Drying chamber for fiberglass

Contents

INTRODUCTION

CHARACTERISTICS OF MANUFACTURED MATERIALS AND

PRODUCTS

PRODUCTION FLOW CHART

FIBREGLASS

DESCRIPTION OF PROCESSES INVOLVED IN HEAT TREATMENT OF THIS FIBERGLASS

MATERIAL BALANCE CALCULATION

THERMAL PLANT CALCULATION

AUTOMATION OF DRYING PROCESS

SAFETY, HEALTH AND ENVIRONMENTAL SOLUTIONS FOR FIBERGLASS

CONCLUSION

LIST OF SOURCES USED

INTRODUCTION

The fields and volume of application of polymer composite materials in the world industry are growing every year. New technologies and design solutions are emerging. Fiberglass occupies the largest part of the composites market, due to its relative cheapness and ease of manufacture. In Russia, the active use of fiberglass began in the late 1990s. The main areas of application were construction, electricity, oil production, housing and communal services, transport, mining, sports and recreation products and much more.

Fiberglass - a type of composite materials - plastic materials consisting of fiberglass filler (glass fiber, quartz fiber, etc.) and binder (thermosetting and thermoplastic polymers).

Until recently, fiberglass was used mainly in aircraft engineering, shipbuilding and space technology. The widespread use of fiberglass was restrained mainly due to the lack of industrial technology that would allow the mass production of profiles of complex configuration with the required dimensional accuracy. This task was successfully solved with the creation of pultrusion technology. There are many methods that allow mass production of fiberglass products of various configurations, optionally profiles - for example, RTM, vacuum molding.

Fiberglass is one of the most affordable and affordable composite materials. The main costs in the production of fiberglass products fall on technological equipment and labor, the costs of which are high due to labor intensity and high time costs for production. Accordingly, at the moment, fiberglass products are lost at the price of metal products due to the time-consuming and long process of gluing fiberglass parts, which causes great difficulties in mass production.

The most advantageous use of fiberglass in small-scale production. Large scale production becomes more advantageous when vacuum molding is used. Contact molding can also be advantageous if the price of labor is low.

Fiberglass is one of the most important types of plastic masses. Due to the combination of high mechanical strength at low specific gravity with good electrical insulation characteristics and thermophysical properties, fiberglass is used to manufacture a wide variety of products in various industries and technologies.

Description of processes during heat treatment of this fiberglass

The conveyor dryer differs significantly from tunnel and multi-tier dryers. Conveyor dryer has vertical travel of heat carrier. This movement, first, intensifies the heat exchange between the material and the heat carrier by passing the latter through the material layer, which makes it possible to significantly reduce the heat treatment time and increase the economic efficiency of the process.

In chamber dryers, the temperature and humidity of the drying agent varies over time. After the moisture content of the material has decreased to a certain value, the temperature is raised and the relative humidity of the drying agent is decreased. This mode change is carried out several (2-3) times during drying.

The drying agent is circulated in the chamber and tunnel dryers both by natural convection and by fans.

Chamber is made of metal and insulated by mineral wool mats. Combustion products of natural gas and air are used as heat carrier for drying and curing. Natural gas of the Saratov field is used.

Chamber (1) has two chain conveyors - upper (2) and lower (3). A layer of glass fiber (4) coated with resin moves on the lower conveyor. The position of the upper conveyor is adjusted depending on the thickness of the article. Fuel is burned in furnace (5), diluted with spent coolant through pipeline (6). Mixture of fuel combustion products, spent heat carrier and air with temperature 1701800C is supplied through pipeline (7) to chamber (1), is sucked through material layer, removes moisture from it and converts resin to viscous-flowing state. The resin impregnates the glass fiber and then solidifies.

The coolant passes through the material, is cooled to 1301400C and is sucked by the fan. Part of spent heat carrier is discharged to atmosphere through pipeline.

Automating the drying process

The purpose of the control of the drying process is to provide drying of the incoming wet solid material to a predetermined humidity value. The object of control during automation of the drying process is represented by a conveyor dryer, in which the drying agent is flue gases produced in the furnace. An indicator of the efficiency of this process is the humidity of the material leaving the dryer, and the purpose of the control is to maintain this parameter at a certain value. The main disturbing factors of the process are changes in the flow rate of the material and its humidity, as well as changes in the flow rate and initial temperature of the drying agent - coolant.

The humidity of the dry material is determined on the one hand by the amount of moisture supplied with the wet material and on the other hand by the amount of moisture removed therefrom during drying. The amount of moisture supplied with the wet material depends on the consumption of this material and its humidity, as well as on the consumption of the drying agent.

The material flow rate determines the capacity of the dryer, which should generally be constant. Therefore, it is necessary to follow the path of stabilizing the flow rate of the wet material, which provides a given capacity and eliminates disturbances in this channel. Automatic dispensers are installed for this purpose. The vacuum in the dryer is easily stabilized by varying the flow rate of the drying agent withdrawn from the dryer. The temperature is determined by all the parameters in cash, and also by the intensity of the process of evaporation of moisture from the material. It can be stabilized by varying the flow rate or temperature of the drying agent. It should be noted that the range of variation of the latter parameter is substantially limited due to safety requirements and the possibility of decomposition of the material to be dried. Thus, all parameters affecting the performance indicator cannot be stabilized, in particular, disturbance will occur as a result of a change in the initial humidity of the material and drying agent, particle size distribution of the material, etc.

In the dryer, the material distribution as well as the hydrodynamic conditions of its flow with the drying agent may vary. Therefore, it is advantageous to take the humidity of the solid material as the main controlled parameter, and the control effect is carried out by changing the flow rate of the drying agent. However, in the absence of a reliable device for continuously measuring the humidity of the material, as well as at large delays in the dryer, the temperature of the drying agent in the drum is used as a control parameter. This is useful from the point of view of dynamics, since this amount reacts faster to disturbances. Temperature regulator sensor is installed within the first third of dryer length as heat carrier temperature changes more intensively at the beginning of apparatus than at its end. This also reduces the latency of the object. Sensor is mounted directly on drum surface, and its free ends are connected to transmitting converter through special current collector with movable contacts.

Automatic monitoring, alarm and protection parameters. Unregulated mode and input parameters shall be monitored. All parameters are subject to alarm, changes of which can lead to an emergency or serious violation of the process mode and, ultimately, to a change in the control criterion. The Auto-Protect parameters are those parameters in which the Auto-Protect devices must operate and prevent the emergency situation from occurring if the deviation is not allowed. When the temperature of the drying agent rises dangerously, a signal must be sent to the maintenance personnel at the inlet of the dryer and the motor stops. In addition, when the motor stops, the protection shall be activated and the material supply to the dryer shall be stopped. When the temperature of the drying agent at the inlet of the dryer exceeds the permissible value, which leads to overheating of the material, and the motor stops, the alarm must be turned on. At the same time, the supply of wet material is turned off as protection.

Conclusion

In this course project, a conveyor dryer in the production of fiberglass was considered. Technological and economic analysis of fiberglass was carried out. Fiberglass makes it possible to manufacture products of any complex shape, and represents the best solution in such areas as industrial and residential construction, transport: automotive, car building, energy, shipbuilding, engineering, the entertainment industry. Fiberglass is not afraid of ultraviolet rays. When heated, it does not release poisonous substances. Absolute environmental cleanliness is another advantage of this material.

The design of a horizontal drying and impregnating machine has also been studied. Process calculation of the drying plant was made, material balance was drawn up.

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