Shanghai & Beijing with transit visa

Hi there, I'm a German citizen going for an urgent visit to Shanghai and Beijing. The visa procedure is too long as I need to be in China already around 15th of November. My agenda is:

Dubai - Shanghai - Seoul - Beijing - Seoul - Shanghai - Dubai

Is the transit visa accepted for this? Or how long must I leave Shanghai for before I can enter Beijing on a transit visa?

Waiting for your urgent reply.

Thanks a lot.