ES2366844A1 - Thermal shock absorber. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

The thermal shock absorber consists of a tool, inside which a stable and uniform temperature zone is achieved, for use in verifications or calibrations carried out in situ. It is constituted by a core of great thermal conductivity, and an outer capsule of low thermal conductivity. The core is a cylinder, in whose upper base are the holes to insert the probes to be compared. The side walls are composed of fins evenly distributed. The core envelope is designed to attenuate the temperature oscillations within the chamber due to the regulation cycles. The capsule consists of two pieces, the body and the lid. The exterior geometry of the body is a cube and inside it has a cylindrical hollow of dimensions equal to the core. The lid has a cube shape, in the central part it has holes to pass the cables of the probes. (Machine-translation by Google Translate, not legally binding)

Description

Thermal shock absorber

Object of the invention

The present invention relates to a thermal absorber, consisting of a block inside which a stable and uniform temperature zone is achieved, which will be used in the verifications and calibrations of temperature recorders and thermometers that are carried out in situ .

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Background in the state of the art

In order to perform the temperature test in the verification of temperature recorders and thermometers according to Order ITC 3701/2006 regulating the meteorological control of the Status of temperature recorders and thermometers for the transport, storage, distribution and control of products to temperature controlled, it is necessary to create an area where the temperature is uniform and stable, and is within a range of ± 5ºC of the temperature that the equipment to verify works habitually.

With the present invention it is intended to provide a solution to the current problem posed in the temperature test in the verification of temperature recorders and thermometers in situ , since the tools that currently exist in the market to create homogeneity and stability in temperature do not they meet the needs of laboratories for meteorological control, both for the time required in the test and for the difficulty in handling by bulky ones.

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Explanation of the invention.

An area or medium with uniform temperature we can describe as the one in which the temperature takes the same value in the entire domain determined by the zone or medium. Be You can say that the temperature is homogeneous throughout the domain.

Thermal stability in an area or medium comes defined by the ability of this medium to maintain the constant temperature at a value regardless of the value that Take the temperature outside of this.

The thermal conductivity of the medium or zone goes very significantly influence the characterization of a medium in terms of uniformity and stability, since a medium with good thermal uniformity requires high thermal conductivity while that to keep the temperature stable requires that the thermal conductivity be low.

For the purpose of this invention, half isothermal we consider as a medium where a temperature zone is created controlled with respect to stability and uniformity.

Isothermal media, among others, can be:

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Bathrooms of liquid: various liquids are used such as distilled water, alcohol, oils, salts, or the like, and, depending on the temperature to which it is necessary to perform the calibration, they are circulated and stir to create a uniform temperature zone in the margin from -120ºC to 500ºC.

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Ovens of resistances: they use heating resistances based on alloys of different materials to heat an internal enclosure. They work in the range of 350ºC to 1100ºC.

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Climatic chambers: normally used as half the air The working temperature range is very varied.

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Isothermal media present as main features:

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Stability and uniformity.

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Margin of use

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Compatible fluids (in bathrooms), with viscosity, thermal conductivity and expansion characteristics, specific heat, etc.

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Heating elements and refrigerators

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Control parameters.

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Probe of control.

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Configuration for calibration of probes

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There are different thermometric fluids for thermostated baths depending on the range of use, the Stability and homogeneity These might be:

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Ethanol / methanol (-100.0) ° C.

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Ethylene glycol / water (-30.95) ° C.

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Silicone oils (50,300) ºC.

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You go out molten (300,550) ° C.

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Air (dry ovens and climatic chambers).

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The isothermal means found currently in the market they create uniformity through a flow in movement, either gas or liquid. In this way they ensure that in all points where the fluid is consigned have the same temperature To create stability, these media use insulators and technical means for temperature regulation interior, such as resistors and evaporators.

To perform the temperature test in periodic verification or after repair of registrars of temperature and thermometers for measuring the temperature of the air according to the aforementioned Order ITC / 3701 we will have an uncertainty maximum verification of ± 0.5ºC for class 1 and ± 1 ° C for class 2 equipment.

If the verification is done in the laboratory these uncertainties are not complicated to achieve, since in this one you have the necessary facilities to create stability and uniformity, necessary to meet the established uncertainty in to the Order. In the laboratories of Temperature there are bathrooms at controlled temperature, dry ovens, climatic chamber, etc. For to be able to carry out the test in these fixed installations it is necessary disassemble the equipment installed in the truck or cold store to be able to send it to the laboratory and reinstall it later in its original location This procedure has the problem that it does not seem convenient to have to disassemble the equipment with its probes of their usual location, to perform the tests of verification, both for cost, since some probes are installed inside the wall of the boxes of the cameras, as if in its subsequent installation you can commit Some assembly defect.

Taking into account the above, it is convenient that verifications be made on site . In this case, the verification will be carried out taking into account the working conditions in which the measuring equipment is usually found, which means that the facilities must be functioning under those conditions.

The problem we face is the variation of temperature in the form of cycles that exist inside the cameras where the probes of the equipment to be verified are located, due to the refrigeration cycles of the cameras themselves.

The cycles of the cameras intended for food transport and storage are around an amplitude of 4 ° C and a period of 15 minutes. It has to be said that these cycles are caused by the regulation of the camera itself since it is continuously transferring heat abroad to through losses due to walls, enclosures, etc. She's lost of heat causes the chamber air temperature to rise. By therefore, to keep food at a stable temperature and controlled, the camera's own regulation will lower the temperature when it reaches a certain value by means of Timely mechanisms, usually evaporators. This action of regulation will bring the chamber air temperature below of the setpoint temperature up to a value set by the camera regulation.

This regulation is the cause of the cycles of temperature inside the cold room. For keep food at setpoint temperature so stable, the cameras regulate with small temperature amplitudes, which entails short periods of time.

The invention that we are developing in this exhibition aims to solve the problem previously, and, for the purposes of this report, we will define a medium isothermal where the temperature is uniform and close to the average chamber temperature, and stable, attenuating the cycle of existing temperature in the facilities where the probe works of the equipment to verify.

Thus, the proposed invention, called "thermal shock absorber", is a block inside which we get a stable and uniform temperature zone that will be used in the checks carried out in situ .

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The thermal shock absorber is composed of a high thermal conductivity core, and an outer capsule Composed of a material with low thermal conductivity. The function of the core is to achieve a good thermal coupling between the standard probe and the probe to verify, that is, that the temperature is homogeneous in said core, in order to achieve a good thermal coupling between probes, in short, good uniformity.

The geometry and dimensions will be determined for the desired stability in the center of the core, therefore, This will also depend on the outer capsule.

As for core stability, it will be that that allows a variation of temperature in this one inferior to a certain interval This interval will be defined by the maximum acceptable uncertainty to perform the verification or calibration.

We will define the material of the capsule envelope, since this one, next to the capsule design will influence significantly in the core dimensions.

The manufacturing material of the capsule envelope will be the one whose fundamental characteristic is that of a Low thermal conductivity

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Description of the drawings

To complement the description that is being performing and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical realization of it, is accompanied as an integral part of said description, a set of drawings where with character Illustrative and not limiting, the following has been represented:

Figure 1.- Shows plan, profile and a view in perspective of the nucleus.

Figure 2.- Shows plan, profile and a view in perspective of the capsule.

Figure 3.- Shows plan, profile and a view in perspective of the cover.

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In these figures, the numbered elements are relate below:

one.

Core holes.

2.

Fins

3.

Hole cylindrical body.

Four.

Cover holes.

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Preferred Embodiment Example

By way of example of preferred embodiment of Thermal shock absorber, this can be carried out from the following main bodies or parts until the set:

The "thermal shock absorber" is composed by a core of great thermal conductivity, and an outer capsule Composed of a material with low thermal conductivity.

The function of the nucleus is to get a good thermal coupling between the standard probe and the probe to be verified, is say, that the temperature is uniform in said core, so get a good thermal coupling between the probes, in short, good uniformity

As for geometry and core dimensions, It is a cylinder whose upper base is the holes (1) to insert the probes to compare, the side walls are composed of fins (2) evenly distributed in order facilitate heat transfer and thus reduce the time of wait for the cylinder to take the temperature of the chamber.

The core or capsule shell is designed to attenuate temperature fluctuations inside the chamber due to regulation cycles. The capsule consists of two pieces, the body and the cover.

The outer geometry of the body is a cube. In the interior has a cylindrical recess (3) of dimensions equal to nucleus. The lid also has a cube shape, in the central part It has holes (4) to pass the cables of the probes.

It is not considered necessary to extend this description so that any subject matter expert understands the scope of the invention and the advantages derived therefrom. The technology used and its applications will be susceptible to variation as long as this does not involve an alteration in the Essentiality of the invention.

Claims (2)

1. Thermal shock absorber characterized by being constituted from a core and an outer capsule, in which the core is a cylinder whose upper base includes holes for inserting the probes to be compared, and the side walls are composed of fins that They are evenly distributed. 2. Thermal shock absorber according to claim 1, characterized in that the shell of the core or capsule is designed to attenuate the temperature fluctuations within the chamber due to the regulation cycles, said two-piece capsule, the body and the lid. The outer geometry of the body is a cube, inside which it has a cylindrical hollow of dimensions equal to the core. The cover also has a cube shape, and in the central part it has holes to pass the probe cables.