US1678089A - Method of and apparatus for cleaning high-pressure boiling apparatus - Google Patents

Description

July-24, 192s. 1,678,089

G. ULLMANN METHOD 0F `ANI) APPARATUS FOR`CLEANING HIGH PRESSURE BOILING APPARATUS Filed Aug. 25,1926

Klaren/01" G. Z7!! m a 777/ ,guy/n( Patented July 24, 192s.

UNITED- STATES PATENT OFFICE.

Gus'rAv ULLMANN, or' VIENNA, AUSTRIA.

METHOD 0F AND APPARATUS FOR CLEANING HIGH-PRESSURE BOILING APPARATUS.

Application led August 23, 1926, Serial No. 131,090, and in Austria August 28, 1925.

' VIn the high pressure boilino apparatus employed in industry for purifying or for dissolving different materlals the pressure must be released i. e., a so-called blow-oli:l must be effected rior to the treatment following on the boiling operation. The pressure has hitherto been released simply by opening a blow-off valve provided generally in the upper part of the boiler. This method of operation presents a number of disadvantages which are hereinafter explained as regards high pressure boiling apparatus employed in the textile industry for cleaning the raw material.

After the conclusion of theboiling yoperation which usually takes a few hours, the alkaline solution has absorbed the impurities contained inthe textile materials. During the boiling operation the material is more or less packed together and'a layer of scum or mud like matter consisting of this solution and impurities, collects above the materia-l. VIf the blow-off valve be opened not only doesthe steam produced by therelease of the pressure pass off but considerable quantities of the solution are carried off with it due to the continued evaporation. If the boiler is blown off into the atmosphere these impurities are spread into the immediate surroundings. The surrounding air is laden with evil smelling and unsanitary particles of alkali and suc-h, and neighbburing vegetable growth is destroyed. The blowing off of the hot solution under pressure into the blow off gutter or the like which is also eected destroys the walls of the gutter in a short time. Moreover as a result of the longcontinued evaporation very often too4 much of the solution escapes and the material being cleaned is no longer completely covered by the liquid and air penetrates the fibres soaked with the solution as a result of which vegetable textile fibres as is Well known are seriously damaged. Apart from this the dirtiest mud like yportions of the solutionimmediately above the material remain in the dome of the boiler and in the subsequent washing generally efected by water flowing downwardly from the upper end through the boiler such portions are.

carried through the whole contents of the boiler again so that not only is the washing out of theboiler rendered ditlicult but the dirt which is difficult to remove subsequentiy sett-les on the already treated textile bres.

ofi' valve water or other cleaning liquid is introduced into theI boiler as aresult of which the scourings are diluted and the mass of scum and mud collected particlularly in the dome portion washed away. By this method moreover the duration of the blowing off operation is considerably shortened.

The impurities taken up by the solution present the further disadvantage that in boiling apparatus having pre-heaters the impurities settle in the tubes of the pre-heater. Experience has shown that the impurities adhering to the tube walls of the pre-heater can easily be removed as long as no cooling has occurred. After the conclusion of the blow-off and after cooling of the pre-heater the impurities adhere so firmly that they can no longer be simply washed away and consequently the ,tubes of such pre-heaters have hitherto been gradually reduced in diameter by hard coatin s which settle on them which coatings affect le transfer of heat and extend the time of treatment. Eventually the tubes have to be removed and freed from the adhering incrustation by a laborious process which gene-rally. seriously damages the tubes.

In accordance with the present invention this disadvantage is also avoided by washing the pre-heater directly after the conclusion of` the boiling process i. e., at the same time as the pressure in the boiler is released, the solution flowing out of the boiler (which solution is being diluted by the cleaningliq-- uid introduced into the boiler) being preferably led through the pre-heater and serving for washing the latter.

The invention includes apparatus for carrying out the new method and also all methods of using high pressure boiling apparatus in which the release of the pressure presents similar difficulties to those in apparatus for cleaning textile materials; for example in apparatus for treating cellulose and the like.

rlwo embodiments of high press re boiling apparatus in accordance with the invention and suited for cleaning textile fibres are illustrated in the accompanying drawing.

Figure 1 shows the boiler alone with this improvement and Figure 2 shows the boiler with a preheater attached. The letters apply to equivalent parts in both figures.

Referring to the drawing a denotes the boiler which in the usual manner is provided wit-h upper and lower perforated sieve plates b and c between which the material to be treated is introduced and it may be made sectional to facilitate removal. To t-he cover d is connected the blow-ofi pipe f which is provided with a valve g and extends into a receiver t. In the domed space z' is located a pipe j formed with perforations distributed over its length and connected by means of a pipe k and a three-way cock 'w with a water pressure supply. The pipe is so arranged as not to interfere with the introduction and removal of the material to be treated. Water under pressure can also be supplied by means of a pipe k2 having a valve to a pipe 0 into which leads the draw-off pipe p of the receiver h. The water under pressure flows through a nozzle g into the pipe o and in consequence has an ejector action on the liquid flowing out of the receiver h. The pipe o. like the draw ofi' pipe 1' of the boiler a opens into the gutter s. By means of a separate pipe 104 cold water can be introduced into the container h.

On the conclusion of the boiling or like operation the blow-ofil valve g and the water valve lw are opened, and the dirty upper part of the solution, therefore, is forced by the water under pressure into the receiver h and is condensed by the cold Water contained therein. A partial vacuum is thus produced in the receiver It which vacuum considerably accelerates the outflow of the liquid from the boiler. This cold water, the pressure of which must always be somewhat greater than that within the boiler canbe preheated or may contain admixtures. The water flowing into the dome i dilutes the solution therein and washes the dome thoroughly while at the same timeprotecting the material under treatment from contact with air. The textile material between the perforated sieve plates b, c, remains full of solution as the water fiowing from the pipe z' passes off through the pipe f which presents a smaller resistance to the water than the mass of textile material.

The release of the pressure and the blowoff of the boiler requires only quite a small part of the time hitherto required for this purpose while by the dilution of the solution being discharged all the disadvantages referred to above are avoided.

After the blow-off the dome z' ofthe boiler in which the greatest part of the impurities had collected, is thoroughly cleaned and in consequence subsequent washing of the material can be effected with much less work, in a much shorter time and much more effectively than usual, because the impurities contained in the dome z' are no longer spread over the Whole mass of material and 'no' longer require to be washed out of suoli maprovided with the pre-heater t in which the.

solution is led in circulation through the boiler a and through the tubes of the preheater t by means of a pump or the like and the pipes f and r. The water under pressure for washing the dome z' passes into the boiler a through the pipe le which is adapted to be closed by a valve la. The receiver i is connected with the tube system arranged in the pre-heater t by a pipe ain which is interposed a valve o. As in the construction shown in Fig. 1 the outlet pipe p opens into a branch 0 leading to the gutter in which branch is arranged a nozzle q to which water under presure is supplied by means of the' pipe k2 fitted with a valve The branch 7c serves for filling the receiver z. with water.

On blowing off the boiler the circulation pump for the solution is first stopped, then the valves e, w and are opened so that the solution fiowing ofi' passes through the tube system of the pre-heater t, Washes it and only then passes into the receiver L. The liquid fiowing through the pre-heater t which liquid is gradually becoming cleaner carries off with it the impurities produced in the previous boiling operation and clinging to the walls of the tubes and leads it' away in one working operation with the blowing-off operation.

In the pipe f is disposed a three-way cock e to which a third water pressure pipe k3 is connected. By means ofI this three-way cock, the boiler a can be filled with water independently of the pre-heater t while the pre-heater can be washed independently of the boiler a.

Between the dome z' and the receive L may be provided a separate pipe corresponding to the pipe f in the construction shown in Fig. l, so that in blowing-off the boiler a, the pre-heater may be cut off if it is unnecessary to Wash out thelatter.

The invention is applicable to high-pressure boiling apparatus of all kinds, even those provided with a central circulating pipe or those lin which the .blow-off valve is disposed at the lower end of the boiler. In such latter circumstances the cleaning liquid is introduced into the bottom space of the boiler. The cleaning liquid may,even in boilers fitted with a blow-off valve arratus, comprising, introducing into the boiler at the same time as it is blown olf, a cool liquid diluent for diluting and cooling the solution and sludge thereof which are to be blown ofi' from said boiler.

2. A method of cleaning high pressure boiling apparatus employing chemical solution for purifying or dissolving materials, said apparatus having a preheater in conjunction with the boiler comprising, introducing into the boiler at the same time as it is blown ofi', a cool liquid diluent for diluting and cooling the solution and the sludge thereof which are to be blown off from said top 4cool liquid diluent for diluting and cooling boiler, and simultaneously washing out the preheater with the diluted solution issuing from the boiler.

3. The method as claimed in claim 1 comprising t-he additional step of leading through the preheater the hot solution which is being continuously diluted by liquid introduced preferably into the top part of said boiler and using such solution to wash out the preheater.

4. method of cleaning out pressure boiling apparatus which includes besides the boiler, r preheater and a condenser, comprising introducing into the boiler adjacent the at the time the boiler is blown off of a the solution and sludge thereof which are to be blown ofi1 from the boiler and at the same time washing out the preheater with I the hot solution which is being continually diluted by the cool liquid diluent, said diluted solution being led into said condenser, mixed therein with cooling water and thereby still further diluted and then led olf into theopen at a pressure approximately that of the atmosphere. i

5. Apparatus for purifying and charging or dissolving material through the agency of a hot chemical solution comprising a boiler having a dome, a perforated sieve plate within said boiler, a distributing pipe extending into said boiler for introducing a diluting liquid to said boiler at the Vtime of blowing olf said boiler, said distributing pipe being located in the dome above the perforated sieve plate, and a condenser through which is discharged the solution diluted by the introduced liquid and freed from pressure above that of atmosphere.

6. Apparatus as claimed in claim 5v including a waste pipe connected to the condenser, an injector intercalated to said waste pipe and means-fpr feedin water under pressure to said e]ector where y the solution from said condenser is further diluted and,

drawn off.

7. Apparatus as claimed in claim 5 including a preheater interposed in the path of the solution discharging from said boiler.

8. Apparatus for the purifying and dissolving of material through the agency of a hot chemical solution including a boiler, a blow off conduit therefor, a pipe for supplying liquid under pressure to said boiler at the time of blowing ott' the boiler for diluting and cooling the liquid and sludge of the chemical solution, a preheater for the incoming solution interposed in said blow off conduit, and a valved liquid pressure supply pipe communicating with said preheater, for flushing it independently of the supplying of liquid under pressure to said boiler.

In testimony whereof I have signed my name to this specification.

i GUSTAV ULLMANN.

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