The Wave filter housing is optimized, and there are several sub-cavities for storing ammonia in the inner air bag.

By using the above technical scheme, the air bag is separated into a multi-ovary cavity, the ammonia gas is evenly stored in the sub-cavity, such a setting can avoid when a worm invasion when all the ammonia is released, the taste is pungent; In addition, such a setting does not have to be scrapped after the insect invasion once, the need to replace the airbag waste material.

As preferably, there are more than one second through hole on the upper cover, and a waterproof and breathable film is arranged on the second through hole.

By using the above technical scheme, the relative molecular weight of ammonia is less than the relative molecular weight of air, so the release of ammonia gas will produce upward movement trend; ammonia gas can be dispersed outward from the second through hole; second, during the working process, the heat generated by the internal electronic components can also be dispersed from the second through hole. Avoid heat accumulation in the filter housing, so that the internal electronic components after heating the resistance to increase, affecting the normal operation.