SU1762089A2 - Device for adjustment of loose material drying process - Google Patents

Abstract

Usage: drying of bulk materials in a drum dryer. Essence: the device contains temperature sensors installed in an e-drum connected via a converter to the inputs of the selection unit, the outputs of which are connected to the inputs of the unit calculating the average temperature of drying gases whose output is connected to the input of the fuel consumption regulator. 3 il.

Description

The invention relates to a technique for drying bulk materials in a drum dryer and can be used in various industries and is an improvement on the known device described in ed. St. USSR Ns 1204900.

The known device for automatic control of the drying process includes temperature sensors installed in the drum, connected by means of a temperature signal converter and an additional mechanism to the fuel consumption regulator. At the same time, temperature sensors are installed evenly around the perimeter of the drum cross section, and the converter is equipped with a selection unit of the smallest signal size.

The disadvantage of the described device is that it does not provide the required accuracy of determining the moisture content of the dryer, since the temperature of the material is measured, drying of which takes place in the first period (evaporation of external moisture) when the temperature of the material is almost constant.

The object of the further invention is to improve the quality of the drying.

The goal is achieved by the fact that the device regulating the drying process in a drum dryer according to the author. St. No. 1204900 is additionally equipped with a unit for calculating the average temperature of drying gases, the inputs of which are connected to the outputs of the selection unit, and the output to the input of the fuel consumption regulator.

The temperature of the flue gases, measured by the claimed device, is proportional to the amount of heat spent on drying the material and, therefore, proportional to the moisture content of the dryer, which will use this parameter to regulate the drying process.

Supplying the known device with an additional calculating unit installed between the signal selection unit and the fuel consumption regulator will improve the quality of measurement and humidity control of the dried material according to an indirect parameter — the temperature of the drying gases inside the drum due to

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more high correlation between the specified parameters.

The technical solutions that have features similar to the features distinguishing the main and claimed additional invention from the prototype have not been revealed by the authors, which indicates that the proposed device meets the criterion of significant differences.

FIG. 1 shows a diagram of the device for automatic control of the drying process of bulk materials; in fig. 2 shows the layout of the material temperature sensors; in fig. 3 shows functional diagrams of the selection unit 4 and the unit 11 for calculating the average temperature of the drying gases.

The device consists of a rotating drum 1, temperature sensors 2, a block

3 converting voltage into a current signal, signal selection unit 4, fuel consumption controller 5, actuator 6, temperature setting device 7, fuel supply regulator 8, slip rings 9, pullers 10, computing unit 11.

The number of sensors is chosen such that when the drum rotates at least one of them is underlayed by the material being dried. Inside the drum 1, temperature sensors 2 are installed at the same distance from each other in the amount determined by the formula:

 1 + 1,

where is the whole part of the number;

n is the number of temperature sensors;

R is the inner radius of the drum;

1 - the length of the arc segment occupied by the material being dried during the rotation of the drum.

The arc length of a segment for a different material is different and depends on the angle of repose of the bulk material, since the internal angle of the segment is approximately equal to twice the angle of repose of the bulk material. Each sensor 2 is connected to an individual contact ring 9 mounted on the axis of the drying drum 1. Each ring is associated with a puller 10 connected to the input of the unit

4 selections. The minimum number of temperature sensors when filling at least 15% of the cavity of the drum is 4.

The outputs of the voltage-to-current signal conversion unit 3 are connected to the inputs of the signal selection unit 4, the outputs of which are connected to the calculation unit 11 for calculating the average temperature of the drying gases.

The output of the latter is fed to the input of the fuel consumption controller 5.

The controller 5 through the actuator 6 is connected to the regulatory body 8 of the fuel supply. In order to maintain the required temperature of the drying gases, temperature controller 7 is connected to the controller 5. The device works as follows.

Signals from sensors 2, corresponding to the measured temperature inside drum 1, are transmitted through ring sliding contacts to the inputs of converters 3, where they are converted into proportional current signals. From the outputs of the transducers 3, signals are fed to the selection unit 4, where the selection of the smallest current signal occurs. Block 4 (Fig. 3a) consists of n (according to the number of

temperature sensors) threshold elements whose setpoint is obviously higher than the material temperature and lower than the flue gas temperature. The temperature sensors are mounted in the drum in such a way that at one time only one of them is in contact with the material.

At the output of the selection unit 4, all signals are separated, except for the signal having

the smallest value.

These signals, corresponding to the temperature of the drying gases in the characteristic volume of the drum, are fed to the input of block 11, in which these signals are summed, the result is multiplied by a constant coefficient K. So in

In block 11, the mean temperature value received at

a block of signals corresponding to the temperature of the drying gases in several points distributed around the perimeter of the drum; The output signal of the block 11 is fed to the fuel consumption controller 5, where it is compared with the signal of the setpoint 7.

Depending on the magnitude and sign of the error signal, the regulator 5 through the actuator 6 changes the position of the regulator 8, sets the fuel consumption required to maintain the set temperature.

An additional invention in combination with the main one will provide an increase in the quality of measurement and control of the moisture content of the dried material based on the temperature of the drying gases inside the drum.

In addition, this technical solution will improve the working conditions by regulating the process by which the dust content in the exhaust gases is reduced to

Claims (1)

It will also have a favorable effect on the environmental situation of the environment by reducing dust emissions to the atmosphere. The invention The device regulating the process of drying bulk materials according to ed. St. Ns 1204900, characterized in that, with In order to improve the quality of drying, it is additionally equipped with a unit for calculating the average temperature of drying gases, the inputs of which are connected to the outputs of the selection unit and the output to the input of the fuel consumption regulator. phi.1 FIG. 2 fa.1 tfepaefffa / t / s / gelhem / tg 8x.2 / 70 / 0g &# d / Ј / bh.l / 7ff / 0ea & bw o / 7e / it / g Bwx / Yay / x.2 db / x / 7 L, rr-1