Precision Machine Products, Inc.

Precision Measurement, Inc.

Other

Badger Meter, Inc.

Lyn R Kennedy

William H Clingman, Jr

Instrument and method for heating value measurement by stoichiometric

Disclosed is a method and apparatus for taking a constantly proportional flowing sample of gas flowing through a main line having a first flow restriction therein. According to the teachings of the present of invention, such an apparatus includes a sample line connected to the main line so as to draw a flowing sample of gas from the main line at a point upstream from the first flow restriction; a second flow restriction in the sample line, the second flow restriction being very small relative to the main and sample lines and the first flow restriction; and structure that equalizes the pressure downstream of the first and second flow restrictions.

Method and apparatus for taking a proportional sample of flowing gas in

Disclosed is a method for taking a constantly proportional flowing sample of gas flowing through a line and which is part of measuring and determining the total energy flow, that is, BTUs per minute, of combustible gas flowing through a line such as a pipeline. One method includes taking a continuous sample of the gas flowing through the line which sample is a constant proportion of the gas flowing through the line, and burning the sample in equipment which supplies air to the sample in an amount which maximizes its burning temperature. The flow rate of air which produces the maximum burning temperature of the sample is a flow rate which is directly proportional to the rate of energy flow in the main pipeline. Alternately, the flow rate of air which produces a stoichiometric mixture is directly proportional to the rate of energy flow in the main pipeline. Still further, if an excess of air is flowed to the flame, the amount of excess unconsumed oxygen is also a function of the rate of energy flow in the main pipeline. One or another of these parameters is measured.

Method of taking a proportional sample of flowing gas in a line

Gas is vented through a very small orifice or pore with substantially stable pressures before and after the orifice. The orifice is designed so that the expansion through it is similar to a Joule-Thompson expansion of the gas. With ideal gas, this occurs isothermally. The flow through this orifice is determined for a selected pressure drop across it and the square of this flow is inversely proportional to the relative density. With real gases there is a slight error introduced due to a supercompressibility of the gas, but this is offset by an error in the opposite direction believed to be due to the Joule-Thompson cooling of the gas as it passes through the orifice. Substantially exact error cancellation is obtained within a preferred operating range of the pressure drop across the orifice for a given orifice diameter.

Method and apparatus for measuring the relative density of gases

Disclosed are methods and apparatus for measuring and determining the total energy flow, that is, BTUs per minute, of combustible gas flowing through a line such as a pipeline. One method includes taking a continuous sample of the gas flowing through the line which sample is a constant proportion of the gas flowing through the line, and burning the sample in equipment which supplies air to the sample in an amount which maximizes its burning temperature. The flow rate of air which produces the maximum burning temperature of the sample is a flow rate which is directly proportional to the rate of energy flow in the main pipeline. Alternately, the flow rate of air which produces a stoichiometric mixture is directly proportional to the rate of energy flow in the main pipeline. Still further, if an excess of air is flowed to the flame, the amount of excess unconsumed oxygen is also a function of the rate of energy flow in the main pipeline. One or another of these parameters is measured. Also disclosed is equipment capable of effectively performing the several steps of the method.

Method and apparatus for determining total energy flow in a gas line

Disclosed is a method and apparatus for measuring and controlling volumetric flow rate of gases. The apparatus includes a measurement chamber of fixed volume in a flow line, a controllable inlet valve upstream from the chamber, and flow regulator means for establishing constant flow output downstream from the chamber. Also provided are measuring and control equipment including a pressure sensor in the chamber, means for controlling operation of the inlet valve, timing means, and means for calculating volumetric flow rate. The method involves closing the inlet valve at a chosen time for a selected interval, to interrupt flow into the measurement chamber, while maintaining constancy of flow out of the chamber. During at least part of the interval in which the inlet valve is closed, the pressure decrease is measured, and the rate of pressure decrease is calculated by dividing the measured pressure drop by the time measured by the timing means. The thus calculated rate of fall of pressure is directly related to the volumetric flow rate, which is thus determined.

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Ovilla, TX, United States of America

Lyn R Kennedy