MXPA01008508A - A low thermal stress case connect link for a straight tube coriolis flowmeter - Google Patents

Abstract

Case connect links of a straight tube Coriolis flowmeter couple a balance bar/flow tube junction to the flowmeter case. Each case connect link has at least one out of plane bend in its surface to allow the case connect link to expand/contract in response to temperature differentials between the internal elements of the flowmeter. The expansion/contraction permitted by the out of plane bend prevents structural damage to the case connect link as well as to the flowmeter elements to which it is connected.

Description

CONNECTION ROD FOR THUNDERSTORM LOW CASE FOR A CORIOLIS FLOW METER WITH STRAIGHT TUBE FIELD OF THE INVENTION This invention relates to a straight tube Coriolis flow meter and in particular to a connecting rod for the box or case that provides a reduced heat stress for a straight tube Coriolis flow meter.

PROBLEM It is already known that the internal elements in a straight tube Coriolis flow meter are subjected to stress when the flow meter is subjected to conditions in which temperature differences develop within a part or between various parts of the meter. flow. These differences in temperature can cause an expansion / contraction part to be coupled. For example, the expansion / contraction of the flow tube in a different amount than the expansion / contraction of the flow meter elements to which the flow tube is connected, can REF: 132088 to tension the flow tube beyond the limits of its permissible deformation. Accordingly, if the flow tube expands an excessive amount with respect to the box or case and its extreme projections, the flow tube may suffer a warping. On the contrary, if the flow tube contracts an excessive amount with respect to the extreme projections of the box or case, it can develop ruptures or tears or it can flex and be permanently deformed. Attempts have been made to minimize the problems associated with thermal shrinkage / expansion in the flow tubes of the Coriolis meters. A solution uses materials that have similar expansion coefficients so that the expansion / contraction between all the elements is uniform. Another solution uses a pre-stressed flow tube so that it can change in its length a modest amount without excessive internal stresses. Another solution uses bellows near the ends of the flow tube so that the flow tube can change in its length without altering the tension. Another solution provides elbows or bends in the flow tube so that changes in length are absorbed by the segment of the flow tube containing the elbow or bend. Another solution is to slide-fit the ends of the flow tube to the ends of the box or case. These solutions reduce the problems associated with the thermally induced length changes of the flow tube with respect to the elements of the flow meter to which the flow tube is connected. However, these solutions have not solved the problems of thermally induced diameter changes in the flow tube. These diameter changes cause stress in other elements of the Coriolis flow meter that include those that couple the flowmeter case or casing to the vibrating elements of the flow meter including the flow tube and its surrounding compensation bar. It is already known to use rods or connecting links for a box or case, for coupling the vibrating end nodes of a flow tube to the box or casing of the flow tube. This is done to prevent extreme nodes from vibrating excessively during unbalanced conditions. Excessive vibration of the end nodes is undesirable because it causes changes in the flow sensitivity of the meter. Undesirable vibratory deflections in the reinforcement bar (where the end nodes reside) is prevented by coupling the reinforcement bar to the link or connecting rod oriented transversely both with respect to the vibratory direction of the flow tube and the axial direction of the tube. flow. One end of the link or connecting rod for the box or case is connected to the inner wall of the box or case; the other end of the link or connecting rod for the box or case is connected to the reinforcing bar or the end of the reinforcing bar. The link or connecting rod for the box or case of the prior art is a leaf spring element, flat, relatively thin, which is flexible in a twisting or twisting mode and does not inhibit the rotation of the flow tube and the compensation bar at the desired vibration nodes. However, the link or connecting rod for the box or case prevents the end nodes from being transposed in the direction of activation or impulse under the unbalance conditions. Each link or rod prevents its respective end node from being transposed by the coupling rigidly of the end node to the relatively large mass of the box or case. The link or connecting rod for the box or case thereby improves the accuracy of the meter in the measurement of the materials of higher density or lower than the nominal. A flow meter having a link or connecting rod for the box or case of this type is shown in patent EP-0759542A1, published on February 26, 1997. U.S. No. 5,850,039 discloses a Coriolis flow meter wherein the flexible membranes coupled to a flow tube and a box or case flex in response to the thermal changes of the flow tube and the case or case to minimize axial stress on the flow tube. In Coriolis flow meters of the straight tube type that use the links or connecting rods for the box or case, the flow tube extends over the entire length of the flow meter with the ends of the flow tube that they are connected to the projections on the end of the box or case. The compensation bar is typically parallel to the flow tube and can be either a separate parallel element or a cylindrical element surrounding the flow tube. The compensation bar is shorter in length than the flow tube so that each end of the compensation bar is connected by a reinforcing bar to a near end portion of the flow tube. The reinforcing bar typically is a relatively short circular element extending transversely from the end of the compensation bar to the location of the near end of the flow tube. The vibration node of the reinforcement bar / flow tube combination normally lies in the reinforcement bar during the vibrational equilibrium conditions. Without the links or connecting rods for the box or case, when the materials of a nominal density relatively higher or relatively lower than the normal density flow into the flow tube, the vibrating node can be moved from the reinforcing bar axially towards inside, towards the center of the flow tube for a heavy material or axially outward, towards the end protrusions for relatively light materials. These vibrational imbalance conditions cause the reinforcing bar to vibrate as a part of the vibratory system and, in doing so, shorten or prolong the vibratory length of the flow tube to which it is connected. This change in the length of the active portion of the flow tube is undesirable since it produces undesirable changes in the flow sensitivity of the flow meter by altering the distance between the nodes and the devices that detect mechanical movement. The use of links or connecting rods for the box or case placed transversely with respect to the direction of activation or impulse of the tube of flow and the axis of the tube, force to the nodes of vibration of the combination of tube of flow / bar Reinforcement / compensation bar to stay in the reinforcement bar. The use of links or connecting rods for the box or case achieves the goal of minimizing the undesirable vibrations of the compensation bar regions within the flow meter during the conditions of the vibrational imbalance associated with the processing of the heavier materials or excessively light. Although the use of links or connecting rods for the box or case minimizes undesirable vibrations in straight tube Colioris flow meters, the links or connecting rods for the box or case are subjected to structural damage when the temperature of the material in the flow tube differs from the temperature of the box or case. Under such conditions, the end of the reinforcing bar of the links or connecting rods for the box or case may move in the radial direction at a different distance than the end of the box or case due to different amounts of the contraction / expansion. thermal of the diameter of the flow tube. This leads to the links or connecting rods for the box or case being subjected to stress or compressive loads that can strain and damage the elements to which they are connected. Therefore, it can be observed that it is a problem to minimize the structural damage to these links or connecting rods for the box or case that result from the different amounts of thermal contractions / expansions of the box or case and the region of the bar. compensation. It can be seen from the above that one aspect of the invention is a Coriolis flow meter comprising: a flow tube; a compensation bar oriented substantially parallel to the longitudinal axis of the flow tube; first and second ends of the compensation bar coupled to the opposite end end portions of the flow tube; a box or case containing the compensation bar and the flow tube; link means or connecting rod for the box or case that attach the first and second ends of the compensation bar to an internal wall of the box or case; at least one bend or bend out of plane in the connecting means or connecting rod for the box or case, to make possible the changes in the effective dimension of the links or connecting rods for the box or case in response to the differences between the flow tube and the box or case.

Another aspect is that the flow tube is substantially straight. Another aspect is that the compensation bar is substantially cylindrical and surrounds the flow tube. Another aspect is that the box or case is cylindrical and is oriented substantially parallel with respect to a longitudinal axis of the flow tube. Another aspect is that the connecting means or connecting rod for the box or case are elongated and substantially flat and have a longitudinal axis oriented substantially perpendicular to the longitudinal axis of the flow tube and the compensation bar; the connecting means or connecting rod for the elongated box or case coupling the first and second ends of the compensation bar to an internal wall of the box or case; and at least one elbow or bend out of plane in the elongated link means or rods which makes possible the changes in the effective length of the links or connecting rods for the box or case in response to the thermal differences between the flow tube and the box or case. Another aspect is that the connecting means of the box or case comprise: a first and a second links or connecting rods of the box or case placed at each end of the compensation bar on the opposite sides of the compensation bar; first and second end on each of the links or connecting rods of the box or case that attach the first and second ends of the compensation bar to the internal wall of the box or case. Another aspect is that the connecting means or connecting rod for the box or case comprise first and second substantially circular diaphragms placed at the opposite ends of the compensation bar; each diaphragm has a surface whose outer end couples the first and second ends of the compensation bar to an internal wall of the box or case; and at least one elbow or fold out of the plane at the surface of the diaphragm which makes possible the changes in the effective diameter of the diaphragm in response to the thermal differences between the flow tube and the box or case. Another aspect is that the links or connecting rods for the box or case are elongated and have a plurality of elbows or folds out of the plane on the surface of the connecting means or connecting rod for the elongated box or case that make changes in the effective dimensions of the links or connecting rods for the elongated box or case in response to the thermal differences between the flow tube and the box or case. Another aspect is that the flow tube has a constant diameter for the full length of the flow meter. Another aspect is that the connecting means or connecting rod for the box or case are elongated and have a curved surface which makes it possible for the connection means of the box or case to change its effective length in response to the thermal differences between the tube of flow and the box or case; the ends of the curved surface of the connecting means or connecting rod for the elongated box or case couple the first and second ends of the compensation bar to an internal wall of the box or case. Another aspect is that the connecting means or connecting rod for the box or case comprise a first link or connecting rod for the box or case and a second link or connecting rod for the box or case; the first link or connecting rod for the box or case engages one side of the inner wall of the box or case to a first side of the compensation bar; the second link or connecting rod for the box or case engages an opposite side of the inner wall of the box or case with a second side of the compensation bar; and a central portion of the connection means of the box or case define a reinforcing bar that couples the flow tube to the compensation bar. Another aspect is a Coriolis flow meter that comprises: a straight flow tube; a cylindrical compensation bar that surrounds the flow tube and oriented substantially parallel to the longitudinal axis of the flow tube; first and second ends of the compensation bar coupled to the opposite end end portions of the flow tube; a cylindrical box or case containing the compensation bar and the flow tube and oriented substantially parallel with respect to the longitudinal axis of the compensation bar; first and second circular diaphragms defining the connecting means or connecting rod for the box or case coupled to each end of the compensation bar and having a surface oriented substantially perpendicular to the longitudinal axis of the flow tube and the compensation bar; the outer end of each diaphragm couples the first and second ends of the compensation bar to an inner wall of the box or case, and at least one elbow or fold out of the plane on one surface of each diaphragm makes possible changes in diameter Effectiveness of each diaphragm in response to thermal differences between the flow tube and the box or case. Another aspect is that each diaphragm has an internal portion that defines a reinforcing bar that connects the flow tube and the compensation bar. Another aspect of the invention is a method of operating a Coriolis flow meter having a flow tube adapted to receive a flow of material and generate the output information pertaining to the material flow; The flow meter further has a compensation bar oriented substantially parallel to the longitudinal axis of the flow tube, first and second ends of the compensation bar coupled by the reinforcing bar to the opposite end portions of the flow tube, a box or case containing the flow tube and the compensation bar; and connection means or connecting rod for the box or case that attach each end of the box or case of the compensation bar to the portions of the internal wall of the box or case; The tube; the method comprises the steps of: vibrating the compensation bar and the flow tube in phase opposition during a flow condition of the flow meter material to generate the output information pertaining to the material that is flowing; and compensating the flow meter for conditions of varying temperature differences between the box or case and the flow tube by flexing an elbow or fold out of the plane on a surface of the connection means of the box or case to facilitate the changes in the effective dimensions of the connecting means or connecting rod for the box or case in response to the varying temperature differences between the flow tube and the box or case.

SOLUTION The above problem is solved and an advance is achieved in the art according to the present invention which provides a connection link for the box or case having an elbow or fold out of the plane which allows it to expand / shrink in response to the presence of thermal expansion / contraction without permanent damage to the link or connecting rod for the box or case or the elements of the flow meter to which it is connected. According to a first exemplary embodiment, each link or connecting rod for the box or case comprises a thin element which is elongated and which extends between the inner wall of the box or case of the flow meter and a reinforcing bar or end of the compensation bar. The link or connecting rod for the box or case is placed transversely with respect to the reinforcing bar so that the elongated axis of the link or connecting rod for the box or case is transverse with respect to the longitudinal axis of the flow tube and also be transverse to the direction of activation or impulse of the flow tube. The link or connecting rod for the box or case of the present invention contains at least one elbow or fold out of the plane in the portion of the link or rod extending from the end of the reinforcing bar to the inner wall of the box or case. Each elbow or fold out of the plane comprises a fold that allows each half of the link or connecting rod for the box or case to expand or contract in the radial direction in response to thermal differences without permanent structural deformation. The elbow or fold out of the plane may also comprise one or more acute folds, a series of folds similar to an accordion or alternatively may comprise a curved or arc-shaped configuration. According to another possible embodiment of the invention, the connecting rod or rod for the box or case may comprise a diaphragm having at least one fold or the like with the circumference of the diaphragm coupled to the internal walls of the box or case. The central portion of the diaphragm is connected to the union of the reinforcement bar, the flow tube and the compensation bar. The end portion of the flow tube extends through a hole in the center of the diaphragm and is connected to the ends of the box or case. The link or connecting rod for the box or case provided in accordance with the present invention can accommodate the thermal differences and deform or contract substantially in response to the radial expansion / contraction of the flow tube and the compensation bar without damage to the material comprising the link or connecting rod for the box or case. This makes it possible for a flow meter equipped with the link or connecting rod for the box or case of the present invention to process the materials in an environment in which there may be large differences in temperature between the different parts of the flow meter without causing structural damage to the link or connecting rod for the box or case or the elements to which they are connected.

DESCRIPTION OF THE DRAWINGS The above and other advantages and features of the invention can be better understood through a reading of the following detailed description thereof, taken in conjunction with the drawings in which: Figure 1 describes a Coriolis flow meter of straight tube of the previous art that has a link or connecting rod for the box or case. Figure 2 describes the additional details of the flow meter of Figure 1.

Figure 3 depicts an end view of the flow meter of Figure 1 taken along section 3-3 of Figure 1. Figure 4 depicts a straight tube Coriolis flow meter having connecting links or rods for the box or case in which the present invention takes shape. Figures 5, 6, and 7 describe alternative embodiments of the links or connecting rods for the box or case comprising the present invention.

Detailed description Description of Figure 1 Coriolis flow meters are characterized by a flow tube through which the material flows while causing the flow tube to vibrate at its resonant frequency. When the materials are not flowing, each point on the flow tube vibrates in phase with each other point on the flow tube. Two devices of detection of the mechanical movement placed in different points on the tube of flow generate sinusoidal signals that have the same phase when no material flows and have a difference of phase between them when the material flows. This phase difference is due to the Coriolis forces generated by the flow of the material through the vibratory flow tube. The magnitude of the phase difference between any two points along the length of the flow tube is substantially proportional to the flow velocity of the flow mass of the materials. Coriolis mass flow meters employ signal processing that determines this difference in phase and produces an output signal that indicates the flow velocity of the mass in the company of other information pertaining to the flow material. Figure 1 depicts a sectional view of a straight tube Coriolis 100 flow meter of the prior art having a box or case 101 enclosing the elements of the flow meter including the flow tube 103 and the surrounding compensation bar 102. The flow tube 103 extends axially within the case or case 101 and is connected at its ends 108 and 109 to the end projections 107. The end projections 107 are connected by a neck 106 to the ends 104 of the case or case 101. The flow tube 103 is surrounded by the compensation bar 102 and is connected to the ends of the compensation bar 102 by the reinforcing bars 111. The active portion 115 of the flow tube 103 are the intermediate reinforcing bars. 111. The extensions 113 and 114 of the flow tube are the intermediate projections 107 and the reinforcing bars 111. The elements 116 and 117 are the extreme vibration nodes of the active portion 115 of the flow tube. 103 during the normal operating conditions of the flow meter. The links or connecting rods of the box or case comprise the elements 112a and 112b on the left and the elements 112c and 112d on the right. The links or connecting rods for the box or case stabilize the vibratory elements of the flow meter to keep the vibration node at location 116 on the left and at location 117 on the right during normal operating conditions as described subsequently. Each link or connecting rod 112 for the box or case is connected at a first end to the outer wall 124 of the compensation bar 102 and at a second end to the inner wall 105 of the box or case 101. The flow meter 100 also includes the organ motor or exciter D for vibrating the flow tube 103 and the compensation bar 102 out of phase at the resonant frequency of these elements with the material flowing inside the flow tube 103. The flow meter 100 includes the detection mechanism of the left mechanical movement LPO and the right mechanical movement detection mechanism RPO which are coupled to the flow tube 103 and the compensation bar 102 to detect the Coriolis response to the vibration of the flow tube filled with the material. The mechanism of detection of the left mechanical movement LPO, the driving member or exciter D, and the right mechanical movement detecting mechanism RPO are connected to the electronic devices 122 of the meter by the conductors 118, 119 and 121. The electronic devices 122 of the meter apply an activation or impulse signal to the motor member or exciter D on route 119 to energize the driving member or exciter D so that it vibrates the flux tube 103 filled with the material and the compensation rod 102 out of phase, at the resonant frequency of these elements . The output signals generated by the left mechanical movement detection mechanism LPO and the right mechanical movement detection mechanism RPO are extended on the conductors 118 and 121 to the electronic devices 122 of the meter. The electronic devices 122 of the meter receive these signals and process them to generate the information, including the flow velocity of the mass, of the material that flows in the flow tube 103. The information generated by the electronic devices 122 of the meter is applied on Route 123 to a circuit of use not shown. The vibration system of the flow meter 100 comprises the flow tube 103, the reinforcing bar 111 and the compensation bar 102. The vibration nodes of these elements lie in the left and right reinforcement bars 111 during the normal operation of the flow meter in which the material having a nominal density flows through the flow tube 103. A vibration system always maintains its dynamic equilibrium and under these conditions, the dynamic equilibrium is maintained at the vibration nodes 116 and 117 which they represent the location of no movement and are in the reinforcing bars 111. Under these conditions, the links or connecting rods for the box or case are not required to stabilize the vibrations of the internal elements of the flow meter 100 since the meter Flow 100 operates these under ideal conditions. However, ideal conditions do not always exist and, the density of the material that is flowing may either increase or decrease from the nominal value at which the vibration nodes exist at locations 116 and 117. When the density of the material increases, the dynamic balance or balance of the vibration system is maintained when the vibration nodes move inward from the locations 116 and 117 along the flow tube 103. In contrast, for the materials of a lighter density, the nodes of vibration they try to move out to the left of location 116 and to the right of location 117 to keep the vibrational structure in dynamic equilibrium. If the links or connecting rods for the case or case 112 were not present, the vibration nodes could move out of the reinforcement bar 111 when the density of the material becomes heavier or lighter. Under such conditions and with the links or connecting rods for the box or case 112 that are not present, the reinforcing bar 111 could vibrate transversely with respect to the longitudinal axis of the flow tube 103. This could change the vibration length of the tube. of flow 103 and change the flow sensitivity of the meter by altering the distance between the vibration nodes and the mechanical movement detection mechanisms LPO and RPO. The links or connecting rods for the case or case 112 minimize the transverse vibrations of the reinforcement bar 111. The rods do this by allowing the forces associated with these attempted vibrations of the reinforcement bar 111 to be extended through the links or connecting rods for the box or case 112 to the inner wall 105 of the box or case 101. The box or case 101 is of a sufficient volume so that it can absorb these vibrations without any significant vibration of the case itself or case . Therefore, with the present links or connecting rods for the box or case 112, the vibration node of the vibrating structure comprising the flow tube 103, the reinforcing bar 111, and the compensation bar 102 within the reinforcement bar 111 for all reasonable levels of material density that can be found by the flow tube 103. The flow meter of the prior art of Figure 1 has the disadvantage that the differences in temperature between the flow tube 103 and the box or case 101 can cause structural damage to the internal elements of the flow tube 103 when the links or connecting rods for the case or case 112 attempt to expand or contract in their length in response to differences in temperature at which the they are submitted. The reason for this is that one end of each link or rod is connected to the inner wall 105 of the box or case 101 which has a first temperature, while the other end of each link or rod is effectively connected to the tube of flow 103 at a different temperature.

Description of Figure 2 Figure 2 illustrates the problem encountered by the flow meter 100 when the temperature of the flow tube 103 is higher than the temperature of the box or case 101. Under this condition, the reinforcement bar 111, the flow tube 103, and the compensation bar 102 increases in diameter due to thermal expansion. The links or connecting rods for the case or case 112a and 112b also attempt to increase their lengths since their end portions are connected to the flow tube 103 which is at a higher temperature. However, the end portions connected to the inner wall 105 of the box or case 101 can not move outwardly because the box or case 101 is at a lower temperature and is extremely rigid. Under such conditions, the links or connecting rods for the box or case 112a and 112b are bent and assume an outwardly curved position represented by the dotted lines 212a and 212b. Or they may assume a curved inward position (not shown) or a link or rod could be curved outwards and the other link or rod could be curved inwardly (not shown). The forces and stresses to which the links or connecting rods for the box or case 112 are subjected under these conditions can bend these elements beyond their normal limits of deformation and subject them to permanent mechanical damage in which the accuracy of the Flow meter is degraded.

Description of Figure 3 Figure 3 is an end view taken along the line 3-3 of the section of Figure 1. It can be seen that the links or connecting rods for the box or case 112 are flat and the narrow flat elements correcting the inner wall 105 of the box or case 101 and the outer surface of the compensation bar 102. The reinforcement bar 111 is a circular washer-like element which connects the compensation bar 102 with the flow tube 103 and which has a central opening for receiving the flow tube 103.

Description of Figures 4, 5, and 6 Figure 4 illustrates a Coriolis flow meter 400 in which the present invention takes shape.

The Coriolis flow meter 400 comprises a flow tube 103, a surrounding compensation bar 102, the reinforcement bar 111, the connecting links or rods for the box or case 412a and 412b, and a surrounding box or case. The Coriolis 400 flow meter is similar to the Coriolis 100 flow meter of Figures 1 and 2 in all its aspects except for a difference in the links or connecting rods for the box or case. Thus the drawing of Figure 4 and the following paragraphs are directed to a description of these differences. To minimize the complexity of the drawing, Figures 4, 5, 6 and 7 do not show the protrusions 107, the neck 106, the ends 104 of the box or case, or the motor or exciter D and the mechanical movement detection mechanisms. LPO and RPO of Figure 1. It is understood that the modalities of Figures 4, 5, 6 and 7 include these elements. In Figure 4, the links or connecting rods for the box or case 412a, 412b, 412c and 412d (links or rods 412) differ from the links or connecting rods for the box or case 112a and 112b of Figures 1 and 2 in which each link or connecting rod for the case or case 412 has a fold 401 in its middle portion. The fold 401 allows each link or connecting rod for the case or case 412 to expand or contract in its length without adversely affecting other elements of the flow meter 100. It is assumed that the temperature of the flow tube 103 decreases significantly due to the material cold flowing through the flow tube. If this is the case, the compensation bar 102, the reinforcement bar 111 and the flow tube 103 contract and are reduced in diameter. Also, the inner leg 403 of each link or connecting rod for the box or case 412 becomes much colder than the temperature of the portion 404 of the outer leg which is connected to the inner wall 105 of the box or case 101. Under these conditions, the leg 404 remains constant in its length while the leg 403 becomes colder and contracts. In the contraction, the mouth portion 402 of the fold 401 is caused to open to accommodate the contraction of the leg 403 resulting from a reduction in the diameter of the compensation bar 102 and the flow tube 103. Similarly , if the temperature of the flow tube increases, this increase in temperature expands the diameter of the compensation bar 102 and the flow tube 103 and expands the leg 403. By doing so, the mouth 402 of the fold 401 is caused to closure to accommodate the increase in the diameter of the compensation bar 102 and the flow tube 103 and the increase in the length of the leg 403. It can be seen that changes in the temperature of the flow tube 103 are imparted to the bar of reinforcement 111, the compensation bar 102, and the leg 403 of the link or connecting rod for the box or case 412. However, because of the presence of the fold 401 and its mouth 402, the link or connecting rod for the box or case 412 can accommodate the contraction or expansion in the length of leg 403 without any structural damage to the link or connecting rod for the case or case 412 or to the elements to which it is connected. An extreme view of Figure 4 could be similar to Figure 3 except that the links or rods 112a and 112b do not contain the fold 401 of the links or rods 412. The elements 405 and 406 are the junction of the legs 404 and the wall inner 105 of the box or case 101. The flow tube 103 and the elements 113 on Figure 4 extend to a constant diameter for their entire length between their inlet and outlet end protrusions 107 on Figure 1. This constant diameter is advantageous because it improves the cleaning capacity of the flow meter for applications where sanitary conditions are desired.

Figure 5 describes an alternative embodiment of the invention comprising the flow meter 500 in which the links or connecting rods for the box or case 512 (512a, 512b, 512c and 512d) do not have a single fold 401 but in Instead of this they have a plurality of sinusoidal-like corrugations 501. These corrugations allow the links or connecting rods for the box or case 512 to expand or contract without structural damage to them or to the structures to which they are connected. The elements 511 are reinforcing bars. Figure 6 describes another alternative embodiment of the invention comprising the flow meter 600 wherein the links or connecting rods for the case or case 612 (612a, 612b, 612c, and 612d) have a permanently curved shape. This curved shape allows the links or connecting rods for the case or case 612 to either expand or contract at their length without permanent structural damage to the elements of the flow meter to which they are connected. The reinforcing bars 611 are connected to the links or connecting rods for the case or case 612 and couple the flow tube 103 to the compensation rod 102. The links or rods 612 are narrow elements as shown for the links or rods 112a and 112b in Figure 3. The elements 601 and 602 are the junction of the outer end of each link or connecting rod for the box or case and the inner wall 105 of the box or case 101.

Description of Figure 7 Figure 7 still describes another alternative embodiment of the invention comprising the flow meter 700 in which the links or connecting rods for the box or case comprise a circular diaphragm 712 having a central opening 702 for receiving the flow tube 103 The circumference 703 of the diaphragm 712 is fixed to the inner wall 105 of the box or case 101. The diaphragm 712 is fixed to both the flow tube 103 and the ends 710a and 710b of the compensation bar 102 and performs the multiple functions of a reinforcement bar and a link or connecting rod for the box or case. Flat surfaces 704 and 705 of diaphragm 712 have a fold 701 which is similar to fold 401 in Figure 4. This fold 701 allows diaphragm 712 to contract / expand in diameter in response to thermal changes in tube diameter of flow without permanent deformation either with respect to itself or to the structural elements to which it is connected. The portion of the surface between the compensation bar 102 and the flow tube 102 functions as a reinforcing bar. Although the present invention has been described as comprising a part of a single straight tube Coriolis flow meter, it is to be understood that the present invention is not so limited and can be used with other types of Coriolis flow meters that include flow meters of a single tube of curved or irregular configuration as well as Coriolis flow meters having a plurality of flow tubes.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (14)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A Coriolis flow meter, comprising: a flow tube; a compensation bar oriented substantially parallel to the longitudinal axis of the flow tube; first and second ends of the compensation bar coupled to the opposite end end portions of the flow tube; a box or case containing the compensation bar and the flow tube; connecting means or connecting rod for the box or case that attach the first and second ends of the compensation bar to an internal wall of the box or case; characterized in that it comprises: at least one elbow or fold out of the plane in the connecting means or connection rod for the box or case, to make possible the changes in the effective dimension of the means of the link or connecting rod for the box or case in response to thermal differences between the flow tube and the box or case.
2. 2. The Coriolis flow meter according to claim 1, characterized in that: the flow tube is substantially straight.
3. 3. The Coriolis flow meter according to claim 1, characterized in that: the compensation bar is substantially cylindrical and surrounds the flow tube.
4. 4. The Coriolis flow meter according to claim 1, characterized in that: the box or case is cylindrical and oriented substantially parallel to a longitudinal axis of the flow tube.
5. The Coriolis flow meter according to claim 1, characterized in that: the means of the link or connecting rod for the box or case are elongated and substantially flat and have a longitudinal axis oriented substantially perpendicular to the longitudinal axis of the tube. flow and the compensation bar; the means of the link or connecting rod for the elongated box or case coupling the first and second ends of the compensation bar to an internal wall of the box or case; and at least one elbow or fold out of plane in the links or connecting rods for the elongated box or case that makes possible changes in the effective length of the connecting means or connecting rod for the elongated box or case in response to the thermal differences between the flow tube and the box or case.
6. 6. The Coriolis flow meter according to claim 1, characterized in that: the connection means to the box or case comprise: a first and a second link or connecting rods for the box or case placed at each end of the compensation bar on opposite sides of the compensation bar; external ends on the links or connecting rods for the box or case that attach the first and second ends of the compensation bar to the internal wall of the box or case.
7. The Coriolis flow meter according to claim 1, characterized in that: the connecting means or connection rod for the box or case comprise a first and a second substantially circular diaphragms placed on the opposite ends of the compensation bar; each diaphragm has a surface whose external end couples the first and second ends of the compensation bar to an internal wall of the house or box; and an elbow or fold out of the plane on the surface of the diaphragm, which makes possible changes in the effective diameter of the diaphragm in response to thermal differences between the flow tube and the box or case.
8. 8. The Coriolis flow meter according to claim 1, characterized in that: the connecting means or connection rod for the box or case are elongated and have a plurality of elbows or bends outside the plane that make the changes in the length of the connecting means or connecting rod for the elongated box or case in response to the thermal differences between the flow tube and the case or case.
9. 9. The Coriolis flow meter according to claim 1, characterized in that the flow tube extends to a constant diameter for the entire length of the flow meter.
10. The Coriolis flow meter according to claim 1, characterized in that the connection means or connecting rod for the box or case are elongated and have a curved surface that makes it possible for the connection means of the box or case change their effective length in response to thermal differences between the flow tube and the box or case; the ends of the curved surface of the connecting means or connecting rod for the elongated box or case couple the first and second ends of the compensation bar to an internal wall of the box or case.
11. 11. The Coriolis flow meter according to claim 10, characterized in that the means of the link or connecting rod for the box or case comprise a first link or rod connection of the box or case and a second link or rod connection of the box or case; the first link or connecting rod for the box or case couples the inner wall of the box or case to a first side of the compensation bar; the second connection means or connecting rod for the box or case engage an opposite side of the inner wall of the box or case to a second side of the compensation bar; and a center of the connecting means or connecting rod for the box or case, defines a reinforcing bar that couples the flow tube to the compensation bar.
12. 12. The Coriolis flow meter according to claim 1, characterized in that it comprises: a first and a second circular diaphragms defining the connection means or connection rod for the box or case coupled to the ends of the compensation bar and having a surface oriented substantially perpendicular to the longitudinal axis of the flow tube and the compensation bar; the diaphragm couples the ends of the compensation bar to an internal wall of the box or case; and at least one elbow or fold out of the plane on the surface of each diaphragm makes possible the changes in the effective diameter of each diaphragm in response to the thermal differences between the flow tube and the box or case.
13. The flow meter according to claim 12, characterized in that each diaphragm has an internal surface defining a reinforcing bar connecting the flow tube and the compensation bar.
14. 14. An operating method of the Coriolis flow meter according to claim 1, comprising the steps of: vibrating the compensation bar and the flow tube in opposition to phase during a flow condition of the flow meter material for generate the output information that belongs to the material that is flowing; and characterized in that it comprises: compensating the flow meter for the conditions of the variable temperature differences between the box or case and the flow tube, by flexing an elbow or fold out of the plane on a surface of the connecting means or rod connection for the box or case, to facilitate changes in the effective dimensions of the connecting means or connecting rod for the box or case in response to the variable temperatures of the flow tube and the box or case.