MXPA99008497A - System for weighing and refilling domestic canisters with lp gas - Google Patents

Abstract

La presente invención se refiere a un sistema para pesar y recargar tanques cilíndricos de uso doméstico con gas Lp que consiste en una báscula para pesar tanques cilíndricos, una plataforma donde se colocan los tanques, dicha plataforma es de placa de acero antirresbalante, cuenta con tres vigas soldadas a la placa en forma de"Y". Un conjunto de cables lleva información del peso del tanque de la báscula a una computadora especialmente diseñada para pesar tanques, dicha computadora registra e1 peso del tanque vacío, el cual se llena con gas LP para uso doméstico que proviene de un tanque de almacenamiento, a través de una manguera conectada a la computadora. Los cables se encuentran detrás de un poste vertical situado atrás del tanque, para que no ejerzan ningún tipo de fuerza sobre el tanque en el momento de la operación. La plataforma tiene soldadas unas vigas, las cuales presentan unos dispositivos que comprenden tornillos y unas piezas de material polimérico resistente, dichas piezas se apoyan sobre unas cazoletas que se encuentran fijadas a unos largueros que forman una estructura rectangular, ubicada abajo de la plataforma, dicha estructura es elúnico sostén de la plataforma y por ende del tanque cuando se realiza la operación de pesada y llenado del tanque. Todo el sistema tiene como objetivo que la pesada y llenado del tanque sea exacto y preciso conforme a la regulación mexicana.

Description

SYSTEM FOR WEIGHING AND RECHARGING DOMESTIC CILINDRICAL TANKS WITH LP GAS TECHNICAL FIELD OF THE INVENTION: The present invention relates to cylindrical tanks for domestic use, particularly with systems for recharging said tanks with LP gas for domestic use.

BACKGROUND: Up to now the filling of cylindrical tanks for domestic use with liquefied petroleum gas (LP gas) is not done with precision; mainly because the tank that is weighed is supported on the base of the scale, which is irregular so the tank "dances" from one side to another while being filled with LP gas, which causes the measurement of the final weight is not exact, the same effect results from the irregularity of the base of the tank, which is due to its construction and mainly to the rough treatment that has been given to the tank, for which the base of the tank is not even and this has an effect on the fact that the final measurement is not exact, it also influences the hose through which the tank is filled with LP gas. The hose, often in the traditional system to fill the cylinders with LP gas, influences the final measurement of the weight, either by the angle, inclination or position of the hose that exerts a force on the tank while it is full . Even more evident is the influence of the aforementioned hose when it is literally recharged on the tank, which is common in the current system for filling cylindrical tanks for domestic use with liquefied petroleum gas (LP gas).

Regarding gas tank filling systems, the authorities have recently implemented stricter standards and have been more demanding in their compliance. At the same time, the user public demand a better service every time, which together with a more competitive market, has resulted in the need to modernize and update the system of filling of domestic use cylindrical tanks for LP gas, so that in addition to fulfilling With the demands of the authorities, the user is provided with a service of quality and fair price.

Currently the LP gas cylinders have been filled with a mechanical arm scale called Roman, connected to a switch that has evolved as follows: 1) Originally mercury was used 2) Later mechanical type 3) Late optical type In the traditional system the switch cuts the current of a solenoid valve in the filling manifold and the procedure is as follows: 1) An empty tank is placed on the platform of the scale, the indicator of the weight of the scale is at the bottom of it. 2) The required final weight is calibrated, including the weight of the tank, which means that the final weight is the sum of the weight of the tank and the gas, this leads to an error as will be explained later.

The traditional system has the following disadvantages: 1) It requires continuous maintenance in the mechanical part to maintain accuracy, this means that in a certain time the scale can not be used, it also results in a higher operating cost. 2) The base of the scale has a size of 60 x 70 cm, which causes measurement problems, particularly if the cylinder is placed near the edges (eccentricity of the scale), this means that the more separated from the center of the If the scale is the cylinder, the greater the degree of error in the measurement. 3) Due to the working method of the mechanical mechanism, this causes the roll of the cylinder while the tank is filled with gas, which causes oscillations in the measurement. 4) The state of the switch influences the measurement. The switch is a piece that requires continuous maintenance and intermittent wear or lack of timely maintenance leads to erroneous readings.

) The traditional system does not have a "cradle" that prevents the scale from moving from its place, the cradle is a piece of cast steel that surrounds the base of the scale and that keeps it level.

The uncertainty or degree of error in the calculations is an important parameter to consider if the measurements made are reliable, for this calculation is considered first half of the smallest measure of the scale, this is due to the ability of the human eye to disern where the midpoint is located between two lines or near points. This calculation arises from each measurement made that is added to the subsequent uncertainty measurements, so that it is increasing, is independent of the measurement of physical properties such as weight, mass, speed, etc.

For example, suppose that the empty cylindrical tank weighs 15 kg, has capacity for 30 kg of gas and is weighed with a scale on whose scale the smallest division is 1 g, the uncertainty is 0.5 g. If to consider that the tank has been filled to its maximum capacity, the weight of the tank and the gas must be added (as in the traditional technique), when the scale indicates 45 Kg, the tank will be considered as filled with the maximum gas capacity, for which it has dragged an uncertainty of 1.0 g with only two measurements. Considering that other factors like the hose, the unevenness of the base of the scale and the base of the tank, the bailoteo of the tank during the filling operation, the eccentricity of the scale and that in occasions the operator sustains also influence in the measurement the tank to prevent it from moving and unintentionally, applies a force on the tank that alters the measurement.

In practice, a difference of around 10 Kg of uncertainty has been found between the measurement of a tank filled with the traditional technique and the same tank filled with the technique of the present invention. It is important to remember that the smaller the measure of uncertainty, the more reliable the measurement will be.

To eliminate the aforementioned drawbacks, a filling monitoring system called Troya was installed by the company Pegasus Control, S.A. of C.V. This system consists of a small computer connected to the base of the scale that records exactly the weight of the tank, both empty and full.

The filling monitoring system transmits to the Roman the weight that is on the platform through a load cell of type "s" placed on the rod that goes to the "swings", said system electronically drives the solenoid, eliminating the effect of the mercury switch in the measurement.

Another drawback of the traditional technique is caused by the position of the hose with which the gas is supplied to the tank, said hose influences the measurement of the weight of the tank, either by the inclination with respect to the tank, the tension or that it is recharged over the tank during the filling operation.

The filling of cylindrical tanks for domestic use with liquefied petroleum gas (LP gas) is done by measuring the weight of said tank; first weigh empty, then the type of tank is recognized and finally the tank is filled with LP gas up to the "official weight" of said tank in kilograms of LP gas.

The present invention is directed to the following objectives: An object of the present invention is to provide a system for accurately filling the amount of gas with which a cylindrical household tank for LP gas is filled.

An object of the present invention is to provide a system for accurately weighing an empty cylindrical tank for domestic use for LP gas.

An object of the present invention is to provide a system for accurately weighing a cylindrical household tank for LP gas that has been filled with said gas.

An object of the present invention is to provide a system for obtaining, by computerized means, the amount of gas with which a cylindrical tank for domestic use for LP gas is recharged.

Other objects will be apparent to the person skilled in the art in the light of the following description and together with the accompanying photographs.

BRIEF DESCRIPTION OF THE DRAWINGS: Figure 1: It is a photograph of the system as a whole, seen at an angle, which includes a cylindrical tank for LP gas for domestic use resting on the platform, disconnected from the hose that supplies the gas to the tank and in position to carry out the weighing .

Figure 2: It is a photograph of the system as a whole, seen at an angle, showing all the external parts of the system without the cylindrical tank for LP gas for domestic use to observe the platform.

Figure 3: It is a photograph from another angle of photograph 2 with the platform removed.

Figure 4: It is a photograph that is observed, from behind the post, the hose by which gas is supplied to the tank, in its original position of swan neck and held by the clamp to keep the hose firm.

Figure 5: It is a photograph from top to bottom in which the "Y" of the platform is observed.

Figure 6: It is a photograph showing an approximation of the well below the platform, where the structure of the lower load cell is observed.

Figure 7: It is a photograph that shows from top to bottom an approximation of the well that is under the platform, where the structure of the lower load cell is observed.

Figure 8: It is a photograph that shows from an angle close to the floor an approximation of the well that is under the platform, where a corner of the lower load cell is observed.

Figure 9: It is a photograph that shows from an angle close to the floor an approximation of the well that is under the platform, where one of the two points where the fixing screws that give greater stability to the platform are located.

Figure 10: It is a photograph that shows an approach of one side of the lower part of the platform.

DETAILED DESCRIPTION OF THE INVENTION: In FIGURE 1, the complete system is observed with a cylindrical tank for LP gas for domestic use (1) supported on the platform (2), behind the tank and attached to the platform is a pole (3) located vertically, the which has an inclined beam that joins the post (3) from a lower side thereof with the platform (2) so that said post (3) has greater support.

The gas pipe (6) is connected with a hose (4) after the stop valve of the gas pipe (5), said hose (4) is attached to the pole (3) remaining in the shape of a gooseneck, so that it does not touch the tank (1) at any time during the operation, nor does it exert any pressure on it.

The filling monitoring system (8) called Troy of the company Pegasus, S.A. de C.V., is a computer that is connected to the gas pipe and after the connection with the hose (4). The computer (8) gives the exact reading of the weight in kilograms of the tank (1), both empty and full, when the tank is full, the measurement recorded in the Troy (8) is the weight of the cylinder that is found filled with gas, since tare the hose eliminates the weight of it.

Behind the post (3) is the data cable duct (16), by which the computer (8) receives the data of the weight of the tank (1) and of the gas that is supplied.

Adjacent to two sides of the platform (2) and in the shape of "L" is the cradle (17), it is a non-skid cast steel sheet of approximately 3.13 millimeters (2/16 inch) to approximately 4.69 millimeters (3 / 16 inch) that has the purpose of stabilizing and leveling the platform (2) and to avoid wobbling.

In FIGURE 2, the complete system is observed without the cylindrical tank for LP gas for domestic use (1), to show the platform (2), which is smaller than the one traditionally used and the post (3) is fully appreciated and attached to the platform (2).

In FIGURE 3, the complete system is observed where the platform (2) is separated from its place to expose the well (9), which will be explained in detail later.

When moving the platform, the position of the hose (4) does not change and therefore the tension in said hose (4) does not increase, which guarantees that when the platform (2) is put in place, the hose (4) will not influence the final or initial measurement of the weight of the tank (1).

In FIGURE 4, it is observed, from behind the post (3), the hose (4), by which the gas is supplied to the tank (1), in its swan neck position, fixed to said post (3) by means of the clamp (15) located behind the post, which guarantees that no movement in the part of the front of the post (3) will move the hose (4) that supplies the gas to the tank (1).

In FIGURE 5, the platform (2) is observed in its position to support the tank (1), where a "Y" (10) is shown, which is formed by short sections of beams welded to the base of the scale so that it forms each arm of the "Y" (10), with a separation of approximately 120 ° between one arm and another. The "Y" (10) has the purpose of providing support to the tank (1), and to prevent it from dancing while the gas is being supplied to the tank (1), which guarantees that the reading of the computer will not be affected ( 8). The fact that the lines made by short sections of beams welded to the base of the scale so that they form each arm of the "Y" (10), with a separation of approximately 120 ° in the short welded beams have the shape of "Y" (10), has the advantage of providing greater stability to the tank at all times of the operation. The arms of the "Y" (10) have the advantage of providing sufficient support, either to a small tank or a large one, which would not happen if the welding lines, described here, were parallel, in the form of a circle, a triangle or any other figure. If the base of the tank (1) is deformed, simply rotate the tank (1), already placed on the platform (2), until it is the point of greatest stability for the tank (1) with the base deformed. At a right angle, a cast steel sheet of approximately 4.69 mm (3/16") called a cradle (17) is located at the side and the rear side of the platform (2).

In FIGURE 6, an approach to the well (9) is observed with the platform (2) removed, in which the metallic angular profiles of 38 millimeters (11/2 polished) (12) attached to the platform (2) are appreciated. , where the fixing devices or supports (11) of the platform are located. The profiles (12) describe an angle of 90 °, they are attached to the platform (2) by means of screws and nuts. The supports (11) are screws with nuts screwed to the angular profiles (12), said supports are conventional, so they are not described in detail, but consist of an inverted screw screwed to the angular profile (12), at the far end of the angular profile (12) is a circular piece with a piece of polymeric material (for example polyurethane), it is observed within the well (9) the structure of the lower load cell, whose structure is a rectangle formed by quarter beams of support, two short and two long that form a right angle between a short beam and a long beam.

In FIGURE 7, the well is observed from above and the fixation devices or cups (14) found on the support beams (13) of the platform (2), which are firmly welded to the metal base, can be seen. or cradle (17) located next to the platform (2). The support beams (13) are the true support of the platform (2) and the entire system. The polymeric material of the support points (11) of the platform rests on the cups (14).

In FIGURE 8, a corner of the structure of the lower load cell is observed, the platform (2) has four vertical support points, located at the corners of the lower load cell, which is formed from the beams of support of the platform (13), whereby it is easy to level the platform (2) by means of the nuts and screws of the support points (11) of the platform.

FIGURE 9 shows part of the well (9) and the structure of the lower load cell, where two fixing screws (18) are located. One of which emerges from one of the long beams of the structure of the lower load cell and the other from one of the short beams (not shown in the figure, only that of the long beam is indicated). Both screws leave the stringers adjacent to the anti-slip sheet of the cradle (17) and horizontally they go to the metal angles (12) attached to the platform. These screws have the purpose of preventing the cradle from moving and destabilizing the measurement.

In FIGURE 10, the platform (2) is seen tilted to show a side and the bottom of said platform (2), which shows that the only support platform (2) are the apollo points ( 11) of the platform on the cups (14, are not observed in this figure.

Advantages of the present invention with respect to the traditional filling system of domestic LP gas cylindrical tanks: 1) The continuous maintenance of the mechanical parts, since all the mechanics is eliminated with the introduction of a lower load cell. 2) The problem of eccentricity was eliminated by reducing the size of the platform. 3) The wobble was eliminated with the anti-slip sheet, the "Y" at the base of the scale, the use of the cradle, the fixing of the hose and the screws that hold the platform underneath. 4) The uncertainty in the measurement of the weight was eliminated with a scale designed to weigh cylindrical tanks, which eliminates the use of the Roman.

) A post was installed that eliminates the influence of the weight of the hose, which is controlled at a known weight and tared with the platform so that it does not interfere with the measurement.

While the preferred embodiment of the invention has been described and illustrated, we know that several changes can be made without departing from the spirit and scope of the invention.

The preferred embodiment of the invention of which property or privilege is claimed is claimed as follows:

Claims (10)

CLAIMS:

1. - System for weighing and recharging cylindrical tanks for domestic use with Lp gas characterized by comprising: A) A scale for weighing cylindrical tanks for domestic use. B) An anti-slip cast steel sheet with a thickness of approximately 3.13 millimeters (2/16 inch) to approximately 4.69 millimeters (3/16 inch) arranged in "L" adjacent to the base of the scale. C) A post attached to the base of the balance located vertically, which has an inclined beam that joins the pole from a bottom side of this with the platform so that the pole has more support. D) A hose that comes from the general gas pipeline and by which gas is supplied to the tank, said hose is attached to the pole being in the shape of a gooseneck, so that it does not touch the tank at any time during the operation. , does not exert any pressure on it. E) A filling monitoring system. F) A data cable duct through which the computer receives data on the weight of the tank and the gas that is supplied. G) The platform or base of the scale, where a "Y" is shown, which is formed by short sections of beams welded to the base of the scale so that each arm of the "Y" forms with a separation of 120 ° between one arm and another. H) Below the base or platform of the scale is a well where the lower load cell is housed, whose structure is a rectangle formed by four support beams, two short and two long that form a right angle between a short beam and another long one. I) Fixing devices or cups that are on the support beams of the platform, which are firmly welded to the metal base that surrounds the platform. J) The structure of the lower load cell, located under the platform, has four vertical support points, located at the corners of the lower load cell, which is made up of the support beams of the platform, the Polymeric material of the support points of the platform rests on the cups. K) Two fixing screws are located in the structure of the lower load cell. One of which emerges from one of the long beams of the structure of the lower load cell and the other from one of the short beams. Both screws exit from the side rails adjacent to the crib's anti-skid sheet and horizontally they go to the metal angles attached to the platform.

2- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 1, characterized in that the non-slip cast steel sheet, called the cradle, is approximately 3.13 millimeters (2/16 of an inch) to approximately 4.69. millimeters (3/16 of an inch), has the purpose of stabilizing and leveling the platform and avoid wobbling, it is located adjacent to two sides of the platform and in the form of "L".

3- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 1, characterized in that the computer is connected to the gas pipe and after the connection with the hose.

4- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 3, characterized in that the computer gives the exact reading of the weight in kilograms of the tank, both empty and full, when the tank is full , the measure that is recorded in the Troy is the weight of the gas that is destroyed by the cylinder, since the tare weight of the tank is eliminated.

5- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 1, characterized in that behind the pole is the data cable duct, through which the computer receives the weight data of the tank and the gas that is released.

6- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 1, characterized in that the metallic angular profiles of 38 millimeters (11/2 inches) are joined to the platform, in said metallic angular profiles there are the fixation devices or supports of the platform.

7- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 6, characterized in that the angular metal profiles form an angle of 90 °, they are attached to the platform by means of screws and nuts.

8- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 7, characterized in that the supports are screws with nuts screwed to the angular profiles, consist of an inverted screw screwed to the angular profile, in which At the far end of the angular profile there is a circular piece with a piece of polymeric material (for example polyurethane).

9- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 5, characterized in that the cables through which the computer receives the data of the weight of the tank, from the scale, are located within a duct joined to the vertical post located behind the tank, so that they do not present tension and do not exert force on said tank at the time of weighing and filling.

10- System for weighing and recharging cylindrical tanks for domestic use with Lp gas, according to clause 7, characterized in that in the structure of the lower load cell, two fixing screws are located. One of which emerges from one of the long beams of the structure of the lower load cell and the other from one of the short beams. Both screws exit from the side rails adjacent to the crib's anti-skid sheet and horizontally they go to the metal angles attached to the platform. These screws have the purpose of preventing the cradle from moving and destabilizing the measurement.