CN219762365U - On-line viscosity control system - Google Patents

Abstract

The utility model provides an in-line viscosity control system for a biopolymer for a food casing, wherein the in-line system comprises a homogenizer (3), wherein the control system comprises a rheology sensor (1), which rheology sensor (1) is adapted to be placed in an outlet pipe (4) of the homogenizer (3) in a position such that a resonator (2) of the rheology sensor (1) is kept in contact with the biopolymer, the control system being further provided with a controller (5) and a processor (6), which processor (6) has program means for collecting data about the resonance frequency and damping of the rheology sensor (1) and converting these data into viscosity values.

Description

On-line viscosity control system

Technical Field

The former is part of the technology of manufacturing food casings (biopolymers, such as collagen) and in particular controlling the viscosity of the highly plastic aqueous protein dispersion from which the casing is extruded.

Background

Artificial collagen casings are made from aqueous dispersions of fibrous collagen that exhibit non-newtonian plastic mechanical behavior. The dispersion having the appearance of a paste-like substance is extruded in a tubular manner through a nozzle having a very fine annular groove. The viscosity of these dispersions is the most decisive rheological parameter and the implementation of an in-line viscosity measurement system is a tool to ensure correct extrusion operations.

The viscosity of the fibrous collagen paste used to make the casing is an extremely important parameter, as the proper development of the extrusion process depends on this viscosity. Which describes suitable or unsuitable collagen materials for extrusion and which in turn depends on the concentration of collagen in the dispersion and the size and uniformity of the collagen fibers in the fiber paste, which is a dispersion of collagen fibers that are water-swollen in an aqueous liquid phase.

On the one hand, a constant viscosity indicates that the material is homogeneous and thus that the dispersion of collagen fibers has good regularity of size and diameter, which in turn will ensure smoothness of the paste during its passage through the extrusion nozzle. On the other hand, the constant viscosity ensures a good functioning of the driving system and the electric circuit, which transport the paste until it passes through the extrusion nozzle, which prevents the variation of the quality and thickness of the tubular film obtained, which is an essential aspect of manufacturing artificial casings.

Viscosity control can be performed in the laboratory as a conventional off-line operation by using a rotational viscometer known in the art. Although the assessment is accurate and reliable, there are drawbacks to them in terms of intermittence, thus requiring additional work in terms of sample collection and laboratory testing and result recording. In the case of obtaining an undesirable value, the reaction capacity for solving the problem is reduced, resulting in loss of efficiency in the process.

For all these reasons, there is a need for a continuous monitoring system (in-line) of the viscosity values of the substances to be extruded, which system is moreover not affected by undesired vibrations.

Disclosure of Invention

The main object of the present utility model is the design of a continuous monitoring system for the viscosity of collagen substances used in the extrusion of food casings for filling products. For this purpose, the present model shows a rheosensor located in the extrusion line, in particular adjacent to the outlet pipe of the homogenizer. The system is also provided with a controller, a processor, and optionally means for displaying data.

More particularly, the present utility model proposes an in-line viscosity control system for a biopolymer for a food casing, wherein the in-line system comprises a homogenizer and comprises a rheology sensor adapted to be placed in an outlet pipe of the homogenizer in a position such that a resonator of the rheology sensor is kept in contact with the biopolymer, the control system being further provided with a controller and a processor having program means for collecting data relating to the resonance frequency and damping of the rheology sensor and converting these data into viscosity values. Optionally, the resonator of the rheological sensor is a torsional resonator.

In a continuous process in which the fluid to be measured passes through a structure that may be subjected to significant vibrations due to high pressure discharge treatment and homogenization of the fluid, replacing the transverse resonator with a rheological resonator is an improved solution.

Drawings

To assist in a better understanding of the features of the utility model and to supplement the description, the following drawings are attached as part of the description, which are illustrative in nature and not limiting:

fig. 1 shows a rheology sensor suitable for use in the present model.

Fig. 2 is a diagram of the utility model in which the sensor of fig. 1 is in an optimal position for on-line operation.

Detailed Description

The principle of measuring the viscosity of a fluid under constant motion is based on resonant frequency vibration techniques. A resonator is an oscillator placed in a liquid that vibrates with a constant amplitude of motion. By detecting the power required for the vibration, the viscous behaviour of the liquid can be measured. The active part of the vibration measuring sensor is a rod driven by constant electrical energy. The amplitude and frequency of the vibrations vary depending on the kinematic viscosity, since the degree of damping of the vibrations depends on the fluid viscosity. For the present utility model, a rheology sensor has been selected. The rheometric sensor vibrates under torsion. Their resonators rotate about their own axis rather than vibrate laterally. The rheology sensors are more easily isolated from the structure on which they are mounted. They are also less disturbed by environmental vibrations than the side resonators.

Referring to fig. 1, the present utility model provides a rheology sensor 1, the rheology sensor 1 having a resonator 2 inside. The resonator vibrates in the fluid, and the fluid affects the vibration of the resonator. The measurable characteristics of the resonator, both its resonant frequency and damping, are affected by the characteristics of the fluid, in this case a biopolymer such as collagen. By measuring its effect on the resonator, the viscosity of the fluid and its density can be determined.

The fluid affects the rheology sensor in two ways:

1. the denser fluid increases the mass loading of the resonator and thus the greater the fluid density, the lower the resonant frequency;

2. friction between the resonator and the fluid increases its damping and therefore the more viscous the fluid, the wider and smaller the resonance peak of the sensor.

The sensor of the present utility model also preferably uses a torsional resonator in which the two ends of the sensor rotate in opposite directions, thereby counteracting the reaction torque in the components of the sensor. The sensor includes a controller and a processor provided with the necessary software to determine the resonant frequency and damping of the resonant sensor to convert these measurements into viscosity values using an algorithm.

The end part of the resonator vibrates under the torsion effect; any point on its surface experiences microscopic vibrations of less than one thousandth of a millimeter, which are affected by the properties of the fluid. The rheological resonator produces a velocity gradient in the fluid; the gradient shears the fluid while absorbing energy from the resonator. This energy loss is measured and used to calculate the viscosity of the fluid. The resonator frequency and damping are affected by the fluid forces acting on the resonator. The contact surface of the resonator with the fluid is cylindrical.

When the surfaces vibrate under torsion, they move parallel to themselves. The vibrating surface drags the fluid as it vibrates, creating an oscillating velocity gradient in the fluid. Wherever the velocity gradient is in the fluid, there is shear force due to the resistance of the fluid to shear. This is the meaning of viscosity. Fluid shear absorbs energy from the resonator. This is known as damping. Only newtonian fluids have a constant viscosity independent of the shear rate applied. In non-newtonian fluids, the viscometer reading depends on the shear rate at which the measurement is made. Non-newtonian fluids have a wide range of behavior types; two typical behaviors are shear thickening and shear thinning.

In a non-newtonian fluid, the shear stress can be expressed as a function of shear rate. This is called the flow curve. The slope of the flow curve at the predetermined shear rate is the apparent viscosity. Viscometers typically have no controlled shear rate and for non-newtonian fluids only a generally known shear rate. The reading of the viscometer at a comparable shear rate is proportional to the slope of the flow curve at that shear rate. The shear-thinning (less viscous) material measured with the rheosensor will show a reading that decreases with increasing rotational resonator speed. The faster the rotation, the faster the shear fluid. For newtonian fluids, the torque on the resonator will increase in proportion to the speed. For a shear-thinning fluid, the torque/speed ratio decreases with increasing rotational resonator speed.

High reproducibility and high reproducibility in homogeneous fluids can be achieved using a rheometric sensor; this means that the same instrument provides the same reading in the same fluid in a short time. Thus, regardless of whether the characteristics of the rheology sensor are dependent on the shear rate, the rheology sensor provides a very reliable measure of the regularity of the characteristics of the fluid in the process. This is very important when the sensors are located on a parallel production line; the sensor will give a measure of consistency of viscosity even during prolonged production.

Referring to fig. 2, in this utility model, a rheology sensor 1 is connected to an outlet tube 4 of a fibrous collagen dispersion in a homogenizer 3. The rotary resonator 2 of the rheosensor 1 will remain in permanent contact with the fluid. This location of the rheology sensor 1 is suitable because it is in the homogenizer at the location where the collagen dispersion acquires its final rheology before extrusion.

The other end of the sensor is connected by a cable to a controller 5 for starting and performing continuous measurements, and to a processor 6 (of a computer or mobile device, such as a telephone or tablet) and to a device 7 for displaying data; the controller 5 may preferably be mounted on a wall or in the vicinity of the extrusion line or another place with greater protection. The controller 5 is connected via a wireless network, bluetooth or cable to a processor 6, the processor 6 being used for data acquisition and processing, the processor having program means for collecting data relating to the resonance frequency and damping of the rheology sensor 1 and converting these data into viscosity values.

Those skilled in the art will appreciate in view of this specification and the accompanying drawings that the inventive concepts have been described in terms of some preferred embodiments of the inventive concepts, but that various modifications may be introduced in the preferred embodiments without departing from the inventive concepts of the inventive concepts as they are claimed.

Claims (2)

1. An in-line viscosity control system for a biopolymer for a food casing, wherein the in-line system comprises a homogenizer (3), characterized in that the control system comprises a rheology sensor (1), which rheology sensor (1) is adapted to be placed in an outlet pipe (4) of the homogenizer (3) in a position such that a resonator (2) of the rheology sensor (1) is kept in contact with the biopolymer, the control system being further provided with a controller (5) and a processor (6), which processor (6) has program means for collecting data about the resonance frequency and damping of the rheology sensor (1) and converting these data into viscosity values.

2. The in-line viscosity control system of claim 1, wherein the resonator of the rheological sensor is a torsional resonator.