Gravity dust collector

The invention provides a gravity dust collector. The gravity dust collector comprises a body, a gas inlet pipeline, a gas inlet pipe and a gas outlet pipe, an impurity removing door, an ash discharging device, an upper lattice plate and a lower lattice plate, wherein the body comprises an upper cylinder body and a lower cone body; the lower cone body is connected to the lower part of the upper cylinder body, so that the body is in a cavity structure; the gas inlet pipeline is arranged in the upper cylinder body; the gas inlet pipe and the gas outlet pipe are connected with the upper cylinder body or the gas inlet pipeline and respectively used for inputting raw coke oven gas and outputting smoke after removing dust; the impurity removing door is arranged on the side wall of the lower cone body; the ash discharging device is connected to the bottom end of the lower cone body; the gas inlet pipeline or the inner wall of the body is coated with an anti-corrosion high-temperature resistant protection layer; the u