The problem of urban garbage has brought serious adverse effects on urban management, urban natural environment, living environment of residents, human health and people's mental state. The proper handling of the increasing amount of urban garbage has become an increasingly urgent problem of urban management. The common treatment of municipal waste includes landfill, composting, pyrolysis, incineration and other four ways. According to the sustainable development strategy, the goal of garbage disposal should be to realize harmlessness, reduction and resourcefulness. Incineration is the fastest and most effective technical method to realize the reduction of waste, at the same time, incineration can completely eliminate harmful bacteria and viruses, and energy can be recovered. Waste incineration treatment of the main equipment for the waste incinerator, after investigation, analysis and application of research to get the waste incinerator refractory materials must have the performance of: (1) excellent high-temperature volumetric stability: (2) excellent high-temperature strength and abrasion resistance (3) excellent resistance to temperature fluctuations caused by thermal shock stability (4) excellent resistance to corrosion (CO, CI2, SO2, NO2, high temperature) (4) excellent resistance to erosion (CO, CI2, SO2, NO2, high-temperature melt, alkali metal steam, etc.) performance; (5) excellent construction performance drink performance-price ratio: (6) excellent heat insulation and heat preservation performance. 10 years, with the incinerator technology to incinerator large-scale incinerator, resource and automation of the direction of the development of the incinerator refractory materials have undergone a major change. Performance in the largest technological advances: (1) the amount of unshaped refractory materials rose to about 75%. It greatly simplifies the form of complex parts of the construction process, enhance the integrity of the furnace lining and airtight, to extend the service life. Its production process also saves energy, has a better performance-price ratio (2) the application of refractory fiber can make the heat loss and heat storage loss is greatly reduced. The incineration temperature of the garbage incinerator is not very high, still contains a certain amount of unburned combustibles, a certain amount of heavy metals and dioxins, if not handled properly, placed arbitrarily or arbitrarily landfill will be on the atmosphere or groundwater, soil and other serious pollution. In order to solve the secondary pollution of waste incinerator incineration ash will be used waste ash melt curing treatment technology. The technology research does not contain chromium (6-valent chromium pollution of the environment) refractory materials, that is, AL2O3-ZrO2 quality, AL2O3-MgO quality, SiC quality, etc. with good resistance to erosion and other high-temperature performance of the refractory materials, is the current research and to solve the problem of the life of the waste ash slag melting furnace and industrialization of the promotion of the problem of the direction of the technology. This is also for the garbage slag melting treatment technology in our country to promote the harmless refractory material preparation technology and application technology research focus and key.
One: types of garbage incinerator
(1) push type incinerator is the introduction of combustion gas from the lower part of the grate, dragging the grate to make the garbage continuous combustion. Suitable for large quantities of garbage, widely used in large cities for waste incineration.
(2) fluidized bed incinerator is the heat storage sand as a thermal medium instantaneous waste incineration. Sand and reactive substances (containing high alkali substances, etc.) are not incinerated, regulate the working temperature of up to 1000 ℃ to control the sintering of sand in order to prevent overheating, can be quickly sludge and other highly water-containing materials incineration. Suitable for use in small and medium-sized cities for waste incineration and sewage sludge, industrial waste incineration.
(3) rotary incinerator is the use of radiant heat inside the furnace to fully incinerate the waste. Mainly used for sludge and waste liquids and other industrial incineration waste incineration.
Two: waste incinerator with SiC refractory materials
Waste incinerator processing waste working temperature is generally not more than 1200 ℃, but the incineration of garbage produced by the gas (CI2, So2, CO, etc.) on the refractory material and its serious chemical erosion.
The incinerator refractory materials are roughly divided into refractory bricks and non-shaped refractory materials. The former is mainly clay brick, high alumina brick, silicon carbide brick: the latter to clay, high alumina, silicon carbide castables and clay, high alumina plastic-based. With the waste incinerator technology large-scale, large-scale resources, incinerator refractories have also undergone tremendous changes.
The incinerator combustion chamber furnace temperature up to 1000 ~ 1300 ℃: slag on the side wall refractory brick damage is very serious, often out of accidents. From the service life and corrosion-resistant type of consideration, the use of SiC brick is favorable.
The plastic in the garbage and sodium chloride and other salts on the wall of the pipe corrosion is very serious, in order to protect the water pipe, began to use dense quality SiC castables, the advantages of which are in the middle, the upper part of the durability is good, the construction efficiency, the disadvantage is that it is difficult to dismantle. Generally used SS-1 (SiC85%), SS-2 (SiC40%), SA-1 (AL2O3 53%). The use of its SiC refractory material is mainly difficult to adhere to the slag and good corrosion resistance.
According to the experiments SiC system lining in the incinerator can be used according to ① temperature: ② FeO and other metal oxides: ③ H2O, CO2 and other oxidizing gases in the use of the conditions of the decision of the SiC content and materials. In addition, SiC lining should not be used in the molten slag line above the oxidizing atmosphere layer, the best in the bottom of the furnace to limit the use of the reduction atmosphere is appropriate to use the following.
Summary: the proper disposal of municipal garbage and industrial waste has become an urgent issue of contemporary urban management. Casually, with the development of China's waste incinerator, the development of efficient, economical incinerator refractories become the key to promote waste incineration technology.