Dirt separation for impingement cooled turbine components

A turbine component comprising:

• a body having a leading edge and a trailing edge, said body having a radially outer edge and a radially inner edge;
• an impingement tube receiving within said body and including a radially outer portion and a radially inner portion, with said radially inner portion for receiving air from a radially inner source and said radially outer portion for receiving air from a radially outer source, said radially inner and outer portions having impingement air holes for directing impingement air to a position adjacent said leading edge of said body, and at least said radially outer portion being configured to direct a greater volume of impingement air to a aft end, spaced from said leading edge and in a direction toward said trailing edge of said body, than is directed toward said leading edge.

A method of reducing dirt flow toward a leading edge of a hollow airfoil comprising the steps of:

• (1) providing a airfoil, and an impingement tube within said airfoil, with a radially outer impingement tube portion and a radially inner impingement tube portion, directing a radially outer air source into said radially outer impingement tube portion, and directing a radially inner source into said radially inner impingement tube portion;
• and
• (2) shaping said outer impingement tube portion such that it minimizes dirt moving toward a leading edge of said radially outer impingement tube portion.