US1520549A - Thermostatic couple - Google Patents
Thermostatic couple Download PDFInfo
- Publication number
- US1520549A US1520549A US641168A US64116823A US1520549A US 1520549 A US1520549 A US 1520549A US 641168 A US641168 A US 641168A US 64116823 A US64116823 A US 64116823A US 1520549 A US1520549 A US 1520549A
- Authority
- US
- United States
- Prior art keywords
- couple
- nickel
- chromium
- thermostatic
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 18
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 11
- 229910045601 alloy Inorganic materials 0.000 description 9
- 239000000956 alloy Substances 0.000 description 9
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000005350 fused silica glass Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- 229910052804 chromium Inorganic materials 0.000 description 4
- 239000011651 chromium Substances 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 238000004031 devitrification Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910000623 nickel–chromium alloy Inorganic materials 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000000788 chromium alloy Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 210000002445 nipple Anatomy 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000006903 response to temperature Effects 0.000 description 1
- 239000011034 rock crystal Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/01—Control of temperature without auxiliary power
- G05D23/02—Control of temperature without auxiliary power with sensing element expanding and contracting in response to changes of temperature
Definitions
- This invention relates to thermostatic couples and particularly to such couples available for use at high temperatures as the responsive element in'known types of temperature responsive mechanism, such as pirometerathermostatic regulatorsand the Such couples operate by differential expansion.
- the prime requisite of any two materials to be used conjointly is that they have different coeflicientsof expansion.
- the ideal condition is that each substance shall have a substantially constant coefiicient of expansion throughout the regulative temperature range, or at any rate that the differential coefficient of the two substances shall be as nearly constant aspossible within this range. Otherwise the sensitiveness of the instrument will vary with the temperature.
- Alundum used for the tube or sheath element is fragile and is subject to fracture when used in furnaces, by mechanical injuries received during charging of the, furnace. Moreover, the white fused silica which was heretofore used in practice, al-
- the white silica ware is made by fusing silica sand, while the transparent ware is made by fusing transparent rock crystal.
- the transparent ware is stronger and has a slightly higher specific gravity but aside from these characteristics the two classes of ware are generally considered as substantial equivalents.
- the probable explanation is that the white silica ware contains minute air bubbles which form nuclei for devitrification.
- nickel chromium alloy is more or less elastic. For very high temperatures, say those in excess of 2000 the best alloy known to us consists approximately of 80%- nickel and 20% chromium. For relatively lower'temperatures, such as 1400 F., a much will meet all practical'requirements. Furthermore, as is well known, it is possible to substitute for chromium, in whole or in part, other metals of the chromium group.
- the chromium group we mean the group as defined in the periodic table, namely:
- chromium chromium, molybdenum, tungsten and uranium.
- nickel other metals in the nickel group which includes nickel, cobalt and iron.
- V A considerable range of alloys having the desired properties is available and the selection of a particular composition for a particular case is dependent upon economic conditions and the maximum temperature to be encountered. As a general rule, the higher the temperature the less quantity of iron it is permissible to use in the alloy, and as pure, or even approximately pure, nickel chromium alloys are expensive, it is commercially impractible to use the pure alloy except where necessary to meet extreme high temperature conditions.
- This plug 5 is formed at its inner end with a recess or seat to secure and support the rear end of the fused silica rod 6.
- The" front end of rod 6 is housed in and abuts against.
- the lever 11 through a knife edge 17 actuates in an opening direction a hinged valve 18 urged in the opposite direction by a spring 19.
- the valve 18 controls the leak port 20, forming a part of a well known system of temperature regulations.
- An expansible element for mechanical thermostats composed of an alloy consisting v of nickel and 20% chromium.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Materials For Medical Uses (AREA)
Description
. J. OTTO ET AL THERMOSTATIC COUPLE Filed May 24, 1923 Patented 1).... 23, 1924.
' UNITEDTSTATES 1,520,549. PATENTOFFICE.
' ARTHUR J..0'1T0 AND CARL A. OTTO, or MILWAUKEE, ISCONSIN, ASSIGNORS To JOHNSON SERVIQE COMPANY, or MILWAUKEE, wIscoNsIN, A CORPORATION or WISCONSIN;
THERMOSTATIO COUPLE.
, Application filed May 24, 1928. Serial No. 641,168.
To all whom it may concern:
Be it known that we, ARTHUR J. O'rro and CARLA. O'r'ro. citizens of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new anduseful Improvements in Thermostatic Couples, of which the following is a specification. i
This invention relates to thermostatic couples and particularly to such couples available for use at high temperatures as the responsive element in'known types of temperature responsive mechanism, such as pirometerathermostatic regulatorsand the Such couples operate by differential expansion. Hence the prime requisite of any two materials to be used conjointly is that they have different coeflicientsof expansion. The ideal condition isthat each substance shall have a substantially constant coefiicient of expansion throughout the regulative temperature range, or at any rate that the differential coefficient of the two substances shall be as nearly constant aspossible within this range. Otherwise the sensitiveness of the instrument will vary with the temperature.
At ordinary temperatures these requirements can readily be met by simple selections of material. At high temperatures many special considerations enter. The substances must be fusible only at high temperatures. They must be chemically inert so as to resist chemical interaction with each other, and with chemically active gases (such as furnace gases, vapors met with in metallurgical furnaces, etc.) even at high temperature. They must not be subject to changes of form or to progressive changes of either physical or chemical characteristics either by long continued heating, or by alternate heating and cooling. They must be reasonably goodconductors ofoheat, to ensure rapid response to temperature changes. They must not be subject to frac-' ture by relatively rapid and marked changes of temperature. Finally the materials mustbe susceptible of standardized manufacture, both as to composition and form.
Remembering that these devices, to be useful at all, must be capable of a reliable regulating function within a few degrees Fahrenheit, it is readily seen that their effective differential movements are extremely minute, and that the maintenance uniform of the properties, alluded to above is necessary 1n t e very highest degree. Many substances which on careful preliminary consideration seem highly promising develop defects, often very elusive, when subjected'to the conditions of actual service.
In a prior patent, to A. J. Otto, N0.
1,337,367, is describedand claimed a thermostatic couple composed of fusedsilica and alundum, and this type of couple has gone into extensive use and has successfully met the requirements of high temperature re "lation. It has however, some practical 11mitations-which we have succeeded in overcoming by the present invention.
Alundum used for the tube or sheath element is fragile and is subject to fracture when used in furnaces, by mechanical injuries received during charging of the, furnace. Moreover, the white fused silica which was heretofore used in practice, al-
though a-remarkably stable substance, was
found to be subject after long periods of use to slight devitrification. atthe surface sufiicient to change the adjustment of the thermostat.
The white silica ware is made by fusing silica sand, while the transparent ware is made by fusing transparent rock crystal. The transparent ware is stronger and has a slightly higher specific gravity but aside from these characteristics the two classes of ware are generally considered as substantial equivalents. We have found,'however, that under the conditions of use as the neutral element of the thermostatic couple', the transparent silica is far better than the white silica for the reason that it is virtually free from the devitrification above described. The probable explanation is that the white silica ware contains minute air bubbles which form nuclei for devitrification.
In'the preferred form of the couple form- 'ing the subject matter of this application,
I use transparent fused silica as the relatively inert element and one of the heat resisting so-called nickel chromium alloys as the relatively expansible element.
' The term nickel chromium alloy is more or less elastic. For very high temperatures, say those in excess of 2000 the best alloy known to us consists approximately of 80%- nickel and 20% chromium. For relatively lower'temperatures, such as 1400 F., a much will meet all practical'requirements. Furthermore, as is well known, it is possible to substitute for chromium, in whole or in part, other metals of the chromium group. By the chromium group we mean the group as defined in the periodic table, namely:
chromium, molybdenum, tungsten and uranium.
Similarly, we may substitute for nickel other metals in the nickel group which includes nickel, cobalt and iron. One, such specific substitution, i. e., the. substitution of iron, for part of the nickel, has been suggested. V A considerable range of alloys having the desired properties is available and the selection of a particular composition for a particular case is dependent upon economic conditions and the maximum temperature to be encountered. As a general rule, the higher the temperature the less quantity of iron it is permissible to use in the alloy, and as pure, or even approximately pure, nickel chromium alloys are expensive, it is commercially impractible to use the pure alloy except where necessary to meet extreme high temperature conditions.
The resistance to oxidation offered by these alloys is an important factor when they are used in conjunction with fused silica, for the reason that metallic oxides attack fused silica in some degree so thattheir presence, particularly at high temperatures, is to be avoided. a
The preferred construction of the couple and its application to a thermostatic control device of the pneumatic type, are shown in the accompanying drawing, which chiefly in vertical axial section.
In this drawing 1' s a supporting plate into which is threaded the nipple 2 making part of the body 3 of the thermostat. Into the end of nipple 2 is threaded a.-tube ref an alloy such as above described. The rear end of tube 4 is closed by a' threaded plug,
preferably also of the same 'alloy.- This plug 5 is formed at its inner end with a recess or seat to secure and support the rear end of the fused silica rod 6. The" front end of rod 6 is housed in and abuts against.
The lever 11 through a knife edge 17 actuates in an opening direction a hinged valve 18 urged in the opposite direction by a spring 19. The valve 18 controls the leak port 20, forming a part of a well known system of temperature regulations.
- This structure, with the exception ofthe couple 6 is'familiar to those skilled in the art and is illustrated merely to make 'clear] one practical application of the invention.
What is claimed is: 1 1. An expansible element for mechanical thermostats composed of an alloy consisting.
of 55% or more of a metal or metals of the nickel group and the remainder of a metal or metals of the chromium group.
2. An expansible element for mechanical thermostats composed of an alloy consisting v of nickel and 20% chromium.
,In testimony whereof we have signed our names to this specification.
CARL A. OTTO. ARTHUR J. OTTO.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US641168A US1520549A (en) | 1923-05-24 | 1923-05-24 | Thermostatic couple |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US641168A US1520549A (en) | 1923-05-24 | 1923-05-24 | Thermostatic couple |
Publications (1)
Publication Number | Publication Date |
---|---|
US1520549A true US1520549A (en) | 1924-12-23 |
Family
ID=24571226
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US641168A Expired - Lifetime US1520549A (en) | 1923-05-24 | 1923-05-24 | Thermostatic couple |
Country Status (1)
Country | Link |
---|---|
US (1) | US1520549A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2466515A (en) * | 1949-04-05 | Thermomagnetic safety pilot | ||
US2691710A (en) * | 1946-07-17 | 1954-10-12 | Stewart Warner Corp | Flame detector |
US2963909A (en) * | 1956-03-22 | 1960-12-13 | Carrier Corp | Thermostat sheath |
US3165823A (en) * | 1959-06-26 | 1965-01-19 | Eaton Mfg Co | Metallic surface coating and method for making the same |
-
1923
- 1923-05-24 US US641168A patent/US1520549A/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2466515A (en) * | 1949-04-05 | Thermomagnetic safety pilot | ||
US2691710A (en) * | 1946-07-17 | 1954-10-12 | Stewart Warner Corp | Flame detector |
US2963909A (en) * | 1956-03-22 | 1960-12-13 | Carrier Corp | Thermostat sheath |
US3165823A (en) * | 1959-06-26 | 1965-01-19 | Eaton Mfg Co | Metallic surface coating and method for making the same |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Singh et al. | Determination of the mean solid-liquid interface energy of pivalic acid | |
US1520549A (en) | Thermostatic couple | |
US2705746A (en) | Apparatus for the improvements in thermostats or heat controls | |
US2210526A (en) | Temperature controlling means | |
US4191053A (en) | Temperature-responsive actuator | |
US2366091A (en) | Temperature responsive device | |
US2691690A (en) | Thermocouple element composition | |
US2147108A (en) | Rate of climb indicator | |
US2275719A (en) | Rate of climb indicator | |
US2154030A (en) | Automatic temperature regulator | |
US1819987A (en) | Thermostatic apparatus | |
US2285287A (en) | Automatic control apparatus | |
US2267115A (en) | Hydrometer | |
US2639189A (en) | Vapor pressure thermometer | |
US1652546A (en) | Thermostatic material | |
US1689814A (en) | Thermostatic element | |
US2058426A (en) | Thermostat | |
US1294688A (en) | Pyrometer, &c. | |
US1678889A (en) | Thermostatic material | |
US868264A (en) | Compensation device for torsional pendulums. | |
US1337529A (en) | Thermostat | |
US1337367A (en) | High-temperature thermostat | |
GB372732A (en) | Improvements in or relating to temperature regulators | |
US3127776A (en) | Liquid metal floated gyroscope | |
US2283059A (en) | Control instrument |