Exhaust device for printing waste gas and ventilation system for printing workshop

The utility model relates to the technical field of printing equipment, in particular to a printing waste gas exhaust device and a ventilation system for a printing workshop. The cleaning mechanism comprises a water pump, a liquid storage tank, a liquid inlet pipe, an annular nozzle, a water outlet pipe, a three-way pipe, a tap water pipe and a connecting pipe, the water pump is fixedly installed on the right side of the gas-collecting hood body, and the liquid storage tank is fixedly installed on the left side of the gas-collecting hood body; a water inlet of the water pump is communicated with a liquid inlet pipe of which one end penetrates through and extends into the liquid storage tank. According to the exhaust device for the printing waste gas and the ventilation system for the printing workshop, through the arrangement of the cleaning mechanism, when many oil dirt impurities adhere to the interior of the gas collecting hood, cleaning liquid is sprayed firstly to dissolve oil dirt, then water is sprayed