RU2112223C1 - Method of determination of briquetted production and device intended for its realization - Google Patents

Abstract

FIELD: weight measurement technology. SUBSTANCE: carrying air interlayer is produced under article to be briquetted, free forward motion is imparted to article, excess pressure in air interlayer is measured, and this pressure is integrated in time during which interlayer acts upon article. In this case pressure is measured under article moving evenly. Article weight is determined by formula

, where G is article weight; p is excess pressure in interlayer under article; a is longitudinal size of article; b is transverse size of article; K_pl is proportionality coefficient depending on geometrical place of excess pressure measurement; K_f is proportionally coefficient depending on form of article bearing surface; t is time during which article is kept above pressure measurement place; τ is running time. Device intended for method realization has pneumatic conveyer with pneumatic chamber, upper wall of which is perforated, excess pressure sensor, and integrating unit which sums up instantaneous pressure values coming from pressure sensor. Device also has time interval meter, and computing unit which processes information supplied from integrating unit and time interval meter. Pneumatic conveyer consists of acceleration section, axes of perforation holes of which are inclined towards article movement, and measurement section, axes of perforation holes of which are vertical. Sensor measuring the excess pressure in carrying interlayer is positioned in middle part of measuring section and is connected to time interval meter. EFFECT: higher measurement results. 2 cl, 1 dwg

Description

 The invention relates to a weight measuring technique and can be used in the equipment of automatic lines for forming or filling purposes of food and processing industry enterprises.

 There is a method for determining the mass of the product during pneumatic transport and a device for its implementation [1], in which a carrier air gap is created under the transported product, the product vibrations are caused by a short-term pressure pulse and the product mass is determined along the perimeter of its free vibrations.

 A device for determining the mass of the transported product contains a pneumatic conveyor with a power chamber, nodes of excitation and measurement of vibrations, and the excitation node is placed in the power chamber and is made in the form of a pulse voltage source connected to two electrodes installed between themselves with a spark gap, and the vibration measurement node is made in the form of two photosensors of lateral displacements and a measuring instrument of time intervals.

 The insignificant thickness of the carrier air gap under the transported product leads to the fact that the amplitude of free vibrations of the product is small, and this complicates the measurement of the period and reduces the reliability of the measuring device.

где
p - избыточное давление во вспомогательной воздушной прослойке;
S - площадь боковой грани изделия;
V - скорость движения изделия после прекращения воздействия вспомогательной воздушной прослойки;
m - масса изделия;
K - коэффициент пропорциональности, зависящей от места измерения избыточного давления;
t - время воздействия вспомогательной воздушной прослойки.The closest to the proposed method in essence of the invention is a method for determining the mass of briquetted products [2], which consists in creating a carrier air layer under the transported product, creating an auxiliary air layer between the side face of the initially stationary product and the conveyor restrictive wall for a fixed time, measuring the excess pressure in the auxiliary air layer, integrate this pressure over the time during which the layer acts on Leah, then determine the rate of the free translational motion of the product and the product weight is determined by the formula

Where
p is the excess pressure in the auxiliary air gap;
S is the area of the side face of the product;
V is the speed of the product after the cessation of the auxiliary air gap;
m is the mass of the product;
K is the coefficient of proportionality, depending on the place of measurement of overpressure;
t is the exposure time of the auxiliary air layer.

 A device for determining the mass of briquetted products, including a straight section of a pneumatic conveyor with a main pneumatic chamber, the upper wall of which is perforated, two photosensors connected to a time interval meter, characterized in that it contains an additional pneumatic chamber with a perforated side wall, an overpressure sensor installed between the perforated side the wall of the additional chamber and the side face of the product, an integrating unit that sums up the instantaneous pressure values from the pressure sensor, a valve that shuts off the supply of compressed air to the additional chamber, as well as a computing unit that processes information from the integrating unit and time meter, while the photosensors are located along the supporting surface of the pneumatic conveyor.

 The disadvantage of this method is the complexity of the measurement process and, as a result, the low reliability of the devices (in addition to the measuring signal from the pressure sensor, two signals from photosensors are used).

 The technical task is to increase the reliability of non-contact weight measurement of piece briquetted or packaged products by reducing the number of measuring signals.

,
где
G - вес изделия;
p - избыточное давление в воздушной прослойке под давлением;
a - продольный размер изделия;
b - поперечный размер изделия;
K_м - коэффициент пропорциональности, зависящий от геометрического места измерения избыточного давления;
K_ф - коэффициент пропорциональности, зависящий от формы опорной поверхности изделия;
t - время нахождения изделия над местом измерения давления;
τ - текущее время.The essence of the invention lies in the fact that a carrier layer is created under the transported product, the product is brought into free translational motion, the overpressure in the air layer is measured, this pressure is integrated over the time during which the layer acts on the product, while the pressure is measured under uniformly moving product, and the weight of the product is determined by the formula

,
Where
G is the weight of the product;
p is the overpressure in the air gap under pressure;
a is the longitudinal size of the product;
b is the transverse size of the product;
K _m - the coefficient of proportionality, depending on the geometrical place of measurement of excess pressure;
K _f - the coefficient of proportionality, depending on the shape of the supporting surface of the product;
t is the residence time of the product above the place of pressure measurement;
τ is the current time.

 To determine the weight of briquetting products, a device is used that includes a horizontal pneumatic conveyor with a pneumatic chamber, the upper wall of which is perforated, an overpressure sensor, an integrating unit that sums up the instantaneous values received from the pressure sensor, a time interval meter, a computing unit that processes information from the integrating unit and a time meter gaps, while the pneumatic conveyor consists of a section of acceleration, the axis of the perforations of which are inclined towards two zheniya product and measurement site, the axes of which are vertical perforations, and a sensor that measures overpressure in the bearing interlayer is located in the middle of the measurement site and connected to meter intervals.

где
S - площадь опорной поверхности изделия.The technical result is achieved by the fact that the weight of the product hanging on the air gap is equal to the total pressure force on the supporting surface from the side of the layer

Where
S is the area of the supporting surface of the product.

где
x - координата по оси, направленной вдоль конвейера;
a - продольный размер изделия;
b - поперечный размер изделия;
K_м - коэффициент пропорциональности, зависящий от геометрического места измерения избыточного давления;
K_ф - коэффициент пропорциональности, зависящий от формы опорной поверхности изделия.For products of the correct form (the supporting surface of which is close to rectangular), we can assume

Where
x is the coordinate along the axis directed along the conveyor;
a is the longitudinal size of the product;
b is the transverse size of the product;
K _m - the coefficient of proportionality, depending on the geometrical place of measurement of excess pressure;
K _f - the coefficient of proportionality, depending on the shape of the supporting surface of the product.

где
V - скорость равномерного движения изделия;
τ - текущее время;
t - время, за которое изделие проходит над местом измерения давления.With uniform movement of the product along the pneumatic conveyor above the place of pressure measurement, the dependence

Where
V is the speed of uniform movement of the product;
τ is the current time;
t is the time during which the product passes over the place of pressure measurement.

или

Преимущество способа, позволяющее создавать высоконадежные измерительные устройства, в том, что для определения веса используется лишь один измерительный сигнал (давление).Having replaced the variable τ by t and accordingly changing the integration limits in formula (2), we obtain

or

The advantage of the method, allowing you to create highly reliable measuring devices, is that to determine the weight is used only one measuring signal (pressure).

 The drawing shows a device that allows you to implement the proposed method.

 A device for determining the weight of products (products 1, 2) includes a horizontal pneumatic conveyor, consisting of an acceleration section 3 and a measurement section 4, on the surface of which there is an overpressure sensor for the air gap 5 connected to an integrating unit 6 and a time interval meter 7, which the queue is connected to the computing unit 8.

 The device operates as follows.

 The product is placed on the acceleration section. Under the action of jets of air flowing from inclined perforations and a carrier layer formed between the supporting surface of the product and the pneumatic conveyor, the product moves accelerated towards the measurement site. At the measurement site, the product moves uniformly, since the force of air resistance is negligible, and the action of the jets flowing from the holes is perpendicular to the direction of movement. When the product “floats” over the zone of the overpressure sensor, the air gap acts on the sensor, which produces a signal corresponding to the instantaneous value of the overpressure at the point of the supporting surface of the product located above the sensor. In the presence of this signal, an integrating unit and a time interval meter work, the information from which arrives at the computing unit.

 Based on the information received and the predefined values of the dimensions of the product, the computing unit, taking into account the relative position of the pressure measuring point and the shape features, determines the weight of the product according to formula (5).

Claims (2)

1. The method for determining the weight of briquetted products, which consists in creating a carrier layer under the briquetted product, bringing the product into free translational movement, measuring the overpressure in the air layer, integrating this pressure over time, during which the layer acts on the product, which differs the fact that the pressure is measured under a uniformly moving product, and the weight of the product is determined by the formula

where G is the weight of the product;
p is the excess pressure in the air gap under the product;
a is the longitudinal size of the product;
b is the transverse size of the product;
K _m - the coefficient of proportionality, depending on the geometrical place of measurement of excess pressure;
K _f - the coefficient of proportionality, depending on the shape of the supporting surface of the product;
t is the residence time of the product above the place of pressure measurement;
τ is the current time.  2. A device for determining the weight of briquetted products, including a horizontal pneumatic conveyor with a pneumatic chamber, the upper wall of which is perforated, an overpressure sensor, an integrating unit that sums up the instantaneous pressure values coming from the pressure sensor, a time interval meter, a computing unit that processes information from the integrating unit and measuring time intervals, characterized in that the pneumatic conveyor consists of a section of acceleration, the axis of the perforations of which are inclined in the direction of movement of the product, and the measuring section, the axis of the perforation holes of which are vertical, while the sensor measuring the overpressure in the carrier layer is located in the middle of the measuring section and is connected to the time interval meter.