Refractory materials selected for fluidized bed waste incinerator

Refractory materials selected for fluidized bed waste incinerator

01. Overview of the foreword

Fluidized bed technology is a general term for a type of incineration technology based on fluidization. Fluidized beds can be divided into bubbling fluidized beds, circulating fluidized beds and rapid fluidized beds. In the early days, the bubbling fluidized bed was the main method, and gradually developed to the current circulating fluidized bed. The domestic fluidized bed incineration technology is becoming increasingly mature, so this requirement is proposed.

The fluidized bed waste incineration system should at least include a waste feeding device, ignition device, air distribution device, incineration boiler, air supply system, air induction system and other auxiliary devices.

The fluidized bed waste incineration line adopts continuous operation mode. Except for force majeure, the incineration line of the waste incineration plant should be arranged for maintenance in an orderly manner to meet the requirements of 365-day operation throughout the year. The annual cumulative operating hours of a single furnace incineration line should be greater than 7,200 hours and should not be less than 8,000 hours. If the incineration line of a single furnace is less than 8000 hours, the waste incineration plant should adopt the following methods according to the actual situation to ensure the harmless treatment of waste throughout the year: (1) Set up a backup furnace; (2) Enlarge the design of the waste storage pit; (3) ) landfill disposal.

02.Incineration boiler refractory materials

The physical and chemical performance index specifications of refractory materials for fluidized bed waste incineration boilers should refer to YB/T 4108 "Wear-resistant refractory bricks for circulating fluidized bed boilers" and YB/T 4109 "Wear-resistant refractory castables for circulating fluidized bed boilers" 》Requirements implemented.

Refractory materials should be selected according to the design requirements of the boiler manufacturing unit to meet the specific requirements for wear resistance and high temperature resistance. After the refractory materials arrive, they should be organized in time for storage to avoid adverse effects caused by open-air storage. When refractory materials are installed and used, corresponding test blocks should be made to test the relevant material strength.

After the masonry and installation of refractory materials for fluidized bed incineration boilers are completed, the oven must be baked strictly in accordance with the temperature rise curve provided by the refractory manufacturer.

Fluidized bed waste incineration boiler refractory materials and their masonry are very important. Its wear resistance, sealing and insulation properties directly affect the normal operation of the incineration boiler and the safety of the operators. Boiler furnace wall masonry construction can minimize heat dissipation loss, improve the economy of boiler operation, and prevent combustion smoke from leaking out of the furnace and flue and injuring people.

Currently, there are two standards for refractory materials used in circulating fluidized bed boilers, namely metallurgical standards and power industry standards, which are managed by the National Refractory Materials Standardization Technical Committee and the China Electric Power Industry Power Station Metal Standardization Technical Committee respectively, namely the two standards we mentioned at the beginning of the article. standards, YB/T 4108 "Wear-resistant refractory bricks for circulating fluidized bed boilers" and YB/T 4109 "Wear-resistant refractory castables for circulating fluidized bed boilers", regarding refractory materials for fluidized bed waste incinerators There are currently no specifications for physical and chemical performance indicators.

03. Function classification

At present, refractory materials used in fluidized bed incineration boilers in China can generally be divided into three categories according to their functions:

1. Wear-resistant refractory bricks, castables, plastics and mortars;

2. Refractory bricks, castables and mortar of refractory materials;

3. Bricks, castables and mortar of refractory insulation materials.

Commonly used varieties of wear-resistant refractory materials include phosphate bricks and castables, sillimanite bricks and castables, silicon carbide bricks and castables; corundum bricks and castables; wear-resistant refractory bricks and castables; and silicon nitride bonded Silicon carbide products, etc.

As there is currently no unified standard for refractory materials for fluidized bed waste incinerators in China, when selecting refractory materials, the design unit should choose refractory materials that are better than those of conventional circulating fluidized bed combustion boilers to achieve wear resistance and durability. Specific needs for high temperatures.