Recirculation, replenishment, refresh, recharge and backflush for a photographic processing apparatus

An apparatus for processing photosensitive materials, which comprises:

• a tank through which a processing solution is pumped;
• a rack having integral means to facilitate its insertion and removal from said tank, said rack and said tank are relatively dimensioned so that a small volume for holding processing solution and photosensitive material is formed between said rack and said tank;
• means for circulating the processing solution through the small volume;
• means for filling the small volume and said circulating means, from the lowest elevation point of the small volume and the lowest elevation point of said circulation means, with processing solution to prevent air from being entrapped in the processing apparatus;
• means for emptying the small volume and said circulating means, from the lowest elevation point of the small volume and the lowest elevation point of the small volume and the lowest elevation point of said circulating means, of processing solution to prevent processing solution and particulate matter from being entrapped in the processing apparatus;
• means for controlling said emptying means and means for backflushing said circulating means and the small volume to remove any particulate matter.