Bloomery: Adjustable air blower, copper tuyeres

For my next smeltings I built an adjustable air blower. For this purpose, I installed a 1500W electric motor from a vacuum cleaner inside a wooden box. Inside, the box is separated in two compartments: One compartment acts as a silcencer, whereas the other compartment contains the motor. The air is sucked in through the silcencer and leaves the box on the other side. The compartments are each sealed by a wooden cover plate. One plate bears the adjustable resistor from the motor driving unit. By this feature it is possible to adjust the motor from zero-speed to full power continuously.
My plan is to use the electric air blower and the goat skin bellows alternately. The air will be blown into the furnance by a nozzle, made from copper. I made three tuyeres from copper pipe, as shown in the pictures.

The adjustable air blower

The adjustable air blower

The enclosed compartments of the air blower

The control panel of the air blower

Copper tuyeres

Copper tuyeres