US1387463A - Superheat-regulator - Google Patents

Description

UNITED STATES PATENT OFFICE.

BENJAMIN BROIDO, OF NEW YORK,. N. Y., ASSIG-NOR TO THE SUPER/HEATER COM,- PAN'Y, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SUPERHEAT-REGULATOR.

Specification of Letters Patent.

Patented Aug. 16, 1921.

Application filed May 2, 1918. Serial No. 232,149.

T all whom it may con cern Be it knownthat I BENJAMIN Bnoioo, .i citizen of the United tates, and resident of the city of New York, State of New York, have invented certain new and useful Improvements in Superheat-Regulators, of which the following is a specification.

My invention relates to superheaters and has particular reference to devices whereby the degree of superheat may be automatically regulated and the superheater and engine protected against excessive tempera tures. Its object is the provision of improved apparatus for this purpose.

The following description, to be read in connection with the accompanying drawings, which are hereby declared to form part hereof, will make clear the nature and operation of my device. In the drawings, Figure 1 is a longitudinal sectional view of a water tube boiler with my invention ap plied; Figs. 2 and 2 are enlarged views, partly in section and with portions broken away, of some details of Fig. 1; Fig. 3 is a,

detail like Figs. 2 and 2 of a modification; Fig. 4 is a view like that of Fig. 1, with 'partsomitted, of another-modification; Fig.

5 is an enlarged detail of this modification; Figs. 6 and 7 are some detailson -a still larger scale; ,Fig. 8 is a sectional view of another type of boiler with my invention applied. Fig. 8 is an enlarged detail of this form; Fig. 9 is a detail'of a valve used in all of the forms so far referred to; and Fig. 10 is a view of a modification wherein electric means are employed for moving the damper.

The boiler 1 of Fig. 1 may be of any preferred construction. It is set in the housing 2, in the forward upper'part of which there is the space 3, set off from the main "boiler space by the wall 4, but communicat- The passage 5 is controlled by the two dampers 13.and 14, and gases can pass through it only when neither damper is entirely closed. The extent the passage is open is governed by the damper which is closed the farther. Each of the two dampers is connected to a counter-weight by means of a flexible cable 16, passing over a fixed pulley 17. These counterweights are each of substantially the same weight as its damper.

Under the wei hts 15 arethe two vertical cylinders 18 and 19 (see Figs. 2 and 2 within which move the pistons 20 and 21, connected with the weights 15 by means of the piston rods 22 and 23.

The two ends of cylinder 18 are connected to valve 28 by the pipes 24 and 25; and the two ends of cylinder 19 are similarly connected to valve 29 by means of pipes 26 and 27.

To the valves 28 and 29 pressure fluidwhich may be of any preferred kind, 6. 9., water or air,is admitted by means of pipes 30 and. 31 respectively. Ripes 32, 33, 34, and 35 areexhaust pipes and open to any desired points.

The valves 28 and 29 are identical in construction, and one of them is represented on an enlarged scale in Fig. 9. In the casing the valve proper 41, of the balanced piston type. reciprocates. The port 42. to which the pressure fluid is carried by pipe 30 is stems 38 and 39 in one direction or the other with changes in the temperature at the points where the thermostatic elements are located. 'I have not shown the construction of these elements in detail. as their specific structure forms no part of my invention. Any form of devices of this type that, directly or indirectly, is capable of giving the required motion to the valves in conformity with the temperature changes over the. temperature ranges involved will answer.

The action of the apparatus will now be readily understood. From Fig. 1 it will be clear that of the gases generatedin the furnace a portion flows through the opening 7, between the fire-bricks 11, over the superheater 8 and out through opening 5 to rejoin the remaining portion which has passed over the first bank of tubes in the boiler, and to pass together with them through the remaining passes of the boiler and out through 12 to the stack. It will be equally clear that the proportion of gases passing through the superheater space depends upon the position of the two dampers 13 and 1 1. \Vhen either or both of them are closed, no gases will sweep over the superheater; and the proportion is always determined by the one which is lowered the farther.

Suppose that in the operation of the plant the temperature of the steam in 10 rises from some cause to a point above the predetermined desired maximum. The thermostatic element 37 will then give the valve 29 the position indicated in Fig. 2*, connecting the upper end of cylinder 19 to the exhaust and the lower end to the pressure supply. This will result in the piston 21 and its weight 15 moving upward and damper 14 moving down. The flow of hot gases over the superheater will be somewhat checked and the superheat as a consequence somewhat cut down. The valves 28 and 29 are small relatively to the cylinders 18 and 19, and the mo tion of the pistons 20 and 21 and the connected dampers correspondingly slow: Before the damper 14 has sensibly passed the position required the thermostatic element, sensitively following the change in temperature, gives the valve its neutral position in which it admits pressure to neither end of cylinder 19.

The opposite action, 1'. the action required when the steam temperature in 10 falls too low will be to admit ressure to the upper end of 19 and thus to raise the damper and allow a freer flow of gases over the superheater. During normal operation of the plant the regulation just described might be is greatly reduced or entirely shut off, and during the firing up period, before there is any steam in the boiler, the thermostat 37 does not act, and the unchecked gas flow over the superheater would endanger it as there would be no steam flow to carry ofi' the heat. The action of the other thermostat and connected damper however prevent any damage. \Vhen no steam flows through the superheater, the gases passing along its elements have no heat abstracted from them and reach the exit 5 at a temperature substantially as high as when they enter the superheater chamber. Vith the steam flow reduced but not completely cut ofi, a proportion-ate rise over the normal temperature at 5 results. The effect on the thermostatic element 36 is such that it causes valve 28 to assume its lower position and to admit actuating pressure fluid to the lower side of piston 20, thus causing the piston to rise and the damper 13 to close partly or wholly. This interrupts the gas flow through the chamber 3, and so prevents injury to the superheater.

Vith the temperature at the point 5 nor mal, no injury to the superheater by the hot gases can occur, and the device is set, so that at such times damper 13 is wide open. But even when this condition prevails, the temperature of the steam may be above the predetermined point; in which case damper 14 will assume the necessary partly closed position.

An arrangement similar to that described above, but having only one damper and one counterweight, is illustrated diagrammatically in Fig. 3. The two cylinders 18 and 19 with their valves 28 and 29 and thermostatic elements 36 and 37 are precisely as before in construction. The single counterweight 15 is acted on by the upper ends of the piston rods 22 and 23, which however are not connected with it. The counterweight 15 is connected to the single damper by a flexible cord running over a fixed pulley, and is just heavy enough to raise the damper as far as the positions of rods 22 and 23 permit.

When the temperature at thermostatic element 36 is above the desired point, valve 28 will admit actuating fluid to the under side of piston 20, and thedamper will be lowered irrespective of the position of valve 29; and similarly if the steam temperature is too high, 37 will cause valve 29 to admit pressure to the cylinder 19 at its lower end and thus the damper to close. The damper will therefore always assume the position dictated by the thermostat tending to give it th more nearly closed position.

In the form shown in Fig. 4, and which represents the form of this type at present preferred by me, there is also only one damper, designated 13, and one counter weight 15, and there is here in addition only sufiicient. But when the steam consumption one cylinder 18". There are however again as if 29 were absent.

two valves 28 and 29 withftheir connected thermostatic elements 36 and 37 located respectively in the gas and steam spaces as before. In the enlarged diagrammatic view of Fig. 5 the two ends of cylinder 18 will be seen to be connected with -the two steam ports of each of the valves 28 and 29 by means of the pipes 24, 25, 26, and 27. Valves 28 and 29 are slightly modified from the form of Fig. 9 described above. Their form is illustrated on a larger scale in Fig. 6. The modification consists in the fact that a spring-controlled valve 48 is inserted into the lower exhaust pipe. This valve is seated by its spring, and remains seated at all times except when the valve 41' is down sufficiently to close port 45. The small pin 48 then comes into contact with the valve 48 and unseats it, allowing the trapped fluid to escape through pipe 48 The lower part of the-cylinder 1 8 has leading from it the pipe 49, in which is inserted the valve 50, illustrated on an en- "larged scale in Fig. 7. The casing 51 has fitted in its cylindrical interior the reciprocable valve 52, which thespring 53 tends to hold in position to interrupt flow through pipe 49, but which a sufficient amount of pressure from pipe 54 will move along so flow through 49 is possible. Pipe 54 leads from some point in communication with the upper end of the cylinder 18.

To trace the operat1on of this device, suppose first that both the gas and steam temperatures are excessive. assume the lower position "and valve 29 its position to the left, both admitting-pressure to the bottom .of cylinder 18. same time the fluid from the upper end of the cylinder is free to escape through pipes 24 and 26 and the exhaust 47 of each of. the.

valves 28 and 29. Pipe 54 has no pressure in it and 50 remains closed.

If the gas temperature 'is'too high and the steam temperature normal, valve 29 will have its mean position, and 28 will act to close the damper the required amount just A corresponding state of aflairs exists when the steam temperature is excessive and the gas temperature normal. Y

If both temperatures are too low, valve 29 will move to the right .and valve 28 up. Both will then admit pressure to the upper end of the cylinder, pipe 54 will convey this pressure to valve 49 and open it, and the piston 20 is free to move down and open the damper.

Should the gas temperature be too high and the steam temperature too low, valve 26 will be in its lowest position and 29 at the right. mitted to the lower end of cylinder 18* by valve 28*. The pressure admitted by valve 29 will be discharged through exhaust port Valve 28 will All the I Pressure will then be ad:

47 of valve 28, and valve 49 will have no pressure delivered to it 'by pipe 54. The piston 20. will consequently be urged upward and the damper be closed. The waste of pressure fluid involved in this case is not serious, as the valves 28 and 29 are relatively very small; and moreover the condi tion of affairs stated will in practice occur only rarely if ever. 1

Another theoretically possible condition is that the gas temperature is too low and the steam temperature too high. This condition is just opposite of the'one just discussed and involves an inconsequential waste of pressure fluid through the exhaust port 47 of valve 29. The damper will be closed just as in the preceding case.

In Fig. 8 is shown a boiler of a different type with my invention applied. The damper, 13 is here not of a reciprocating kind but rotary, being keyed to and rotating' with shaft 55. Also keyed to shaft 55 is the arm 56. Engaging slot 57 of arm 56 (see Fig. 8 is pin 58, which is carried by the piston .rod 22*. The cylinder 18, in which the piston moves, and the valves and their connections to the cylinder are exactly as in'the form of Figs.'4 and 5. The two thermostatic elements 36 and 37 are again respectively located in the path of the gases after they have passed over the superheater and in the pipe lOcarrying the superheated steam.

The action is strictly analogous to that of Figs. 4 and 5, the upward motion of the piston rotating tlie damper 13 into its closed position. and the downward motion opening it.

In the form of my invention shown in Fig. 10 there are shown electrical means of moving the damper 13. From theline 59 currentis carried through the pole-changing switch 60 to the motor 61: The motion of the motor is geared down by any preferred means the proper amount to the drum 62. on which is wound, or from which is unwound, the flexible cord 16, which runs over fixed pulleys 17 and 17", and whose farther end is attached to damper 13*.

The pole changer 60 is held in open position by springs 63 as long as neither of coils 64 or 65 is energized by current from transformer 66. In circuit with coil 65 is the switch 67, which is opened by coil 68, in series with coil64, whenever current flows through the latter. Switch 69 closesthe circuit through. coil.65.,.switch-67.,and transformer 66, whenever it is in its position to ward the right; and opens this circuit and closes the one through coil 64. coil 68, and transformer 66 whenever it is in its position toward the left. Similarly, switch 70 closes ,the'first named circuit, '5; 6. through. coil 65,

other circuit, 71. 6. through coils 64 and 68 and transformer 66, in its downward position. It should be noted that if either of the switches 69 or 70 makes the circuit through coil 68, the circuit throughcoil 65 is broken at switch 67.

The position of the switches 69 and 70 is controlled by the thermostatic elements 36 and 37. ith the temperatures too high these thermostats close switches 69 and 70 toward the left and downwardly respectively; and with the temperatures below the desired points, these switches close toward the right and upward respectively.

Vith current flowing through coil 64, and pole changer-60 thrown to the left as a consequence, motor 61 moves to partly close damper 13*. On the other hand, with pole changer 60 drawn to the right by coil 65, the motor moves to raise the damper. The motion of the motor .is geared down so far that before the damper has sensibly passed the correct position the thermostatic elements have adjusted themselves to the changed condition and the motion of the motor is stopped.- It will be evident that proper safety devices will be used in practice to prevent motion of the drum 62 and damper 13 beyond a certain point in either direction, so that no damage can result from this cause.

lVhen the temperatures at the thermostats are as desired, the switches 69 and 70 are held in open position by springs 71.

It will be clear that the details of my invention may be varied in a great number of particulars without departing from its spirit. Thus the specific form of valves used in the form employing pressure fluid may be different from that shown, as their structure does not enter into my invention. One variation I wish to point out regards the location of the thermostat reacting to the gas temperature. Under some circumstances it is desirable to locate it at some other point than at the outlet from chamber 3, and by showing and describing it as located there I do not wish to be understood as limiting myself to that particular position. It will prove desirable in some cases to locate it near the entrance or near the middle of the chamber.

These and similar variations will occur in practising my invention, and the appended claims are meant to include them.

What I claim is 1. In apparatus of the class described the combination of a chamber, a superheater in said chamber, said chamber having openings for the entrance and exit of heating gases, and means acting responsively to the temperature of the-gases to control the passage of the gases through said chamber.

2. In apparatus of the class described the combinationof a chamber, a superheater in said chamber, said chamber having an inlet and a damper-controlled outlet for heating gases, and automatic means to move said damper toward its open position when the gas temperature at the outlet falls below a predetermined point and to move it toward its closed position when the gas temperature rises above a second predetermined point.

3. In apparatus of the class described the combination of a chamber, a superheater in said chamber, said chamber having an inlet and an outlet for heating gases, a damper controlling said outlet, operating means for said damper, means tending to cause said operating means to act in response to the temperature of the gases, and other means to make them act in response to the temperature of the steam.

4. In apparatus-of the class described the combination of a chamber, a superheater in said chamber, said chamber having an inlet and an outlet for heating gases, a damper controlling said outlet, operating means for said damper, means tending to cause said operating means to move the damper toward its closed position when the temperature of the gases leaving the chamber is above a predetermined point and to move it toward its open position when it is below a second predetermined point, and other means tending to cause said operating means to move the damper toward its closed position when the temperature of the steam leaving the superheater is above a predetermined point and to move it toward its open position when it is below a second predetermined point.

5. In apparatus of the class described the combination of a chamber, a superheater in said chamber, said chamber having an inlet and a damper-controlled outlet for heating gases, operating means for said damper, means tending to cause said operating means to move the damper toward its closed position when the temperature of the gases leaving the chamber is above a predetermined point and to move it toward its open position when it is below a second predetermined point, and other means tending to cause said operating means to move the damper toward its closed position when the temperature of the steam leaving the superheater is above a predetermined pointand to move it toward its open position when it is below a second predetermined point, those of the two means. tending to make the damper-operating means act, prevailing which tend to cause them to move the damper toward its closed position.

6. In apparatus of the class described, the combinationof a boiler, a furnace, a superheater. means to pass a portion of the gases directly from the furnace over the siiperheater, means to control the relative amount of gases so passed over the superheater, said means acting in response to the temperature of the gases leaving the superheater.

7. In apparatus of the class described, the combination of a boiler, a furnace, a superheater, means to pass a portion of the gases directly from the furnace over the superheater, means to control the relative amount of gases so passed over the superheater responsive to the temperature of either the gases or the steam leaving the superhcater. and assuming the position dictated by whichever of the two tends to make the amount smaller.

BENJAMIN BROHX

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