The winners of the largest Powerball jackpot in Iowa appeared in Des Moines Wednesday to claim their prize.Lottery officials said 20 Quaker Oats employees from Cedar Rapids won the $241 million jackpot.  A bus with about 50 people on board arrived in Des Moines Wednesday morning to claim the prize.It's estimated that each will receive about $5.6 million after taxes.The "Shipping 20" said workers from the plant have been buying Powerball tickets for the past 15 years.Eleven of the workers said they will retire, some said Friday will be their last day on the job.The workers said they plan to file an injunction to stop a list of their names from being made public.The ticket was sold at a Hy-Vee grocery store in Cedar Rapids for the June 13 drawing.It's the seventh ticket sold in Iowa to win the Powerball jackpot. The amount is the 15th largest Powerball jackpot won to date.