Perhitungan Kapasitas Blower di Blok satu Main Shaft PT. Nusa Alam Lestari (NAL), Site Sapan dalam.

Administratively, the mining concession area of PT NAL included in Prambahan,Talawi district, the city of West Sumatra province Sawahlunto, the distance betweenthe mine with a desert city (provincial capital boast) ± 90 km east of the city ofPadang.In mid-2011 PT. Nusa Alam Lestari plans to conduct underground mining systemwith some one with no consideration as to be open pit stripping ratio with a value thatreaches 1:16. In this case to support underground mining operations it is veryimportant to the needs of the air inside the mine that is useful for increasing workefficiency because as it is known that the concentration of dust and gas productionwill increase.In underground mining system with room and pillar method of PT. Nusa AlamLestari divided into 3 blocks of mining blocks, where each block consists of twomain holes for drainage which is the main shaft and auxiliary shaft fresh air to inhaledirty air. Ventilation system to be used in block 1 is a blow to the system main shaftand the suction holes in the auxiliary shaft hole. Where the air is needed to block amain shaft consists of the need for workers as many as 20 people, to dilute themethane gas and temperature control in the mine.At block a main shaft consists of two panels of coal mining that require air for 110.30m3/menit and to face development needs air for 137.03 m3/menit. So the total airrequirement is equal to 247.33 x 1.5 (quantity factor) = 229.54, or about 3.825m3/second m3/menitBased on the quantity of air required for all needs to block a main shaft had to use theair blower with a capacity of more than 229.54 m3/menit.