US3683692A — Process and apparatus to calculate and measure th…

Claim 1

Independent Claim 182 words

Apparatus for counting and measuring the flow of a gaseous fluid in a pipeline by measuring the quantity of heat necessary to raise the temperature of a given quantity of the fluid, comprising a sensing means disposed in the gaseous flow and a reference means disposed in a dead-end cavity containing the gaseous fluid in a manner to be sensitive to fluid temperature but insensible to the flow of this fluid, in which each of the sensing means and reference means comprises a heat resistor for continually heating the adjacent fluid in order to elevate its temperature to a given quantity and a detection element sensitive to the temperature, the sensing means comprising also a heat compensating resistor, means responsive to a difference between the temperatures of the two detection elements for controlling the amount of current passing through said heat compensating resistor so as to cause the heat compensating resistor to maintain the said elevation of the temperature of the fluid flowing past said sensing means, and means for measuring continually the amount of current passing through said heat compensating resistance.

Claim 2

Dependent Claim 182 words

Apparatus for counting and measuring the flow of a gaseous fluid in a pipeline by measuring the quantity of heat necessary to raise the temperature of a given quantity of the fluid, comprising a sensing means disposed in the gaseous flow and a reference means disposed in a dead-end cavity containing the gaseous fluid in a manner to be sensitive to fluid temperature but insensible to the flow of this fluid, in which each of the sensing means and reference means comprises a heat resistor for continually heating the adjacent fluid in order to elevate its temperature to a given quantity and a detection element sensitive to the temperature, the sensing means comprising also a heat compensating resistor, means responsive to a difference between the temperatures of the two detection elements for controlling the amount of current passing through said heat compensating resistor so as to cause the heat compensating resistor to maintain the said elevation of the temperature of the fluid flowing past said sensing means, and means for measuring continually the amount of current passing through said heat compensating resistance.

Claim 3

Dependent Claim 136 words

Apparatus according to claim 1, including a measuring head having a body, in which the sensing means and the reference means are both disposed in said measuring head, a tubular flow divider block inserted into the pipeline through which flows the gaseous fluid for which it is desired to measure flow, said flow divider block being fixed to the measuring head body and communicating with the measuring head, on the one hand by an entry orifice for applying fluid to the measuring head and on the other hand by a discharge orifice by which the gas flow directed into the measuring head rejoins the principle flow, the entry orifice being furnished with a calibrated port, a removable transverse plate provided with calibrated perforations located in the flow divider block between the entry orifice and discharge orifice.

Claim 4

Dependent Claim 71 words

Apparatus according to claim 2, including means defining an annular chamber in the body of the measuring head, the entry orifice of said directed gas flow opening into said annular chamber, said gas flowing in said annular chamber before reaching said sensing and reference means, the calibrated port associated with the entry orifice being very small so that the directed gas flow is agitated to a turbulent movement in said chamber.

Claim 5

Dependent Claim 44 words

Apparatus according to claim 3, including a hollow ring, thermally insulated, disposed in the interior of the annular chamber, so that the fluid takes the temperature of this ring, said ring having the same thermal phase shift as the probe of the sensing means.

Claim 6

Dependent Claim 65 words

Apparatus according to claim 4, in which the cavity of the ring communicates at its lower portion with a first dead-end cavity in which is disposed the reference means and with a second similar cavity in which iS disposed the sensing means, this second cavity also communicating at its upper portion with a conduit connected directly to the delivery orifice of the directed gas flow.

Claim 7

Dependent Claim 36 words

Apparatus according to claim 5, in which the interior walls of the two cavities, in which are respectively disposed the reference means and sensing means, are coated with a thermal insulating material, such as plastic material.

Claim 8

Dependent Claim 140 words

Apparatus according to claim 1, including a measuring head incorporating said dead end cavity and further incorporating a through flow cavity, in which the reference means and the sensing means are essentially comprised of two identical metallic probes each in the form of a bell, said reference means probe being located in said dead end cavity and said sensing means probe being located in said through flow cavity, said bells each having a recess containing a metallic alloy into which are respectively received the heating resistor and the detecting element for the reference means, and the heating resistor and the detecting element and the heat compensating resistor for the sensing means, a provisional resistance, of the same nature as the heat compensating resistor of the sensing means, being also inserted into the recess of the probe of the reference means.

Claim 9

Dependent Claim 99 words

Apparatus according to claim 1 in which the two detecting elements sensitive to the temperature of the gas flow are comprised of thermistors, said difference responsive means including means connecting said thermistors in two adjacent branches of a Wheatstone bridge, a monostable multivibrator supplying the heat compensating resistor of the sensing means, and means for amplifying the unbalance of the bridge and controlling the functioning of said monostable multivibrator, said means for continual measuring of the current passing through the heat compensating resistor comprising a milliammeter and a filter circuit connecting same in parallel with said heat compensating resistance.

Claim 10

Dependent Claim 26 words

Apparatus according to claim 8, including an impulse counter, controlled by the monostable multivibrator and acting as a total counter by integration of the fluid flow.

Claim 11

Dependent Claim 61 words

Apparatus according to claim 9, including an electrical supply and in which the counter has a current consumption equivalent to that of the heat compensating resistor and is supplied current by said supply in phase opposition to said heat compensating resistor in a fashion to assure the constant loading of said supply and in proportion to the flow of gaseous fluid.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1975-08-15	1976-02-14	1976-08-15	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1979-08-15	1980-02-14	1980-08-15	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1983-08-15	1984-02-14	1984-08-15	$7700.00	Window Closed / Lapsed

Process and apparatus to calculate and measure the flow of a gaseous fluid

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