Quality appraisal of inclined push grate furnace

inclined push grate furnace is the core equipment in industrial boilers, waste incineration power generation and other fields. It realizes the turning and advancement of the fuel layer through mechanical reciprocating motion to ensure combustion efficiency and pollutant control. Inclined push grate furnaces can be used for incineration of domestic waste, adapting to mixed waste with high moisture content and low calorific value to achieve reduction and harmless treatment (such as Everbright Environment's reciprocating grate furnace, with a daily processing capacity of more than 1,000 tons); used in industrial coal-fired boilers to optimize coal combustion efficiency and reduce SO₂ and NOx emissions (such as Zhongke Environmental Protection's domestically produced grate furnace technology, the thermal efficiency is increased to 30%); used in the utilization of biomass energy, processing of high-volatile fuels such as straw and sludge, and promoting the development of renewable energy.

Compared with traditional fixed grates, inclined grate furnaces rely on modular design, layered air supply control and anti-corrosion material application to occupy a dominant position in the context of stricter environmental protection policies. They are the key technical equipment to achieve the "double carbon" goal.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide quality appraisal services for tilt-push grate furnaces. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for the quality appraisal of tilt-push grate furnaces.

With the large-scale application of equipment, quality dispute cases occur frequently. The focus of judicial disputes is:

1. Compliance issues: whether to use coal-fired grates that have been eliminated by the state (such as in the XX County case Ⅱ type boilers were forced to be eliminated due to environmental failure);

2, material and structural defects: insufficient temperature resistance of the grate pieces led to deformation, cracking of welds and leakage;

3. Combustion efficiency and emissions: CO, dioxins and other pollutants exceed standards, or energy consumption is too high due to design defects;

4. Control system stability: Automatic combustion control (ACC) fails, causing safety accidents or production interruptions.

inclined push grate furnace quality identification technical methods include:

1, material performance testing

1) composition analysis: detecting the grate sheet material (such as Cr and Ni content of ductile iron QT500-7) through a spectrometer to evaluate high temperature resistance and corrosion resistance;

2) coating detection: using SEM-EDS analyzes protective paint components (such as polysiloxane polyether copolymer) to verify its heat resistance and antioxidant capabilities.

2, structural and process verification

05, environmental adaptability test

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2 Humidity and heat cycle: -40℃~+85℃ temperature cycle test to evaluate the reliability of electronic components; wear resistance test: simulate 100,000 reciprocating movements, and record the wear amount of the grate plate (standard ≤0.5mm/10,000 times).

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A waste incineration plant of the applicant signed a "Purchase Contract for Inclined Grate Furnace" with an environmental protection equipment company of the respondent, agreeing to purchase 3 sets of equipment with a daily processing capacity of 800 tons. Half a year after it was put into operation, the grate pieces broke frequently, causing the furnace to be shut down for maintenance, and the dioxin emissions exceeded the standard. The incineration plant believed that the equipment had design defects and demanded compensation. The equipment company argued that the problem stemmed from fluctuations in the calorific value of the waste or improper operation, and the two parties went to court.

Identification and analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information, contract technical agreements, on-site investigation case materials and other data of the "inclined grate furnace", and made the following quality analysis opinions:

The material of the inclined grate furnace involved is ordinary cast iron, and the Cr content is only 1.2%, it is easy to be brittle and fracture under high temperature; the thickness of the protective paint is less than 0.1mm, and the corrosion area reaches 30% after the salt spray test. The installation angle deviation of the grate plate reaches ±5°, resulting in uneven pushing resistance and local stress concentration; the primary air distribution hole has a clogging rate of more than 20%, and insufficient combustion leads to the generation of dioxin.

The manufacturer failed to provide temperature-resistant materials and reasonable structural design as per the contract, which constituted a fundamental breach of contract.

The quality appraisal report of the inclined push grate furnace should include the following contents:

1. The purpose and basis of the appraisal.

2. Model, specification, manufacturer and other information of the equipment being identified.

3. Identification method.

4. Identification results (including whether there are quality problems, causes of problems, etc.).