US1938072A - Method and apparatus to control the concentration of boiler waters - Google Patents

Description

1933- G. H. KARLSTEEN METHOD AND APPARATUS TO CONTROL THE CONCENTRATION OF BOILER WATERS 3 Sheets-Sheet 1 Filed May 10, 1932 |NVENTOR Gusianflfiar/skm ATTORN EYS Dec. 5, 1933. G. H. KARLSTEEN METHOD AND APPARATUS TO CONTROL THE CONCENTRATION OF BOILER WATERS Filed May 10, 1932 3 Sheets-Sheet 2 INVENTOR ATTORNEYS & b.

Dec. 5, 1933. G. H. KARLSTEEN 2 METHOD AND APPARATUS T0 CONTROL THE CONCENTRATION OF BOILER WATERS Filed May 10, 1932 3 Sheets-Sheet 3 w 711ml:

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INVENTOR fi asiau [iffizclsleen ZM MM ATTORNEYS Patented Dec. 5, 1933 METHOD AND APPARATUS TO CONTROL THE CONCENTRATION OF BOILER- WATERS Gustav H. Karlsteen, Tonawantla, N. Y., assignor' V to Dunlop Tire and Rubber Corporation, Buffalo, N. Y., a corporation of New York Application May 10, 1932. Serial No. 610,507 9 Claims. ((-31. 122 1) My invention relates to a method of controlling feed water which may be controlled in any suitthe hardness of water in a boiler or steam generable manner. I ator, or to controlling the concentration of dis- In controlling the blowdown control valve from solved salts in such water in such a manner'that the hydrometer, a constant level of the blowthis hardness or concentration will be held bedown water, the density of which is being meas- 6O tween narrow limits, ured, is maintained by a suitable arrangement The water fed to boilers usually contains some of overflow and leak' of the blow-down liquid. dissolved salts which may, for example, be the The cooling of the blow-down water may be acsulphates, chlorides or carbonates of alkaline complished in any-suitable apparatus but, pref- 19 earth metals. As water is evaporated from the erably, by giving up its heat to a portion of the 65, boiler or generator, the concentration of these cold feed water the volume of which is governed salts increases and may reach a point where the by a suitable by-pass valve controlled by the salts will be precipitated out of the water, formtemperature of the cooled blow-down water. The ing scale on the inner surface of the boiler walls. opening of the blow-down control valve or, its

Maintenance of the concentration of the various rate of opening or closing, may be proportioned 70. salts or dissolved material in the boiler water to the density ofthe blow-down water to obtain below .a certain concentration at which the mamore delicate control of the latter. terials precipitate out of solution, without ex- The various features of the invention are illuscessive withdrawals from the boiler, enables the trated in the accompanying drawings, in which- 2c boiler to be economically maintained in a clean a Fig. 1 is a diagrammatic sketch, parts being 715 condition and also without corrosion. shown in section, of an apparatus embodying the As the demand for steam usually varies orflucinvention. tuates, causing more rapid evaporation at some Figs. 2 .and 3 are, respectively, plan and eletimes than at others and thus a more rapid convation of a modifiediorm of control mechanism centrating effect, it is difficult manually or by actuated by the density of the blow-downliquid. ordinary controlmeans to so control the supply Fig. 4 is a vertical sectional View taken on line and withdrawal of water from the boiler as to 4-4 of Fig. 2, and

maintain the water within the boiler at the de- V Fig. 5 is a vertical sectionalview taken on line sired concentration, or even the desired limits of 5--5 of Fig. 3. i j 30 concentration. Referring more particularly to Fig. l of the 7 An object of my invention is to provide a means drawings, the exhaust water or blow-down and an apparatus by which the concentration of from the boiler passes through a pipe 10 into water within the boiler will be maintained within heating elements 11 of a heat exchanger 12 in the desired limits of concentration, regardless which the blow-down gives up'heat tocold feed :35 and independently of the rate of evaporation of water flowing through the heat receiving element steam, or of other conditions of operation; and or chamber 13 of the heat exchanger. The also to provide means whereby the concentration quantity or relative proportion of cold feed water of the boiler water may be detected with great to hot blow-down is so controlled as to maintain exactness and accuracy; and to provide control a constant temperature of the cooled blow-down 40 means quickly responsive to said means. flowing from the element 11 through an outlet With these and otherobjects in view which will pipe 14. To this end the cold feed water supply more fully appear from the following description, from a pipe 15 passes through a by-pass or prothe invention comprises the method and appaportioning valve 16 into a pipe 17 leading to the ratus described and defined in the following specchamber 13 of the heat exchanger. The warm 45 ification and claims. feed water from the chamber 13 passes through In my invention water withdrawn from the an outlet pipe 18 to the boiler. The valve 16 boiler and commonly known as blow-down, is maybe moved to pass a greater or smaller amount cooled to a definite or predetermined temperaof feed water to the pipe 1'7 and heat exchanger ture. At this temperature the density of the 12, the remaining quantity-of feed water being 50 liquid is measured by a hydrometer, or other lay-passed through a pipe 19 to the pipe 18.

suitable means, and the position of the hydrome- The opening of the valve 16 is controlled in ter., or other density measuring means, is used accordance with the temperature of the cooled to control the opening of the valve controlling blow-down by passing the latter from the pipe 14 the outflow of blow-down water from the boiler. into a temperature regulator 20 which controls Such blow-down water will be replaced by fresh the valve 16. In the drawings a pneumatic or fluid pressure means is shown by way of example for transmitting changes in the temperature regulator 20 to the valve 16. For this purpose the temperature regulator controls a valve 21 between a fluid pressure supply pipe 22 and a pipe 23 which leads to' a pressure chamber and diaphragm device 24 associated with the valve 16 and controlling the position of the latter by a link and. crank mechanism 25.

It will be apparent that the temperature regulator may move the valve 21 to admit a greater or smaller quantity of fluid pressure to the pipe 23 and thim increase or decrease the pressure within the diaphragm chamber 24-which, acting against the spring 26, moves the valve control crank to the appropriate valve opening.

From the temperature regulator 20 the blowdown, now at a constant predetermined temperature, flows through a pipe 27 and through a water meter 23 to a valve 29 the extent of opening of which is controlled by a float 30 in a float chamber 31. blow-down escapes through an outlet pipe 32 and a control valve 33a. As the control valve 33a is opened and blow-down Water flows out of the float chamber 31, the float 39 falls, opening the valve 29 to admit additional blow-down. The opening of the valve 330: is controlled by the density of blow-down permitted to leak from the float chamber 31 through the openings 33 into a constant level chamber 34, from which it overflows through an overflow pipe 35 at the exhaust side of the valve 33a. The level of the water in the constant level chamber 34 may be controlled by raising or lowering the overflow pipe 35. The level in chamber 34 is, however, lower than the level in the float chamber 31 so that it is always maintained.

To control the opening of the valve 33 a suitable hydrometer 36 is provided in the chamber the height of which is controlled by the density of the liquid in the chamber 34 and the level of liquid therein. Changes in position of the hydrometer 36 are transmitted through a stem 37, lever 38, link 39, lever 40, link 41 and lever 42 to the stem of a control valve 43.

If the density of the blow-down increases, the hydrometer 36rises and the valve 43 is lowered, thereby opening communication through this valve from the fluid pressure supply pipe 22, through the pipe 44 and pipe 45 to a pressure control 46 which may be of the diaphragm type, controlling the opening or closing of the valve 33a through a suitable stem 47, crank arm 43 and spring 49. As the valve 33a is opened, a larger quantity of blowdown flows out of the float chamber 31 through the outlet pipe 32 until the density of the blow-down decreases, whereupon the hydrozneter 36 lowers, lifting the valve 43 until the pipe 45 is placed in communication with an outlet port 50, thereby exhausting pressure from the diaphragm chamber 46 and permitting the spring 49 to close or partly close the valve 332.

It will thus be apparent that the blow-dotvn is reduced to a constant temperature at which the density of the liquid has a definite relation to the concentration of salts or impurities in it, and that this density then controls the flow of blow-down to bring the blow-down to a predetermined density and concentration.

Instead of using the mechanical control mechanism shown in Fig. 1, electric mechanism, Figs. 2 to 5, may be employed between the hyclrcrneter or density measuring element and the pressure control valves. In this embodiment of the in- From the float chamber 31 the venticn the hydrometer stem 37 is connected to a balanced lever 51 pivoted on bearing points 52 and delicately balanced by adjustable weights 53.

A contact terminal 54 is mounted on one arm of the lever 51 and makes substantially frictionless contact with a vertical series of separate contacts 55 in a laminated insulating core 56 at one side of the lever 51. The contact terminal 54 is connected through the lever 51 and supporting bearings 52 to a lead wire 57 connected to a suitable source of electricity, and the several contact terminals 55 are connected through separate conductors 53 to separate the individual electromagnets 59, 60, 61, 62, 63 and 64, one for each contact, and from these magnets to a common return lead 65. Each of the magnets 59-64 is provided with an armature 66 pivoted at one end on the upper end of a standard 67 so that as the electro-magnets are individuallyenergized they attract and tilt their respective armatures 66 downwardly. The free extending portions of each of the armatures 66 are supported on a common plate 68 through adjustable screws 69 Which are threaded through the armature 66 and rest upon the upper surface of the plate 68. The plate 68 is rigidly mounted on a rock shaft 70 supported in the standard 67 and is counter-balanced by an adjustable weight 71 on a counterbalancing lever 72. The adjusting screw 69 of each of the levers66 is so adjusted that the ends of the armatures 66 are progressing at slightly higher elevations from the armature above the electro-magnet 59 to that above the electromagnet 64. Consequently when contact is made with the uppermost oi the contacts 55 and the electro-magnet 59 is energized, the lowermost armature, above the magnet 59, is depressed a slight distance. This depresses the plate 68 against the action of the counter-balancing Weight 71.

When the next magnet is energized, the next higher armature is depressed, still further depressing the plate 63 and rocking its rock shaft 70, and this action proceeds until the last electromagnet'64 is energized, at which time the rock shaft will have been rocked to the limit of its rocking position. There is, therefore, a rocking of the shaft 70 proportionately to the tilting of the lever- 51 but without imposing any resistance or load on the latter.

The tilting of the rock shaft 70 serves to open proportionately an air valve 73 corresponding in its function to the air valve 43 of the modification shown in Fig. 1. This opening of the air valve 73 proportionately to the rocking of the shaft 70 is accomplished by an eccentric, or equivalent device, 74 which acts on the valve stem 75 of the valve 73, moving it a distance depending upon the rotation of the shaft 70 and opening the valve '73 correspondingly. The opening of the valve 73 to a greater or less extent controls the admission of fluid under pressure from the supply pipe 44 to the supply pipe 45 and through the latter to a control valve such as the valve 330, of Fig. 1. The outflow of Water from the'float tank 31 is, therefore, increased or decreased proportionately to the opening or closing of the valve 73. An air leak 76 may be provided in the valve 73 whereby the pressure transmitted to the diaphragm chamber 46 of the valve 330; may be controlled directly at the valve 73.

The control parts of the valve73 may also be adjusted toward or from the eccentric 74 and rock shaft 70 by means of a screw -77'so that the degree of opening of the valve for any given position of the shaft may be manually controlled. It will be apparent that the various elements of the apparatus may be made in any suitable form to accomplish their intended functions. The several contacts 55 may, for example, be made of brass and separated and insulated one from the other by interposed layers of mica or other insulation.

Other types of contacts, such as mercury contacts, may be employed instead of the specific type illustrated.

What I claim is:

1. Apparatus of the type described which comprises means for reducing the temperature of boiler water to a determinate temperature, and means controlled by the density of said Water at said temperature to control the flow of said water.

2. Apparatus of the type described which comprises means for reducing the temperature of boiler water to a determinate temperature, means for maintaining a body of said water at said temperature at a determinate level, and means positioned proportionately to the density of said water at said level to control the flow of said water.

3. Apparatus of the type described which comprises means for reducing the temperature of exhaust boiler Water to a determinate temperature, a float valve chamber and a float controlled inlet valve to said chamber, a constant level chamber receiving a limited supply of water at said determinate temperature and having an overflow to maintain a constant level, a hydrometer in said constant level chamber, and a vlave controlled by said hydrometer to control the outflow from said float chamber.

4. Apparatus of the type described which comprises means for reducing the temperature of exhaust boiler water to a determinate temperature, a constant level chamber having an overflow and receiving water from said temperature reducing means, a hydrometer in said constant level chamber, and a valve controlled by said hydrometer to control outflow of exhaust boiler water.

5. Apparatus of the type described which comprises means to reduce the temperature of exhaust boiler water to a determinate temperature, a constant level chamber receiving said water from said temperature reducing means and having a constant level overflow, a hydrometer in said constant level chamber, a series of branch electric circuits having individual electric contacts, means controlled by the position of said hydrometer to close successive branch circuits at successive elevations of said hydrometer, a valve to control the flow of said boiler exhaust water, and means controlled by successive branch circuits to open said valve to increasing openings.

6. Apparatus of the type described which comprises means to reduce the temperature of exhaust boiler water to a determinate temperature,

a constant level chamber receiving said water from said temperature reducing means and having a constant level overflow, a hydrometer in said constant level chamber, a series of branch electric circuits having individual electric contacts, means controlled by the position of said hydrometer to close successive branch circuits at successive elevations of said hydrometer a valve to control the exhaust of boiler water, means controlled by sucicessive branch circuits to open said valve to increasing openings, and means for adjusting the opening of said valve relative to said branch electric circuits.

7. Apparatus of the type described which comprises means for reducing exhaust boiler water to a determinate temperature, means for maintaining a volume of said water at said temperature at a determinate level, a hydrometer in said volume of water, an electric circuit having separate branches, individual electro-magnets in said branches, means controlled by the position of said hydrometer to close selectively and in succession said branch electric circuits, individual armatures for said electro-magnets, a pneumatic control valve, means for opening said valve progres' sively as successive electro-magnets are energized, a boiler water outflow valve, and pneumatic means controlled by the opening of said pneumatic valve to open proportionately said boiler outflow control valve.

8. Apparatus of the type described which comprises a heat exchanger to receive exhaust boiler water and feed water in heat exchange relation, means controlled by the temperature of the cooled exhaust boiler water from said heat exchanger to control the relative quantities of ex- 105 haust and feed Water to maintain a determinate temperature, a float valve chamber receiving said cooled exhaust boiler water, a float valve controlling the admission of said cooled boiler Water to said float valve chamber, a constant level chamber positioned and connected to said float valve chamber to receive continuously a supply of water therefrom, a constant level overflow in said constant level chamber, a hydrometer in said constant level chamber, a valve controlled by said hydrometer, an outlet valve from said float chamber, and pneumatic means controlled by said hydrometer control valve to control the opening of said outlet valve from said float chamber.

9. Apparatus of the type described which com- 120 prises a heat exchanger to receive exhaust boiler water and feed water in heat exchange relation, means controlled by the temperature of the cooled exhaust boiler water from said heat exchanger to control the relative quantities of ex- 125 haust and feed water to maintain a determinate temperature, a float valve chamber receiving said cooled exhaust boiler water, a float valve controlling the admission of said cooled boiler water to said float valve chamber, a constant level cham- F13 ber positioned and connected to said float valve chamber to receive continuously a supply of water therefrom, a constant level overflow in said constant level chamber, a hydrometer in said constant level chamber, a valve controlled by said 1 hydrometer, an outlet valve from said float chamber, and pneumatic means controlled by said hydrometer control valve to open said outlet valve of said float chamber proportionately to the position of said hydrometer.

GUSTAV H. KARLSTEEN.

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