I. Introduction

Sludge dryer, also known as sludge drying equipment or sludge drying equipment, is a kind of equipment that evaporates the water in sludge through heating and dehydration, thus realizing the drying treatment of sludge. It is widely used in sludge drying treatment in municipal sludge, printing and dyeing sludge, paper-making sludge, electroplating sludge and other fields, and can also be used for agricultural use and as fuel.

Second, the working principle

The working principle of sludge dryer is mainly based on hot air circulation system and stirring device. Hot air is evenly blown into the dryer through a special nozzle to exchange heat with sludge. At high temperature, the water in the sludge will evaporate quickly, and the stirring device in the equipment will turn the sludge continuously, so that it can be fully exposed to hot air, thus accelerating the evaporation process. After a period of treatment, most of the water in the sludge will be evaporated to form dry solid particles.

Third, the equipment structure

Sludge dryer is mainly composed of feeding system, drying system, slag discharge system, exhaust system and electrical control system. Among them, the drying system includes induced draft fan, breaking device, belt feeder, rotary drum, heat source and other components. The working area includes material guide area, inclined lifting plate area, cleaning area and discharging area.

Material guide area: wet sludge enters this area and contacts with high-temperature hot air to quickly evaporate water. When the material is copied by the board with large guide angle, it will be guided to the next working area if it is not bonded.

Inclined lifting plate area: wet sludge has been in a loose state with low moisture content in this area, and the material has no bonding phenomenon in this area. After heat exchange, the material reaches the required moisture state.

Cleaning area: wet sludge is picked up by the board in this area to form a material curtain, and it is easy to form the phenomenon of sticking to the drum wall when the material falls. Because the equipment is designed with a cleaning device, the cleaning device can clean the materials adhered to the inner wall and break the agglomeration of the material balls, thus increasing the heat exchange area and improving the drying rate.

Discharge area: the drum is not equipped with a copying plate in this area, and the materials roll and slide to the discharge port in this area to complete the whole drying process.

Fourth, characteristics and advantages

High dehumidification efficiency: the multi-stage energy-saving drying process is adopted, which obviously improves the dehydration and dehumidification capacity and saves energy by more than 50% compared with the traditional drying method.

No dry tail gas emission: the whole drying device is fully enclosed, and the odor does not overflow, so there is no need to install a tail gas treatment system. At the same time, the discharged condensate has a low COD content and does not need a complicated treatment process.

It is safer to operate at low temperature: when working at the fully enclosed low temperature of 50~75℃, the sludge is dried in granules, and the granules are basically not stirred, and there is basically no dust generation, dust and explosion hazards.

High thermal efficiency: multi-stage energy-saving technology is adopted to save operating costs.

Modular design: the whole equipment is made of corrosion-resistant high-quality stainless steel, and its service life is more than 15 years. Modular design makes site assembly convenient and occupies small space.

Wide application range: The sludge dryer can be used for drying sludge with various viscosities, with a wide application range.

V. Application fields

Sludge dryers are widely used in decorative building materials, metallurgical industry, chemical plants, concrete and other fields. After the whole drying process, sludge can be reused as an effective secondary resource, such as the production of bio-organic fertilizer.

VI. Purchase and Maintenance

When choosing a sludge dryer, it is necessary to consider the water content, viscosity, treatment capacity and use after drying. At the same time, we need to pay attention to the performance, price, after-sales service of the equipment and the strength and reputation of the manufacturer.

In the process of use, it is necessary to maintain the equipment regularly, including cleaning the inside of the equipment, checking the operation of hot air circulation system, stirring device and electrical control system, finding and solving problems in time, ensuring the normal operation of the equipment and prolonging its service life.

To sum up, sludge dryer has been widely used in the field of sludge treatment because of its advantages of high efficiency, energy saving, environmental protection and safety. In the process of purchasing and using, it is necessary to fully understand the performance and characteristics of the equipment, and choose and operate according to the actual needs.