Glass bottle liquid melting condition detection and melting process

1 Introduction

The melting kiln is undergoing a complex high-temperature physicochemical change process, completing the melting process from the batch material to the qualified glass liquid. Because of the high temperature, people cannot directly observe the internal flow conditions of the glass liquid, and cannot measure the temperature distribution and flow velocity distribution inside the glass liquid. Therefore, it is impossible to understand how clarification deteriorates, inclusions are generated, a large number of striae, and crystallization and other fusion failures are how produced. The glass melting furnace in operation is like a living human body. There is something wrong with the glass melting process in the melting furnace. There is also the need for a doctor in the furnace to make a diagnosis. Through observation, smell, questioning, and diagnosis, diagnostic tools like the X photos are used. CT scanning and other methods to find the fault of the furnace conditions, in order to determine the technical measures to improve the furnace, to achieve the purpose of curing the kiln. What methods can be used to diagnose a melting failure? After years of hard work by engineers and researchers, the following three methods have been developed for the diagnosis and detection of glass melting furnaces.

2, thermal measurement

Among the actual measurement methods, the comparatively mature ones are the thermal kiln heat measurement and the heat balance calculation of the glass melting furnace. This measurement task is like a physical examination performed by the hospital. In the temperature measurement project, the temperature on the surface of the melting furnace can be measured to determine the magnitude of the heat dissipation. The measurement data can not only provide energy-saving basis for the furnace, but also can indirectly determine the internal flow conditions of the molten glass in the furnace. The full thermal calibration can be completed by the testing center of China International Glass Engineering Co., Ltd. The following is one of the surface temperature test diagnosis examples that indirectly determine the flow conditions of molten glass inside the furnace. Yang Zhiqiang, from Tongji University School of Materials, and others, used a measurement method for the temperature distribution of the outer surface of the pool bottom in the diagnostic study of the melting process of inclusions in a 450-ton float glass melting furnace of Kunming Glass Co., Ltd., through the temperature distribution of the outer surface. The temperature distribution of the glass bottom can be inferred indirectly, and the position of the bottom equilibrium point of the two convection currents in the inner glass can be inferred, which provides powerful first-hand data support for the diagnosis of the melting process. Practice has proved that this is a good method.

After the glass melt of the melting furnace is discontinued and emptied, the flow pattern of the glass flow can be verified by observing the traces of the molten glass on the bottom of the glass melting furnace and the refractory material on the wall of the glass furnace to determine the flow pattern of the molten glass during the operation of the furnace. The general situation provides the basis for analyzing and formulating the direction of further improvement of the furnace. The method used by the Institute of Materials Science at Tongji University in float glass furnace kiln diagnosis is to prove the consistency between numerical simulation and physical simulation and actual furnace conditions, and to enhance the knowledge of the molten glass flow in the melting furnace. .

The flow trajectory of the glass particles in the glass flow of the actual melting furnace can be determined by the isotope tracking method. First, the isotope particles are put into the batch materials, and a detection device is arranged around the melting furnace to locate the motion process of the isotope particles and trace the motion track of the isotope particles. This method requires high technical requirements and is difficult to implement. It is rarely used in practical projects. Another method is the contrast method. In the feeding method, the contrast agent is added in a pulse method, a gamma ray emitting device is arranged on the side of the glass kiln wall, a synchronous receiving device is arranged on the other side, and both sides synchronously scan the glass of the glass melting furnace. Due to the strong gamma-ray absorption ability of the contrast element, the liquid can obtain the two-dimensional electron image of the melting furnace, and the dynamic concentration distribution information in the glass liquid can be obtained through the image analysis.

If infrared cameras are used to record the temperature distribution of the outer surface of the furnace, the infrared temperature distribution characteristics of the furnace can also be obtained through infrared image analysis to determine whether the internal process conditions are reasonable. This technique is one of the practical and feasible testing techniques. The infrared image can also be used to support the verification of the calculation result of the outer surface temperature distribution of the large scale obtained by numerical simulation.

In actual operation, the temperature of the specified point in the melting furnace can be measured by an optical pyrometer in different parts of the observation hole, and the information of the glass melting condition in the large-scale float glass melting furnace can be indirectly obtained. Using this method can sometimes get better results.

3, physical simulation

Due to the difficulties of actual measurement and the limited information obtained, in most cases, the actual measurement data is not enough to diagnose the melting conditions of the glass melting furnace, which is not enough to diagnose the problem and provide a basis for the transformation of the melting furnace. In addition to the diagnostic analysis of the furnaces that are currently in operation, it is sometimes necessary to demonstrate new kiln types and new technological innovations for the furnaces. Physical simulation and numerical simulation methods will be two other very effective methods.

The physical simulation method is one of the effective ways to reproduce the glass flow conditions in glass melting furnaces. A large number of model experiments are used in the field of fluid mechanics to study engineering problems. For example, it is impossible to study dynamic data such as buoyancy and resistance during flight. It is impossible to measure directly on the sky. Only the principle of relative motion can be used to test in-flight aerodynamic data through model tests and improve the work; With the interaction of water and sediment, model tests are also very powerful tools. The movement of glass flow in a melting furnace can also be studied by simulation tests.

The physical simulation is based on the laws of similarity of fluid mechanics, and the simulation fluid motion model corresponding to the glass melt of the melting furnace is established. Under similar boundary conditions, the simulated flow patterns and temperature distributions can be observed, measured and photographed. The simulated glass change law helps to diagnose the change of glass flow caused by the change of kiln type and other process parameters, and determine the influence of the corresponding flow pattern on the molten glass melting process.

In addition to the physical simulation of the molten glass flow field and temperature field in a large melting furnace, the physical simulation of the electric field distribution in an all-electric furnace is also very effective. According to the physical simulation, the electrode arrangement, power supply mode, and power supply parameters can be obtained. Liquid convection state and temperature distribution and other information are used to guide the design of all-electric furnaces and to solve the basis for melting obstructions. This proportional model previews the operating conditions of the all-electric melting glass kiln and is superior to the full-scale fused numerical simulation in terms of intuitive, inductive and electrical parameter reliability.

The large-scale glass melting furnace simulation laboratory of the School of Materials of Tongji University was established under the support of the Department of Science and Technology of the former State Building Materials Administration. For nearly ten years, nearly 30 manufacturers in the glass industry have provided physical simulation tests to reveal the melting furnace. The law of glass flow provides a rich basis for experimental research.

In 2006, the glass melting furnace simulation laboratory of the School of Materials of Tongji University provided Kunming Glass Group with a diagnostic research service for the causes of inclusions in glass melting furnaces. This problem plagued the manufacturer for one and a half years, and diagnosed problems through simulation experiments. The key lies in the fact that, based on the diagnosis, the manufacturer has formulated a reasonable solution to make the melting process barriers quickly improve. Based on the long-term technical service provided to the glass industry, the glass melting furnace simulation laboratory of the School of Materials of Tongji University has formed its own theoretical hypothesis to explain the process of glass melting. These theoretical assumptions based on experiments and practices are large melts. The glass melt process in the kiln provides a good basis for analysis. After practice tests, according to some theoretical assumptions, the prediction of the melting process characteristics is in good agreement with the actual operating conditions.