Hatches only seem to eat resources when they are onscreen.
I have set up a system for hatches to eat surplus resources, and send the resulting coal to distant generators via conveyor rail. The system correctly sends coal along the rail when the hatches are onscreen, but once the screen is moved elsewhere, the flow of coal dries up.
If the screen is moved back to the hatches, they start eating resources again.
1. Open attached save file. 2. Observe hatch farm in lower left side of base, and coal generators on upper right side. 3. Move screen outside of hatch farm, and observe the flow of coal to the generators stop. 4. Move the screen to the hatch farm, and observe the flow of coal resume.