WO2010133722A1

WO2010133722A1 - Automated machine for performing alternating immersion tests

Info

Publication number: WO2010133722A1
Application number: PCT/ES2010/000194
Authority: WO
Inventors: David LISTÁN GALÁN; Mariano MARCOS BÁRCENA; Franscisco Javier Botana Pedemonte; José Miguel SANCHÉZ SOLA
Original assignee: Universidad De Cádiz
Priority date: 2009-05-18
Filing date: 2010-05-05
Publication date: 2010-11-25
Also published as: ES2375898A1; ES2375898B2

Abstract

The machine makes it possible to perform tests on test specimens of various materials in total or partial immersions in liquids of different compositions and concentrations not only simultaneously but also in differentiated, programmed tests under different conditions. The machine likewise allows exhaustive control of the test atmosphere for drying the elements, optionally allowing the simulation of air currents with controlled conditions for the forced drying of the test specimens, and at the same time controlling the various parameters of the test liquid in order to avoid undesired variations, offering the possibility of activating corrective measures. By means of the control system thereof, it is possible to totally automate the process, the recording of parameters of the test by means of different sensors and the storage thereof for subsequent analysis thereof.

Description

AUTOMATED MACHINE FOR THE PERFORMANCE OF ALTERNATE IMMERSION TESTS.

FIELD OF THE INVENTION

The present invention describes an automatic device for performing tests, both short and long-term, under controlled conditions, without the need for monitoring of the machine operator.

It allows tests to be carried out on different materials: metals, plastics, rubber, in total or partial dives, in liquids of different compositions and concentrations, both simultaneously and in differentiated and programmed tests with different conditions.

BACKGROUND OF THE INVENTION

The materials are affected by the means of exposure to which they are subjected. Any small variation in the conditions of that medium may involve the acceleration of the corrosion process of the materials immersed in it. That is why it is currently necessary to simulate these environments in the laboratory, as accurately or precisely as possible, to study the behavior of different materials or their coatings against diversity of media.

There is a great diversity of inventions related to test apparatus. Among them, we can highlight as more similar to this invention those described in U.S Pat. No. 4,698,507 and especially that described in the U. S Pat. No. 4,282,181. A brief description of these devices and how they differ from the apparatus shown in this invention are added below.

US Pat. No. 4,698,507, describes a device that subjects the sample to expansion and contraction by cooling and heating the test samples to through immersion in liquid at constant temperature and heating in the drying zone by infrared lamp. The entire process occurs in the presence of light (particularly ultraviolet light) that affects the samples, in addition to possible contaminants added to both the test liquid and the drying air.

U. S Pat. No. 4,282,181, describes a device to accelerate the corrosion process by immersing samples in test liquid and subsequent drying in a temperature controlled zone. The change of position between the immersion and drying zones is carried out by pneumatic actuation.

Although the purpose, especially of the device described in the 4,282,181 patent could be the same as that proposed in the present invention, this invention offers a series of differences with respect to the previous ones, which we highlight below.

As a first difference, we can mention that the devices listed above lack their own autonomy time. Unlike these, our invention incorporates an accumulator or rechargeable battery, which depending on its capacity gives the device a time of its own autonomy. This has the following advantages, firstly it allows its use during unwanted cuts of the electricity supply, avoiding the loss of data, especially harmful in long-term tests, thus increasing the Skill of the tests, and secondly it allows the transfer of the machine for conducting tests in situ or in real environments that do not have an electrical connection.

Our invention, unlike the previous ones, precisely controls the immersion position of the samples in the test liquid. For this purpose, the exact position of the car that supports the test samples, as well as the variations in the level of the test liquid, are controlled by a series of devices. This allows precise partial immersion of the samples and control the evaporation effect that would cause unwanted variations in the concentration of the samples, modifying the initial test parameters. On the other hand, our invention differs from the previous ones in that it performs the exhaustive automation of the test, controlling and recording all the necessary parameters of the test liquid (temperature, PH, conductivity, concentration and oxygen level among others) and the air of drying (temperature, speed and relative humidity among others). The control system analyzes these variables as input signals and will activate the relevant outputs, activating the necessary devices to correct possible deviations of said parameters, by means of filling pumps, heating resistors, oxygen pump etc.

Another difference with respect to the two previous patents is that the inventions described in them lack auxiliary systems (filling pumps, multiple tanks), which perform the automatic replacement or renewal of the test solution or the compensation of the level variations due to the evaporation effect, maintaining parameters, such as concentration, PH or the time of preparation of the solution within controlled limits at all times. This is essential for precise long-term tests.

They also differ in relation to the present invention in that they lack systems to oxygenate the test solution and create an alternative movement of the test liquid by agitation or reciprocating movement of the cuvettes. This allows abrasive particles (sand) to be added, which will more accurately simulate the effect of the tides or waves, accelerating the corrosion and deterioration process of the test samples.

This invention differs from that described in the U. S Pat. No. 4,282,181 in which the test zone is isolated and heated, in this way it is possible to register values and simulate in the laboratory a great diversity of different situations or environments. It also allows simulating winds when forced drying is carried out by means of controlled and thermo-regulated air flow of the test specimens when it is in the drying zone.

Another feature of this invention, which does not contemplate the U. S Pat. No. 4,282,181 is the performance of alternate immersion tests of specimens subjected to controlled traction. A final notable difference is the incorporation of a second independent test cart that allows the device's test capacity to be doubled.

DESCRIPTION OF THE INVENTION

The present invention consists of a machine whose objective is to accelerate the corrosion process, subjecting the materials to alternate dives under controlled conditions at all times. It consists of two programmable test carts in a completely independent way, which are responsible for carrying out the vertical guided movement, with a controlled position in the descent for the immersion of the specimens and rise for the drying of the same. The electric drive of these cars is carried out by means of a low-voltage motor-reducer, for whose power a rechargeable battery or accumulator has been incorporated, which, depending on its capacity, will provide the device with its own autonomy time. This has the following advantages, first of all it will allow its use during unwanted cuts in the power supply, avoiding the loss of data, especially harmful in long-term tests, thus increasing the reliability of the tests, and secondly it will allow the transfer of the machine for conducting tests in situ or in real environments that do not have an electrical connection.

The lowering position of the cars is precisely controlled by an electronic device that we will call an encoder. This device translates the number of turns of the motor shaft into linear displacement by a certain ratio. Another device, made of inert material, is immersed in the test liquid to control its level, emitting signals proportional to its variation. After the relevant signal emitted by this device, other auxiliary devices (filling pump) would be activated, distilled water being added to compensate for this evaporation effect, keeping the parameter of the test liquid concentration constant at all times. The joint operation of these devices allows, in the first place, to perform tests with precise partial immersions, in order to be able to study the corrosive attack of the specimens on the edge line or the separation of means, and secondly to control the evaporation effect of the test liquid, especially notable in long-term tests, which would cause undesired variations in the concentration thereof, modifying the initial parameters of the test.

The test liquid will be placed in buckets made of inert material or glass. Depending on the size of the cuvette needed to perform the test, it is possible to perform the test of all the specimens in a common solution, or separate the specimens into different cuvettes, using different solutions in the same programmed test.

This is achieved thanks to the use of stackable cuvettes in another stack that covers the maximum testing capacity of the machine. These cuvettes are positioned by means of a register under the bar that will carry the specimens and that is solidly attached to the carriage that performs the vertical movement.

The test machine is equipped with the necessary sensors to control and record the necessary parameters of the test liquid such as its PH, temperature, oxygen level, concentration, etc. These variables will be analyzed as input signals by the control system. , which will activate the relevant outputs, to activate the necessary devices to correct possible deviations from said parameters, by means of filling pumps, heating resistors, etc.

The machine has also been provided with a multiple tank and a filling pump, to allow the replacement or automatic renewal of the test liquid, depending on the data recorded for the dissolution and the preparation time of the same, which allows replacement when necessary.

Likewise, the machine has components that allow to oxygenate the test solution and create currents by agitation or reciprocating movement of the cuvettes, controlling and recording if the speed of the liquid was necessary, with the intention of simulating the effect of the tides or waves, by adding abrasive particles (sand). Although any method that achieves a correct oxygenation of the solution would be valid, it is proposed for this invention to place the cuvettes on a base that causes a controlled reciprocating movement by means of an eccentric system, which causes a certain swell in the test liquid that will facilitate the exchange gaseous. Simulation of sea waves, with the addition of abrasives (sand) would also help speed up the corrosion process. It is advisable for the oxygenation system to use an external system to the cuvettes or in case of having internal elements to manufacture them in inert plastic materials following the line established in the present invention in terms of materials.

The test machine has a protective housing for each easily removable carriage, which isolates the test atmosphere from the outside environment, where the immersion and drying zone of the specimens is located.

All the components of the machine located inside this atmosphere, under the protective housing, have been designed for manufacturing in inert plastic materials or glass. The rest of the external components are designed in specific aluminum alloys with the appropriate protective coating or treatment. This characteristic of the materials allows the use of a wide range of solutions as a test liquid.

Isolating the test area has allowed the incorporation of a device for air conditioning, in this way it is possible to simulate in the laboratory a great diversity of different situations or environments, for this it has been necessary to incorporate into this atmosphere a series of sensors that allow controlling and record parameters in the air throughout the test such as temperature and relative humidity among others. At the same time, this same device allows for forced drying by means of controlled and thermo-regulated air flow of the test specimens when they are in the drying zone, simulating winds. From these air currents it is possible to control and record their temperature and air speed.

The control system allows you to program each test carriage independently. For this it is necessary to introduce as basic programming parameters; the immersion time, the drying time and the number of cycles that must be performed in the test, with these parameters the system will calculate and display on the screen the end date of the test, the option of entering instead of the number of cycles, the end date in this case the system will calculate and display in screen the number of cycles you will perform in the test. After this data, the system will visualize all possible test options, for its activation or deactivation, and depending on the type and complexity of the required test it will be necessary to enter data such as the height of the specimens in the case of partial dives or the drying air temperature among others.

This system has a data storage device that allows you to download previously programmed data to avoid the need for reprogramming of tests and ensure accurate repetition, allowing identical tests with different materials or coatings.

The machine also allows to place, with the help of some accessories, specimens subjected to controlled traction / compression for their alternate immersion test. Although any design of a tool that causes tensile / compressive loads on the specimen could be valid, as long as it is made of appropriate materials that do not alter the test solution, a simple tool composed of a central nut is proposed in the present invention. and in which threaded at its ends bolts with opposite threads (left and right), which cause according to the number of turns applied in the nut a certain traction in the specimen (see figure 3). The applied load can be measured by strain gauges or by the ratio of the number of turns.

Finally, mention that the invention allows the total automation of the process, data recording to obtain tables in order to avoid dependence on facilities and any personnel once the test is scheduled.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1.- Perspective of the rendering obtained on a simplified virtual model of the device described in this memory. In it you can see the two opposite test carts, the insulation elements of the test atmospheres, the cuvettes or containers to contain the solution, the drive and control mechanisms among others.

FIG.2.- Perspective view of the invention from its right side, including detail of the main components. The figure distinguishes:

1. Support for the vertical movement of the specimens.

2. Mobile carriage that moves through support 1.

3. Worm gear motor with self-locking to prevent free fall of the specimens from their upper position.

4. Vertical position controller, which has been called an encoder.

5. Separator that has a bellows coupled to seal the elements that isolate the test atmosphere.

6. Bar to carry the specimens.

7. Hook to hold test specimens.

8. Test tube.

9. Cuvette of the type that covers the maximum size of the test bar.

10. Cuvette of the type that can be positioned inside the previous one.

11. Device for controlling the liquid level inside the cuvette. 12. Protective housing, to maintain a heated and controlled isolated atmosphere in the test area.

13. Describe the possible incorporation of heating resistors and sensors.

14. Forced drying device.

15. Multiple tanks (amber glass or opaque inert plastic) and auxiliary filling pumps.

16. Base structure of the testing machine.

17. Control panel.

18. Touch screen.

19. Connectors to facilitate the connection of auxiliary devices or sensors that may be necessary.

20. Sensor to measure the speed of the drying wind.

21. to 23. Sensors to control the test atmosphere.

FIG. 3.- Useful for subjecting tensile test specimens. The figure distinguishes:

A. Bolt threaded to the right.

B. Bolt threaded to the left.

MODE OF EMBODIMENT OF THE INVENTION.

On a housing, reflected in figure 2 by reference 16, two sets of elements described in the same figure are arranged with references 1-2-3-4-5-6-7, responsible for carrying out the vertical movement of the specimens, being represented as 1 the support element and 2 the mobile car that slides on the previous device on teflon skates or similar maintenance-free and high corrosion protection. Element 3 represents the worm gear motor with self-locking to prevent free fall of the specimens from their upper position. This motor operates at low voltage and is powered by a battery that allows, depending on its capacity, to provide the device with a period of autonomy to avoid data loss during scheduled tests or the performance of tests in real environments where no The power supply is possible. Element 4 is responsible for controlling the vertical position of the specimens, this element called encoder accurately counts the turns that the motor performs, differentiating the direction. From that data through a conversion it is easy to know the vertical displacement of the specimens for each turn fragment made by the engine. Element 5 is only a separator that has a bellows coupled to seal the elements that isolate the test atmosphere. Element 6 is the bar that will carry the specimens. This element is already located inside the test atmosphere, so this element and all those that meet that condition must be manufactured in a material as inert as possible (glass, Teflon, PVDF). The elements located outside the test atmosphere, such as the support structure indicated in the figure with the number 16, will be manufactured in the appropriate alloys and with the necessary coatings to allow the device to cover the performance of tests over a wide range of solutions. On the device 6, hooks are placed, referenced as 7, preferably made of glass, although any inert material is valid, which will hold the test specimens marked with the number 8 in the figure. These specimens will be samples of materials with or without coatings or real pieces on which the tests will be carried out. The controlled vertical movement of the carriage 2 places the specimens in partial or total immersion in the cuvettes marked with the numbers 9 and 10. Two types of cuvettes are orientatively arranged. A main one, referenced as 9, which covers the maximum size of the test bar and another auxiliary 10, which can be positioned inside the previous one and allows to divide the main cuvette into five, with the intention of testing in the same test different test pieces or solutions. These cuvettes will preferably be made of glass although any other inert material is acceptable. If necessary it is possible to replace these cuvettes with standard laboratory vessels. The cuvettes allow the incorporation of heating and sensor resistors, reflected in the figure as 13, to control the necessary parameters of the test liquid such as temperature or PH among others.

The liquid level is controlled by the device marked with the number 1 1. Once the cuvettes are filled, the zero of this meter is established and any level variation will be detected, activating the appropriate corrective measures. These corrective measures would be as appropriate:

a) The drive of carriage 2 to lower the specimens always keeping the surface of the immersion specimen constant, that is to say an invariable border line between states.

b) Activation of multi-tank filling pumps 15 to keep the volume of test liquid and concentration constant.

The entire test is carried out in an isolated, heated and controlled atmosphere, thanks to the protective housing designated as 12, which delimits the test area. This element is easily removable if it is necessary to carry out tests in situ or with real atmosphere.

When the specimens are located in the immersion or drying position it is possible to activate a forced drying device 14, with which it is possible to create an air stream with controlled parameters such as speed, temperature and humidity between others, by means of a series of sensors indicated in the figure with the numbering 20, 21, 22 and 23.

The control system, which has been represented in the figure by means of a frame 17, has joints that allow its orientation depending on the car to be programmed. On its front it incorporates a programmable touch screen 18, which will facilitate the establishment of the test parameters, among others, the drying and immersion times, the number of cycles, the start or end date, the dissolution renewal time, the selection of the type of drying and the representation of graphs of each one of the parameters controlled in the test. This touch screen could optionally be replaced by a wireless control.

The control system has a series of connectors, represented by reference 19, to facilitate the connection of auxiliary devices or sensors that may be necessary.

The entire test will be governed by a PLC or PC located within table 17, which will receive the necessary inputs from the sensors, encoder or entered by the operator by the screen and will activate a series of outputs depending on the programming performed, which they will start the engines, the filling pumps and the drying device among others.

WAY THAT THE INVENTION IS SUSCEPTIBLE OF INDUSTRIAL APPLICATION

It is not considered necessary to make this description more extensive so that any person skilled in the art understands the scope of the invention and the advantages derived therefrom.

The materials, shape, size and arrangement of the elements will be subject to variation, provided that this does not imply an alteration to the essentiality of the invention. The terms in which this report has been described must always be taken broadly and not limitatively.

Claims

1. Automated machine for performing alternate immersion tests, characterized by:

to. Have autonomy thanks to an accumulator or rechargeable battery.

b. Possess a series of devices, which allow to control both the exact position of the car that supports the test samples, as well as the variations of the level of the test liquid, allowing precise partial immersion of the samples and controlling the evaporation effect that would cause variations not desired concentration of the same, modifying the initial parameters of the test.

C. Carry out the complete automation of the test, controlling and recording all the necessary parameters of the test liquid (temperature, PH, concentration and oxygen level among others) and of the drying air (temperature, speed and relative humidity among others), analyzing these variables as input signals and activating the necessary devices to correct possible deviations from said parameters, by means of filling pumps, heating resistors, oxygen pump etc.

d. Understand auxiliary systems (filling pumps, multiple tanks), which perform the automatic replacement or renewal of the test solution or the compensation of the level variations due to the evaporation effect, maintaining parameters, such as concentration, PH or dissolution preparation time within controlled limits at all times, which allows for accurate long-term tests.

and. Include elements to oxygenate the test solution and create an alternative movement of the test liquid by agitation or reciprocating movement of the cuvettes, which allows abrasive particles (sand) to be added, which will more accurately simulate the effect of the tides or waves accelerating the corrosion and deterioration process of the test samples.

F. Understand elements that allow to simulate winds when performing forced drying by means of controlled and thermo-regulated air flow of the test specimens when it is in the drying zone.

g. Include elements for performing alternate immersion tests of specimens subjected to controlled traction.

h. Incorporate a second test cart that allows to double the test capacity.

i. Be equipped with a data storage device that allows you to download previously programmed data to avoid the need for reprogramming of tests and ensure accurate repetition, allowing identical tests with different materials or coatings.

Automated machine for performing alternate immersion tests, comprising:

to. A structure (16) to which at least two housings (12) are attached for the establishment of a heated and controlled insulated atmosphere, which delimit the test area, easily removable to allow the realization of tests in situ or with real atmosphere, within which a forced drying device (14) is placed, by means of which it is possible to create a controlled and thermoregulated air flow, by means of a series of sensors (20-23).

b. A box, called a control system (17), inside which is a PLC, or PC for the control of all the elements of the test machine, attached to the housing by means of a joint that allows its orientation depending on the carriage to be programmed, whose front is a touch screen (18) that will facilitate the establishment of the test parameters, and on whose side it has a series of connectors (19), to facilitate the connection of auxiliary devices or sensors that may be necessary.

C. At least two devices for automated vertical movement of the specimens, each consisting of a support element (1), through which a mobile carriage (2) travels, thanks to an endless screw motor with self-locking (3), which operates at low voltage and is powered by a battery, which is complemented by an element called encoder (4), responsible for controlling the vertical position of the specimens (8), which will be held by hooks (7), in turn subject to a rod holder (6).

d. At least two cuvettes, in which it incorporates a device for the control of the level of liquid that they contain (1 1), inside which heating resistors and sensors (13) can be incorporated, to control the necessary parameters of the liquid of test such as temperature or PH among others, and these can be of two types:

i. Those covering the maximum size of the test bar (9)

ii. Those that can be positioned inside the previous one and allows the main cuvette to be divided into five, with the intention of testing different test pieces or solutions in the same test (10).

and. Auxiliary systems composed of:

i. Filling pumps and multiple tanks to perform the automatic replacement or renewal of the test solution, or the compensation of the level variations due to the evaporation effect, keeping the concentration, pH, or dissolution time parameters within limits controlled at all times. ii. A system to oxygenate the test solution and create an alternative movement of the test liquid by agitation or reciprocating movement of the cuvettes, controlling and recording if the velocity of the liquid was necessary, with the intention of simulating the effect of the tides or waves , by adding abrasive particles.

iii. A system that allows alternate immersion of specimens subjected to controlled traction.