Device and method for the replacement of out-of-date developer

A method for replacement of at least one expired component of a pourable medium, comprising the steps of:

• providing a container from which at a removal output at least the one expired component of the pourable medium is removed and into which a quantity of at least one of fresh pourable medium and a fresh component is supplied at a supply input;
• providing said input and said output for the container such that a predetermined fill level of the pourable medium in the container remains approximately the same;
• positioning said supply input such that it is dependent upon a pressure created by the pourable medium in the container at an output of the supply input into said container when the pourable medium is substantially at said predetermined fill level in order to block inflow from the supply input;
• and
• regulating the fill level of the pourable medium in the container by addition of the supply quantity caused by a lower pressure at the output of said supply input when the pourable medium is below said predetermined fill level and by said blocked inflow when the pourable medium is substantially at said predetermined fill level, wherein a developer to develop a latent image is provided as the pourable medium.