Wireless detection system for papermaking machine dryer surface temperature

Abstract

The invention discloses a wireless detection system for papermaking machine dryer surface temperature. The wireless detection system comprises a plurality of wireless temperature sensors, a radio frequency antenna, a wireless data receiver and an industrial personal computer, the wireless temperature sensors are embedded into a working wall of a dryer, a radio frequency signal wire is connected between every two wireless temperature sensors, an output end of each radio frequency signal wire is connected with the radio frequency antenna, the radio frequency antenna is mounted on the side wall of the dryer and transmits temperature data to the wireless data receiver, the wireless data receiver is connected with the industrial personal computer through a communication cable, the wireless temperature sensors transmit the temperature data on the wall of the dryer to the wireless data receiver, the wireless data receiver transmits the received temperature data to the industrial personal computer, the detected data are read by the industrial personal computer, and real-time online measurement of the dryer surface temperature is realized.

Description

technical field [0001] The invention belongs to the field of light industry technical engineering, and relates to a temperature detection device in the papermaking machinery and equipment industry in the pulping and papermaking engineering, in particular to a wireless detection system for the surface temperature of a drying cylinder of a paper machine. Background technique [0002] Paper machine drying cylinder is installed in the drying section of paper machine and is a special equipment for paper drying. Steam is passed through to heat the outer surface to a certain temperature, and the paper web passing through the surface is dried through a series of drying cylinders to achieve the paper quality. Purpose. During the process, most of the steam is condensed into water and discharged through the siphon. There are generally multiple drying cylinders in the paper machine to dry the paper continuously, especially the fourdrinier paper machine usually has dozens of drying cyli...

AI Technical Summary

Problems solved by technology

There are generally multiple drying cylinders in the paper machine to dry the paper continuously, especially the fourdrinier paper machine usually has dozens of drying cylinders working together. If there is a large amount of accumulated water inside, the heat transfer effect of the high-temperature steam will quickly deteriorate, resulting in a drop in the surface temperature of the dryer, which will have a very adverse effect on the drying of the paper. Seriously affect the speed of the paper machine, and at the same time increase the load of the motor driving the dryer, increasing the power consumption

Another situation is that a certain degree of corrosion or scaling has occurred inside one or several dryer cylinders, resulting in inconsistent surface temperature of the dryer cylinders, which also seriously affects the uniformity of paper web drying, and paper sticking is prone to occur on the surface of the dryer cylinders

[0003] The drying cylinder rotates around the axis when it is working, so the surface temperature is difficult to detect

At present, there are mainly two methods to detect the surface temperature of the dryer cylinder. One is to install a contact surface temperature sensor on the outer surface of the dryer cylinder for direct detection. The surface senses the temperature. Once the sensor bearing gets stuck, the original rolling friction becomes sliding friction, which will cause scratches on the smooth surface of the dryer, destroy the surface finish of the dryer, and easily stick to paper, causing damage to the paper and causing damage to production. adverse effects

The more sensors are installed, the greater the probability that the sensors will damage the surface quality of the dryer, so they cannot be installed in large quantities on the paper machine. In order to avoid scratches on the dryer, usually only 1-2 sensors can be installed on the blank areas at both ends of the dryer. Due to the small number of sensors and the limited location, it is difficult to reflect the temperature of the paper machine in the width direction of the paper web, and it is difficult to detect once the temperature unevenness of the drying cylinder occurs

Especially when water accumulation occurs in the drying cylinder, the temperature of the area in contact with the paper web decreases rapidly due to the cooling effect, and the temperature sensor is located on the side where the fresh steam is introduced, the heating effect of the steam is strong, and the measured temperature is still high. It can not reflect the cooling condition of the accumulated water in the dryer

Due to the defects of the contact sensor, some dryer cylinders in some paper machines do not install temperature sensors, but use formulas to estimate the surface temperature of the dryer cylinders based on parameters such as the steam inlet temperature, pressure, condensate water temperature, and flow rate of the dryer cylinders. The first method also has deficiencies, the estimated temperature will be quite different from the actual value, and it is impossible to judge the consistency of the surface temperature of the drying cylinder

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