US2270067A - Continuous boiler blowdown apparatus - Google Patents

Description

Jan. 13, 1942. P. E. MADDEN A 2,270,067

CONTINUOUS BOILER BLOWIOWN APPARATUS 2 Sheets-Sheet 1 Filed May 23, 1938 Jan. 13, 1942. A|= E. MADDl-:N 2,270,067

CONTINUOUS BOILER BLOWDOWN APPARATUS Filed May 23, 19:58 2 sheets-smet 2 s; A y

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` f' I v Para? Jaa/a/efe Patented `lian. 13, 1942 coN'rlNuoUs BoILER BLoWDoWN APPARATUS Paul E. Madden, Chicago, Ill.

Application May 23, 1938, Serial No. 209,568

8 Claims.

My invention relates to improvements in boiler treatment apparatus and has for one object to provide an apparatus which is applicable to continuous boiler blow down. Another object is to provide a new and improved form of apparatus for boiler sludge deconcentration. Another object of my invention is to provide means for protecting the continuous blow down nozzle or orice against clogging. Other objects will appear from time to time throughout the specification and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein- Figure 1 is a side elevation of a boiler showing my apparatus in position;

Figure 2 is a detail section through the heat interchange and sludge deconcentration portion of the apparatus;

Figure 3 is a detail section through a modified form of the apparatus where the sludge deconcentrator has been omitted;

Figure 4 is a detail section through a further modification omitting heat interchange.

Like parts are indicated by like characters throughout the specication and drawings.

It is understood that the purpose of a continuous blow-down from a steam boiler and the like is to maintain the concentration of salts and other deposits in the liquid in the boiler at a substantially constant point. All that is necessary in order to do this is to provide for means which will continuously vbleed off or blow down from the boiler a controlled quantity of water. Preferably this water is drawn from the boiler at the point where the solids concentration is a maximum. So far as my invention is concerned, it makes no difference how this is done or what kind of a collector or where the pipe is connected to the boiler. Suice it to say, there must be a continuous connection with the liquid contents of the boiler such that a continuous quantity of the liquid is blown down. The actual amount discharged depends, of course, upon the size of the boiler, the character of the water fed to it and the rate at which steam is evaporated and it is desirable to provide means which can be easily set or adjusted by the operator to change or control the rate of flow. It is highly important that when this is done the setting be accurate and definitely known to the operator as even a slight deviation from the correct blown down rate will result in greatly decreased efficiency in boiler operation.

I propose also to associate with the continuous blowdown, sludge deconcentration means whereby the water in the boiler in much larger quantity than that blown down will circulate through a sludge deconcentration chamber, the sludge being deposited or settled out in that chamber, the water with a smaller amount of sludge being returned to the boiler.

The continuous blow down takes out of the boiler system not merely precipitated solids but solids in solution. The sludge deconcentrator takes care only of precipitated solids. Under some circumstances, it is sufcient to use the continuous blow-down alone. Under many circumstances, it is desirable to useboth the continuous blow-down and sludge deconcentrator and I propose to combine the two so as to have each assist in the operation of the other.

In connection with continuous blow down, if the blow-down water is dischargedwithout further treatment, the heat of that water is lost and' wasted. Therefore, it is frequently desirable to use a heat interchange arrangement whereby the blow-down water will transfer some of its heat to the boiler feed water, which water is subsequently returned to the boiler, thus decreasing heat loss. Y f

Moreover, in order to promote circulation of the water through the sludge deconcentrator, it is desirable also to provide means for cooling water after it has left the boiler and before it reaches the sludge deconcentrator as otherwise satisfactory circulation through the sludge deconcentrator cannot be relied upon.

By combining the sludge deconcentrator 'and continuous blow-down with the heat interchange desirable for both and by further using the continuous blow-down to assist circulationthrough the sludge interchange zone, Iobtain a materially improved result. i

I is the upper, 2 is the lower drumjand'3 are the circulating water tubes joining the twodrums of a boiler. The water level is as' indicated. y1?,1i`s a blowdown pipe, the intake end of which lies beneath the level of the water in the boiler. The discharge end is connected to a heat interchange header 5, closing one columnr 6, of a heat interchanger. This heat interchanger has another parallel column 'l provided with a header 8, to which is connecteda discharge pipe 9, leading,to an adjustable metering continuous blowfdown valve I0. Associated with the headers 5 and 8, are water tubes Il, through which the boiler blow-down water may circulate. Boiler `feed water enters through a pipe I2, into the upper end ofthe heat interchange column' 1, passes down around the pipes I I, across through a connecting pipe I3 to the lower end of the column 6 up around the pipes I I and out through a pipe I4 to discharge into the feed water heater 35 shown diagrammatically.

The lower ends of the columns S and 'I communicate with passages I5 and IB respectively, which passages each communicate with the top of a drum or sludge deconcentrator I'I, which sludge deconcentrator is provided with a discharge passage I8 at the bottom, controlled by a valve I9. Immediately below the column 1, and at the upper end of the passage I6, is a screen 20, the orices of which are small enough so that any particle which passes through the screen may pass through the metering nozzles in the valve I0 without clogging.

2I, is a pipe leading from the passage I6 to communicate with the pipe I4, so that water may circulate from the pipe I4, through the column i5, passage I5, into the sludge deconcentrator I'I, thence out through the passage I6, and pipe 2l, to the boiler. Because the boiler feed water is colder than the water withdrawn from the body of the boiler, the temperature in the pipes II, will be reduced, thus tending to promote downward ow of water through the sludge deconcentration system.

A portion of the water which leaves the boiler 4, instead of returning to the boiler through the pipe 2l, passes up through the column 'I, being further cooled by contact with the feed water and is discharged through the pipe 9, to the continuous blow down valve Il), and thence through the pipe 22, for discharge from the boiler syst-em.

23 is a sampling cock whereby the water from the continuous blow down may be sampled.

With this arrangement the desired flow of water from the boiler through the column 5, is

promoted in the change in temperature resulting from the heat interchange. It is further encouraged by the fact that there is a continuous withdrawal from the system of water from the pipe 9 so that these two factors both tend to promote flow, or thermostatic circulation, of water to and through the sludge deconcentrator.

If it is desired for any reason to eliminate the sludge deconcentration idea from the system altogether, there is substituted for the passages i I5 and I6, a single chamber 24 having two upper branches 25 and 26, 25 being equipped with a screen 20, as was passage I5 in Figure 2. The blow down water comes downwardly through the pipes II, is discharged into the chamber 24,y

through the passage 25. Its direction is reversed. Its Velocity is decreased by the increase in size of the chamber, solid matter is settled out in the chamber 24 and water free from large particles which might tend to clog the metering valve passes up through the screen 20, and tubes II, to the continuous blow-down as shown in Figure 3.

If, in addition it is desired to omit the complication of the heat interchange, then a header 21, is substituted for the header 5, on the pipe 4. This header has a pipe 28, extending downwardly inside the chamber 29, associated with the header. The screen 30, is at the top of the pipe.A The chamber 23, the discharge valve Ill associated with its lower end, and the pipe 9, is connected to the header above the screen 30, so that the water from the boiler passes down into the chamber through the pipe 2B, is reduced in velocity, its direction is reversed, large particles of scale or other sediment are settled in the chamber 29 and the water free from sediment passes through screen 30 to blow-down pipe 9 thence through the metering valve which controls the rate of flow.

The metering valve controlling the continuous blow-down here illustrated is identical with the valve illustrated in my co-pending application covering a metering valve though obviously any desirable type of metering valve might be used interchangeably with it in the system here illustrated.

I claim:

1. In a continuous blow-down system for boilers and the like, two generally parallel vertical housings connected at their lower ends, means for feeding cooling water to one and withdrawing it from the other at their upper ends, hot water pipes extending through both said housings, a supply pipe connected to the hot water pipes at the top of one of said housings, a metering valve and a connection between it and the hot water pipes in the other housing, a connection between the hot water pipes in both housings including a settling chamber.

2. In a continuous blow-down system for boilers and the like, two generally parallel vertical housings connected at their lower ends, means for feeding cooling water to one and withdrawing it from the other at their upper ends, hot water pipes extending through both said housings, a supply pipe connected to the hot water pipes at the top of one of said housings, a metering valve and a connection between it and the hot water pipes in the other housing, a connection between the hot water pipes in both housings including a settling chamber and a connection between the Vboiler and the hot water system above the top of the settling chamber.

3. A water treating apparatus adapted to be associated with a boiler, comprising a pair of parallel vertically disposed hollow columns, separate headers closing the upper ends of each, a single header having a U-shaped chamber closing and joining the lower ends of the columns, apertured partitions in top and bottom of each column, a pipe connected to the header at the top of one column, pipes located in the columns registering with the apertures in the partitions, a discharge pipe leading from the other upper header, a metering valve therein, a boiler supply pipe communicating with the upper end of one of said columns, a passage joining the lower ends of the columns, and a boiler supply pipe leading from the upper end of the second column, the passage and pipes being located between the apertured partitions.

4. A water treating apparatus adapted to be associated with a boiler comprising a pair of parallel vertically disposed hollow columns, separate headers closing the upper ends of each, a single header having a U-shaped chamber closing and joining the lower ends of the columns, apertured partitions in top and bottom of each column, a pipe connected to the header at the top of one column, pipes located in the columns registering with the apertures in the partitions, a discharge pipe leading from the other upper header, a metering valve therein, a boiler supply pipe communicating with the upper end of one of said columns, a passage joining the lower ends of the columns, and a boiler supply pipe leading from the upper end of the second column, the

; passage and pipes being located between the apertured partitions, the discharge pipes and the boiler supply pipes being so related that the liquid in the two systems associated with said pipes flows in opposite directions.

5. A water treating apparatus adapted to be associated with a boiler, comprising a pair of parallel vertically disposed hollow columns, separate headers closing the upper ends of each, a single header having a settling chamber closing and joining the lower ends of the columns, apertured partitions in top and bottom of each column, a pipe connected to the header at the top of one column, pipes located in the columns registering with the apertures in the partitions, a discharge pipe leading from the other upper header, a metering valve therein, a boiler supply pipe communicating with the upper end of one of said columns, a passage joining the lower ends of the columns, and boiler supply pipe leading from the upper end of the second column, the passage and pipes being located between the apertured partitions, a sludge pipe communicating with the settling chamber at its lower extremity and a valve controlling said pipe.

6. A water treating apparatus adapted to be associated with a boiler, comprising a pair of parallel vertically disposed hollow columns, separate headers closing the upper ends of each, a single header closing the lower ends of the columns, apertured partitions in top and bottom of each column, a pipe connected to the header at the top of one column, pipes located in the columns registering with the apertures in the partitions, a discharge pipe leading from the upper header, a metering valve therein, a boiler supply pipe communicating with the upper end of one of said columns, a passage joining the lower ends of the columns and a boiler supply pipe leading from the second column, the passage and pipes being located between the apertured partitions, an elongated vertically disposed settling chamber supported by the single header, there being a passage in the header between each column and the settling tank, a water return pipe communicating with one of the passages in the single header and leading thence to the boiler at a point below the point from which the boiler discharge pipe leads.

7. A water treating apparatus adapted to be associated with a boiler, comprising a pair of parallel vertically disposed hollow columns, separate headers closing the upper ends of each, a single header closing the lower ends of the columns, apertured partitions in top and bottom of each column, a pipe connected to the header at the top of one column, pipes located in the columns registering with the apertures in the partitions, a discharge pipe leading from the other upper header, a metering valve therein, a boiler supply pipe communicating with the upper end of one of said columns, a passage joining the lower ends of the columns and a boiler supply pipe leading from the second column, the passage and pipes being located between the apertured partitions, an elongated vertically disposed settling chamber supported by the single header, there being a passage in the header between each column and the settling tank, a water return pipe communieating with one of the passages in the single header and leading thence to the boiler at a point below the point from which the boiler discharge pipe leads, the pipes being so disposed that the water discharged from the boiler passes downwardly through one column into the top of the settling tank, thence upwardly through the other column to the discharge, the pipe returning to the boiler being connected with the passage leading to the header from which the boiler water is discharged, the pipes associated with the feed water system being adapted to cause circulation through the columns in the opposite direction.

8. A continuous blow down system for boilers and the like including a heat interchange housing having hot and cold water compartments, an inlet and an outlet for the cold water compartment, means for supplying boiler water to the hot water compartment, and a settling chamber below, directly connected to, and adapted to receive boiler water and sediment directly from the hot water compartment, all of the walls of the hot water compartment and the settling chamber except the iloor of the latter, being so disposed as to guide settled sediment directly from the hot water compartment, under the force of gravity independent of the flow of the boiler water to the floor of the settling chamber, a passage leading upwardly from the upper portion of the settling chamber for the discharge of the boiler water, a metering valve in the passage for the discharge of the boiler water controlling the flow of water therethrough, means for returning to the boiler part of the water originally supplied to the heat interchange housing after it has been cooled and sedimentation has been settled out from it.

PAUL E. MADDEN.

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