SU966591A1 - Device for measuring thermophysical characteristics - Google Patents

Description

one

The invention relates to a bakery production technique and is intended to measure thermophysical characteristics primarily in determining readiness of the dough.

A device for measuring thermophysical characteristics is known, comprising a resistance thermometer, a power source, an electronic bridge, a linear heater, coaxially located with a resistance thermometer, a rheostat with which the electronic bridge is zero, two time relays for controlling the power source and a resistance thermometer, amplifier, reversing motor and bridge power switches (1.

The disadvantages of the known device are - manual setting zero, uneven heating of the resistance thermometer, the lack of control of the temperature of the test material, which does not allow to obtain a high accuracy of measurement of thermophysical characteristics.

It is also known a device for measuring thermophysical characteristics preferentially in determining the readiness of a dough, comprising two thermal converters, associated

With a digital counter and a DC bridge through the control unit, and the power supply connected to the latter 2.

However, this device does not allow to determine thermophysical with great accuracy. characteristics, due to the longer cooling time of the resistance thermometer used in the calculation of the thermophysical characteristics, and taken from the chart tape, which makes the error in the calculation

10 cutting dough that does not have optimal properties will lead to irretrievable losses of dough going to the preparation of the finished product, as well as significantly affect the quality of the latter.

15

The aim of the invention is to increase the quality of the finished product.

The goal is achieved by the fact that, in a device for measuring thermophysical characteristics, mainly in determining readiness

Claims (2)

20 tests containing two thermal converters associated with a digital counter and a DC bridge through a control unit and a power source connected to the latter. 39 a distinctive feature is that it is equipped with a comparator and a DC amplifier, while the DC bridge is connected to the input of the latter, one of the outputs of the DC amplifier is connected directly, and the other is connected via a successive capacitor, a source follower and a voltage divider with a comparator, the output of which is connected to a digital meter .. In this case, the capacitor is charged to the amplitude value of the voltage supplied from the DC amplifier, which through the bridge post This current and control unit is connected to thermocouples - resistance thermometers, a high-impedance source repeater that connects the low-impedance output of the amplifier to the high-resistance comparator input, a voltage divider used to reduce the amplitude voltage coming from the condensate device -0 times and receiving u. Uj. Q, a comparator that compares the voltage from the DC splitter with the voltage coming directly from the amplifier (J while cooling the thermal converter. Fig. 1 shows a diagram of the proposed device; Fig. 2 shows the cooling curve of the thermal converter and the voltage of the amplifier constant) The device consists of two thermocouples 1 and 2, which, through control unit 3, are connected to a constant current bridge 5 of a direct current source 4, connected through a control unit 3 to a thermal converter 1, an amplifier 6 DC connected by one output to the comparator 10 directly BeHHOj and the other output through a capacitor 7, a source follower 8 and a voltage divider 9, while the comparator 10 is connected to a digital counter 11, the other input of which is connected to the control unit 3. Device works as follows: The dough after kneading is placed in a fermentation tank, where a measuring transducer is installed, consisting of measuring 1 and compensating 2 thermal converters. Thermal converter 2 eliminates the influence of the test temperature on the measurement results. When the device is operated, the control unit 3 switches the thermal converter 1 to 4 direct current with a switch. When the thermal converter 1 is heated, the input of the direct current amplifier 6 is short-circuited and the capacitor 7 is discharged. At the end of the heating, the thermocouple 1 to the temperature T0, the output of the 5 DC bridge, in the arms of which thermocouples 1 and 2 are located, is connected to the DC amplifier 6 and the digital counter 11 is started. The voltage from the output of the amplifier 6 charges the capacitor 7 to the amplitude value and, which through the source follower 8 enters the voltage divider 9 with the division factor Q, which at the output produces the voltage id C, -Q. The comparator 10, as the thermal cooling temperature of the thermocoupler i compares U, to the voltage at the output of the amplifier Uy, and as CD becomes equal to Uy, i.e., the thermal converter 1 with the warm-up temperature That cooled to T Q Td at a given Q, the comparator 10 stops digital counter And, from which the duration of the cooling of the thermal converter Sokh. is taken out. By the values of the cooling timer of the thermal converter it is possible to monitor the process of fermentation of the dough, determining its readiness by calculating. The use of a device for measuring thermophysical characteristics is reliable in operation and provides high accuracy in measuring the thermophysical characteristics of dough at the stages of ripening and final proofing, which will improve the quality of the finished bread, increase labor productivity, and automate the process of dough preparation. The economic effect from the introduction of the device at a bakery with a capacity of 60 tons / day for sliced sticks of wheat flour 1 s, weighing 0.4 kg will be 7000 rubles / g. Apparatus of the Invention A device for measuring thermophysical characteristics, mainly in determining the readiness of a test, comprising two thermal converters associated with a digital counter and a DC bridge through a control unit and a power source connected to the latter, in order to improve the quality of the finished product , it is equipped with a comparator and a DC amplifier, while the DC bridge is connected to the input of the latter, one of the DC output amplifier is connected directly successively, and the other through successively located capacitor, the source is repeated-; A voltage divider and voltage divider with a comparator whose output is connected to the digital counter. Sources of information taken into account during the examination 1. USSR author's certificate No. 131119, cl. G 01 N 25/18, 1960. 2. USSR author's certificate W 637672, cl. G 01 N 33/10, 1978 (prototype). TO and tfc s an on FIG. 2