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US 4,896,542 AGranted
Portable wastewater flow meter
OwnerRobert M. Hunterinventor
Life of this patent
Estimating the term…
Abstract
A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.
Claims6
In the process of metering the flow of liquid which is flowing by gravity in an elongated pipe that is open to atmosphere, wherein:
- tubular venturi metering device is installed in the pipe, which has an open-ended bore therethrough having an axis extending end-to-end thereof,
- arranging the device in the pipe so that the axis of the bore is disposed substantially parallel to the longitudinal axis of the pipe and the bore thus has an end which is normally oriented upstream of the liquid flow in the pipe and an end which is normally oriented downstream of the liquid flow in the pipe,
- the bore having an axially inwardly tapered entrance section adjacent the upstream end thereof which converges toward the axis of the bore in vertical planes paralleling the axis of the bore relatively toward the downstream end of the bore but terminates short of the axis of the bore so that a throat is formed in the bore which opens to the downstream end thereof,
- forming a liquid seal between the device and the pipe at the outer periphery of the device so that the liquid in that section of the pipe disposed upstream from the upstream end of the bore of the device, is constrained to flow through the bore of the device, relatively toward the downstream end thereof,
- determining the static pressure head in the liquid in the aforesaid upstream section of the pipe when the liquid is flowing in the pipe at a depth less than that adapted to fill the upstream pipe, to meter the flow in the pipe for the less than full condition thereof,
- configuring the cross-sectional area of the throat, relative to that of the pipe, transverse the respective axes thereof, so that the throat will fill with liquid substantially simultaneously with the upstream section of the pipe, when the liquid depth rises therein, and
- providing means whereby the static pressure head of the liquid in the throat of the device and the upstream section of the pipe can be determined when both the upstream section of the pipe and the throat are filled, so that the difference between the latter two pressure heads can be determined to meter the flow in the pipe for the full condition thereof, and thereby enable the flow in the pipe to be metered for the full condition thereof as well as the less than full condition thereof and the transition therebetween,
- the improvement wherein:
- arranging the device in the pipe with its axis and the top of its throat horizontal thus leveling the device,
- the bore having an axially outwardly tapered exit section adjacent the downstream end thereof which diverges from the axis of the bore in vertical planes paralleling the axis of the bore relatively toward the end of the bore that is normally downstream,
- providing means whereby the static pressure head of the liquid in the throat of the device and in both the entrance section and the exit section can be determined, so that the difference between the static pressure heads in the entrance section and in the exit section can be used to determine the direction of flow and, hence, the actual upstream end of the device, and, during the less than full condition, an appropriate correction factor for metering the flow rate, and so that the difference between the throat pressure head and the actual upstream pressure head can be determined to meter the flow in the pipe for the full condition thereof.
8 more elements
In the combination wherein there are:
- an elongated pipe which is open to atmosphere and adapted for the flow of liquid by gravity therein,
- a tubular venturi metering device installed in the pipe and having an open-ended bore therethrough which has an axis extending end-to-end thereof,
- the device being arranged in the pipe so that the axis of the bore is disposed substantially parallel to the longitudinal axis of the pipe and the bore thus has an end which is normally oriented upstream of the liquid flow of the pipe and an end which is normally oriented downstream of the liquid flow in the pipe,
- the bore having an axially inwardly tapered entrance section adjacent the upstream end thereof, which converges toward the axis of the bore in vertical planes paralleling the axis of the bore and in that axial direction of the bore relatively toward the downstream end of the bore, but terminates short of the axis of the bore so that a throat is formed in the bore which opens to the downstream end thereof,
- means for forming a liquid seal between the device and the pipe at the outer periphery of the device so that the liquid in that section of the pipe disposed upstream from the upstream end of the bore of the device, is constrained to flow through the bore of the device, relatively toward the downstream end thereof, and
- first means for determining the static pressure head of the liquid in the aforesaid upstream section of the pipe when the liquid is flowing in the pipe at a depth less than that adapted to fill the upstream section of the pipe, to meter the flow in the pipe for the less than full condition thereof,
- the cross-sectional area of the throat being configured relative to that of the upstream section of the pipe, transverse the respective axes thereof, so that the throat will fill with liquid substantially simultaneously with the upstream section of the pipe, when the liquid rises therein, and
- there being second means for determining static pressure head of the liquid in the throat of the device and in the upstream section of the pipe when both the upstream section of the pipe and the throat are filled, so that the difference between the latter two pressure heads can be determined to meter the flow in the pipe for the full condition thereof, and thereby enable the flow in the pipe to be metered for the full condition thereof, as well as the less than full condition thereof and the transition therebetween,
- the improvement comprising
- means for leveling the device,
- an axially outwardly tapered exit section adjacent the downstream end of the bore which diverges from the axis of the bore in vertical planes paralleling the axis of the bore relatively toward the end of the bore that is normally downstream,
- means for determining the static pressure head of the liquid in the throat of the device and both in the entrance section and in the exit section whereby the difference between the static pressure heads in the entrance section and the exit section can be used to determine the direction of flow and, hence, the actual upstream end of the device, and during the less than full condition an appropriate correction factor for metering flow rate and whereby the difference between the throat pressure head and the actual upstream pressure head can be determined to meter the flow in the pipe for the full condition thereof.
9 more elements
Dependencies are inferred from the claim text.