- De stuurinrichting en het ankerspil omgebouwd op stoom.
- Elektrische verlichting (t.b.v. zoeklicht) geïnstalleerd bij Smit in Slikkerveer.
- Bepantsering vervangen door platen van smeedijzer met een stalen oppervlak.
- Armstrong kanons worden vervangen voor een modern 28 cm. achterlaadkanon.
- Bemanning bestaande uit; 115 opvarenden (incl. commandant en 6 officieren).
History of steam up to about 1900
Archimedes may have used a steam cannon to destroy Roman ships with burning projectiles, engineer Cesare Rossi of Neapolitan University Federico II suggested at a conference in Syracuse. Rossi thinks the sun, through hollow mirrors, would have heated water in the cannon to steam. The device fired real fire bombs weighing 6 kilograms, filled with sulfur, bitumen, pitch and calcium oxide. He calculated that they could get about 150 meters far. He claims as proof that in 2006 a team from the U.S. Massachusetts Institute of Technology in Cambridge built and successfully tested such a gun. The first actually functioning device that can be referred to as a “steam engine” was already developed by a certain Heron, in 10-70 Anno Domini.
The Aeopile of Heron
An Aeopile is a type of pan-shaped boiler in which water is heated to above 100° C, eventually forming steam. This steam is transported through two upright tubes to a sphere that can rotate on those tubes. Steam escapes from this sphere through two exhaust pipes and collides with a right-angled piece of these pipes. The rapidly escaping steam gives the metal pipes an opposite force, a reaction force, that makes the sphere spin. The name was derived from the Greek Aeolis. This is the Greek god of wind and pila means ball (because of the spherical pressure chamber). It is an early example of the application of Newton’s widely known third law: action = reaction. This also makes it the earliest known example of a steam engine and a precursor to the steam turbine, jet engine and rocket. However, no practical application could be linked to this invention because at that time manual labor was mostly performed by slaves, who were present in sufficient numbers.
The Piston Steam Engine
The next in history to engage in steam engines was the Spaniard Blasco de Garay in 1543. And, over 100 years later, another inventor the Frenchman, Denis Papin. In 1690, he invented the first reciprocating steam engine. This machine functioned as follows: Papin used a piston with a cylinder in which he boiled a little water at the bottom. The steam pressure made the piston go up. Then he removed the fire. The space under the piston cooled, the steam condensed and a vacuum was created. Atmospheric pressure then pushed the piston down and lifted the weights. Indeed, steam has 1700 times the volume of water used for it. Unfortunately, his machine worked very inefficiently and was therefore not economically viable. In fact, here he had demonstrated everything that others could later continue: the compressive force of steam and that of the atmosphere.
Thomas Savery and Thomas Newcomen
English inventor Thomas Savery obtained the first patent for a steam engine in 1698. His machine was intended to pump water from mines and was thus given the name of: Engine to raise water by fire. His machine could pump water, in two steps, first to a height of 9 meters by using the pressure difference created when steam condensed and then using a steam pump to raise it to 15 meters.
Newcomen’s steam engine
Another British inventor, Thomas Newcomen, combined the technology of Savery’s machine with Papin’s reciprocating steam engine and transferred the power of expanding-and then condensing-steam via chains and balance arms to vertical pumps. In 1712, Newcomen thus built a better-functioning atmospheric steam engine with the steam cylinder on top of the boiler, which actually drained water from many British mines in the 18th century. A disadvantage was that this steam engine was not very efficient due to the cumbersome manual operation (by at least two men), and the condensation of steam in the steam cylinder by injecting cold water. So the first true steam engine was an “atmospheric” machine or vacuum machine. They are called an atmospheric machine because atmospheric pressure does the work.
The machine works as follows:
– Steam pressure is let into the steam cylinder through a valve.
– The piston goes up.
– Then close the tap and open the adjacent water tap.
– This causes a little water to flow into the cylinder. As a result, steam condenses in the cylinder.
– The piston now has negative pressure at the bottom and above it is atmospheric pressure plus the weight of the unbalanced lever.
– The piston goes down. The machine operates on the vacuum created by condensation of steam.
Steam engine from Watt-Boulton
Scottish inventor James Watt was commissioned, in 1763 by the University of Glasgow, to repair a broken Newcomen steam engine. He came up with a number of improvements, Watt noted that the steam engine lost a lot of energy because the piston and cylinder in the machine were constantly being cooled and then had to be heated again. Watt went looking for a solution and found it a year later. He built a steam engine in which steam was not condensed in the cylinder itself, but in a separate condensing vessel. In 1769, he patented this method. Partly with the help of businessman Matthew Boulton, Watt managed to build his first double-acting steam engine in 1784, which was patented that same year and consumed as much as 75 percent less coal than the old steam engine.
Condensation principle and general operation
The condenser is James Watt’s THE great invention, and is crucial to the operation of his steam engine. Using a condenser, steam can be forcibly reduced to the phase of water. Condensation makes the volume of water 1700 times smaller than the volume of steam. The remaining space cannot be filled in a sealed condenser, leaving only a vacuum. This vacuum causes a force through which a motion can be created. To this day, the condenser is an important part of almost every steam power plant.
Types of condenser
There are two types of condensers in use, the surface condenser and the mixing condenser. The surface condenser consists of a cold spiral cooling water pipe against which the steam condenses. Very little condensate is formed and this condensate has a quality almost equal to distilled water. This condensate is often used as boiler feed water. And especially on marine vessels, this is an important application. Water is usually used as the cooling medium. In the mixing condenser, the spent steam is mixed with water. This creates a large amount of heated water. This water has a quality equal to that of the cooling water. If the cooling water contains a lot of lime and/or sludge, so does the condensate. So the water from a mixing condenser is bad to use as boiler water. With a mixing condenser comes a wet air pump. This pump maintains the vacuum and removes not only the mixture of cooling water (injection water) and condensed spent steam, but also the air that enters the condenser through various causes. This air comes from the little air always present in the cooling water and from leaks in the condenser. Furthermore, the condenser also always contains some water vapor. Where there is water there is always water vapor. This water vapor must also be pumped out. As a result of the water vapor, it is not possible to create a complete vacuum in a mixing condenser, the remaining water vapor always leaves some pressure.
Machines, operating with or without Condensation
In a steam engine, working with condensation, the spent steam is led to a condenser to be condensed into water in it while in a machine, working without condensation, the spent steam escapes into the outside air. The latter kind of machines were sometimes called high-pressure machines, by which they meant that these machines worked with high, that is atmospheric, back pressure. This spent steam, the voltage of which is slightly higher than the vapor circuit pressure, still possesses a large amount of heat energy, much of which, with an efficient arrangement, can still be converted into mechanical work. To this end, an extension would have to be given to the plant, which in some cases encountered such serious practical objections that people were content with less favorable steam consumption. (steam locomotives, pile drivers). The advantages, associated with working with condensation, are:
* the back pressure behind the piston can be about 1 atm. are smaller, making the useful suction pressure about 1 kg per square centimeter greater;
* the boiler can be fed with hot water of about 70°C, the which brings a significant fuel saving
* the feed water can be pure distilled water, and this advantage is important with regard to boiler life and maintenance costs.
Machines, working with condensation, are again split into two types, namely: A. machines, working with surface condensation; B. machines, working with injection condensation.
A. Machines, operating with surface condensation
In these machines, the spent steam is compacted into water in the condenser by bringing it into contact with cooled surfaces formed by a large number of narrow thin-walled, metal pipes through which cooling water flows. The big advantage here is immediately apparent,. The spent steam remains separated from the cooling agent, so pure water is available for boiler feed. On board steam-powered ships, almost without exception, one has surface condensation.
B. Machines operating with injection condensers or mixing condensers
In these machines, the spent steam is brought into direct contact with the cooling water, now called injection water. In this process, the condensate, mixed with the foreign water, is transported to the boiler as feed water, and will cause boiler scale on the boiler flame pipes. This method of condensation is also called mixed condensation and is not used today.
The energy gain in condensation
A steam engine is always open and exposed in the atmosphere. That means there is atmospheric pressure on all parts. The spent steam must be discharged against this pressure. Thus, at a steam pressure of 6 atmospheres, only 5 atmospheres can be utilized without further provisions. When condensation is used, in which a vacuum is created, the steam can be discharged to a condenser in which there is a pressure of about 0 atmosphere. At a steam pressure of 6 atmospheres, almost the entire 6 atmosphere pressure can then suddenly be used. This then produces a power gain. The exact pressure gradient within the cylinder can be determined using a diagram compression gauge.
In the years that followed, Watt made several more improvements, using only steam pressure as motive power. Thus, the piston was propelled by both lower and upper pressure. (Double Effect). The steam engine became a great success in Britain in the late 18th century, thanks in part to the application of a subsequent invention viz. “James Watt’s parallel motion,” in which a back and forth motion is transformed into a rotational motion. The steam engine found application in mining, in industry, as well as in pumping stations and later in ship propulsion. Watt is the one who introduced horsepower (hp) as the unit of power for classifying steam engines. Later indications of power unit became so many “Watts” or so many “kWatts.” Even later on Oct. 11. 1960 the unit of power in the SI system was named after him: 1 watt = 1 joule/second. (joule: a unit of mechanical, electrical or thermodynamic energy) The steam engine Jan Blanken had built into the pump house of the Droogdok in Hellevoetsluis in 1801 was of the Watt-Boulton ” à Double effect” type.
The conversion of a back and forth motion into a turning motion
(Edited to Source: Association of Friends of the Four North Koggen Steam Engine Museum by Hans Walrecht)
James Watt’s original single machine was closed from the top. The fresh steam first entered the top of the cylinder, creating a slight overpressure there, and then fed into the bottom of the cylinder through a balance tube. Here, by cooling the steam under the piston, a vacuum was created and the piston was pushed down. On each stroke, the piston rod pulled down a chain connected to the balance arm. At the other end of the balance arm was the pull chain of the pump piston. In 1784, James Watt made his machine double-acting, with the goal of obtaining a rotary motion that could be used in industry. This prevented him from using a chain because now the piston not only pulls the balance arm but also has to push the arm up. Therefore, the piston rod must be coupled directly to the balance arm. But the head of the balance arm, in an arc, also makes slight lateral movements relative to the steam engine. The solution to this problem at the time was the parallel movement. This is a system based on a parallelogram, formed by 4 pivot points and two support points which are attached to two horizontal beams, anchored in the wall, and also rotatable.
The construction of a steam engine
This drawing is a schematic illustration of a simple double-acting vertical piston steam engine in which the main parts are indicated by a letter A. Cylinder cover B. The cylinder C. The piston D. Steam slide box E. Piston rod. The piston is firmly connected to the piston rod , which exits through the cylinder bottom by means of a gland H steam tight. At the bottom of the piston rod is the crosshead L, which forms the hinged connection between the piston rod and the connecting rod O. In fact, at the bottom of the piston rod is attached a die, which, as the figure on the right shows, bears a cross pin on both sides.
Around these pins grip the cross pin metals, which lie in the fork at the top end of the connecting rod. The lower end of this rod is coupled to the crank pin R of the crankshaft using crank pin metal Q. This crankshaft consists of the crank pin, both crank cheeks S and both shaft necks U. The shaft necks each rotate in two main shaft metals, which rest in pillow blocks V, which are called the main shaft blocks. In the underside of the main shaft block, lies the lower metal. This is made of Babbith or White Metal which is an alloy of metals: 45.6% zinc; 40% lead; 13%antimony and 1.5% copper. This metal is used with slower-running axles, and is one with the foundation W of the machine. The upper metal, also from Babbith, is pressed on by a cap with bolts. The cylinder made of cast iron rests, with two feet forming one with it, on two columns K, which are attached to the foundation W. In this figure, the left column is made of cast iron, the other of wrought steel. The cast column is provided with a wide sliding surface N, called slate. Along this guideway runs a leislof M, attached to the die of the crosshead and thus moving up and down simultaneously with the piston. The guideway serves to absorb the lateral pressures that occur as a result of the oblique positions of the connecting rod in the crosshead. In large machines such as the Triple expansion machine, both columns are usually made of cast iron. They then have the same shape and are also both slated, so the crosshead now has two slate slats. The steam sliding box D, fitted with a removable lid at the top, is one unit with the steam cylinder. In this cabinet there is a purely flat section F, called the steam sliding mirror in which horizontally arranged rectangular openings are provided, which serve as steam channels. The lower and upper channels are the steam ports, which discharge into the cylinder below and above the piston. The middle channel, the drain port, leads to a round opening, to which a pipe A.S.(Drain Steam) is connected. Over the plane of the mirror moves the steam slide G. It is in the form of a container closed on five sides. Hence the name bucket slide. The open inside has flat edges that fit cleanly on the mirror. The slide is moved up and down by means of an eccentric disk T attached to the crankshaft, around which an eccentric ring grips; this ring is pivotally connected to the steam slide rod J by means of an eccentric rod P, which in turn passes through a stuffing box in the bottom of the steam slide case and is attached to the steam slide here inside. Both the cylinder and the steam sliding case have a well-insulated lining on the outside to prevent heat radiation. This type of engine, but as a three-cylinder engine, the so-called Triple-expansion engine, was installed during WWII in the so-called Liberty ships that sailed in convoy across the North Atlantic to Murmansk.
Types of steam engines
Watt and Boulton had patented their designs until the year 1800, so other steam engine developers were bound by these patents. So after 1800, the industrial revolution erupted, with one design after another seeing the light of day based on James Watt’s ideas.
(Edited from the Source : History of technology in the Netherlands. The genesis of a modern society 1800-1890 part V and also study books Steam Engines for Marine Engineering by Moree)
Single and double acting machines
A single-acting steam engine is still rare. Only in small auxiliary tools such as feedwater pumps, etc., where efficiency is not such a big issue. Karl Schmid’s DC steam engine, equipped with trunk piston or crosshead, is single-acting. See image to the right. A double-acting steam engine is one in which steam is admitted both above and below the steam piston. With equal cylinder capacity and equal number of revolutions, the power of a double-acting steam engine is about twice that of a single-acting one; moreover, the gait of a double-acting machine is quieter. The difficulties associated with the double-acting internal combustion engine due to the very high voltages and temperatures are not encountered with the double-acting steam engine. However, extra care must be taken, especially when using superheated steam, with the packing bushings, steam slide, valve rods and piston rings.
High pressure and expansion machines
In a full pressure machine, steam is allowed into the cylinder throughout the piston stroke. So these machines operate with full admissions and, in keeping with this, we might better call these machines “full admissions machines.” Very economical these machines do not work, but they are already practical considerations, which is why some machines (steam winches, steam steer and steam turnover machines) are still run at full capacity. Direct-acting steam feedwater pumps also operate at full capacity. Expansion machines work with partial admittance, the fresh steam is admitted into the cylinder for only part of the piston stroke, after which expansion of the steam follows. The steam piston reaches the end of the stroke due to the expanding force of the steam.
Direct current and alternating current machines
In a direct-current steam engine, admission of steam takes place over a small portion of the stroke; this is followed by expansion of the steam while about 10% before the end of the stroke, this steam is discharged through channels located in the center of the cylinder in a double-acting engine. The exhaust is not controlled by a slide or valve, but by movement of the piston along openings in the tread. The spent steam does not flow away in the same direction, as in which fresh steam was allowed into the cylinder. This avoids strong cooling along pre-heated surfaces during the exhaust, so initial condensation will be lower.
The exhaust organs at the cylinder ends may be absent and due to the fact that the exhaust openings are located over the entire circumference of the cylinder, the spent steam flows away easily and the back pressure need not be practically much different from the condenser pressure. While boosting the vacuum above 80% in an alternating current steam engine, due to the greater initial condensation, is practically useless, in a direct current steam engine a vacuum of 90% can be successfully applied. In an alternating current steam engine, the spent steam flows back through the same channel at the end of the cylinder, through which the fresh steam has been admitted into the cylinder, and then escapes through the cavity in the steam valve, to the finished steam port. But even if at that end of the cylinder, where fresh steam is admitted into the cylinder, there is a separate channel for discharge of the spent steam the machine is still called an alternating current steam engine.
Valve machines
The machine is called a valve machine if the admittance of fresh steam and the discharge of spent steam are controlled by valves. (e.g., a Lentz valve machine). At the Buffalo in Hellevoetsluis, is a 510 Ihp Lentz valve machine taken from the harbor tug Dockyard VIII. This is a so-called Double Compound Machine which means two equal sets of a High and Low pressure, where the cylinders work 180º to each other and the sets work 90º to each other. So that one can start the machine from any position. In most reciprocating steam engines aboard ships, steam permitting is performed by sliders.
Stationary and non-stationary machines
Stationary machines are those which, solidly fixed to their foundations, are always tied to the same place. The other kind of machines are commonly called land machines. The non-stationary machines can again be divided into two groups, namely: A. machines specially equipped to be transported, in order to be put into operation at any place (locomotive, pile drivers). B. machinery, working in the establishment of which they are part and moving with it (marine machinery locomotives, automobile engines). (The auxiliary machinery on board a ship should be classified as stationary machinery.)
Direct and indirect working machines
By indirect working machines we still mean only the balance machine. A direct working machine means a machine, the piston rod of which is directly connected to the crank pin, to the working tool, or in which the circular motion of the shaft is obtained by a connecting rod and crank mechanism. Of the directly operating machines, only the reciprocating steam engines will be considered. One distinguishes according to the position of the center lines of cylinders:
Horizontal machines
The centerlines of the cylinders lie in a horizontal plane. These machines find almost no further use as propulsion tools. However aboard naval vessels such as the Buffalo and Scorpio, they were common. This was in connection with obtaining a lower center of gravity due to the weight of the gun turret and reducing machine damage in the event of an enemy hit. On board merchant ships, these machines occur as auxiliary tools ( cooling and steering machine, feed water pumps, bilge pumps and winches ).
Vertical machines
The centerlines of the cylinders lie in a vertical plane going through the axis. In most cases, the main tool on board ships is a vertical machine. The shaft is longitudinal to the vessel and under the cylinders, while on the extension of the shaft, which protrudes from the vessel, the propeller shaft is attached.
Diagonal machines
The centerlines of the cylinders lie in planes perpendicular to the axis. The shaft lies longitudinally and below the cylinders (screw ship) The large heads of the connecting rods include a common crank pin and the steam slides derive their motion from a common eccentric. Because of their brevity, these machines sometimes find application aboard river vessels and tugs.
Oscillating machines
These were used as propulsion tools for paddle boats, whose cylinders swing around hollow shafts. The hollow shaft trunnions rest in pillow blocks. One of the taps is used as a supply channel for the fresh steam to the steam sliding cabinet, while the other tap serves as a drain channel for the finished steam. It is short, as the piston rod is connected directly to the crank pin.
Inclined machines
The centerlines of the cylinders lie in one plane that, going through the axis, makes a certain acute angle with the horizontal plane. The shaft is transverse, above the cylinders and has two cranks, which form a 90-degree angle with each other. On either side of the ship, paddle wheels are attached to the shaft where it protrudes outside the ship (paddle boat)
Buffalo’s Maudsley steam engines
The Buffalo’s two steam engines were compound engines. This means they had two cylinders working together in a tandem system. This can be a high-pressure cylinder and a low-pressure cylinder or, as with the Buffalo, two cylinders of the same pressure. They had a recoupled connecting rod to be as compact as possible. They were horizontal machines to lower the ship’s center of gravity and, in the event of a possible hit by enemy artillery, to minimize damage below the waterline. The machines were capable of medium steam pressure of about 25 to 30 psi. (PSI means “Pounds per Square Inch.” 14.2 psi is equal to 1 atmosphere, nowadays bar).
For safety reasons for the engine room personnel, the Navy did not yet want to work with high steam pressure which, at that time 1868, was already 12 bar or 170 psi. The machines each developed a power output of 1100 Ihp. The term Ipk stands for Indicateur horsepower. The machine itself consumes power. What remains for propulsion is axle power the Apk. The square cabinet, above the machinery, is a surface condenser where the spent steam, supplied through the thick pipes, was cooled and compacted into condensate. This condensate was fed back to the steam boilers as feed water. The Buffalo carried a coal supply of 200 tons, which allowed her to stay at sea for 10 days at an average speed of 10 knots.
The Triple Expansion Machine
The triple expansion engine is one of the most widely used steam engines. In particular, they were widely built into the Liberty ships in WWII, sailing in convoy to Murmansk. The triple expansion machine possesses a high, medium, and a low pressure cylinder so that each cylinder must do 1/3 of the work. Steam flows first into the high-pressure cylinder, then into the medium-pressure cylinder and then into the low-pressure cylinder. One allows steam of 12 atm. into the high-pressure cylinder, which then expands there to a pressure of 8 atm. and releases the energy to the piston.
The steam then flows to the medium-pressure cylinder, which has a larger capacity than the previous one (Boyle/Gay-lussac’s law P1 x V1/T1 = P2 x V2/T2) and there, to a pressure of four atm. expands, releasing energy. Finally, the steam continues its way to an even larger cylinder, and then has enough pressure left to perform labor, with the residual pressure being 0.2 atm. The finished steam now flows to a surface (pipe) condenser cooled with cold water to become completely water, by further expansion and condensation, creating a large negative pressure. The eccentric makes the steam slide move, to admit steam to the cylinder through a certain position of the scissor movement, the so-called Stephenson’s scissor. This is meant to obtain a different advance angle of the steam sliders, and make the machine turn the other way. Therefore, each cylinder has two, one for forward and the other for reverse. All these shears are operated simultaneously, through a shaft, by one lever at the maneuvering position. When this lever is moved to the center position, the machine stops. These machines can be either standing or lying down, which depends entirely on the purpose for which they will be used. The exhibit on the Buffalo in Hellevoetsluis features a 180 Ihp Triple Expansion Machine taken from a harbor tug.
The steam slide
The steam supply to the respective cylinders is controlled by a so-called bucket slide driven by an eccentric moved by the crankshaft. One distinguishes exterior and interior loading steam slides. An outside-loading slide refers to a slide in which the fresh steam in the slide box is around the slide body and thus gives a pressure load on the body of the slide. In an inward-loading slide, the steam is fed into the cavity of the slide and the finished steam stands around the slide, with a set of springs keeping the slide pressed to the transom. An ordinary bucket slide is off-loading and not relieving. The fresh steam outside around the steam slide keeps her pressed to the mirror. Sometimes one has additionally attached to the back of the steam slide one or two flat steel springs for the purpose of keeping the steam slide pressed to its transom when there is no steam in the steam slide.
The finished steam can escape through the cavity in the steam slide to the finished steam channel in the transom. This (below) steam slide has a single port opening for inlet and outlet.
With its treads, the slide slides up and down (or back and forth in the case of a lying steam engine) over the transom, from which the steam ports emerge as rectangular openings. A slide with a multiple port opening allows fresh steam to enter the cylinder through two or more channels simultaneously. This is called channel sliding. Steam sliders were always made of hard, fine-grained cast iron. High pressure and superheated steam place high demands on certain parts of the steam engine. A bucket slide, for example, has a large friction surface. That’s not all because the steam pressure also presses against it, making it even more likely that the parts will eat into each other. Therefore, superheated steam is never used in baking slides.
The steam piston is moved by an eccentric, which is a circular disc, attached eccentrically or off-center to the crankshaft. The photo below shows an eccentric of a triple expansion machine. The circular motion of the shaft is changed by the eccentric, the eccentric rod and the steam slide rod into a rectilinear, reciprocating motion of the steam slide. The operation of an eccentric is similar to that of a crank, (crankshaft).
The boiler feed water
Purity of boiler feed water in relation to steam pressure
The distillate from a surface condenser has a fairly high purity. Unfortunately, the condensate did get contaminated with lubricating oil from the cylinder. The condensate then drains first to a so-called hot water tank where the water mass comes to rest. The oil then surfaces as a film and can be skimmed with paper. From there it is pumped to the boiler. The purity of the boiler feed water affects the steam pressure to be achieved. The boiler water temperature determines when salts are deposited on the heated parts of the boiler such as the flame pipes. With contaminated condensate as boiler water feed, which contains e.g. Sodium and Calcium salts, you can only fire up to about 130ºC boiler water temperature. This requires, according to the saturated steam table, a steam pressure of 1.2 kg/cm². With purer boiler feed water, i.e. where there are no salts, you can already heat up further to 180ºC which requires a steam pressure of 12 kg/cm².
Demineralized boiler feed water
In later years, after about 1950, steam pressure could be further increased by first demineralizing the boiler feed water. So stripped of all mineral salts. This is done in a plant containing three types of filters that contain material that can bind hydrochloric acid or caustic soda. These materials are first provided with a positive charge (HCl hydrochloric acid) H+ ions or negative charge (NaOH caustic soda) OH- ions. In the first filter, the cation filter, the positive cations Na+ from the sodium salt (NaCl) are captured by an acidic environment (hydrochloric acid HCl) and replaced by H+ ions. Then in the second filter, the Anion filter, the negative anions the Cl- are captured from it using an alkaline environment (caustic soda NaOH) and replaced by OH- ions. The chemical result is then H2O water. Next, the water stream still passes through a so-called Mixed Bed Filter where post-treatment takes place and the silicon di-oxide (SiO2) is also removed. Namely, this has the property that when superheated high-pressure steam of e.g. 105 kg/cm² is used, when it expands to a lower pressure in a turbine, it precipitates as a hard layer on the blades of a turbine and can throw it into imbalance. When the material in the filters is saturated, they must be regenerated.