In May 2017, a Nanjing Environmental Co., Ltd. ordered Henan Zhengzhou Mining Machinery Co., Ltd. Ф2.2x18m solid (hazardous) waste rotary kiln and supporting secondary combustion chamber for Yichang chemical industry sludge incineration. Due to the installation of the secondary combustion chamber, the harmful components including dioxins in the flue gas can be completely decomposed to meet the environmental protection requirements.

Signing date: 2017-05-21

Processing material: industrial sludge

Processing capacity: 50t/d

Equipment configuration: 1 set of Ф2.2x18m rotary kiln, 1 set of secondary combustion chamber

1. Project overview:

An Environmental Co., Ltd. in Nanjing is mainly engaged in the design and manufacture of three types (A2) of land-based incineration system engineering, water treatment system engineering, soil remediation engineering and pressure vessels, as well as marine incinerators, domestic sewage treatment devices, bilge water separators, seawater dewatering device, central cooler, etc. This project uses rotary kiln + secondary combustion chamber to incinerate garbage and solid waste, and eliminates dioxins in flue gas at a high temperature of 1100 ℃ in the secondary combustion chamber at the end of the kiln to ensure that the exhaust gas is discharged up to the standard.

The project signed a supply contract in May 2017, and the installation and commissioning was completed in January 2018. The design, manufacture, installation and commissioning of the rotary kiln and secondary combustion chamber equipment were all completed by Henan Zhengzhou Mining Machinery Co., Ltd.

2. Solution:

The rotary kiln + secondary combustion chamber supporting equipment used in this project is used for garbage and solid waste disposal incineration and the treatment of harmful components of waste gas. The scheme is unique and the effect is good. The thermal engineering, technical parameters and disposal process of the main equipment are as follows:

1) Host device parameters

Rotary kiln:

Power supply: 380V/50Hz/3Ф, the energy consumption level of the motor is IE2, the insulation level is F level, the protection level is IP54, and the explosion-proof level is dII BT.

Kiln body specification: Φ2200X18000(mm)

Equipment slope: 3:100

Main material of kiln body: Q345R

Kiln head and kiln tail sealing form: fish scales and labyrinth

Support form: two-point support

Transmission form: single-end two-stage transmission, pinion supported by double bearings

Rotary kiln working temperature: 600℃~700℃

Secondary combustion chamber:

Secondary combustion chamber material: Q345

Working temperature of secondary combustion chamber: 1100℃

2) Process flow

The feeding port of the rotary kiln is equipped with a pushing mechanism to ensure continuous feeding. The solid (hazardous) waste is fed into the rotary kiln through the feeding mechanism to be incinerated into high-temperature flue gas and ash. The outlet temperature of the rotary kiln is 800-850℃. After the flue gas enters the secondary combustion chamber, the secondary air is tangentially injected around the secondary combustion chamber, so that a strong vortex field is formed in the secondary combustion chamber, and the combustible components in the flue gas can be removed full burn. At the same time, the secondary combustion chamber adopts a unique structural design, so that the secondary combustion chamber has the function of cyclone dust removal. The flue gas temperature at the outlet of the secondary combustion chamber is greater than 1100°C, and the flue gas stays in the high temperature area for more than 2 seconds, ensuring the complete decomposition of harmful components including dioxins in the flue gas, and meeting the requirements for hazardous waste incineration.

The rotary kiln maintains a stable slag layer with a thickness of about 50mm to protect the refractory layer.

3. Project Site: