CO removal efficiencies reached 89% and 78%, while VOC removal efficiencies reached 90% and 76%, respectively. These results demonstrate that the Venturi self-induced scrubber effectively reduced gas temperature and emission concentrations under the tested operating capacities.