ANALISIS KINERJA MESIN PENYANGRAI (ROASTING) KOPI TIPE SILINDER DATAR BERPUTAR DENGAN SUMBER PANAS GASIFIKASI BIOMASSA

Arjanggi Nasution, Dr. Ir. Bambang Purwantana, M.Agr

2013 | Tesis | S2 Mekanisasi/Teknik Pertanian

Penelitian ini digunakan untuk menetapkan parameter yang mempengaruhi kinerja mesin penyangrai tipe silinder datar berputar yang akan diubah ke bentuk persamaan analisa dimensi. Penelitian dilakukan dengan memodifikasi mesin penyangrai tipe silinder datar berputar berbahan bakar gas LPG menjadi berbahan bakar gas hasil gasifikasi biomassa, memvariasi perlakuan kinerja mesin, mengukur keseragaman kadar air, kerusakan kopi, dan kadar warna kopi hasil penyangraian. Variasi yang dilakukan adalah variasi berat awal kopi dengan berat masing-masing 2 kg, 3kg dan 4 kg; variasi diameter kopi dengan diameter masing-masing kecil (6,41- 6,86 mm), sedang (7,54-8,19 mm) dan besar (8,88-9,06 mm); variasi laju aliran udara dengan laju aliran udara masing-masing katup terbuka penuh (4,4 m/s), katup setengah tertutup (2,2 m/s) dan katup tiga perempat tertutup (1,1 m/s); dan variasi panjang silinder sangria dengan panjang silinder 21 inch, 10,5 inch, dan 5,25 inch. Hasil penelitian menunjukkan bahwa panas pembakaran gas hasil gasifikasi biomassa dapat digunakan untuk menggantikan gas LPG dengan kualitas penyangraian setara light roast dan pengujian hubungan berat akhir kopi (M1) terhadap berat kopi awal (M0), diameter kopi (D), panas jenis kopi (Cp), panjang silinder (Ps), laju aliran udara (Q), gaya gravitasi (g), suhu (T), dan kecepatan putar mesin (ω) adalah sebagai berikut: M = 10 . M x D x g P x Q x ω g D x ω . P x ω g . M − M M . Q x ω Cp x T x g . Mesin penyangrai kopi tipe silinder datar berputar dengan sumber panas gasifikasi biomassa membutuhkan waktu paling sedikit 20 menit untuk penyangraian light roast, nilai kadar air kopinya sudah memasuki kriteria kadar air kopi pada umumnya yaitu 2-5%, nilai kerusakan kopi yang dihasilkan 0% , dan memiliki nilai RGB berdasarkan perbandingan dengan Coffea Roaster Tipe RK-28RCg yaitu light roast kadar red 42.646, kadar green 45.949 dan kadar blue 36.316; medium roast kadar red 47.929, kadar green 48.536 dan kadar blue 41.338; dan dark roast kadar red 17.662, kadar green 10.093 dan kadar blue 10.401 sehingga nilai RGB kopi hasil penyangraian di atas medium roast kopinya tidak matang.

The results are used to set parameters that influence the performance of the roaster machine horizontal rotating cylinder type to be converted to the form of equation dimensional analysis. Research carried out by modifying the roaster machine horizontal rotating cylinder type LPG gas fired to biomass gasification results gas fired, varying the treatment machine peformance, measure the water content uniformity, damage to coffee and coffee color levels results of roasting. Variations that do are variations of coffee with heavy initial weight of each is 2 kg, 3 kg and 4 kg; diameter variations of coffee with diameter of each is small (6.41 to 6.86 mm), medium (7.54 to 8.19 mm) and large (8.88 to 9.06 mm); variations in air flow rate of air flow rate valve of each is fully open (4.4 m/s), half-closed valve (2.2 m/s) and three-quarters of a closed valve (1.1 m/s), and the length variation sangria cylinder with is a 21 inch long cylinder, 10.5-inch, and 5.25 inch. The results showed that the hot combustion gases of biomass gasification can be used to replace LPG gas with equivalent light roast roasting quality and test weight relationships end coffee (M1) to the weight of the coffee baseline (M0), coffee diameter (D), specific heat of coffee (Cp ), the length of the cylinder (Ps), air flow rate (Q), gravity (g), temperature (T), and the engine rotational speed (ω) is as follows: M = 10 . M x D x g P x Q x ω g D x ω . P x ω g . M − M M . Q x ω Cp x T x g . Coffee roaster machines horizontal rotating cylinder type with a heat source of biomass gasification takes at least 20 minutes for light roast, water content of coffee is coffee moisture entering criteria in general 2-5%, total damage resulting coffee is 0%, and RGB value by comparison with Coffea Roaster Type RK-28RCg of the light roast had higher red levels of 42,646, green levels of 45,949 and blue levels of 36,316; the medium roast had higher red levels of 47.929, green levels of 48.536 and blue levels of 41.338, and the dark roast had higher red levels of 17.662, green levels of 10.093 and blue levels of 10.401 so the value of RGB coffee roasters results above medium roast coffee is immature.

Kata Kunci : penyangraian, kopi, gasifikasi biomassa, kinerja, analisa dimensi