US2120874A - Throttling calorimeter - Google Patents

Description

June 14, 1938. STONE THROTTLI NG CALORIME TE R Filed 001'- 14, 1935 liZir Stone;

Patented June 14, 1938 UNITED STATES PATENT OFFECE THROTTLING CALORIMETER Blair H. Stone, El Reno, Okla. Application October 14, 1935, Serial No. 44,995

5 Claims.

The invention relates to improvements: in steam measuring devices generally and more particularly to a throttling calorimeter thereof.

An object of the invention is to provide a throttling calorimeter with means to indicate, by direct reading and/or visual and/or audible signals, the quality of steam in percent of moisture content.

Another object has to do with the provision of the modified throttling calorimeter as aforesaid ,and which is adapted to indicate the percent of moisture content of steam at a point remote from the source of steam generation. 7

Still another object resides in the provision of a measuring device of this class which will operate for either continuous or intermittent indication of the percent of moisture content of steam, the operation thereof being based on the medium of a temperature gage of the Bourdon,

' tube type which is actuated either by the vapor fully described, set forth in the appended claims, I and illustrated in the accompanying drawing,-

in which: a

Figure 1 is a side elevation of the device, in accordance with the instant invention,

Figure 2 is a right hand end elevation thereof, with the indicator gage and. electric-a1 circuits removed, 1 v

Figure 3 is a vertical longitudinal'section taken on the line 3--3 of Figure 2, and

Figure 4 is a'plan view of the Bourdon tube and its associated contacts and wires of the electrical indicating or signal circuits, with the enclosing casing thereof removed.

Referring to the drawing, wherein like characters of reference designate corresponding parts in the several views thereof, the embodiment of the invention, as is shown therein by way of example only, is constituted generally in a throt- -tling calorimeter A to receive a sample of steam from a source or vessel (not shown); a gage 3 having connection with the calorimeter A and its dial calibrated to give readings in percent of moisture content of steam; electrical circuits C leading from controlling contacts within the gage B to audible and visual signal instrumentalities which operate at predetermined settings of the gage to indicate certain percentages of the moisture content of the steam under test; and an automatic boiler blow-down valve D which is cooperative with one of the said signal circuits.

The throttling calorimeter A is comprised in an outer casing or jacket Ill which is substantially cylindrical in form and has its ends closed by plates II and I2. The plate II is preferably screw threaded into the casing or jacket end and has an oppositely nippled openingat its center, with the outer nipple portion I 3 externallyscrew threaded, as at I30, for its attachment to the steam source or vessel from which samples are to be taken for test. The inner nipple portion I4 is in connection with the end plate I5 of a throttling chamber or barrel I6 which is positioned within the casing or jacket ID at the approximate center thereof.

The casing or jacket Ill is provided with an opening in its top side for the packing of its interior, about the throttling chamber or barrel I6, with a heat insulating material H; the said opening being normally closed, by a removable cover I8 which is held in place by screws or the like I8a.

Extending inwardly of the bore of the nipple portions I3I -l is a sampling nozzle I9 which is in the form of a length of metal tubing or pipe having its outer end closed and its inner end open and internally screw threaded for attachment to an orifice plug 29; the latter, in turn, being screw threaded outwardly of an opening in the center of the end plate I5 of the throttling chamber or barrel I 6. The outer end portion of the nozzle'lll is provided with side perforations I9a for the intake of steam there-through and its subsequent passage through the nozzle tothe orifice in the plug 20.

Thethrottling chamber or barrel I6 is pref- .erably cylindrical in form and'has one end in screw threaded connection with the end plate I5 and its other end in similar connection with an end plate 2| carried at the inner end'of the inner nipple portion 24 of an opening in the end plate I2 of the casing or jacket Id. Steam admitted to the throttling chamber or barrel I6 is exhausted therefrom outwardly through a nippled outlet 22, projecting from the lower side of. the chamber or barrel toward the end thereof opposite the orifice plug 20, and from thence outwardly through a nippled outlet 23 projecting through the wall of the casing or jacket Ill. The end. plate H. has its central opening in line with the bores of the inner nipple portion 24 and an outer nipple portion 25 and with the orifice in the plug 20.

Passing inwardly through the bore 26 thus provided is an orifice plug rod or needle valve 21, the inner end of which is tapered off or pointed, as at 21a, for cooperative engagement with the orifice in the plug 20. A coiled spring 28 is engaged over the inner end of the valve rod 21 and is compressed thereon, between the end plate 2| and a shoulder 29 on the valve rod adjacent the pointed or valve end thereof, tonormally tension the latter in closing engagement with the plug orifice. V

The outer nippled portion 25 of the end plate |2, of the casing or jacket II), is provided with a depression in its end face to receive a packing 30 which is held in place by a jam nut 3| and compressed thereby about the valve rod 21.

' Attached to the outer side of the end plate I2, by means of a screw or the like 32, is an angled bracket 33 which carries a cylinder 34 at its free end. The cylinder 34 has its bore 34a disposed in line with the bore 26 passing through the nipple portions 24-25 and the end plate 12 to receive the outer end of the valve rod 21, which end is arranged in screw threaded connection with a piston 35. The inner end of the cylinder 34 is provided with a packing 36 which is compressed in place about the valve rod 21 by means of a jam nut 31.

An operating fluid for the piston is admitted to the bore 34a, of the cylinder 34, through a screw threaded connection 38 and effects a movement of the piston and the valve rod in a direction against the tension of the spring 28 to open the orifice in the plug 20 for admitting steam from the nozzle I9 to the interior of the throttling chamber or barrel I6. 7

Positioned within'the throttling chamber or barrel |6 is an annular bulb or chamber 39 which is stationarily encircled about the spring 28 and the valve rod 21 and has connection with a conduit or tubing 40 leading outwardly of the throttling chamber or barrel through the end plates 2| and I2 to a point of connection with an inlet 42 of the casing 4| of the gage B. V

The gage B is suitably emplaced apart from the calorimeter A and has a Bourdon tube with- .in the casing 4| and connected at oneend to the inlet 42.

the casing 4|, is a usual operating means (not Cooperative with the tube 43, within shown) for the shaft44 of an index or pointer 45 which overlies a dial 46 mounted onone of the outer sides of the casing.

The dial 46 has its face provided with two concentric scales of graduations 41' and 48, the

outer scale ,41 being calibrated to read in percent of moisture content of the steam sampled and the inner scale 48 in degrees of steam quality. V

Cooperative with the Bourdon tube 43, within the casing 4|, is an electric switching means for 1 controlling external indicating circuits C. The

tion in steam boiler operation upon the alternate closing and opening of the circuit with which it is cooperative by the switching means under the control of the gage B.

The switching means is comprised in a link 49 connecting the gage tube 43, through pivot connection 50, with the index or pointer operating means. 'This link 49 is preferably made of an insulating materiaL'such as hard fibre or the like, and is pivoted, as at 50, to the free end of the gage tube 43, somewhat after the manner shown in Figure. 4, and carries a switch arm 5| in angular relation thereto for wiping cooperation with a pair of electric contacts 52 and 53 mounted on an insulated support 54. The contacts 52 and 53 are spaced apart from each otherand from adjacent sides of the switch arm 5|. The support 54 is adjustably fastened in place to the gage casing 4| by means of a slot connected by a conductor 62 to one side of a signal lamp 63. A conductor 64 leads from the other terminal of the current source or battery 59 and directly connects the other side. of the signal lamp 63 and also connects oneside of a second signal lamp 65 by'a branch conductor 66.

An audible signal device, such as an electric bell or buzzer 61, has one of its terminals connected by a conductor 69 to the battery conductor 64 at a point thereon between the points of connection of the samewith the signal lamps 63 and 65, and its other terminal by'a conductor 68 to the conductor at a point thereon between the switch contact 53 and the electromagnet 6|. The switch 52 is .directly connected to the remaining side of the second signal lamp by a conductor 10. r

Inthe operation .of the apparatus. or device thus provided, the calorimeter A is attached to the steam source or vessel (not shown) from which steam is to be sampled 'at the threaded nipple |3, when steam will pass into the nozzle I9 at the perforations I90. The gage B will then be placed in a convenient position, either at the point of temperature or at apoint remote therefrom, and, if the electrical indicating circuits C are employed, ,they will also be suitably located to meet the requirements of the installation. Upon the placing of the calorimeter A the threaded connection 38' will be. coupled to a source of fluid pressure (not shown) for the actuation of the piston 35. With the calorimeter A installed as stated, the nozzle I9 is projected well into the steam mass and is surrounded at all times by steam which is of the same temperature and pressure as that of the steam sample passed through the nozzle to the throttling orifice. 7

Now, by admitting pressure to the cylinder 34, thepiston 35 will be forced to the right and thereby exert a pull on the rod 21 and withdraw the valve point 21a from the orifice; in the'plug 20. This movement of the piston and rod will act to compress the spring 28 between the shoulder 29 and the end plate 2|, so that'the spring will function to return the rod and piston to normal position, with the valve. point 2101. again closing the orifice in the plug 20, when the pressure is released from the piston 35.

Upon the opening of the orifice in the plug 20, by the withdrawal of the valve point 2111 therefrom, steam will pass from the nozzle I9 into the throttling chamber or barrel l6 and about and through the open center of the bulb 39 to the exhaust port nipples 22 and 23. In the passage of the steam sample around the bulb 39, heat therefrom will be transferred to a fluid in the bulb and the conduit or tubing 43 for the actuation of the Bourdon tube 43 in the gage casing 4|; the pressure of this fluid changing with temperature variations of the steam sample.

In the instant disclosure of the invention, a vapor tension type of gage has been described and shown, but it will be obvious that other types of dial thermometers, for instance, a gas filled type thereof, may be substituted therefor, if and when desired. The gage is adjustable for various pressures at its linkage, for instance, from an initially device, if and when set pressure indication, the linkage will be shortened or lengthened respectively for an increase or a decrease in indicated pressure, each adjustment being for a temperature change representative of a one percent change of the pointer on the dial of the gage.

Further in the operation of the apparatus or the switching means and the electrical indicating circuits C, together with the automatic blow-down valve D, are employed, upon movement of the Bourdon tube 43, to swing the link 49 on the pivot 50, for instance to cause 1 the switch arm to wipe over the contact 53,

the circuit will be closed on the current source or battery 55, the electromagnet 5|, the signal lamp 5%, and the bell or buzzer 51; the current passing from the positive terminal of the current source or battery 59 by way of conductor 58, switch arm 51, contact 53, conductor 60, electromagnet 6|, signal lamp 63, and conductor 54 to the negative terminal or" the current source or battery 59. Also, current will flow from conductor 60 by Way of conductor 68,the bell or buzzer 61, and conductor 69 to the current source or battery return conductor 54. In the other or reverse movement of the Bourdon tube43 and the link 49, the switch arm 5! will wipe over contact 52 and close the circuit on the current source or battery 59 and the signal lamp 65 only; the current now passing from the positive terminal of the current source or battery 59 by way of conductor 58, switch arm 5!, contact 52, conductor 10, signal lamp 55, and conductors 56 and 64 to the negative terminal of the current source or battery 58. The signal lamps 53 and 65 will be colored and preferably one different from the other. Thus, both visual and audible signals or indications will be given to the operator making a test on a given steam source. 7

With the alternate closing and opening of the circuit at switch contact 53, the electromagnet 5| will actuate the blow-down valve D correspondingly to open and close positions, and the operation of the valve will be adjustable to percent moisture desired, according to the setting of the switch contacts 52 and 53 with respect to the switch arm 5|.

Considering for the moment the principle of operation of a throttling calorimeter, steam passing through an orifice into fin enlarged space, i. e., a space large enough that the resultant velocity is low, retains practically all the heat energy that would make up velocity energy, and

this retained heat energy acts to superheat the steam. The throttling calorimeter therefore measures this superheat and from thermometer readings the steam quality or percent moisture is calculated. The instant device eliminates all necessity for the use of ordinary mercury thermometers and allowspercent moisture (or steam quality100%-% moisture) to be readily ascertained by direct reading from a Bourdon type of pressure gage, or from an electrical meter (not shown), if the latter be substituted.

An illustrative problem in the use of the apparatus or device, in accordance with the present invention and by reference to the Marks 8t Davis Steam Tables which show that steam at 250# gage has 1202.4 B. t. u., per pound and steam at atmospheric pressure (14.7# gage) has 1150.4 B. t. u., per pound and a temperature of 212 degrees F., is stated as follows:--250# gage steam through throttling calorimeter to atmospheric pressure. Solution:

Item 1.Heat per pound in B. t. u., available for super-heating (sample dry, without moisture) :-1202.4 B. t. u., at 250# gage minus 1150.4 B. t. u., steam at 0#, or atmosphere gives 52.0 B. t. u., per pound, available for superheating.

Item 2.-Specific heat of steam at atmospheric pressure (from tables) :-.47 B. t. u., required per pound per degree F.

Item 3.-Maximum possible superheat in calorimeter, with initial steam 250# gage:--Item.(1) 52.0 B. t. u., divided by Item (2) .470 B. t. u., equals 110.5 degrees F.

Item 4.-Maximum possible temperature in calorimeter, with initial steam 250# gage:-atmospheric temperature of steam plus superheat equals total calorimeter temperature, hence 212 degrees F., plus Item (3) 110.5 degrees F., equals 322.5 degrees F.

Item 5.-Latent heat of evaporation 250# gage steam (Marks 8: Davis Tables) is 821.5 B. t. u., and equivalent to 100% moisture.

Item 6.-1% moisture in steam at 25011 gage is therefore Item. (5) 821.5 B. t. u., divided by 100, which equals 8.215 B. t. u.

Item 7 .-Steam at 250# gage with 1% moisture has a B, t. u., content of 1194.18 B. t. u., (1202.4 B. t. 11., minus, Item (6) or 8.215 B. t. 11.).

Item 8.-1% moisture in steam lowers superheat temperature equivalent to Item (6) 8.215 B. t. u., divided by Item (2) V .47 B. t u., which equals 17.45 degrees F.

Item 9.-Maximum operating range of calorimeter in percent moisture equals Item (3) 110.5 degrees F., divided by Item (8) 17.45 degrees F., or 6.34 percent moisture.

However, it has been determined that a readable range of the calorimeter can be extended to a maximum of about 11% by changing atmospheric pressure to a low vacuum.

In the present instance, the Bourdon tube gage is a thermometer actuated by superheat and it is calibrated to read in percent moisture or steam quality, and it is to be noted that, as shown, the gage index or pointer 45 swings in reverse to the ordinary direction of movement thereof, and that the zero of the scale 41 is at the opposite end from which the index or pointer comes torest, or, in other words, zero percent moisture represents the maximum possible temperature of the superheat of the steam sample. As the percent moisture increases less superheat occurs and at 6.3% moisture and 250# gage, just enough heat is available to give the throttled sample a temperature of 212 degrees F., and the index or pointer 45 moveof the gage corresponding to atmospheric pressure. In other words, the calibrated part of the swing of the index or pointer is between the temperatures 212 degrees and maximum superheat 322.5 degrees E, which represents a range of 6.3% moisture. For normal temperatures, say 69 degrees F., the index or pointer 45 comes to rest off the scales, i. e., the space between the point of rest and that where the graduations begin, which space represents a temperature range of from degrees F., to 212 degrees F.

It is also to be here noted that, since each steam pressure has difierent heat content and latent heat of evaporation, a dial calibrated for one pressure is not entirely correct for any other pressure. The deviation from accuracy is not large, with reference to steam'pressure range permitted on a boiler in operation that does not fluctuate over 25# gage. Many boilers, however, do not fluctuate over '10# gage and therefore, for all practical purposes, the instant apparatus or device will be entirely satisfactory. The error in reading, when the pressure drops, for instance, to scale, is .66 of 1% moisture.

Without further description, it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in instrumentalities employed and minor details of construction and arrangement may be resorted'to without departing in any way from the spirit of the invention, or its scope as claimed.

Having thus fully described my invention, what I claim is:

l. A throttling calorimeter comprising a heat insulated chamber having an intake orifice and an exhaust port, a hollow member within said chamber between the intake orifice'and the exhaust port, said member containing a fluid sensitive to variations in temperature of a heated fluid passed through the chamber for test, means located 'eXteriorly of the chamber for indicating l'75# gage and reading is taken from a 250# ment Will start at the maximurnmeasuring range the variations in transfer of heat fromthe heated fluid to the fluid within said member, a normally closed valve within the chamberto control ingress of the heated fluid to be. tested, and a pressure operated means exteriorly of the chamber and having connection with said valve to actuate it to open position as and when required.

'2. A throttling calorimeter comprising a heat insulated casing, a throttling chamber within said casing and having an intake orifice opening outwardly of the casing, a sampling nozzle projecting from said casing for conveying steam to said orifice, a rod extending inwardly of said casing and into said chamber and having a tapered end to engage in said orifice, spring means normally urging said rod to force the tapered end thereof into closing engagement with said orifice, and pressure operated means for actuating said rod to withdraw the tapered end thereof from said orifice for. admitting steam therethrough from said sampling nozzle.

3. The calorimeter asset forth in claim '2, wherein said pressure operated means is comprised in a cylinder at the outer side of the said casing anda piston'on the outer end of said rod, the cylinder havingan inlet for the pressure to actuate the piston; V

4. The calorimeter asset forth in claim 2, wherein a thermometer bulb is emplaced within said throttling chamber in direct contact with the superheated steam therein, and a dial type of thermometer is connected to said bulb and located exteriorly' of the said casing to indicate the quality of the steam.

5. The calorimeter as set forth in claim 2, wherein a thermometer bulb is emplaced within said throttling chamber in direct contact with the superheated steam therein, and a dial type of thermometer is connected to said bulb and 10-, cated exteriorly of and remotely from said casing to .indicate the quality of the steam, said thermometer being calibrated in percent moisture of the steam sample. I

' 1 BLAIR H. STONE.

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