SU773033A1

SU773033A1 - Method of control for preparation process of electroheated concrete mixes

Info

Publication number: SU773033A1
Application number: SU792727804A
Authority: SU
Inventors: Алексей Георгиевич Комар; Анатолий Анатольевич Рульнов; Георгий Иванович Цителаури
Original assignee: Всесоюзный Заочный Инженерно-Строительный Институт
Priority date: 1979-02-22
Filing date: 1979-02-22
Publication date: 1980-10-23

Description

Изобретение относится к производству строительных материалов и изделий, преимущественно сборного железобетона, и может быть использовано при автоматизации технологических линий, в частности, при непрерывной технологии горячего формования изделий, например, ⁵для производства керамзитобетонных панелей наружных стен с предварительным непрерывным электроразогревом бетонной смеси.The invention relates to the production of building materials and products, mainly prefabricated reinforced concrete, and can be used in the automation of technological lines, in particular, in the continuous technology of hot forming of products, for example, ⁵ for the production of expanded clay concrete panels of external walls with preliminary continuous electrical heating of concrete mixture.

Известен способ управления процессом при- ¹⁰готовления злектроразогретых бетонных смесей с учетом колебаний физических свойств смеси и ее компонентов [1].A known method of controlling the process of preparation of ¹⁰ electrically heated concrete mixtures, taking into account fluctuations in the physical properties of the mixture and its components [1].

Однако этот способ не обеспечивает необходимые условия твердения.However, this method does not provide the necessary hardening conditions.

Известен также способ управления процессом приготовления злектроразогретых бетонных смесей, включающий измерение электросопро. тивленяя бетонной смеси и изменение ее коли- _мчества, подаваемого на разогрев. Указанный способ управления позволяет управлять процессом непрерывного приготовления электроразогретьгх бетонных смесей [2].There is also a method of controlling the process of preparation of electrically heated concrete mixtures, including the measurement of electrical conductivity. resistivity change of the concrete mix and its _m-operation The amount applied to the heating. The specified control method allows you to control the process of continuous preparation of electrically heated concrete mixtures [2].

Однако недостатком способа является отсутствие устойчивых технологических режимов, обеспечивающих получение разогретых смесей в строго заданном диапазоне изменения выходных параметров процесса (температуры) косвенно характеризуемой величиной электросопротивления и подвижности бетонной смеси, так как при электроразогреве изменение значений обеих управляющих воздействии (количества бетонной смеси, подаваемой на разогрев и количества воды затворения) приводит к одновременному изменению обеих управляемых параметров процесса - подвижности бетонной смеси и ее электросопротивлению.However, the disadvantage of this method is the lack of stable technological conditions that ensure obtaining heated mixtures in a strictly specified range of changes in the output parameters of the process (temperature) indirectly characterized by the magnitude of the electrical resistance and mobility of the concrete mixture, since when electric heating changes the values of both control actions (the amount of concrete mixture supplied for heating and the amount of mixing water) leads to a simultaneous change in both controlled process parameters - zhnosti concrete and its resistivity.

Цель изобретения - улучшение формовочных свойств смеси и условий твердения бетона.The purpose of the invention is the improvement of the molding properties of the mixture and the hardening conditions of concrete.

Достигается это тем, что в способе управления процессом приготовления злектроразогретых бетонных смесей, включающем измерение электросопротивления бетонной смеси и изменение ее количества, подаваемого на разогрев, дополнительно измеряют подвижность разогретой бетонной смеси и изменяют количество воды затворения, а изменение количества бетонной смеси осуществляют в зависимости от подвижности смеси и изменение количества воды затворения осуществляют в зависимости от электросопротивления разогретой бетонной смеси.This is achieved by the fact that in the method of controlling the preparation of electrically heated concrete mixtures, including measuring the electrical resistance of the concrete mixture and changing its quantity supplied for heating, the mobility of the heated concrete mixture is additionally measured and the amount of mixing water is changed, and the amount of concrete mixture is changed depending on the mobility mixtures and a change in the amount of mixing water is carried out depending on the electrical resistance of the heated concrete mixture.

Введение указанных дополнительных управляющих воздействий в виде внешних компенсирующих связей между регуляторами расхода бетонной смеси и расхода воды позволяет нейтрализовать вредную взаимную связь подвижности разогретой бетонной смеси и ее электросопротивления, поскольку в одном случае изменение одной из регулируемых величин не будет вызывать одновременное изменение другой.The introduction of these additional control actions in the form of external compensating connections between the flow rate regulators of the concrete mixture and the water flow rate allows to neutralize the harmful mutual relationship between the mobility of the heated concrete mixture and its electrical resistance, since in one case a change in one of the controlled quantities will not cause a simultaneous change in the other.

На чертеже показана схема, поясняющая способ управления процессом приготовления электроразогретых бетонных смесей.The drawing shows a diagram explaining a method for controlling the process of preparing electrically heated concrete mixtures.

Схема содержит бетоносмеситель 1, камеру 2 электроразогрева, регулятор 3 расхода бетонной смеси, регулятор 4 расхода воды затворения, измеритель 5 электросопротивления разогретой бетонной смеси, измеритель 6 подвижности бетонной смеси, канал 7 управления ’’электросопротивление — расход смеси” , канал 8 управления ’’подвижность — расход воды”, корректирующий канал' 9 ’’подвижность - расход смеси”, корректирующий канал 10” электросопротивление — расход воды”.The circuit contains a concrete mixer 1, an electric heating chamber 2, a concrete mixture flow controller 3, mixing water flow controller 4, a heated concrete mixture electrical resistance meter 5, a concrete mixture mobility meter 6, an electrical resistance-mixture flow control channel 7, a control channel 8 mobility - water flow rate ”, corrective channel '9” mobility - flow rate mixture ”, corrective channel 10” electrical resistance - water flow rate ”.

Обе управляемые величины - электросопротив- 35 пение бетонной смеси и подвижность бетоннойBoth controlled quantities - electrical resistance - 35 singing of concrete mix and mobility of concrete

773033. 4 'порциональный величине электросопротивления. Таким образом, изменение расхода бетонной смеси, поступающей на разогрев, предназначенное для поддержания заданного электросопротивления, несмотря на изменение температуры разогретой смеси, не оказывает воздействия на подвижность смеси, поскольку влияние изменений расхода смеси устраняется за счет коррекции расхода воды в зависимости от электросопротивления бетонной смеси.773033. 4 'proportional to the value of electrical resistance. Thus, a change in the flow rate of the concrete mixture supplied for heating intended to maintain a given electrical resistance, despite a change in the temperature of the heated mixture, does not affect the mobility of the mixture, since the effect of changes in the flow rate of the mixture is eliminated by correcting the water flow depending on the electrical resistance of the concrete mixture.

Если же происходит отклонение от заданного значения величины подвижности бетонной смеси, то сигнал от измерителя 6, пропорциональный этому отклонению, по каналу 10 поступает на регулчтор 4 расхода, который изменяет : подачу воды затворения. Одновременно этот же сигнал по корректирующему каналу 9, поступая на регулятор 3 расхода, изменяет подачу бетонной смеси.If there is a deviation from the set value of the mobility of the concrete mixture, then the signal from the meter 6, proportional to this deviation, passes through the channel 10 to the flow controller 4, which changes: the flow of mixing water. At the same time, the same signal through the correction channel 9, entering the flow controller 3, changes the flow of concrete mixture.

Таким образом, изменение расхода воды, предназначенное для поддержания заданной подвижности бетонной смеси, не оказывает поддержания заданной подвижности бетонной смеси, не оказывает влияния на второй управляемый параметр — электросопротивление, поскольку его влияние устраняется за счет коррекции расхода смеси в зависимости от подвижности разогретой бетонной смеси.Thus, a change in water flow designed to maintain a given mobility of a concrete mixture does not maintain a given mobility of a concrete mixture, does not affect the second controlled parameter - electrical resistance, since its effect is eliminated by correcting the flow of a mixture depending on the mobility of a heated concrete mixture.

Claims

The invention relates to the production of building materials and products, mainly precast concrete, and can be used in the automation of technological lines, in particular, in the continuous technology of hot-molding products, for example, for the production of expanded clay concrete panels of external walls with preliminary continuous electrical heating of the concrete mix. There is a known method for controlling the process of preparing electrically heated concrete mixtures with allowance for fluctuations of the physical properties of the mixture and its components 1. However, this method does not provide the necessary curing conditions. There is also known a method for controlling the process of preparing electrically heated concrete mixtures, including the measurement of electro-prop. concrete mixture and the change in the amount supplied to the heating. This control method allows you to control the process of preprocessing electrically heated concrete mixes 2. However, the disadvantage of this method is the lack of stable technological regimes that provide heated mixtures in a strictly specified range of output parameters of the process (temperature) indirectly characterized by the amount of electrical resistance and mobility of the concrete mix, so as with electric heating, the change in the values of both control actions (the amount of concrete mix, my warm-up and the quantity of water) leads to a simultaneous change in both controlled by process parameters - mobility concrete and its resistivity. The purpose of the invention is to improve the molding properties of the mixture and the hardening conditions of the concrete. This is achieved by the fact that in the method of controlling the process of preparing electrically heated concrete mixtures, including measuring the electrical resistance of a concrete mix and changing its quantity supplied for heating, the mobility of the heated mix is additionally measured and the amount of mixing water is changed, and the quantity of concrete mix is changed depending on the mobility of the mixture and the change in the amount of mixing water is carried out depending on the electrical resistance of the heated concrete mixture. The introduction of these additional control actions in the form of external compensating connections between the flow controllers of the concrete mix and the flow of water makes it possible to neutralize the harmful mutual connection between the mobility of the heated concrete mix and its electrical resistance, in one case the change of one of the controlled values will not take place simultaneously. other. The drawing shows a diagram explaining the method of controlling the process of preparing electrically heated concrete mixtures, the Scheme contains a concrete mixer 1, electric heating chamber 2, a concrete mix consumption regulator 3, a mixing water flow regulator 4, a concrete mixture electrical resistance meter 5, a mobility meter 6 concrete mix, channel 7 control electroresistance - mix flow, channel 8 control mobility - water flow, corrective channel 9 mobility - flow rate ai, corrective channel 10 electro resistance ix - water consumption. Both controllable quantities — the electroprotection of the concrete mixture and the mobility of the concrete mixture — are subjected to controlled and uncontrolled disturbances, including, for example, the specific electrical conductivity of the mixture, its initial temperature, temperature, humidity and granule composition of aggregates, etc. as well as controlling effects on the main and cross internal links. The mutual influence of these connections between the controlled parameters is compensated by the introduction of corrective Get inside. The control of the proposed method is as follows. When the readings of the meter 5 of the electrical resistance deviate from the predetermined value, a signal proportional to this deviation is fed through channel 7 to the flow regulator 3 which makes the necessary change in the flow of the concrete mix. At the same time, the water supply is changed with the help of the flow regulator 4, because the channel 8 receives a correction signal synchronously with the main signal, also about 4 times the electrical resistivity value. Thus, a change in the flow rate of the concrete mixture supplied to the heating designed to maintain a predetermined electrical resistance, despite the change in the temperature of the heated mixture, does not affect the mobility of the mixture, since the influence of changes in the flow rate of the mixture is eliminated due to the correlation of water consumption depending on the electrical resistance of the concrete. the mixture, If there is a deviation from the specified value of the mobility of the concrete mix, the signal from the meter 6, proportional to this deviation, on the channel 10 is fed to a flow controller 4 which changes: the supply of the mixing water. At the same time, the same signal through the correction channel 9, which is fed to the flow controller 3, changes the flow of the concrete mix. Thus, a change in the flow rate of water intended to maintain the desired mobility of the concrete mix does not support the desired mobility of the concrete mix, does not affect the second controlled parameter, electrical resistance, because its effect is eliminated by correcting the mix flow rate depending on the mobility. heated concrete mix. Claims The method of controlling the process of preparing electrically heated concrete mixtures, including the measurement of the electrical resistance of the Bechoina mixture and the change in its quantity to be heated, is characterized in that, in order to improve the molding properties of the concrete, mixing and hardening conditions of the concrete, the dimension is measured the mobility of the heated concrete mix and change the amount of mixing water, and the change in the amount of concrete mix is carried out depending on the mobility of the mixture and the change in the amount of mixing water is carried out Depending on the electrical resistance of the heated concrete mix. Sources of information taken into account when examining 1.Mesinev G. G. and others. Electric heating of concrete mixtures during hot molding of products. (Review), M., VNIIZOM, 1970, p., 15-18,

2. USSR author's certificate No. 377311, cl. From 04 To 31/30, 1973 (prototype).