Are you growing your broad beans in the soil or in pots? I assume pots as you are 'lightly spraying them with water', how often do you spray? Better to give the pots a good erin land then let the top inch or so of compost dry out before doing so again.

If you have to plant them out early you can make individual cloches for some of them with plastic bottles with the bases cut off. A bread knife is good for this.

If the beans were planted as deeply as they should have been, once the sprouts are about 5 cm tall they should be able to take a gentle shower from a watering can rose. If the sprouts are very weak and spindly, then they aren't getting enough light: they may recover with more light, or you might have to start over.