WO2014076670A1

WO2014076670A1 - Method and apparatus for treating water in steam boilers

Info

Publication number: WO2014076670A1
Application number: PCT/IB2013/060179
Authority: WO
Inventors: David Sherzer
Original assignee: David Sherzer
Priority date: 2012-11-15
Filing date: 2013-11-15
Publication date: 2014-05-22
Also published as: IL223080A; BR112015010901A2

Abstract

In a steam boiler, a water treatment method is used for reducing sedimentation of solids and minerals in the boiler and for reducing corrosion processes in the boiler. The method comprises treating the water prior to feeding it into the boiler (pre-treatment). The pre-treatment comprises heating the water and recycling the water through a UET reactor for depositing scale in the reactor. Optionally, the method includes pre-treating about 60% of the water, and wherein the rest, or about 40% of the water, is regular raw water leaving the Calcium in the water to be a natural corrosion inhibitor. In a steam boiler, a water treatment apparatus for reducing sedimentation of solids and minerals in the boiler and for reducing corrosion processes in the boiler, comprising means for treating the water prior to feeding it into the boiler (pre-treatment).

Description

Method and Apparatus for Treating Water in Steam Boilers

The present application claims priority from application No. 223080 filed in

Israel on 15 November 2012 by the present applicant and inventor. 5

Technical Field

The present invention relates to methods for water treatment in steam boilers, and more specifically a chemicals-free method for substantially reducing 10 sedimentation of solids and minerals in the boiler and for reducing

corrosion processes in the boiler.

Background Art

15

Steam boilers use heat to convert water to steam. It is known in the art that,

in steam boilers, undesired scale products are generated in the boiler 2

itself, see Figs. 1 and 2. Furthermore, accelerated corrosion may occur.

Prior art methods for water treatment deal with three major problems

in order to avoid or reduce the above-mentioned problems: 20

1. Scale formation and sedimentation is avoided by removing, from the feed

water 12, the hard minerals by softeners 42 or by removing the minerals by

using RO systems.

2. The corrosion inhibiting is currently handled by pre-heating

the feed water and extracting by heat the dissolved gases such 25 as Oxygen and C02 prior to feeding the water into the boiler.

3. Additionally, adding anti-corrosion chemicals in order to

inhibit the corrosion processes.

Figs. 1 and 2 illustrate a system including a steam boiler 2 containing part 30 water 21 and part steam 22. There is a water inlet 12 and a steam outlet 23. Furthermore, Fig. 2 illustrates a system including such water treatment means as a filter 41, water softener 42, deaerator 45 and condense 46,

as well as salt in 43 and brine out 44.

Water in boilers 2 which evaporate water into steam should be treated so as to 5 reduce scale formation in the boiler from the remaining water, as well as to

inhibit corrosion process in the boiler. The natural tendency of water at high

temperatures is to form scale and corrosion products in the boiler.

The traditional methods for fighting scale and corrosion using soft

water or RO water is designed to address the scale deposits problems and the 10 chemicals addition is targeted to inhibit corrosion.

Possible problems with the abovedetailed traditional technologies:

1. Using soft water as a solution to scale problems creates corrosion

problems (reddish water). 15

2. Using soft water creates waste water problems due to the fact that the

softener is regenerated with a high concentration of salt 44. This salt must

be disposed properly and cannot be poured into to the normal sewage

system. 20

3. The chemicals 43 used to inhibit the scale and corrosion formation are

released into the waste water and may have an undesirable effect on the

environment.

25

4. Softeners and chemicals require operating and maintenance attention as

well as logistic and handling - a waste of time and money.

Disclosure of Invention

30

According to one aspect of the present invention, raw water is used instead of chemicals as a source for anti-corrosion inhibitors. Raw water is used in order to pre-treat only about 60% of the water. The rest, or 40% of the water, will be regular raw water leaving the Calcium in the water to be a natural corrosion inhibitor.

The excess of Calcium in the raw water that can potentially form scale will 5 cause a scale deposit in a specifically designed reactor (the UET reactor).

Thus, scale will be deposited in the UET reactor rather than in the boiler.

It is much easier to clean scale from the UET reactor than from the boiler.

10

According to another feature of the present invention, scale precipitation in

the UET reactor is stimulated using a partial electrolysis.

Furthermore, partial "hard" water will be introduced into the boiler; such

water as can be used in the boiler feed without any need for softening the

water or introducing chemicals and while ameliorating the problems of scale or 15 corrosion problems. The water in the boiler system will remain balanced and

therefore scale or corrosion problems are reduced.

This process eliminates the need for chemical introduction.

According to yet another aspect of the invention, water is recycled between the 20 heater and the UET reactor, to accelerate the precipitation of scale, to

prepare the water for use in the boiler.

Furthermore, water is recycled through the UET reactor at a faster rate (volume of water per hour) than the rate water is converted to steam in the boiler.

25

Brief Description of Drawings

Fig. 1 illustrates, by way of example, a prior art steam boiler

application. 30

Fig. 2 illustrates a prior art water treatment method in a steam boiler. Fig. 3 illustrates a system apparatus using the present invention. Fig. 4 illustrates the UET reactor(TM).

Fig. 5 illustrates the new water treatment method in a steam boiler. 5

Best Modes for Carrying out the Invention

The current invention will now be described by way of example and with 10 reference to the accompanying drawings.

Figs. 1 and 2 illustrate prior art systems as abovedetailed.

Fig. 3 illustrates an apparatus using the present invention. Water fed into 15 the system through a water inlet 12 is heated in a hot water tank 1, then

transferred to a steam boiler 2 through a feed pump 31.

As illustrated, the boiler 2 contains part water 21 and part steam 22.

The steam exits the system through a steam outlet 23.

20

For example, in a steam generating system, the water in may flow at a rate

of 5 cubic meter per hour through inlet 12; the system output may be

about 5 ton per hour of steam, out of outlet 23.

In addition to this prior art path of evaporating water into steam, there is a 25 novel path for recirculating water, from the hot water tank 1 through the

recirculation pump 32 and UET reactor 33, back into the tank 1.

In an exemplary system as detailed above, water may be recirculated

at the rate of 50 cubic meters per hour. Preferably, in the recirculation path

water moves at a faster rate than in the normal evaporation path. 30

This accelerated rate of recirculation causes scale deposits at a faster rate in the

UET reactor, to efficiently clean the water to be transferred to the boiler 2. Thus, with scale being deposited in reactor 33, the amount of scale deposited in the boiler is greatly reduced.

Thus, raw water is used as a source for anti-corrosion inhibitors; 5 preferably, raw water is used to pre-treat only about 60% of the water. The

rest, or 40% of the water, will be regular raw water transferred to the

boiler 2, leaving Calcium in the water to be a natural corrosion inhibitor.

The excess of Calcium in the raw water, that can potentially form scale, will

cause a scale deposit in a specifically designed reactor 33 (the UET reactor). 10

Thus, scale will be deposited in the UET reactor 33 rather than in the boiler 2.

Thus, water is recycled between the heater 1 and the UET reactor 33, to

accelerate the precipitation of scale, to prepare the water for use in the

boiler 2. Furthermore, water is recycled through the UET reactor 33 at a faster 15 rate (volume of water per hour) than the rate water is converted to steam in

the boiler 2.

A benefit of this system and method is that it is much easier to clean scale

from the UET reactor 33 than from the boiler 2. 20

Fig. 4 illustrates the UET reactor(TM). An important part of the water

treatment system is the UET reactor 33 herein detailed.

There is a water inlet 331 and a water out 332. An anode 334 is used to

perform a partial electrolysis of the water in the reactor 33, with the outer 25 enclosure of the reactor 33 acting as a cathode 335.

Thus, scale precipitation in the UET reactor 33 is stimulated using a partial

electrolysis.

Furthermore, partial "hard" water will be introduced into the boiler 2; such 30 water as can be used in the boiler feed without any need for softening the

water or introducing chemicals and while ameliorating the problems of scale or corrosion problems. The water in the boiler 2 will remain balanced and

therefore scale or corrosion problems are reduced. This process eliminates the need for chemicals introduction.

Fig. 5 illustrates the new water treatment method in a steam boiler 2.

In this system, water is fed into a steam boiler 2 from a water inlet 12, to be converted into steam at a steam outlet 22.

The system further includes a filter 41, UET reactors 33A, 33B, 33C and condense 46.

The present disclosure further presents an apparatus usable for implementing the abovedetailed methods.

It will be recognized that the foregoing is but one example of an apparatus and method within the scope of the present invention and that various modifications will occur to those skilled in the art upon reading the disclosure set forth hereinbefore.

Industrial Applicability

The invention is applicable in industry, it including methods for water treatment in steam boilers. These are chemicals-free methods for substantially reducing 5 sedimentation of solids and minerals in the boiler and for reducing

corrosion processes in the boiler.

The method may include treating the water prior to feeding it into the boiler (pre- treatment); the pre-treatment comprises heating the water and recycling the water 10 through a UET reactor for depositing scale in the reactor.

In this water treatment method, pre-treating of about 60% of the water may be performed, wherein the rest, or about 40% of the water, is regular raw water

leaving the Calcium in the water to be a natural corrosion inhibitor. 15

Claims

1. In a steam boiler, a water treatment method for reducing

sedimentation of solids and minerals in the boiler and for reducing

corrosion processes in the boiler, comprising

treating the water prior to feeding it into the boiler (pre-treatment), wherein the pre-treatment comprises heating the water and recycling the water through a UET reactor for depositing scale in the reactor.

2. The water treatment method according to claim 1 , wherein pre-treating about 60% of the water, and wherein the rest, or about 40% of the water, is regular raw water leaving the Calcium in the water to be a natural corrosion inhibitor.

3. The water treatment method according to claim 1 or 2, wherein forming two parallel paths for water flow, a first path from a water inlet through heating means and to the boiler to generate steam therein, and a second path from the heating means through the UET reactor and back into the heating means.

4. The water treatment method according to any of the claim 1 to 3, wherein recycling water through the UET reactor at a faster rate (volume of water per hour) than the rate water is converted to steam in the boiler.

5. The water treatment method according to any of the claim 1 to 3, wherein the UET reactor comprises an enclosure for transferring water therethrough, and an electrode located in the enclosure and used as an anode wherein the enclosure itself acts as a cathode, to perform a partial electrolysis of the water passing through the reactor.

6. In a steam boiler, a water treatment apparatus for reducing

sedimentation of solids and minerals in the boiler and for reducing

corrosion processes in the boiler, comprising:

means for treating the water prior to feeding it into the boiler (pre-treatment), wherein the pre-treatment comprises means for heating the water and recycling the water through a UET reactor for depositing scale in the reactor.

7. The water treatment apparatus according to claim 6, further including means for pre-treating about 60% of the water, and means for using the rest, or about 40% of the water, being regular raw water leaving the Calcium in the water to be a natural corrosion inhibitor.