Online Decomposition Rate Analyzer

Product Overview

The online decomposition‑rate analyzer is a fully automated, in‑line monitoring device specifically developed for cement preheaters and calciners. It enables unmanned operation across the entire workflow—automatic sampling of hot raw meal from the fifth‑stage preheater outlet, cooling, sample preparation, and combustion analysis—while delivering real‑time core data on raw meal decomposition rate. This replaces the traditional manual offline sampling and combustion‑based testing approach. The system provides direct connectivity to the DCS and the calciner’s APC intelligent control system, furnishing high‑frequency, real‑time feedback on calciner temperature, coal‑powder feed rate, and tertiary air distribution. By addressing key industry challenges such as preheater blockages, fluctuating decomposition rates, and elevated clinker energy consumption, it serves as a cornerstone of intelligent quality control in the preheating stage of cement production lines.

Industry Pain Points and Application Requirements

The decomposition rate of cement raw meal is a critical indicator for assessing the calcination performance of the decomposition furnace, preventing preheater blockages, and ensuring stable quality of the material entering the kiln. Traditional manual offline measurements, however, suffer from multiple shortcomings:

1. Severe testing lag: The entire process—manual sampling, sample delivery, and muffle‑furnace calcination—takes more than two hours. Following fluctuations in the decomposition furnace’s operating conditions, data feedback is severely delayed, making it impossible to promptly adjust coal and air flow rates.

2. High labor costs: Laboratory analysts must periodically visit the preheater tower to collect hot raw meal; this high-temperature operation carries significant risks, and the entire workflow—sample preparation, calcination, and weighing—is performed manually, consuming substantial laboratory personnel resources.

3. Large measurement error: Inconsistent durations for manual cooling, weighing, and ignition introduce systematic errors due to human操作, leading to distorted decomposition‑rate values and misleading process adjustments.

4. Disconnection of Intelligent Systems: Offline monitoring data cannot be integrated into the central control intelligent optimization platform in real time, making it difficult to achieve fully automated closed-loop control of the calciner and thereby hindering the plant’s digital transformation.

5. Process Safety Hazards: A low decomposition rate can easily lead to skin formation and blockage in the C5 discharge pipe, resulting in frequent line shutdowns for cleaning and a significant reduction in production line availability.

Core Technological Advantages

1. Direct heat recovery from raw meal in the preheater: The sampling unit is directly connected to the discharge pipeline of the five‑stage preheater and features an integrated dual‑cooling system—water‑cooled and air‑cooled—enabling rapid cooling of high‑temperature raw meal without manual handling, thereby significantly improving analytical turnaround time.
2. High-frequency continuous monitoring: It can output a set of decomposition rate and loss-on-ignition data as frequently as every 30 minutes, with high‑frequency measurements capturing the dynamic fluctuations of the calciner and meeting the requirements for real-time process fine-tuning.
3. Fully automated, unattended operation: Automated sampling, sealed conveyance, multi-stage quantitative dosing, high-temperature calcination, precise weighing, and automated residue discharge—entirely without manual intervention, thereby eliminating human‑induced operational errors.
4. Full-domain data interoperability: Standard configuration includes Modbus, Profinet, and DP communication interfaces; detection data is uploaded in real time to the central DCS system, enabling seamless integration with the kiln‑furnace APC expert system for automatic adjustment of coal feed and tertiary air damper positions.
5. Long-term stable operation of the industry: The entire system is highly resistant to high temperatures, dust, and caking, and is equipped with automatic ash‑removal and crucible self‑cleaning modules. It is designed to meet the demands of 24‑hour continuous cement production and can operate reliably online year-round.

System Composition

The online decomposition rate analysis system features an integrated, modular design, comprising three main components: a sampling and pretreatment unit, a sealed conveying unit, and a host‑based analysis unit. It offers flexible on-site installation and straightforward operation and maintenance.

1. Sampling and Pre‑treatment Unit: Installed on the discharge pipeline of preheater C5, it comprises a high‑temperature, wear‑resistant sampler, a water‑cooled cooling system, a vibrating screen, a return‑material bypass, and an on‑site local control cabinet. It performs automated sampling of hot raw material, temperature reduction, screening out excess coarse particles, and returning surplus material to the process pipeline.
2. Closed‑loop conveying unit: negative‑pressure sealed conveying pipeline and fan‑buffered receiving hopper, ensuring no dust leakage throughout the process, protecting samples from moisture and contamination, and enabling stable delivery to the analytical instrument.
3. Analyzer host unit: integrates a multi-stage quantitative dosing mechanism, a high-precision electronic weighing module, a high-temperature muffle furnace for ashing, an automated transfer robotic arm, a residue‑removal system, and an intelligent PLC control system, enabling precise sample weighing, constant‑temperature ashing, secondary weighing, automatic calculation of the decomposition rate, and data storage and upload.

Detection Principle

The equipment employs the loss-on-ignition method to determine the decomposition rate of raw meal.

1. After the hot raw material is cooled and screened, the equipment automatically and precisely weighs the initial sample mass.

2. The sample is placed in a constant-temperature muffle furnace and thoroughly calcined, ensuring complete decomposition of calcium carbonate in the raw material and the release of CO₂.

3. After the calcination is completed and the sample has cooled, an automatic secondary weighing is performed to determine the mass of the residual material.

4. The system incorporates a dedicated algorithm that calculates the loss on ignition by determining the mass difference before and after calcination, and, in conjunction with raw meal reference parameters, automatically converts this into a raw meal decomposition rate, delivering real-time results. This measurement principle conforms to the national standard method for determining raw meal decomposition rate in the cement industry, offering high accuracy and excellent reproducibility, fully aligned with central control process‑management specifications.

Application Value and Benefits

1. Stabilization of the decomposition furnace operating conditions: Real-time decomposition rate data guides the precise adjustment of coal powder and air flow in the calciner, ensuring that the raw meal decomposition rate remains stable within the process target range and reducing fluctuations in the material entering the kiln.
2. Avoiding preheater blockage: Detect anomalies indicating low decomposition rates in advance, adjust process parameters proactively, reduce the frequency of shutdowns caused by C5 skinning and material blockages, and improve line availability.
3. Energy conservation and consumption reduction: Optimize the coal feed rate to the decomposition furnace to prevent overfiring, which wastes fuel, and underfiring, which adversely affects clinker calcination, thereby reducing the overall specific coal consumption of cement.
4. Reducing labor costs: Eliminates the need for laboratory technicians to perform routine high-temperature sampling and offline calcination, reduces manpower requirements at the analytical workstation, and mitigates safety risks associated with high-temperature operations.
5. Standardized Quality Control: Standardize the procedures for calcination and weighing to eliminate human error, thereby ensuring the standardization of raw meal decomposition rate measurement data across the entire plant.
6. Enhance the factory’s intelligent closed-loop system: Address the shortcomings in online monitoring of the preheating section, establish end-to-end data connectivity across the preheater–decomposition furnace–kiln system, and enable intelligent, automated control of the entire cement production process.