Flowmeter batching techniques
In a filling system, a flow rate of a material being dispensed is determined while the material is being dispensed and used to estimate a run-off amount of the material being dispensed. The estimate of the run-off is then used to determine a valve closure time for closing a valve that controls a flow of the material.
1 . A method of operating a filling system, the method comprising:
opening a valve to start a flow of material through a conduit;
while the material is flowing through the conduit:
determining a total amount of the material that has flowed through the conduit;
determining a flow rate of the material flowing through the conduit;
estimating a run-off amount of the material flowing through the conduit based on the flow rate;
determining that the total amount of the material that has flowed through the conduit plus the run-off amount is greater than or equal to a target amount;
in response to determining that the total amount of the material that has flowed through the conduit plus the run-off amount is greater than or equal to a target amount, initiating a closure of the valve to stop the flow of material through the conduit.
2 . The method of claim 1 wherein determining the total amount of the material that has flowed through the conduit comprises calculating TOT t =TOT t-1 +M t Δt, where TOT t is the total amount of the material that has flowed through the flowtube up to present time t, TOT t-1 is the total amount of the material that has flowed through flowtube up to time t-1, M t is the flow rate at time t, and Δt is the interval between time t and t-1.
3 . The method of claim 1 wherein determining the total amount of the material that has flowed through the conduit comprises counting pulses output by a Coriolis flowmeter, wherein each pulse output by the Coriolis flowmeter represents a unit amount of material.
4 . The method of claim 1 wherein determining the flow rate of the material flowing through the conduit comprises:
oscillating the conduit;
sensing a property of the oscillation of the conduit; and
calculating the flow rate based on the sensed property.
5 . The method of claim 1 wherein determining the flow rate of the material flowing through the conduit comprises reading a signal from a Coriolis flowmeter, wherein the signal indicates the flow rate.
6 . The method of claim 1 wherein estimating the run-off amount comprises calculating R=X+M t *Y, where R is the estimated run-off amount, X is a constant amount, M t is the flow rate at present time t, and Y is a run-off time characteristic.
7 . The method of claim 1 wherein initiating the closure of the valve to stop the flow of material through the conduit comprises initiating the closure of the valve less than about 5 seconds after opening the valve.
8 . The method of claim 1 wherein the total amount is a total mass, the flow rate is a mass flow rate, and the target amount is a target mass.
9 . The method of claim 1 wherein the total amount is a total volume, the flow rate is a volumetric flow rate, and the target amount is a target volume.
10 . A flowmeter transmitter comprising:
a parameter determination system configured to determine a flow rate of a material traveling through a flowtube; and
a batch control system configured to estimate a run-off amount of the material based on the flow rate and to determine a valve closure time for a valve associated with the flowtube based on the estimated run-off amount.
11 . The flowmeter transmitter of claim 10 wherein the parameter determination system is configured to determine a total amount of material that has travelled through the flowtube, and the batch control system is configured determine the valve closure time based on the estimated run-off amount and the total amount of material that has travelled through the flowtube.
12 . The flowmeter transmitter of claim 11 wherein the total amount is a total mass, the flow rate is a mass flow rate, and the target amount is a target mass.
13 . The flowmeter transmitter of claim 11 wherein the total amount is a total volume, the flow rate is a volumetric flow rate, and the target amount is a target volume.
14 . The flowmeter transmitter of claim 11 wherein the parameter determination system is configured to determine the total amount of material that has travelled through the flowtube by performing the following calculation: TOT t =TOT t-1 +M t Δt, where TOT t is the total amount of the material that has travelled through the flowtube up to present time t, TOT t-1 is the total amount of the material that has travelled through flowtube up to time t-1, M t is the flow rate at time t, and Δt is the interval between time t and t-1.
15 . The flowmeter transmitter of claim 10 wherein the batch control system is configured to determine the valve closure time by determining whether TOT t +R>=target 2 , where TOT t is the total amount of material that has travelled through the flowtube up to present time t, R is the estimated run-off amount, and target 2 is a target amount.
16 . The flowmeter transmitter of claim 15 wherein the batch control system is configured to estimate the run-off amount by calculating R=X+M t *Y, where R is the estimated run-off amount, X is a constant amount, M t is the flow rate at present time t, and Y is a run-off time characteristic.
17 . The flowmeter transmitter of claim 10 wherein the batch control system is configured to initiate closing of the valve when the valve closure time occurs.
18 . The flowmeter transmitter of claim 10 wherein the flowmeter transmitter is a digital Coriolis flowmeter transmitter.
19 . A filling system comprising:
a conduit to receive a flow of material;
a valve to start and stop the flow of material through the conduit
at least one sensor connected to the conduit; and
one or more processing devices to receive a sensor signal from the sensor and configured to determine a flow rate of the flow of material based on the sensor signal, to estimate a run-off amount of the flow of material based on the flow rate, and to determine a valve closure time based on the estimate of the run-off amount.
20 . The filling system of claim 19 wherein the one or more processing devices are configured to determine a total amount of material that has flowed through the conduit and to determine the valve closure time based on the estimated run-off amount and the total amount of material that has flowed through the conduit.
21 . The filling system of claim 20 wherein the total amount is a total mass, the flow rate is a mass flow rate, and the target amount is a target mass.
22 . The filling system of claim 20 wherein the total amount is a total volume, the flow rate is a volumetric flow rate, and the target amount is a target volume.
23 . The filling system of claim 20 wherein the one or more processing devices are configured to determine the total amount of material that has flowed through the conduit by performing the following calculation: TOT t =TOT t-1 +M t Δt, where TOT t is the total amount of the material that has flowed through the conduit up to present time t, TOT t-1 is the total amount of the material that has flowed through conduit up to time t-1, M t is the flow rate at time t, and Δt is the interval between time t and t-1.
24 . The filling system of claim 19 wherein the one or more processing devices are configured to determine the valve closure time by determining whether TOT t +R>=target 2 , where TOT t is the total amount of material that has flowed through the conduit up to present time t, R is the estimated run-off amount, and target 2 is a target amount.
25 . The filling system of claim 24 wherein the one or more processing devices are configured to estimate the run-off amount by calculating R=X+M t *Y, where R is the estimated run-off amount, X is a constant amount, M t is the flow rate at present time t, and Y is a run-off time characteristic.
26 . The filling system of claim 19 wherein the one or more processing devices comprise a digital Coriolis transmitter processor configured to determine the flow rate of the flow of material based on the sensor signal, to estimate the run-off amount of the flow of material based on the flow rate, and to determine the valve closure time based on the estimate of the run-off amount.
27 . The filling system of claim 19 wherein the one or more processing devices comprise:
a digital Coriolis transmitter processor configured to determine the flow rate of the flow of material based on the sensor signal; and
a programmable logic controller configured to estimate the run-off amount of the flow of material based on the flow rate, and to determine the valve closure time based on the estimate of the run-off amount.
28 . The filling system of claim 27 further comprising an industrial Ethernet connection between the digital Coriolis transmitter and the programmable logic controller.
29 . The filling system of claim 27 further comprising a fieldbus communications connection between the digital Coriolis transmitter and the programmable logic controller.