In a chimney flue, a damper closes off the flue to keep the weather (and birds and other animals) out and warm or cool air in. This is usually done in the summer, but also sometimes in the winter between uses. In some cases, the damper may also be partly closed to help control the rate of combustion.
A little more detail will help us answer your question. If your snacks are pretzels, potato chips, dried fruit or other dry goods, you can take them in your carry-on or checked bag. Snack items that are liquids or gels, like pudding, jello or yogurt, etc., falls under the 3-1-1 rules for liquids for carry-on bags. They can be transported in checked bags.
Regulations for carry-on (cabin) baggage: Wine and hard alcohol in your carry-on or cabin baggage is generally NOT allowed. This is because liquids in quantities larger than 100 ml (3.4 oz.) cannot be placed in your carry-on. An exception to the carry-on rule is made for wine and other spirits purchased in duty-free stores beyond security checkpoints.