STUDY OF EFFICIENCY OF DRUM DRYERS OF METALLURGICAL PRODUCTIONS USING PERFORATED PIPES WITH LOCALIZATION OF HEAT FLOWS

The article presents the design of a drum furnace, providing for the provision of differentiated heat flows through the use of an internal perforated pipe. The design of the presented horizontal drum dryer with a perforated tube having openings is designed to eliminate such technological risk factors as the ignition of the oil component of the processed material, and the metal dispersed material itself having pyrophoric properties. As a result of the numerical simulation using the LS–DYNA program, the temperature and heat fluxes in the quasi-boiling zone of the drained oil-containing dispersed material were determined. The calculations made it possible to establish the dependence of the temperature in the quasi-boiling zone on the number of holes of the perforated pipe. Analysis of the obtained graphs allows us to conclude that the gradient of temperature (heat) flows in fixed sections of the furnace of the quasi-boiling zone.

MINERALISASI EMAS EPITERMAL DI WILAYAH LUBUK GADANG, SOLOK SELATAN, SUMATERA BARAT.

Mineralisasi emas yang terdapat di Lubuk Gadang merupakan bekas tambang Belanda, terdiri atas beberapa tubuh bijih (Simajolelo, Dam Pulau Banda, Poeding 11/Lubang 11), dan terjadi pada lingkungan batuan intrusi (Kapur) yang menerobos Formasi Barisan (Perm). Indikasi emas dan logam dasar ditemukan pada zona filik, propilitik dan argilik yang terjadi karena pengaruhlarutan hidrotermal yang naik bersama-sama intrusi granitik–granodioritik atau disebabkan juga oleh pengaruh dike andesitik–basalt yang terbentuk akibat pengaruh Sesar Besar Sumatera berarah baratlaut-tenggara. Hasil analisa urat kuarsa dan batuan menunjukkan kandungan emas dan perak yang cukup tinggi (0.1 g/t - 1.72 g/t Au dan 309 g/t Ag) yang diikuti dengan kandungan tembaga (Cu) yang rendah, dan seng and timbal yang tinggi (28.19 % Zn dan 23.65 % Pb). Daerah penelitian termasuk dalam zona proses pendidihan (boiling zone) di sepanjang rekahan,dengan temperatur berkisar <150°C sampai ~300°C pada kedalaman dangkal. Data geologi,mineral sulfida, tekstur serta ubahan hidrotermal, menunjukkan bahwa mineralisasi emas yang terbentuk di daerah ini dapat diklasifikasikan sebagai tipe epitermal sulfida rendah.

Characteristics of Transition Boiling in Sodium-Heated Steam Generator Tubes

Thermal fluctuations were measured in the tube wall in the transition boiling zone of a full-scale LMFBR sodium-heated steam generator tube. The tube had an inside diameter = 10 mm, wall thickness = 2.90 mm, heated length = 13.1 m, and material = 2 1/4 Cr-1 Mo steel. Water flowed vertically upwards inside the straight tube, and sodium flowed counter-currently in a surrounding annulus. Results of thermal, spectral, and thermal stress analyses are presented for a test within the normal operating range of LMFBR steam generators. Results of other tests are presented that show the effects and sensitivity of sodium temperature and water pressure on the severity of the thermal fluctuations.