Apparatus for computing BTU content in a sample of gas
AssigneeRosemount Analytical Inc.
InventorFred C. Sittler
Life of this patent
Estimating the term…
Abstract
An apparatus for measuring the BTU content of a gas includes a source of combustion air, a detector and a sample loop or tube connected to a six-port switching valve. The switching valve allows accurate and repeatable quantities of the gas to be obtained and mixed with the combustion air. In a second embodiment, the apparatus includes a second switching valve to obtain samples of the gas at a second pressure and calculate the BTU content at the second pressure. By measuring the BTU content at two different pressures, a quantity related to the volumetric flow of the gas between the two pressures can also be calculated.
Claims17
An apparatus for measuring the BTU content of a sample of gas from a source of gas, the apparatus comprising:
- a source of combustion air;
- a switching valve having six ports, each port being selectively fluidly connected to two of the six ports, wherein a first port is connected to the source of combustion air and is selectively fluidly connected to a second port and a third port, a fourth port connectable to the source of gas and selectively fluidly connected to the third port and a fifth port connectable to a pressure source of a pressure less than that of the source of gas, and a sixth port selectively fluidly connected to the second port and the fifth port;
- a sample tube connected to the third port and the sixth port;
- a detector, connected to the second port, for sensing the heat content of a sample volume of the gas;
- and
- a computer receiving a signal from the detector representative of the heat content of the sample volume of gas and operably connected to the switching valve.
An apparatus for measuring the BTU content of a sample volume of a gas, comprising:
- a source of combustion air;
- a sample tube for holding a predetermined volume of the gas and having a first end and a second end;
- a detector for sensing the heat content of the predetermined volume of gas;
- a switching valve having multiple ports and at least two operating states, the multiple ports being connected to the first end and the second end of the sample tube and being fluidically coupleable to the source of combustion air, the gas, and the detector;
- and
- a computer providing a control signal to the switching valve to select one of the at least two operating states, the computer further receiving a signal from the detector representative of the heat content of the sample volume of gas.
An apparatus for measuring the BTU content of a gas, comprising:
- a source of combustion air;
- a sample tube for holding a predetermined volume of the gas;
- a mixing device for mixing air from the source of combustion air with the predetermined volume of the gas;
- a sensor for sensing the heat content of the predetermined volume of gas;
- a reference sensor for sensing a temperature of the mixed combustion air and the predetermined volume of gas;
- a switching valve having multiple ports and at least two operating states, the multiple ports being fluidically coupleable to the source of combustion air, the gas, the sample tube;
- the sensor and the reference sensor;
- and
- a computer providing a control signal to the switching valve to select one of the at least two operating states, the computer further receiving a signal from the sensor representative of the heat content of the sample volume of gas and a signal from the reference sensor representative of the temperature of the mixed combustion air and the predetermined volume of gas.
Dependencies are inferred from the claim text.