IOT Enabling Of Vacuum Heat Treatment Chambers For Data Acquisition And Analytics
Introduction
The heat treatment industry is at a turning point, in which digital technology has the potential to unlock new ways of managing process variables and enhance productivity in vacuum heat treatment operations. Significant untapped potential for improving productivity lies in the adaptation of Internet of Things (IoT). The Internet of Things refers to the use of embedded sensors, actuators, and other devices that can collect or transmit information about the vacuum furnace operations. The greatest value-creating potential of the IoT is optimizing vacuum furnace operations through the data collection, data computation and maximizing production schedule. This mode of operation requires using sensors, rather than human judgment (and human error), to adjust the furnace’s operational parameters. In addition to optimizing operations, the next most valuable application of internet of things (IoT) in heat treatment is predictive maintenance adaptation and spare parts inventory. Predictive maintenance involves continuously using sensors to monitor furnace components’ performance to avoid breakdowns and to determine when maintenance will be required, rather than relying on regularly scheduled maintenance routines.
A capacitor is a passive two-terminal electrical component that stores potential energy in an electric field. The effect of a capacitor is known as capacitance. The capacitor was originally known as a condenser or condensator. The capacitance of a capacitor is proportional to the surface area of the plates (conductors) and inversely related to the gap between them. Capacitors are widely used as parts of electrical circuits in many common electrical devices. The main element of the capacitor that gives rise to the different properties of the different types of capacitor is the dielectric - the material between the two plates. Its dielectric constant will alter the level of capacitance that can be achieved within a certain volume. Some types of capacitor may be polarised, i. e. they only tolerate voltages across them in one direction. Other capacitor types are non-polarised and can have voltages of either polarity across them. Typically the different types of capacitor are named after the type of dielectric they contain. This gives a good indication of the general properties they will exhibit and for what circuit functions they can be used. The process of capacitors production involves several steps, the first process is called as winding followed by spraying, VHT(vacuum heat treatment ), riveting(support assembly), soldering(cell assembly) and testing(finial assembly). In spraying process there are two types metar and flame spraying is done for 45mins. For metar 7layers of spraying is done and for flame 8 layers of spraying is done.
The spraying thickness is 0. 55 to 0. 65 for metar elements and 0. 65 to 0. 75 for flame elements. when the zinc wire exceeds more than 80mm then it is done in flame. The next step is EC-AC test. Once this test is over the element goes to vacuum heat treatment process (VHT). VHT is controlled by programmable logic controllers (plc).
Several processes are carried out in VHT. The 1st step is evacuation process. The operation time of this process is about 120 minutes and the staring temperature of the element is 25. 9c and there is no change in the end temperature of the element. The run time of this evacuation process is 120mins. Now the 2nd step is nitrogen gas -feeding. The operation time of this process is 2mins.
The staring temperature of the element is 25. 9c and the end temperature of the element should be 60. 0c. The run time of this process is 2mins. Then profile heating-1and profile heating -2 is done. The operation time of profile heating -1 is about 700mins. The starting temperature of the element is 27. 8c and the end temperature is about 70. 0c.
The overall run time of this process is 803mins. In profile heating -2 the operation time is of about 800min.
The start temperature of the element is of 70. 0c and the end temperature is of 103c.
The overall run time of profile heating -2 is about 128min.
Then the next step is vaccum drying. The operation time is about 510mins. The starting temperature is of 111. 1c and the end temperature is about 104. 0c. The run time of this process is 128mins.
The next two steps are vacuum cooling -1 and vacuum cooling -2. The starting temperature of both this process is 0c. The end temperature of this process is 70c. The operation time of vacuum cooling -1 is 800mins and the operation time of vacuum cooling -2 is 275mins. The end temperature of the element in vacuum cooling -2 is 59c. The run time of both the vacuum cooling-1 and vacuum cooling -2 is 0mins.
The last step in vacuum heat treatment is nitrogen cooling -3. The operation time of this process is of about 480mins. The starting temperature is 0c and the end temperature is 40c. The run time of this process is 0mins. The overall time of vacuum heat treatment process is 72hours. The sensors used in vacuum heat treatment are pt100 temperature sensors and vacuum transmitter.
The next process of capacitor production process is riveting also called as support assembly. There are two types of riveting machine. Stud type and clamp type. Riveting machines are used to join the elements together. While compared to manual riveting, automatic machine riveting provides greater consistency, less time and greater accuracy.
The next process is called as cell assembly. In this process a seeming machine is used. Copper strips are soldering on top of each element. This is because in order to absorb high power fluctuation. If high power comes these copper strips absorb. Three elements are joint in a single capacitor. A straw kind of tube is being placed for air circulation. Plastic holders are used in order to avoid contact between aluminium can and element. C and tan delta test is done to measure the insulation quality.
Resins are used for insulation and cooling purpose. Resin is the final testing step called as finial assembly. In this project I am going to work on vacuum heat treatment process to get live data from the temperature sensors using plc(programmable logic control)platform and compare with the previous value in order to improve the performance of the capacitor production and time consumption. The software used in my project is lab-view and the data is being managed by structured query language(SQL) server and stored in cloud.
Literature survey
One of the key objectives of heat treatment is ensuring consistency and high quality results. The furnaces must be of excellent condition in order of extreme high frequency change. When a heat treatment process breaks down, production comes to halt and due to which company faces many critical issues. Therefore companies face unplanned downtime utile the problem is solved. Dr. Aymeric Goldstein in his paper has proposed a concept of predictive maintenance using internet of things. In this paper author has used pdmetric software platform for predictive maintenance. A threshold level has been set so that when the performances decreases or when the maintenance has to done at scheduled time ipsens pdmetric software platform has been used. The goal of predictive maintenance is to apply analytics in order to detect a risk of failure, thus helping even to prevent the failure before even it occurs. The main aim of this author is to understand the convergence of internet of things and big data. Finally the author says pdmetric software is the emerging platform for predictive maintenance and tool for analyzing equipment performance and the maintenance need.
In 2007 Xiaowei Hao, Jianfeng Gu, Nailu Chen, Weimin Zhang, Xunwei Zuo has proposed a paper on 3-D numerical analysis on heating process with an intelligent PID temperature control subroutine has been developed and employed in the computational simulation of the heating process of typical load within vacuum heat treatment furnace. The result indicate that the maximum temperature difference within the load, as well as thermal hysteresis time, decrease with preheating temperature and increase with heating rate. The user defined Pid subroutine was applied successfully for the furnaces temperature control in the simulation of the actual heating process in the vacuum furnaces, which improved the simulation accuracy. The analysis of the simulation on the heating process of the block load revealed that the maximum temperature difference within the load as well as the thermal hysteresis time, decreases with preheating temperature and increased with heating rate. The comparison between simulation results and the experimental proposed numerical model could rather accurately predict the heating process in the vacuum heat treatment furnaces and the simulation could provide important guidance for the design and improvement of vacuum thermal schedule.
In 2003 C. T. Dervosa, J. Novakovica, P. Vassilioub proposed a paper on Vacuum heat treatment of electroless Ni–B coatings. Electroless nickel–boron plating with subsequent rapid heat treatment in vacuum has been tried on steel substrate in an effort to obtain hard engineering coatings. By selected conditions of heat treatment in a high vacuum environment (a type of rapid quenching), the plating can acquire chromium equivalent hardness without the effluents of the hard chromium plating process. The resulting surfaces were examined and characterized under an optical and a scanning electron microscope. The present work targets towards production of nickel boron (Ni–B) electroless coatings with high hardness and high adhesion for usage under adverse mechanical conditions. Electroless nickel is an engineering coating, normally employed because of its excellent corrosion and wear resistance. Due to these properties, electroless nickel coatings have found many applications, including those in petroleum, chemicals, plastics, optics, printing, aerospace, nuclear, automotive electronics, computers textiles, paper and food machinery. During heating, electroless nickel–boron hardens in the same manner as nickel–phosphorus alloys. The principle advantage of electroless nickel–boron is its high hardness and superior mechanical wear resistance. These low temperature treatments result in a finer dispersion of nickel boride and in the formation of iron borides within the coating. After heat treatment, the wear resistance of electroless nickel–boron is equal or exceeds that of hard chromium coatings. The electroless nickel coatings may provide a possible solution for the low-cost hard surface layers, operating under adverse working conditions. The 5-min thermal treatment of the coatings in a high vacuum environment results to a chromium equivalent surface microhardness, which in some cases reaches 2000 HV locally without the environmentally hazardous effluents of the hard chromium plating. Therefore, it may lead towards new fabrication trends concerning surface preparation for specific mechanical wear applications.
Bey Vranckena, Lore Thijsa, Jean-Pierre Kruthb, Jan Van Humbeecka proposed a paper on Heat treatment of Ti6Al4V produced by Selective Laser. The present work shows that optimization of mechanical properties via heat treatment of parts produced by Selective Laser Melting (SLM) is profoundly different compared to conventionally processed Ti6Al4V. In order to obtain optimal mechanical properties, specific treatments are necessary due to the specific microstructure resulting from the SLM process. SLM is an additive manufacturing technique through which components are built by selectively melting powder layers with a focused laser beam. The process is characterized by short laser-powder interaction times and localized high heat input, which leads to steep thermal gradients, rapid solidification and fast cooling. Selective Laser Melting (SLM) process is one of recently developed additive manufacturing techniques that emerged in the late 1980s and early 1990s. SLM offers several advantages compared to conventional production techniques, such as reduction of production steps, a high level of flexibility, a high material use efficiency and a near net shape production. Extra-low interstitial Ti6Al4V (Grade 23) powder was used as a base material for the SLM process. The powder is produced via the plasma-atomization process by Raymor Industries. The equiaxed Ti6Al4V (Grade 5) was hot forged and mill annealed. Due to the specific process conditions and hence specific microstructure, SLM produced parts need to be treated differently than bulk alloy parts.
