1. Workflow of sand washing operation of filter press
The whole process of sand washing operation generally includes sludge sedimentation tank, mud lift pump, mud tank, Mud mixer, filter press feed pump, mud silo, filter press, sump.
1. Wastewater sludge is discharged into the sedimentation tank for sedimentation. At this time, the sludge will sink to the bottom of the tank under the influence of gravity, and will be discharged into the mud tank through the sludge lifting pump port at the bottom.
2. There is a mud mixer in the mud tank to process the incoming sludge with different moisture content, so that the sludge contains even water and prepares for the next step of pressure filtration.
3. The filter piston of the filter press pushes the filter plate to compress, and the filter chamber is formed when the set pressure is reached. The feed pump of the filter press draws the mud from the bottom of the mud tank and enters the filter chamber through the feed port. When all the filter chambers are filled, pressurization is performed to separate solid-liquid. The moisture content of the separated filter cake is as low as 40%. .
4. The filter press is above the mud silo, and the separated filter cake falls directly into the mud silo, which is convenient for post-processing. The separated clean water flows into the sump and can be used for sand washing again.
Second, the use process of sand washing machine equipment
1. Construction preparation
In order to ensure washing To produce clean machine-made sand, the mixing station needs to set up a pool, and choose cleaning equipment with a transmission tank; in order to ensure that the washed sand meets the requirements of medium and coarse sand, and to ensure that the water content of the washed sand is not more than 6% (the water content is too high, the water washing Sand is easy to freeze when used in winter, and the silo should not be unloaded). On the basis of traditional sand washing, it is necessary to add a sand screener, a crusher, a fine particle collector and a vibrating dewatering screen.
2. Processing method
(1) Add a trommel sand screening machine to the front end of the traditional sand washing equipment, and set up a water spray device in the sand screening machine , The machine-made sand transmitted to the drum through the belt is rotated, cleaned and screened in the screening machine, and the machine-made sand passing through the screen leaks into the pool below. The size of the trommel screen should be 4mm mesh. (If the sieve hole is too large, the machine-made sand washed out is too coarse; if the sieve hole is too small, the cleaning will not be clean.)
(2) The larger sand particles in the drum screen are transferred to the end, According to the characteristics of the rotating drum, a chute is added at the end of the drum sand screener, and a small stone crusher is connected below the chute, so that the coarse particles can pass through the chute and flow into the crusher for secondary crushing.
(3) After the secondary crushing, the fraction smaller than the sieve hole size is discharged through the sieve plate, and the coarse fraction larger than the sieve hole size remains on the sieve plate and continues to be hit and ground by the hammer. The size of the sieve plate is 4mm.
(4) The machine-made sand entering the pool shall be cleaned twice by the sand washing machine conveying tank. Above the conveying tank, one or several water spray pipes should be set up to clean the machine-made sand in the tank three times. For cleaning, set a small hole at least every 2cm on the water pipe.
(5) The vibrating dewatering screen should choose equipment with high vibration frequency and large dewatering capacity, so as to ensure that the washed out machine-made sand can be completely dehydrated, and the water content of the dewatered machine-made sand can be stable. Guaranteed within 6%.
(6) The fine sand recovery machine is the water and fine particles that will be lost from the pool, through the mud pump, re-pumped to the screen of the fine particle collection equipment, vibrated and cleaned, and finally passed The belt is transferred to the main belt, which finally completes the entire cleaning process.
