HK1205787B - Indirect mass flow sensor - Google Patents

Description

Indirect mass flow sensor

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

There are vibrating meters, such as Coriolis (Coriolis) mass flow meters, which can directly measure the mass flow of a fluid. While coriolis mass flowmeters have met with great success in various industries, there are certain situations in which coriolis mass flowmeters are undesirable. For example, in some cases, the cost of using high purity metals such as tantalum or titanium for the flow tubes becomes prohibitively expensive in high flow rate situations where the size of the tubes requires an excess of metal. Another situation may be: customers already have density meters or volumetric flow meters installed in their systems and only need the other meters in order to generate mass flow. In these situations, the customer may not wish to replace an existing sensor, but merely add the missing measurement device in order to calculate mass flow using equation (1):

(1)

wherein:

is the mass flow rate;

q is the volume flow; while

ρ is the density.

One problem with using a combination of density and volumetric flow meters, rather than coriolis mass flow meters, to generate mass flow is the problem of excessive wiring involved, as shown in fig. 1.

Fig. 1 shows a prior art mass flow sensor system 10. The prior art mass flow sensor system 10 may include a density meter 11 and a volumetric flow meter 12. A density meter 11 and a volume flow meter 12 are positioned in the flow conduit 5 carrying the process fluid. The density meter 11 may comprise any of the well known density meters such as a coriolis density meter, a moisture meter, an x-ray optical density meter, a gamma optical density meter, and the like. Volumetric flow meter 12 may include any well known meter that measures volumetric flow, such as an ultrasonic flow meter, a magnetic flow meter, a turbine flow meter, a vortex flow meter, and the like.

The prior art mass flow sensor system 10 also includes a central processing system 13. As shown, the densitometer 11 is in electrical communication with the central processing system 13 via electrical leads 14. Similarly, the volumetric flowmeter 12 is in electrical communication with the central processing system 13 via electrical leads 15. Thus, each of the meters 11, 12 sends a signal to the central processing system 13. The central processing system 13 processes the signals received from the density meter 11 to generate density measurements. Likewise, the central processing system 13 processes the signals received from the volumetric flow meter 12 to generate the volumetric flow. The central processing system 13 may then generate a mass flow based on the generated density and volumetric flow. The mass flow may then be provided to a user or another processing system via lead 16. As an alternative, the central processing system 13 may output only the individual density and volume flow rates without calculating the mass flow rate. The customer must then use another processing system to determine the mass flow based on the output from the central processing system 13.

The prior art mass flow system 10 suffers from a number of problems. One problem is due to the increase in the amount of wiring required. While the density meter 11 and the volume flow meter 12 are often positioned relatively close to each other, the central processing system 13 may be positioned remotely from the density meter 11 and the volume flow meter 12. Thus, because each meter 11 and 12 communicates independently with the central processing system 13, the amount of wiring is duplicated.

Another problem with the prior art system 10 is: if it is necessary to replace the density meter 11 or the volume flow meter 12, the central processing system 13 needs to be reprogrammed to receive new signals from the new meters. Typically, the central processing system 13 may be the customer's own device, so that the customer needs to perform the update programming.

Similarly, many users only want to know mass flow rate, and do not necessarily need to know a specific density or volume flow rate. However, in the prior art system 10, the user is only provided with signals indicative of density and volumetric flow rate, and thus the calculation of mass flow rate needs to be performed independently.

Accordingly, there is a need in the art for a system that can provide a mass flow output using a density meter and a volumetric flow meter. Further, there is a need in the art for such a system that can reduce the required wiring, particularly between meters and central processing systems. The embodiments described below overcome these and other problems to achieve an advance in the art. The embodiments described below provide a mass flow system that performs mass flow calculations using one or both of a density meter and a volumetric flow meter. Thus, only one of the meters need be in communication with the central processing system. Thus, the system outputs mass flow and the wiring required to communicate with the central processing system is reduced.

Disclosure of Invention

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

According to one embodiment, a method for generating a mass flow measurement of a process fluid in a fluid conduit is provided. The method comprises the following steps: the density of the process fluid is determined with a densitometer that includes a sensor assembly in fluid communication with the process fluid and densitometer electronics. According to one embodiment, the method further comprises the steps of: the volumetric flow of the process fluid is determined with a volumetric flow meter that includes a sensor assembly in fluid communication with the process fluid and volumetric meter electronics. According to one embodiment, electrical communication is provided between the density meter electronics and the volume meter electronics. The method further comprises the steps of: determining a mass flow rate of the process fluid using at least one of the density meter electronics or the volumetric meter electronics based on the determined density and the determined volumetric flow rate. The method further comprises the steps of: providing the mass flow to a remote processing system in electrical communication with only one of the density meter electronics or the volume meter electronics.

Aspect(s)

According to one aspect, a mass flow sensor system comprises:

a density meter comprising a sensor assembly and density meter electronics configured to generate a density measurement of a process fluid;

a volumetric flow meter comprising a sensor assembly and volumetric meter electronics configured to generate a volumetric flow rate of the process fluid and in electrical communication with the density meter electronics; and

a remote processing system in electrical communication with only one of the density meter electronics or the volume meter electronics and configured to receive a mass flow measurement of the process fluid, the mass flow measurement generated by the density meter electronics or the volume meter electronics based on the generated density measurement and the generated volumetric flow.

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

Preferably, the sensor assembly of the volumetric flowmeter is positioned in-line with a fluid conduit carrying the process fluid and the sensor assembly of the density flowmeter is positioned in a slipstream 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 measurement of a process fluid in a fluid conduit comprises the steps of:

determining the density of the process fluid with a densitometer comprising a sensor assembly in fluid communication with the process fluid and densitometer electronics;

determining a volumetric flow rate of the process fluid with a volumetric flow meter comprising a sensor assembly in fluid communication with the process fluid and volumetric meter electronics;

providing electrical communication between the density meter electronics and the volume meter electronics;

determining a mass flow rate of the process fluid using at least one of the density meter electronics or the volumetric meter electronics based on the determined density and the determined volumetric flow rate; and

providing the mass flow to a remote processing system in electrical communication with only one of the density meter electronics or the volume meter electronics.

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

Preferably, the sensor assembly of the volumetric flowmeter is positioned in-line with a fluid conduit carrying the process fluid and the sensor assembly of the density flowmeter is positioned in a slipstream coupled to the fluid conduit to receive a portion of the process fluid.

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

Preferably, the density measurement comprises an average density.

Drawings

Fig. 1 shows a prior art mass flow system.

FIG. 2 illustrates a mass flow sensor system according to one embodiment.

FIG. 3 illustrates meter electronics according to one embodiment.

FIG. 4 illustrates a mass flow sensor system according to another embodiment.

Detailed Description

Fig. 2-4 and the following description illustrate specific examples to teach those skilled in the art how to make and use the best mode of practice for a mass flow 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 description. Those skilled in the art will understand that: the features described below can be combined in various ways to form multiple variations of mass flow systems. 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. 2 illustrates a mass flow sensor system 200 according to one embodiment. According to one embodiment, the mass flow sensor system 200 may be positioned within a flow conduit 201, the flow conduit 201 receiving a process fluid or some other type of flow stream. The mass flow sensor system 200 can include a density meter 202 and a volumetric flow meter 203. The density meter 202 may comprise any of the well known density meters such as a Coriolis (Coriolis) density meter, a moisture meter, an x-ray optical density meter, a gamma optical density meter, and the like. The particular type of densitometer may depend on the particular application and should in no way limit the scope of the present embodiment. The volumetric flow meter 203 may comprise any well known meter that measures volumetric flow, such as an ultrasonic flow meter, a magnetic flow meter, a turbine flow meter, a vortex flow meter, and the like. According to one embodiment, the density meter 202 and the volume flow meter 203 may be arranged in series, in line with the conduit 201. In the illustrated embodiment, the density meter 202 is positioned upstream of the volumetric flow meter 203, however, in other embodiments, the sequence may be reversed. In an alternative embodiment, the density meter 202 may be disposed in a slip stream (slip stream) that is diverted from the conduit 201 (see FIG. 4).

According to one embodiment, the density meter 202 includes a sensor assembly 204a that receives a flowing fluid. The density meter 202 further includes density meter electronics 204 b. Although the density meter electronics 204b is shown as being physically coupled to the sensor assembly 204a, in other embodiments, the two components may be electrically coupled only via electrical leads. In either case, the sensor assembly 204a is in electrical communication with the density meter electronics 204b via electrical leads (not shown).

According to one embodiment, the density meter electronics 204b may receive sensor signals from the sensor assembly 204 a. The density meter electronics 204b can process the received sensor signals to generate a measured density of the fluid flowing through the conduit 201, as is well known in the art.

According to one embodiment, the volumetric flowmeter 203 includes a sensor assembly 205a that receives the process fluid in the fluid conduit 201. The volumetric flowmeter 203 further includes volumetric meter electronics 205 b. Similar to the density meter 202, although the volume meter electronics 205b is shown as being physically coupled to the sensor assembly 205a, in other embodiments, the two components may be coupled only via electrical leads. In either case, the sensor assembly 205a is in electrical communication with the volume meter electronics 205b via electrical leads (not shown).

According to one embodiment, the volume meter electronics 205b may receive a signal from the sensor assembly 205 a. The volume meter electronics 205b can process the signal and generate a volumetric flow rate, as is well known in the art.

According to one embodiment, the two meter electronics 204b, 205b are in electrical communication with each other via electrical leads 206. The electrical communication between the two meter electronics 204b, 205b allows a generated measurement from one of the meter electronics to be transferred to the other meter electronics. For example, in the illustrated configuration, the density meter electronics 204b can receive the generated volumetric flow rate from the volumetric meter electronics 205 b. By receiving the volumetric flow from volumetric flow meter 203 and the generated density, density meter 202 may generate a mass flow using equation (1). The generated mass flow may then be output to a remote processing system 207 via an electrical lead 208, according to one embodiment. According to one embodiment, the electrical leads 208 may additionally provide power to the density meter 202 and the volume flow meter 203. In some embodiments, the remote processing system 207 may include yet another output lead 209. Output leads 209 may enable communication with, for example, yet another processing system.

According to one embodiment, the remote processing system 207 may be positioned at a distance greater than the distance between the density meter 202 and the volume flow meter 203. However, according to another embodiment, the remote processing system 207 may be located in close proximity to both meters 202, 203. For example, the remote processing system 207 may be positioned at the same distance or a shorter distance than the distance between the density meter 202 and the volume flow meter 203. The particular location of the remote processing system 207 relative to the meters 202, 203 should in no way limit the scope of the present embodiments and will depend on the particular application.

The remote processing system 207 may comprise a general purpose computer, a micro processing system, a logic circuit, or some other general purpose or customized processing device. The remote processing system 207 may be distributed among a plurality of processing devices. The remote processing system 207 may include any manner of integrated or stand-alone electronic storage media.

As can be appreciated, only one of the density meter 202 or the volumetric flow meter 203 is in direct electrical communication with the remote processing system 207. Although in the embodiment shown in fig. 2, the density meter 202 is in direct electrical communication with the remote processing system 207, in other embodiments, the volumetric flowrate meter 203 may be in direct electrical communication with the remote processing system 207. In either case, the amount of wiring required is greatly reduced compared to the prior art system shown in fig. 1. In addition, meter electronics electrically coupled to the remote processing system 207 outputs mass flow. Thus, the remote processing system 207 need not be specially configured to calculate mass flow from density and volumetric flow.

FIG. 3 illustrates density meter electronics 204b according to one embodiment of the invention. It should be understood that: many of the features of the density meter electronics 204b can also be found in the volume meter electronics 205b of the volumetric flow meter 203. However, the description of the volume meter electronics 205b is omitted for brevity of description. The density meter electronics 204b can include an interface 301 and a processing system 303. The processing system 303 may include a storage system 304. The storage system 304 may include internal memory as shown, or alternatively, may include external memory. The density meter electronics 204b can generate the drive signal 311 and supply the drive signal 311 to a driver (not shown) of the sensor assembly 204 a. The density meter electronics 204b can also receive the sensor signal 310 from the sensor assembly 204 a. The density meter electronics 204b can process the sensor signal 310 to obtain a density 312 of the material flowing through the conduit 201. The density 312 may be stored for later use.

In addition to the sensor signal 310 received from the sensor assembly 204a, the interface 301 may also receive the generated volumetric flow 314 from the volumetric meter electronics 205 b. The interface 301 may perform any necessary or desired signal conditioning, such as formatting, amplification, buffering, etc. in any manner. Alternatively, some or all of the signal conditioning may be performed in the processing system 303. Additionally, the interface 301 may allow communication between the density meter electronics 204b and the remote processing system 207. The interface 301 may be capable of any manner of electronic, optical, or wireless communication.

The interface 301 may include a digitizer (not shown) in one embodiment, wherein the sensor signal 310 comprises an analog sensor signal. The digitizer may sample and digitize the analog sensor signal and generate a digital sensor signal. The digitizer may also perform any required down-sampling (decimation), wherein the digital sensor signal is down-sampled, in order to reduce the amount of signal processing required, as well as to reduce the processing time.

The processing system 303 may perform the operations of the density meter electronics 204 b. Processing system 303 may perform the required data processing to implement one or more processing routines, such as mass flow determination routine 313. The mass flow determination routine 313 may use equation (1) along with the generated density 312 and the received volume flow 314 to generate a mass flow 315. The mass flow 315 may then be output to the external remote processing system 207 as discussed above. In some embodiments, the processing system 300 may additionally output a density 312 and/or a volumetric flow 314.

It should be understood that: the meter electronics 220 may include various other components and functions as are well known in the art. These additional features are omitted from the description and drawings for the sake of brevity. Therefore, the invention should not be limited to the specific embodiments illustrated and discussed.

Fig. 4 shows a mass flow sensor system 200 according to another embodiment. In the embodiment shown in FIG. 4, the sensor assembly 204a of the density meter 202 is positioned within a slipstream 401, which slipstream 401 is diverted from the main conduit 201. The slipstream 401 is typically smaller than the conduit 201 so that only a small amount of fluid flows into the slipstream 401. Although the volumetric flow meter 203 is positioned between the first and second ends of the slipstream 401 in the embodiment shown in fig. 4, the volumetric flow meter 203 may be positioned in other areas of the conduit 201. For example, in some embodiments, the volumetric flow meter 203 is positioned slightly beyond the end of the slipstream 401 such that all of the fluid flows through the volumetric flow meter 203, rather than a portion of the fluid bypassing the volumetric flow meter 203. Therefore, it is not necessary to perform correction to cope with the amount of fluid bypassing the volume flow meter 203. However, in many embodiments, the volumetric flow meter 203 will be positioned proximate to the slipstream 401 such that the volumetric flow meter 203 and the density meter 202 measure substantially the same fluid at any given time.

According to the embodiment shown in fig. 4, the sensor assembly 204a may receive a small portion of the fluid flowing through the system 200. This may be advantageous in some embodiments because the sensor assembly 204a may be made substantially smaller than in the embodiment shown in FIG. 2 because the density meter 202 in FIG. 4 receives a smaller flow. Thus, if the density gauge 202 is formed from a high cost material, such as a tube made of titanium or tantalum, the cost of the sensor assembly 204a may be reduced due to the reduced size.

According to the embodiment shown in fig. 4, the two meter electronics 204b, 205b are still in electrical communication with each other, such that only one of the meter electronics 204b or 205b is necessarily in direct electrical communication with the remote processing system 207. In the embodiment shown in fig. 4, it is the volume meter electronics 205b that is in direct electrical communication with the remote processing system 207 rather than the density meter 202. As can be appreciated, in this embodiment, the volumetric meter electronics 205b will be configured to receive the density measurement from the density meter electronics 204b and generate a mass flow based on the received density 312 and the generated volumetric flow 314.

In use, the mass flow sensor system 200 can be used to generate a mass flow based on separately determined volumetric flows and densities generated from two separate sensor assemblies 204a, 205 a. According to one embodiment, the density meter 202 may generate a density measurement 312 as the process fluid flows through the conduit 201. Substantially simultaneously, the volumetric flow meter 203 may generate the volumetric flow 314, according to one embodiment. According to another embodiment, the density meter 202 may generate an average density measurement. For example, the meter electronics 204b can store and maintain a rolling average density determined from prior density measurements. The prior density measurement may, for example, be based on a predetermined number of previously received sensor signals 310.

According to one embodiment, at least one of the meter electronics 204b, 205b may receive a fluid measurement from another meter electronics. For example, in the embodiment shown in fig. 2, the density meter electronics 204b can receive the volumetric flow 314 from the volumetric meter electronics 205 b. Conversely, in the embodiment shown in fig. 3, the volume meter electronics 205b can receive the density measurement 312 from the density meter electronics 204 b. Preferably, the meter electronics that receive the fluid measurement are meter electronics in direct electrical communication with the remote processing system 207. However, the present embodiment should not be limited thereto. For example, in fig. 2, the density meter 202 is in direct electrical communication with a remote processing system 207. In some embodiments, the volumetric meter electronics 205b can receive density measurements from the density meter 202. In yet another embodiment, each of the meter electronics 204b, 205b may transmit the generated measurements to the other meter electronics such that each of the meter electronics 204b, 205b includes both a density measurement and a volumetric flow measurement.

According to one embodiment, once one of the meter electronics includes both the density measurement 312 and the volumetric flow rate 314, the meter electronics can process both measurements to generate the mass flow rate 315. The generated mass flow 315 may then be sent to the remote processing system 207 via the lead 208. If the meter electronics that generate the mass flow are not in direct electrical communication with the remote processing system 207, the generated mass flow may be sent to the meter electronics in direct electrical communication with the remote processing system 207 and the mass flow 315 may then be transmitted to the remote processing system 207.

Thus, as can be appreciated, the remote processing system 207 can receive the combined mass flow from the density meter 202 and the volumetric flow meter 203 without having to separately perform the mass flow calculations. This advantageously simplifies the processing required by the remote processing system 207 and greatly reduces the amount of wiring required. Further, if it is necessary to replace either of the meters 202, 203, the remote processing system 207 does not have to be reconfigured.

According to one embodiment, if both meter electronics 204b, 205b include a density measurement and a volumetric flow measurement, both meter electronics 204b, 205b may generate a mass flow measurement. This allows either of the meter electronics 204b, 205b to send the mass flow measurement to the remote processing system 207. Further, in the event that it is necessary to replace one of the meters 202, 203, the remaining meters can easily provide the mass flow measurement to the remote processing system 207.

The above detailed description of embodiments is not an exhaustive description of all embodiments that the inventors could conceive of falling within the scope of the present description. Indeed, those skilled in the art will appreciate that: certain elements of the above-described embodiments may be combined or eliminated in various ways to form yet further embodiments, and such further embodiments fall within the scope and teachings of the present specification. It should also be clear to the skilled person that: the above-described embodiments may be combined, in whole or in part, to form additional embodiments within the scope and teachings of the present specification.

Thus, while specific embodiments have been described herein for purposes of illustration, various equivalent modifications are possible within the scope of the specification, as those skilled in the relevant art will recognize. The teachings provided herein may be applied to other mass flow systems than just the embodiments described above and shown in the drawings. Accordingly, the scope of the embodiments described above should be determined from the claims that follow.

Claims (10)

1. A mass flow sensor system (200), comprising:

a density meter (202) comprising a sensor assembly (204a) and density meter electronics (204b), the density meter electronics (204b) configured to generate a density measurement of a process fluid;

a volumetric flowmeter (203) comprising a sensor assembly (205a) and volumetric meter electronics (205b), the volumetric meter electronics (205b) configured to generate a volumetric flow of the process fluid and in electrical communication with the density meter electronics (204 b); and

a remote processing system (207) in electrical communication with only one of the density meter electronics (204b) or the volume meter electronics (205b) and configured to receive a mass flow measurement of the process fluid, the mass flow measurement generated by the density meter electronics (204b) or the volume meter electronics (205b) based on the generated density measurement and the generated volume flow.

2. The mass flow sensor system (200) of claim 1, wherein the sensor assembly (204a) of the density meter (202) and the sensor assembly (205a) of the volumetric flow meter (203) are positioned in-line with a fluid conduit (201) carrying the process fluid.

3. The mass flow sensor system (200) of claim 1, wherein the sensor assembly (205a) of the volumetric flowmeter (203) is positioned in-line with a fluid conduit (201) carrying the process fluid, and the sensor assembly (204a) of the density meter (202) is positioned in a slipstream (401) coupled to the fluid conduit (201) to receive a portion of the process fluid.

4. The mass flow sensor system (200) of claim 1, wherein the density measurement and the volumetric flow rate are generated substantially simultaneously.

5. The mass flow sensor system (200) of claim 1, wherein the density measurement comprises an average density.

6. A method for generating a mass flow measurement of a process fluid in a fluid conduit, comprising the steps of:

determining the density of the process fluid with a densitometer comprising a sensor assembly in fluid communication with the process fluid and densitometer electronics;

determining a volumetric flow rate of the process fluid with a volumetric flow meter comprising a sensor assembly in fluid communication with the process fluid and volumetric meter electronics;

providing electrical communication between the density meter electronics and the volume meter electronics;

determining a mass flow rate of the process fluid using at least one of the density meter electronics or the volumetric meter electronics based on the determined density and the determined volumetric flow rate; and

providing the mass flow to a remote processing system in electrical communication with only one of the density meter electronics or the volume meter electronics.

7. The method of claim 6, wherein the sensor assembly of the density meter and the sensor assembly of the volumetric flow meter are positioned in-line with a fluid conduit carrying the process fluid.

8. The method of claim 6, wherein the sensor assembly of the volumetric flowmeter is positioned in-line with a fluid conduit carrying the process fluid and the sensor assembly of the density flowmeter is positioned in a slipstream coupled to the fluid conduit to receive a portion of the process fluid.

9. The method of claim 6, wherein the density measurement and the volumetric flow rate are determined substantially simultaneously.

10. The method of claim 6, wherein the density measurement comprises an average density.