How many people in the canteen must have a grease trap?

In the temporary canteen on the construction site, if the number of diners exceeds 100, a simple and effective grease trap should be set up to discharge the generated sewage into the municipal sewage pipe network after passing through the grease trap.

Oil separation tank is a kind of wastewater pretreatment structure which uses the density difference between oil droplets and water to produce floating effect and remove floatable oil substances in oily wastewater. The structure of grease trap mostly adopts advection. Oily wastewater enters the rectangular oil separation tank through the water distribution tank and flows slowly along the horizontal direction. During the flowing process, the oil product floats to the water surface, is pushed into the oil collecting pipe by the oil collecting pipe or the oil scraper installed on the tank surface, and flows into the dehydration tank.

Heavy oil and other impurities precipitated in the oil separation tank gather in the sludge hopper at the bottom of the tank and enter the sludge pipe through the sludge discharge pipe. After oil separation, the wastewater overflows to the drainage tank for subsequent treatment to remove emulsified oil and other pollutants.

Extended data

Oil pollution treatment principle of oil separation tank

Most grease traps are made of reinforced concrete or masonry. On the rectangular plane, it is divided into 2 ~ 4 grids along the direction of water flow, and the width of each grid is generally less than 6 meters, so as to evenly distribute water. The effective water depth is less than 2 meters, and the length of the oil separation tank is generally more than 4 times the width of each tank.

Oil slick and sludge at the bottom of the oil separation tank are scraped off by chain scraper and sludge scraper respectively. Generally, each grid is equipped with a set of oil scraper and mud scraper and a mud bucket. If a baffle is added in the middle of each compartment, oil scraper and mud scraper are installed on both sides of the baffle, and the mud bucket is a two-stage oil separation tank, the oil removal efficiency can be improved, but the equipment and energy consumption are increased.

If several inclined plates are added to the oil separation tank, the oil removal efficiency can also be improved, but the construction investment is high. In cold areas, in order to prevent oil from freezing in winter, steam pipes can be installed at the bottom of oil collecting pipes for heating. Generally, the grease trap should be covered with a steam pipe under the cover plate, which can keep warm, prevent the grease trap from catching fire and oil products from volatilizing, and prevent dust and sand from entering.