Density meter in electrical communication with a volumetric flow meter and both in electrical communication with a meter electronics that outputs a mass flow measurement

A mass flow rate sensor system (200) is provided. The mass flow rate sensor system (200) includes a density meter (202) including a sensor assembly (204a) and a density meter electronics (204b) configured to generate a density measurement of a process fluid. The mass flow rate sensor system (200) further includes a volumetric flow meter (203) including a sensor assembly (205a) and a volumetric meter electronics (205b) configured to generate a volumetric flow rate of the process fluid and in electrical communication with the density meter electronics (204b). A remote processing system (207) is provided that is in electrical communication with only one of the density meter electronics (204b) or the volumetric meter electronics (205b). The remote processing system (207) is configured to receive a mass flow rate measurement of the process fluid generated by the density meter electronics (204b) or the volumetric meter electronics (205b) based on the generated density measurement and the generated volumetric flow rate.

TECHNICAL FIELD

The embodiments described below relate to, combination mass flow sensor systems, and more particularly, to a density meter in electrical communication with a volumetric flow meter that outputs a mass flow measurement.

BACKGROUND OF THE INVENTION

Vibrating meters, such as Coriolis mass flow meters exist, which can measure a mass flow rate of a fluid directly. While Coriolis mass flow meters have received great success in a variety of industries, there are certain situations where Coriolis mass flow meters are undesirable. For example, in some situations, the cost of using high purity metals, such as tantalum or titanium, for the flow tubes becomes prohibitively expensive in high flow situations where the size of the tubes requires an excessive amount of the metal. Another situation may be where a customer already has either a density meter or a volumetric flow meter installed in their system and simply requires the other meter in order to generate a mass flow rate. In such situations, the customer may not wish to replace the existing sensor, but rather simply add the missing measurement device in order to calculate a mass flow rate using equation (1):
{dot over (m)}=Q*ρ(1)

{dot over (m)} is the mass flow rate;

Q is the volumetric flow rate; and

ρ is the density.

One problem with the combination of a density meter and a volumetric flow meter as opposed to a Coriolis mass flow meter in order to generate a mass flow rate is the excessive amount of wiring involved as shown inFIG. 1.

FIG. 1shows a prior art mass flow sensor system10. The prior art mass flow sensor system10can include a density meter11and a volumetric flow meter12. The density meter11and the volumetric flow meter12are positioned within a flow conduit5carrying a process fluid. The density meter11may comprise any one of well-known density meters, such as a Coriolis density meter, a hygrometer, an x-ray densitometer, a gamma densitometer, etc. The volumetric flow meter12may comprise any well-known meter that measures a volumetric flow rate, such as an ultra-sonic meter, a magnetic meter, a turbine meter, a vortex meter, etc.

The prior art mass flow sensor system10also includes a central processing system13. As shown, the density meter11is in electrical communication with the central processing system13via electrical leads14. Similarly, the volumetric flow meter12is in electrical communication with the central processing system13via electrical leads15. Therefore, each of the meters11,12sends signals to the central processing system13. The central processing system13processes the signals received from the density meter11to generate a density measurement. Likewise, the central processing system13processes the signals received from the volumetric flow meter12to generate a volumetric flow rate. The central processing system13may subsequently generate a mass flow rate based on the generated density and volumetric flow rate. The mass flow rate may then be provided to a user or another processing system via leads16. As an alternative, the central processing system13may simply output the individual density and the volumetric flow rate without calculating a mass flow rate. The customer must then use another processing system to determine the mass flow rate based on the output from the central processing system13.

The prior art mass flow system10suffers from a number of problems. One problem is due to the increased amount of wiring required. While the density meter11and the volumetric flow meter12are often located relatively close to one another, the central processing system13may be located remotely from the density meter11and the volumetric flow meter12. Consequently, because each meter11and12communicates with the central processing system13independently, the amount of wiring is duplicative.

Another problem with the prior art system10is that if either the density meter11or the volumetric flow meter12needs to be replaced, the central processing system13needs to be reprogrammed to receive the new signals from the new meter. Often, the central processing system13may be a customer's own equipment and thus, the customer is required to perform the updated programming.

Similarly, many users simply want the mass flow rate and do not necessarily need to know the particular density or the volumetric flow rate. However, in the prior art system10, the user is only provided signals indicating the density and the volumetric flow rate and is required to perform the calculation of the mass flow rate independently.

Therefore, there is a need in the art for a system that can provide a mass flow rate output using a density meter and a volumetric flow rate meter. Further, there is a need in the art for a system that can reduce the required wiring, especially between the meters and a central processing system. The embodiments described below overcome these and other problems and an advance in the art is achieved. The embodiments described below provide a mass flow rate system that uses one or both of the density meter and the volumetric flow rate meter to perform the mass flow calculation. Consequently, only one of the meters needs to be in communication with a central processing system. Therefore, the system outputs a mass flow rate and the wiring required to communicate with the central processing system is reduced.

SUMMARY OF THE INVENTION

A mass flow rate sensor system is provided according to an embodiment. The mass flow rate sensor system comprises a density meter including a sensor assembly and a density meter electronics configured to generate a density measurement of a process fluid. According to an embodiment, the mass flow rate sensor system further comprises a volumetric flow meter including a sensor assembly and a volumetric meter electronics configured to generate a volumetric flow rate of the process fluid and in electrical communication with the meter electronics of the density meter. According to an embodiment, the mass flow rate sensor system further comprises a remote processing system in electrical communication with only one of the density meter electronics or the volumetric meter electronics. The remote processing system is configured to receive a mass flow rate measurement of the process fluid generated by the density meter electronics or the volumetric meter electronics based on the generated density measurement and the generated volumetric flow rate.

A method for generating a mass flow rate measurement of a process fluid in a fluid conduit is provided according to an embodiment. The method comprises a step of determining a density of the process fluid with a density meter including a sensor assembly in fluid communication with the process fluid and a density meter electronics. According to an embodiment, the method further comprises a step of determining a volumetric flow rate of the process fluid with a volumetric flow meter including a sensor assembly in fluid communication with the process fluid and a volumetric meter electronics. According to an embodiment, electrical communication is provided between the density meter electronics and the volumetric meter electronics. The method further comprises a step of using at least one of the density meter electronics or the volumetric meter electronics to determine a mass flow rate of the process fluid based on the determined density and the determined volumetric flow rate. The method further comprises a step of providing the mass flow rate to a remote processing system in electrical communication with only one of the density meter electronics or the volumetric meter electronics.

ASPECTS

According to an aspect, a mass flow rate sensor system comprises:a density meter including a sensor assembly and a density meter electronics configured to generate a density measurement of a process fluid;a volumetric flow meter including a sensor assembly and a volumetric meter electronics configured to generate a volumetric flow rate of the process fluid and in electrical communication with the density meter electronics; anda remote processing system in electrical communication with only one of the density meter electronics or the volumetric meter electronics and configured to receive a mass flow rate measurement of the process fluid generated by the density meter electronics or the volumetric meter electronics based on the generated density measurement and the generated volumetric flow rate.

Preferably, the sensor assembly of the density meter and the sensor assembly of the volumetric flow meter are located in line with a fluid conduit carrying the process fluid.

Preferably, the sensor assembly of the volumetric flow meter is located in line with a fluid conduit carrying the process fluid and the sensor assembly of the density meter is located in a slip stream coupled to the fluid conduit to receive a portion of the process fluid.

Preferably, the density measurement and the volumetric flow rate are generated substantially simultaneously.

Preferably, the density measurement comprises an average density.

According to another aspect, a method for generating a mass flow rate measurement of a process fluid in a fluid conduit comprises steps of:determining a density of the process fluid with a density meter including a sensor assembly in fluid communication with the process fluid and a density meter electronics;determining a volumetric flow rate of the process fluid with a volumetric flow meter including a sensor assembly in fluid communication with the process fluid and a volumetric meter electronics;providing electrical communication between the density meter electronics and the volumetric meter electronics;using at least one of the density meter electronics or the volumetric meter electronics to determine a mass flow rate of the process fluid based on the determined density and the determined volumetric flow rate; andproviding the mass flow rate to a remote processing system in electrical communication with only one of the density meter electronics or the volumetric meter electronics.

Preferably, the sensor assembly of the density meter and the sensor assembly of the volumetric flow meter are located in line with the fluid conduit carrying the process fluid.

Preferably, the sensor assembly of the volumetric flow meter is located in line with the fluid conduit carrying the process fluid and the sensor assembly of the density meter is located in a slip stream coupled to the fluid conduit to receive a portion of the process fluid.

Preferably, the density measurement and the volumetric flow rate are determined substantially simultaneously.

Preferably, the density measurement comprises an average density.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 2-4and the following description depict specific examples to teach those skilled in the art how to make and use the best mode of embodiments of a mass flow rate system. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these examples that fall within the scope of the present description. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the mass flow rate system. As a result, the embodiments described below are not limited to the specific examples described below, but only by the claims and their equivalents.

FIG. 2shows a mass flow rate sensor system200according to an embodiment. According to an embodiment, the mass flow rate sensor system200can be positioned within a flow conduit201receiving a process fluid or some other type of flow stream. The mass flow rate sensor system200can include a density meter202and a volumetric flow meter203. The density meter202may comprise any well-known density meter, such as a Coriolis density meter, a hygrometer, an x-ray densitometer, a gamma densitometer, etc. The particular type of density meter may depend upon the particular application and should in no way limit the scope of the present embodiment. The volumetric flow meter203may comprise any well-known meter that measures a volumetric flow rate, such as an ultra-sonic meter, a magnetic meter, a turbine meter, a vortex meter, etc. According to an embodiment, the density meter202and the volumetric flow meter203can be placed in series in line with the conduit201. In the embodiment shown, the density meter202is positioned upstream from the volumetric flow meter203; however, in other embodiments, the order can be reversed. In alternative embodiments, the density meter202can be placed in a slip stream, which branches off from the conduit201(SeeFIG. 4).

According to an embodiment, the density meter202comprises a sensor assembly204a, which receives the flowing fluid. The density meter202further comprises a density meter electronics204b. Although the density meter electronics204bis shown as being physically coupled to the sensor assembly204a, in other embodiments, the two components may simply be electrically coupled via an electrical lead. In either situation, the sensor assembly204ais in electrical communication with the density meter electronics204bvia an electrical lead (not shown).

According to an embodiment, the density meter electronics204bcan receive sensor signals from the sensor assembly204a. The density meter electronics204bcan process the received sensor signals to generate a measured density of the fluid flowing through the conduit201as is generally known in the art.

According to an embodiment, the volumetric flow meter203comprises a sensor assembly205a, which receives the process fluid in the fluid conduit201. The volumetric flow meter203further comprises a volumetric meter electronics205b. In a manner similar to the density meter202, while the volumetric meter electronics205bas being is shown physically coupled to the sensor assembly205a, in other embodiments, the two components may simply be coupled via an electrical lead. In either situation, the sensor assembly205ais in electrical communication with the volumetric meter electronics205bvia an electrical lead (not shown).

According to an embodiment, the volumetric meter electronics205bcan receive signals from the sensor assembly205a. The volumetric meter electronics205bcan process the signals and generate a volumetric flow rate as is generally known in the art.

According to an embodiment, the two meter electronics204b,205bare in electrical communication with one another via the electrical lead206. The electrical communication between the two meter electronics204b,205ballows the generated measurement from one of the meter electronics to be communicated to the other meter electronics. For example, in the configuration shown, the density meter electronics204bcan receive the generated volumetric flow rate from the volumetric meter electronics205b. With the volumetric flow rate received from the volumetric flow meter203along with the generated density, the density meter202can generate a mass flow rate using equation (1). According to an embodiment, the generated mass flow rate can then be output to a remote processing system207via electrical lead208. According to an embodiment, the electrical lead208can additionally provide power to the density meter202and the volumetric flow meter203. In some embodiments, the remote processing system207may include a further output lead209. The output lead209can provide communication with a further processing system, for example.

According to an embodiment, the remote processing system207may be located at a distance greater than the distance between the density meter202and the volumetric flow meter203. However, according to another embodiment, the remote processing system207may be located in close proximity to the two meters202,203. For example, the remote processing system207may be located at the same distance or a shorter distance than the distance between the density meter202and the volumetric flow meter203. The particular location of the remote processing system207with respect to the meters202,203should in no way limit the scope of the present embodiment and will depend upon the particular application.

The remote processing system207can comprise a general-purpose computer, a micro-processing system, a logic circuit, or some other general purpose or customized processing device. The remote processing system207can be distributed among multiple processing devices. The remote processing system207can include any manner of integral or independent electronic storage medium.

As can be appreciated, only one of the density meter202or the volumetric flow meter203is in direct electrical communication with the remote processing system207. Although in the embodiment shown inFIG. 2, the density meter202is in direct electrical communication with the remote processing system207, in other embodiments, the volumetric flow meter203can be in direct electrical communication with the remote processing system207instead. In either situation, the amount of wiring required is substantially reduced compared to the prior art system shown inFIG. 1. Additionally, the meter electronics that is electrically coupled with the remote processing system207, outputs a mass flow rate. Therefore, the remote processing system207does not have to be specially configured to calculate a mass flow rate from a density and a volumetric flow rate.

FIG. 3shows the density meter electronics204baccording to an embodiment of the invention. It should be appreciated that many of the features of the density meter electronics204bcan also be found in the volumetric meter electronics205bof the volumetric flow meter203. However, a description of the volumetric meter electronics205bis omitted for brevity of the description. The density meter electronics204bcan include an interface301and a processing system303. The processing system303may include a storage system304. The storage system304may comprise an internal memory as shown, or alternatively, may comprise an external memory. The density meter electronics204bcan generate a drive signal311and supply the drive signal311to a driver (not shown) of the sensor assembly204a. The density meter electronics204bcan also receive sensor signals310from the sensor assembly204a. The density meter electronics204bcan process the sensor signals310in order to obtain a density312of the material flowing through the conduit201. The density312can be stored for later use.

In addition to the sensor signals310received from the sensor assembly204a, the interface301can also receive a generated volumetric flow rate314from the volumetric meter electronics205b. The interface301may perform any necessary or desired signal conditioning, such as any manner of formatting, amplification, buffering, etc. Alternatively, some or all of the signal conditioning can be performed in the processing system303. In addition, the interface301can enable communications between the density meter electronics204band the remote processing system207. The interface301can be capable of any manner of electronic, optical, or wireless communication.

The interface301in one embodiment can include a digitizer (not shown); wherein the sensor signals310comprise analog sensor signals. The digitizer can sample and digitize the analog sensor signals and produce digital sensor signals. The digitizer can also perform any needed decimation, wherein the digital sensor signal is decimated in order to reduce the amount of signal processing needed and to reduce the processing time.

The processing system303can conduct operations of the density meter electronics204b. The processing system303can execute the data processing required to implement one or more processing routines, such as the mass flow rate determination routine313. The mass flow determination routine313can use equation (1) along with the generated density312and the received volumetric flow rate314to generate a mass flow rate315. As discussed above, the mass flow rate315can then be output to the external remote processing system207. In some embodiments, the processing system300may additionally output the density312and/or the volumetric flow rate314.

It should be understood that the meter electronics220may include various other components and functions that are generally known in the art. These additional features are omitted from the description and the figures for the purpose of brevity. Therefore, the present invention should not be limited to the specific embodiments shown and discussed.

FIG. 4shows the mass flow sensor system200according to another embodiment. In the embodiment shown inFIG. 4, the sensor assembly204aof the density meter202is located within a slip stream401, which branches off from the main conduit201. The slip stream401is generally smaller than the conduit201such that only a small amount of the fluid flows into the slip stream401. Although the volumetric flow meter203is positioned between the first and second ends of the slip stream401in the embodiment shown inFIG. 4, the volumetric flow meter203could be positioned at other areas of the conduit201. For example, in some embodiments, the volumetric flow meter203is positioned just outside the ends of the slip stream401such that all of the fluid flows through the volumetric flow meter203rather than a portion of the fluid bypassing the volumetric flow meter203. Therefore, a correction does not have to be performed to account for the amount of fluid bypassing the volumetric flow meter203. However, in many embodiments, the volumetric flow meter203will be positioned close to the slip stream401so that the volumetric flow meter203and the density meter202are measuring substantially the same fluid at any given time.

According to the embodiment shown inFIG. 4, the sensor assembly204acan receive a small portion of the fluid flowing through the system200. This may be advantageous in some embodiments as the sensor assembly204acan be made substantially smaller than in the embodiment shown inFIG. 2as a smaller flow rate is being received by the density meter202inFIG. 4. Therefore, if the density meter202is formed from high cost materials, such as a tube made from titanium or tantalum, the cost of the sensor assembly204acan be reduced due to the reduced size.

According to the embodiment shown inFIG. 4, the two meter electronics204b,205bare still in electrical communication with one another so that only one of the meter electronics204bor205bneeds to be in direct electrical communication with the remote processing system207. In the embodiment shown inFIG. 4, the volumetric meter electronics205bis in direct electrical communication with the remote processing system207rather than the density meter202. As can be appreciated, in this embodiment, the volumetric meter electronics205bwill be configured to receive the density measurement from the density meter electronics204band generate the mass flow rate based on the received density312and the generated volumetric flow rate314.

In use, the mass flow rate sensor system200may be used to generate a mass flow rate based on individually determined volumetric flow rates and densities generated from two separate sensor assemblies204a,205a. According to an embodiment, the density meter202can generate a density measurement312, as the process fluid flows through the conduit201. According to an embodiment, substantially simultaneously, the volumetric flow meter203can generate a volumetric flow rate314. According to another embodiment, the density meter202may generate an average density measurement. For example, the meter electronics204bmay store and keep a rolling average density determined from previous density measurements. The previous density measurements may be based on a predetermined number of previously received sensor signals310, for example.

According to an embodiment, at least one of the meter electronics204b,205bcan receive the fluid measurement from the other meter electronics. For example, in the embodiment shown inFIG. 2, the density meter electronics204bcan receive the volumetric flow rate314from the volumetric meter electronics205b. Conversely, in the embodiment shown inFIG. 3, the volumetric meter electronics205bcan receive the density measurement312from the density meter electronics204b. Preferably, the meter electronics that receives the fluid measurement is the meter electronics that is in direct electrical communication with the remote processing system207. However, the present embodiment should not be so limited. For example, inFIG. 2, the density meter202is in direct electrical communication with the remote processing system207. In some embodiments, the volumetric meter electronics205bmay receive the density measurement from the density meter202. In yet another embodiment, each of the meter electronics204b,205bmay send the generated measurement to the other meter electronics such that each of the meter electronics204b,205bincludes both a density measurement and a volumetric flow rate measurement.

According to an embodiment, once one of the meter electronics includes both the density measurement312and the volumetric flow rate314, the meter electronics can process the two measurements to generate a mass flow rate315. The generated mass flow rate315can then be sent to the remote processing system207via the lead208. If the meter electronics that generates the mass flow rate is not in direct electrical communication with the remote processing system207, the generated mass flow rate can be sent to the meter electronics that is in direct electrical communication with the remote processing system207and subsequently pass the mass flow rate315on to the remote processing system207.

Therefore, as can be appreciated, the remote processing system207can receive a mass flow rate from a combination of density meter202and volumetric flow meter203without having to separately perform the mass flow rate calculation. This advantageously simplifies the processing required of the remote processing system207as well as substantially reduces the amount of wiring required. Additionally, if either of the meters202,203need to be replaced, the remote processing system207does not have to be reconfigured.

According to an embodiment, if both of the meter electronics204b,205bincludes the density measurement and the volumetric flow rate measurement, both of the meter electronics204b,205bmay generate a mass flow rate measurement. This allows either of the meter electronics204b,205bto send the mass flow rate measurement to the remote processing system207. Further, in the event that one of the meters202,203needs to be replaced, the remaining meter can easily provide the mass flow measurement to the remote processing system207.

The detailed descriptions of the above embodiments are not exhaustive descriptions of all embodiments contemplated by the inventors to be within the scope of the present description. Indeed, persons skilled in the art will recognize that certain elements of the above-described embodiments may variously be combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of the present description. It will also be apparent to those of ordinary skill in the art that the above-described embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of the present description.

Thus, although specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present description, as those skilled in the relevant art will recognize. The teachings provided herein can be applied to other mass flow systems, and not just to the embodiments described above and shown in the accompanying figures. Accordingly, the scope of the embodiments described above should be determined from the following claims.