Method and apparatus for detecting and measuring scale
AssigneeRohrback Corporation
InventorsElmond A. Holmes, Gilson H. Rohrback
Life of this patent
Estimating the term…
Abstract
A thermal bridge is employed to compare thermal transfer characteristics of test and reference surfaces immersed in identical fluid environments so as to determine thermal transfer characteristics of the test surface substantially independent of fluid environment. The thermal bridge is balanced, the test surface is caused to be scaled to a greater degree than the reference surface and a comparative measurement is made with the two surfaces exposed to identical fluid environments. The method is performed by a single probe having two or more surfaces that are heated and of which the differential temperatures are monitored. Readings are adjusted to compensate for effects of a varying fluid environment.
Claims49
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon, subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters,
- subjecting said reference surface to said first mentioned fluid environment during said first mentioned step,
- varying the propensity of said first mentioned fluid environment to deposit foulant upon said test surface relative to its propensity to deposit foulant upon said reference surface during said first mentiond step,
- transferring heat between said surfaces and their respective fluid environments, and
- comparing the heat transfer characteristics of said surfaces adjacent their respective fluid environments.
The method of claim 3 wherein said surfaces are caused to have substantially the same thermal characteristics prior to said first mentioned step.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface of said fluid environment whereby foulant may be deposited thereon, subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters,
- comparing the heat transfers between said surfaces and their respective fluid environments,
- said step of comparing including sensing the difference in temperature of said test and reference surfaces, and
- applying to said surfaces respectively first and second heat fluxes differentially adjusted to decrease variation of said difference in temperature with variation of the fluid environments to which said test and reference surfaces are subjected.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat fluid parameters,
- comparing the heat transfers between said surfaces and their respective fluid environments, said step of comparing comprising applying thermal fluxes to said test and reference surfaces,
- comparing the temperatures of said surfaces, and including the step of differentially adjusting the thermal fluxes applied to said test and reference surfaces so as to decrease variation of the temperature comparison with variation of the fluid environments to which said surfaces are both subjected.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters,
- comparing the heat transfers between said surfaces and their respective fluid environments, said step of comparing comprising applying mutually different thermal fluxes to said test and reference surfaces to maintain mutually equal temperatures at said surfaces, and
- comparing the respective thermal fluxes applied to said surfaces respectively.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters,
- comparing the heat transfers between said surfaces and their respective fluid environments,
- subjecting said reference surface to said first mentioned fluid environment during said first mentioned step, and
- varying the propensity of said first mentioned fluid environment to deposit foulant upon said test surface relative to its propensity to deposit foulant upon said reference surface during said first mentioned step.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters, and
- comparing the heat transfers between said surfaces and their respective fluid environments, said last mentioned fluid environments being substantially identical to each other and being different than said first mentioned fluid environment.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters, and
- comparing the heat transfers between said surfaces and their respective fluid environments, including the step of applying a first thermal flux to said test surface during said first mentioned step to enhance the propensity to deposit foulant and applying second thermal fluxes to both said test and reference surfaces during said step of comparing.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters, and
- comparing the heat transfers between said surfaces and their respective fluid environments, including the step of varying the foulant forming conditons present at the interface between said test surface and said fluid environment to thereby change the rate of foulant deposited upon said test surface, said last mentioned step being carried out prior to said step of comparing.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising,
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters,
- transferring heat between each said surface and its respective fluid environment,
- sensing the difference in temperatures of said surfaces,
- sensing a heat transfer characteristic of said last mentioned fluid environments, and
- compensating said sensed difference in temperature in accordance with said sensed heat transfer characteristic.
The method of detecting deposition of adherent precipitate upon a surface which comprises:
- providing first and second surfaces,
- exposing said surfaces to a fluid which may deposit an adherent precipitate thereon,
- varying the propensity of said first mentioned fluid environment to deposit foulant upon said test surface relative to its propensity to deposit foulant upon said reference surface during said second mentioned step,
- exposing said surfaces to fluid environments having a known relation of heat flow parameters,
- enhancing heat flow between said surfaces and said fluid environments, and
- comparing heat transfer characteristics of said first and second surfaces adjacent said fluid environments having a known relation of heat flow parameters.
The method of detecting deposition of adherent precipitate upon a surface which comprises:
- providing first and second surfaces,
- exposing said surfaces to a fluid which may deposit an adherent precipitate thereon,
- enhancing the deposition rate on said first surface with respect to the deposition rate on said second surface to thereby induce more deposition of adherent precipitate on said first surface than on said second surface, and
- comparing heat transfer of said first and second surfaces to fluid environments having a known relation of heat flow parameters, said step of enhancing comprising providing different temperatures at said first and second surfaces.
The method of detecting deposition of ahderent precipitate upon a surface which comprises:
- providing first and second surfaces,
- exposing said surfaces to a fluid which may deposit an adherent precipitate thereon,
- enhancing the deposition rate on said first surface with respect to the deposition rate on said second surface to thereby induce more deposition of adherent precipitate on said first surface than on said second surface,
- comparing heat transfer characteristics of said first and second surfaces, and
- providing heat inputs to said first and second surfaces relatively adjusted to unbalance temperature difference at said surfaces in a sense to decrease sensitivity to changes in fluid environment.
The method of monitoring foulant accumulation upon a surface that has been exposed to a fluid that may be foulant comprising:
- exposing said surface and a reference surface to a common fluid,
- comparing the heat transfer between said common fluid and each said surface, and
- compensating for initial differences in thermal transfer characteristics of said surfaces by applying compensatory differential heating thereto when said surfaces are in mutually similar conditions of surface accumulations.
The method of monitoring foulant accumulation upon a surface that has been exposed to a fluid that may be foulant comprising:
- exposing said surface and a reference surface to a common fluid,
- comparing the heat transfer between said common fluid and each said surface, and
- compensating said comparing of heat transfer according to variation of heat transfer characteristics of said common fluid.
The method of monitoring foulant accumulation upon a surface that has been exposed to a fluid that may be foulant comprising:
- exposing said surface and a reference surface to a common fluid,
- comparing said heat transfer between said common fluid and each said surface, and
- controlling said common fluid according to variations of its heat transfer characteristics, thereby to decrease said variations.
A foulant probe comprising:
- first and second surfaces,
- means for heating said surfaces,
- means for measuring temperature of said surfaces,
- a probe sheath having first and second areas thereof forming said test and reference surfaces respectively,
- said means for heating comprising a heater having first and second heater portions mounted within said sheath and positioned at said first and second areas respectively,
- said means for measuring temperature comprising first and second sleeves interposed between each of said heater portions and said first and second areas respectively, and
- first and second heat sensing elements connected with said first and second sleeves adjacent said first and second sheath areas respectively.
A thermally sensitive foulant probe comprising
- an elongated cartridge having first and second heater elements mounted thereto at first and second areas thereof spaced axially along said cartridge,
- a first sleeve circumscribing said cartridge in close thermal contact with said first area thereof,
- a second sleeve circumscribing said cartridge in close thermal contact with said area second thereof,
- an elongated probe sheath circumscribing said cartridge and said sleeves in close thermal contact with said sleeves, and
- first and second temperature sensing devices fixed to and between said probe sheath and said first and second sleeves respectively.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to be measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for measuring the temperature of said surfaces to generate a measurement signal,
- a source of heater power,
- means for applying said power to said heating means, and
- means for compensating said measurement signal in accordance with variations of said heater power.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to be measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for measuring the temperature of said surfaces to generate a measurement signal,
- said heating means comprising means for providing relative heating to said surfaces in a predetermined relation that yields a decreased change in difference between said temperatures for changes in said fluid environment.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to be measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for measuring the temperature of said surfaces to generate a measurement signal, and
- means responsive to said fluid environment for compensating said measurement signal in accordance with a characteristic of said fluid environment, said characteristic of said fluid environment being one of the characteristics of viscosity and flow velocity.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to be measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for measuring the temperature of said surfaces to generate a measurement signal,
- means responsive to said fluid environment for compensating said measurement signal in accordance with a characteristic of said fluid environment,
- said means for compensating said measurement signal comprising means for sensing a characteristic of said fluid environment that varies its thermal effect upon said test and reference surfaces,
- means responsive to said last named sensing means for generating a fluid environment signal, and
- means for adding said fluid environment signal to said measurement signal.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to be measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for measuring the temperature of said surfaces to generate a measurement signal,
- means responsive to said fluid environment for compensating said measurement signal in accordance with a characteristic of said fluid environment,
- said means for compensating comprising means for sensing a characteristic of said fluid environment that varies its thermal effect upon said test and reference surfaces, means responsive to said last named sensing means for generating a fluid environment signal representative of changes in said fluid environment,
- means for combining said measurement signal with said fluid environment signal,
- means for generating a compensation signal that is a function of said combined measurement and fluid environment signal, and
- means for combining said compensation signal with said measurement signal to provide an indication of foulant on said test surface as compared to said reference surface, said indication being compensated for variation of said fluid environment.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to be measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for measuring the temperature of said surfaces to generate a measurement signal that indicates foulant propensity, and
- including means responsive to said fluid environment for varying said fluid environment to decrease variation of a heat flow parameter thereof.
The method of monitoring foulant propensity of fluid of a fluid system comprising the steps of
- flowing fluid from said system over reference and test surfaces,
- enhancing the propensity of said fluid to deposit foulant upon said test surface during a foulant period,
- flowing fluids having a known relation of heat flow parameters over said test and reference surfaces respectively during a measuring period,
- applying heat flux to both said surfaces during said measurement period to enhance transfer of heat therefrom to said fluids, and
- measuring transfer of heat from said test and reference surfaces to said fluids during said measuring period.
A thermal probe adapted to be immersed in a fluid environment to detect foulant propensity thereof, said probe comprising
- test, fluid environment, and reference surfaces, test and reference heaters adjacent said test and reference surfaces respectively,
- means for differentially measuring temperature at said test and reference surfaces, and
- means responsive to temperature of said fluid environment surface for compensating the differentially measured temperature of said test and reference surfaces.
A thermal probe adapted to be immersed in a fluid environment to detect foulant propensity thereof, said probe comprising:
- test and reference surfaces,
- test and reference heaters adjacent said test and reference surfaces respectively,
- means for differentially measuring temperature at said test and reference surfaces,
- means for providing heating power to said heaters, and
- means for effecting a difference in the heating power applied to said heaters to compensate for differences in thermal characteristics of the heat path including said reference surface and its associated heater and the heat path including said test surface and its associated heater.
A thermal probe adapted to be immersed in a fluid environment to detect foulant propensity thereof, said probe comprising:
- test and reference surfaces,
- test and reference heaters adjacent said test and reference surfaces respectively,
- means for differentially measuring temperature at said test and reference surfaces,
- said surfaces comprising first and second portions of a probe body of thermoelectric material,
- said means for differentially measuring temperature comprising a first wire joined to said first probe body portion,
- a second wire connected to said second probe body portion, said wires being formed of a thermoelectric material different than the material of said probe body, and
- means for measuring the voltage difference between said wires at points thereof remote from their respective junctions with said probe body to thereby measure the temperature difference between said junctions.
A foulant probe adapted to be immersed in a fluid environment of which the foulant propensity is to measured, said probe comprising:
- first and second measuring surfaces,
- means for heating said surfaces,
- means for differentially measuring the temperature of said surfaces to generate a measurement signal, and
- means responsive to said fluid environment for compensating said measurement signal in accordance with a characteristic of said fluid environment.
A method of testing a fluid environment for a propensity to deposit foulant upon a surface immersed therein comprising:
- subjecting a test surface to said fluid environment whereby foulant may be deposited thereon,
- subjecting both a reference surface and said test surface to fluid environments having a known relation of heat flow parameters,
- comparing the heat transfers between said surfaces and their respective fluid environments,
- sensing a heat transfer characteristic of said last mentioned fluid environments, and
- compensating said comparison of heat transfers in accordance with said sensed characteristic.
A thermally sensitive foulant probe comprising
- an elongated probe sheath,
- first and second heater elements spaced axially along said sheath,
- a first sleeve circumscribing said first heater element in close thermal contact therewith,
- a second sleve circumscribing said second heater element in close thermal contact therewith, said elongated probe sheath circumscribing said heater elements and said sleeves in close thermal contact with said sleeves, and
- first and second temperature sensing devices fixed to said first and second sleeves respectively adjacent said sheath.
Dependencies are inferred from the claim text.