Experimento para quantificar a eficiência de aspersão de líquidos: aplicação em distribuidores espinha de peixe

This paper describes a device developed on the pilot scale and a simple approach to compare liquid distributor efficiencies. The technique consists basically of analyzing the mass of the liquid collected in 21 vertical pipes measuring 52 mm in internal diameter and 800 mm in length placed in a quadratic arrangement and positioned below the distributor A 50 mm thick acrylic blanket that does not disperse liquids was placed between the distributor and the pipe bank to avoid splashes. Assays were carried out with ladder-type distributors equipped with 4 parallel pipes each for a column measuring 400 nun in diameter as an example of the application. The number (n) of orifices (95, 127, and 159 orifices/m(2)), orifice diameter (d) (2, 3, and 4 mm) and the flowrate (q) (1.2; 1.4; and 1.6 m(3)/h) were varied. The best spread efficiency, which presented the lowest standard deviation, was achieved with 159 orifices, 2 mm and 1.4 m(3)/h. The pressure (p) at the distributor inlet for this condition was only 51000 Pa (0.51 kgf/cm(2)), while the average velocity (v) was 6.3 m/s in each orifice. These results show some limitations of the practical rules used in distributor designs.

O mercado brasileiro do século XIX: uma visão por meio do comércio de cabotagem

The Brazilian market in the XIX century: an approach through the cabotage commerce. The maritime commerce consisted of the main way of circulation of the goods between the Brazilian provinces until the second half of century XIX. Although the relatively big importance of the flows of commerce with the exterior, we note significant exchange of goods by sea between the Brazilian regions since the colonial period. A part of these exchanges derived from products destined in last instance to the foreigner or imported of the exterior. However, another part elapsed of national goods that had not arrived at be exported to the international market. Many goods for the colonial and imperial consumption had circulated by the Brazilian coasts in expressive sums. From the information raised for the imperial period, especially the decades of 1860 and 1870, we verify that most of the goods commercialized between the provinces consisted of national products destined to the internal consumption.