Brief Analysis of Heating Mode of Roller——Electromagnetic Heating Roller
作者：管理员 时间：2020-06-04 09:12 来源：未知
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Most rollers on the machine do not need heating, but a few rollers do, we call the heating roller.
Heating roller is widely used in papermaking, printing, photocopying, textile, rubber, plastic, chemical fiber and other industries in the preheating, drying, shaping, laminating, embossing, embossing, composite and other production processes, mainly used for the heating and thermal processing of products. The roll is heated in a manner that heats the product running on the roll by turning it.
According to the different heating way, heating roller can be divided into two categories: fluid heating and electric heating. Fluid heating is mainly heat conduction oil, water, steam these three media; Electric heating is mainly divided into direct heating of electric heat pipe and electromagnetic induction heating.
1. Heat conduction oil heating roller
This is the most commonly used heating roller, most of the current heating roller using heat conduction oil heating. The advantage is the structure is relatively simple, low cost. Insufficient is easy to scale after long time use, resulting in uneven temperature; Limited by the nature of the heat conduction oil itself, the temperature should not be too high (generally not higher than 250); External oil pump circulation is required. Access to roller through rotary joint not only wastes extra energy, but also has the risk of oil leakage.
2. Water heating roller
The structure of the water heating roller is similar to that of the heat conducting oil heating roller. Limited by water temperature (less than 100 under open system), the roll surface temperature is difficult to exceed 80. If the use of ordinary tap water, the inner wall of the roller also has the problem of scaling; The external pump cycle also has additional energy waste.
3. Steam heating roller
The steam heating roller passes the steam into the roller for heating through the external steam pipe connected with the rotary joint. The roller has simple structure and low cost. Also, due to the rapid rise in steam pressure with temperature, the roller temperature is not too high (generally no more than 180). With national restrictions on the use of boilers, the number of steam heating rollers is rapidly declining.
4. Electric heating roller
Most electric heating USES electric heating rod as the heat source, so theoretically the roller can be heated to a very high temperature. The electric heating rod in the existing electric heating roller is not completely in contact with the roller, so there are two ways of heat transfer: conduction and radiation. If heat transfer is not properly handled, the uniformity of roller temperature is often not good. For this reason, many manufacturers have oil holes in the roller wall, the heat conduction oil into it, so that through the heat conduction oil soaking effect, can make the roller temperature become more uniform. But if the heat consumption is particularly high, the uneven phenomenon will be very serious. In addition, there are other problems with the addition of heat conducting oil, which will be discussed later.
5. Electromagnetic induction heating roller
It is the most technically advanced of the heating rollers and was invented in 1964 by Nippon electric co., LTD. After more than 50 years of development, the company still monopolizes the high-end heating roller market. At present, China has several companies with proprietary intellectual property rights and production capacity of electromagnetic induction heating roller. Electromagnetic induction heating roller can not only achieve a high roll temperature (above 400), and clean, energy saving. Good temperature uniformity can also be achieved after embedding good temperature averaging technology.
Therefore, the electromagnetic induction heating roller is an ideal heating and processing tool for many high-end materials. At the same time, because the structure is complex, its cost is also necessarily higher. This is also the biggest obstacle to the large-scale application of electromagnetic induction heating roller.
