The urban sludge dryer can dry materials with 90% water content to the finished product in one go. In response to the characteristic of easy agglomeration during the sludge drying process, the material plate structure of the general single channel dryer has been changed, and a combined self-cleaning device has been adopted, greatly expanding the application range of the single channel dryer. It can not only dry various types of sludge, but also various high viscosity materials.
Urban sludge enters the guide plate of the dryer through a chute from the feeder. As the cylinder rotates, the sludge is guided to the inclined lifting plate and lifted to the center of the cylinder. It gradually falls to form a material curtain, and high-temperature airflow passes through it, causing the sludge to preheat and evaporate some of the water. When the sludge falls and moves onto the movable grate wing, the material is mixed with the preheated grate wing, transferring heat to the material and causing some of the water to evaporate. At the same time, the material carried by the wing plate is lifted and sprinkled multiple times, and the material undergoes convection and contact heat exchange with the hot air flow. The cleaning device buried in the material also slides down the inner side of the arc-shaped lifting plate, sweeping away the material adhering to the inner wall of the lifting plate. After the cleaning device rotates along the vertical line of the cylinder, it is then dragged on the back of the circular arc lifting plate to clean the material adhering to the outer wall of the lifting plate. As the cylinder rotates continuously, some of the water evaporates and the sludge is further dried. At the same time, the cleaning device also plays a crushing role in the sludge ball, improving the drying speed. Finally, after the sludge is dried, it becomes a loose material with low moisture content and is discharged from the discharge port.
The sludge dryer mainly consists of a cylinder, a supporting device, an actuating device, and an end sealing device. The sewage cylinder is the substrate of the sludge dryer, which not only conducts heat and mass transfer processes inside, but also plays a role in moving and conveying materials. The supporting device of the cylinder is composed of three parts: a rolling ring, a supporting wheel, and a blocking wheel. The weight of the entire cylinder is transmitted to the supporting roller through the rolling ring, which rolls on the supporting roller and blocks the axial movement of the cylinder.\
Main characteristics of urban sludge dryer
1. High thermal capacity coefficient and high thermal efficiency. By combining the crushing and stirring device with the rotary cylinder, the total heat transfer coefficient of the sludge dryer is increased to 2-3 times that of a regular rotary dryer. The crushing and stirring device crushes the material, increasing the contact area between the material and the hot air, while also preventing the short circuit of the hot air, making full use of the heat of the hot air.
2. The product particle size is uniform. Due to the addition of flocculants during the dehydration process of sludge from urban sewage plants, the viscosity of the sludge increases, making it prone to agglomeration during the drying process, which not only affects the drying effect but also increases the difficulty of utilization. In a sludge dryer, the mixing and crushing device and the kiln type movable plate inside the cylinder act to break the mud before it hardens, and the final output is uniformly sized particles (about 2mm), making the subsequent treatment or utilization process of sludge more convenient.
3. Easy to operate and operate. The sludge dryer is equipped with an automatic control system, and the biogas burner has a large and small burner combustion mode. The end of the drying drum is equipped with a temperature sensor, which controls the size conversion of the burner head through the temperature sensor, thereby controlling the humidity inside the drying drum and preventing excessive temperature from causing sludge coking. The speed of the rotary drum can be adjusted through the control cabinet.
4. Environmental protection and energy conservation. The sludge dryer uses biogas generated during sludge digestion treatment as heating energy, greatly reducing the cost of sludge drying and creating a new application field for the comprehensive utilization of biogas.
5. Unique arch breaking and vibration device. Effectively solved the problems of material bonding with the body and lifting device, as well as material agglomeration and movement obstruction during the drying process.
