(Bloomberg) The sale of Medline Industries Inc. to a consortium of private equity firms has brought one of the world’s wealthiest families into the limelight.The deal, valued at more than $30 billion, stands to rank among the biggest transactions ever involving a family-owned business. The proceeds from the majority investment by Blackstone Group Inc., Carlyle Group Inc. and Hellman & Friedman will largely flow to the Mills, a Chicago-based clan who’ve been in the medical supply business for