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doc. Ing. František PANÁČEK, CSc.

doc. Ing. František PANÁČEK, CSc. (*1936)

1990 – 1997 proděkan FTOP pro pedagogickou práci

1990 – 1997 člen vědecké rady FTOP

Narozen v roce 1936 v Dobroutově, okres Jihlava.

                Maturoval na Gymnáziu v Jihlavě.  V letech 1954-1960 studoval na Fakultě technologie paliv a vody VŠCHT v Praze, na Katedře koksárenství a plynárenství. V letech 1960-1961 byl zaměstnán  jako samostatný projektant v Energoprojektu. Od roku 1961 působil na VŠCHT v Praze jako asistent, od roku 1964 jako odborný asistent na Katedře energetiky. V roce 1967 obhájil kandidátskou disertační práci na téma „Tvorba a hodnocení oxidických ochranných vrstev v parních generátorech“. V roce 1990 obhájil habilitační práci na téma „Koroze energetických zařízení“ a stal se docentem v oboru „Chemické a energetické zpracování paliv“.

Ve výzkumné práci se zabýval sledováním tvorby oxidických vrstev v parních generátorech, hodnocením oxidických vrstev ve varných trubkách, chemickým čištěním energetických zařízení, korozí a inhibicí koroze, korozní problematikou chladících okruhů.

Jedlickova, V.; Panacek, F. Effect of humic substances on the corrosion rate of steel in cooling waters. (2000), CHEMagazin, 10(6), 10-11.

Corrosion rate of microalloyed low-C steel was evaluated at 45° in the cooling waters contg. high-mol. wt. natural humic substance at 0-40 mL/L. The corrosion rate was typically decreased at 5 mL/L for the steel contg. C 0.05, Mn 0.24, Si <0.01, Ni 0.12, Cr 0.07, Cu 0.07, P 0.014, and S 0.013%.

Kubal, M.; Panacek, F. Potential-pH diagram for Fe-H2O-citric acid system. (1995), British Corrosion Journal,30(4), 309-11.  

The thermodn. of the Fe-H2O-citric acid system are summarized in the form of potential-pH diagrams calcd. from published std. Gibbs free energies of formation of the various species considered.  The influence of citric acid on the behavior of iron is characterized by a decrease in the stability of Fe(OH)2, Fe(OH)3, and Fe3O4 but the stability region of Fe3O3 is substantially less affected.

Kubal, M.; Panacek, F. Passivation of carbon steel in complexing organic acids. (1993), Scientific Papers of the University of Chemical Technology Prague , 1, 153-9.  

The action of citrate and complexonate as chem. passivators for carbon steel in neutral and basic solns. has been studied in relation to their concns., pH-value, and the presence of aggressive chloride ions.  Above a certain pH value (pHcrit.), citrate and complexonate passivate the carbon steel surface, previously covered by a non-protecting, invisible oxide film and keep the passive state in aerated soln., even in the presence of chloride, with practically zero corrosion rate.  After decreasing pH below the pHcrit corrosion potential abruptly falls to the region of active corrosion. 

Kubal, M.; Panacek, F. Removal of chromium-containing compounds by contacting wastewaters with iron filings. (1994), Chemicky Prumysl, 44(2), 41-3, 64.  

A method for removing chromium compds. from wastewater by contacting with iron filings has been investigated.  At 100° Cr6+ pptd. in an easily sedimenting form.  The rate of redn. increased with decreasing pH and with increasing proportion of the iron filings.  Under suitable conditions Cr6+ can be removed within less than 30 min; the residual concn. of dissolved Cr3+ is 0.5 to 0.7 mg L-1.

Panacek, F.  Corrosion during operation and shutdown of steam condensate pipe systems. (1990), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv,  D58, 77-89.  

The corrosion resistance and type of corrosion attack of metal and alloy specimens were investigated in a returned steam condensate from industrial and municipal plants.  Steam supplied into the heat distribution network was optionally treated by alkalizing with NH3.  The corrosion rate of C steels CSN 11373 and CSN 12022 exceeded the acceptable values in all returned condensates and was 100-370 μm/yr.  When pitting corrosion occurred, the max. penetration was to a depth of 900 μm/yr.  The effect of alkalizing of steam with NH3 on decreasing the corrosion rate was ambiguous because the condensate compn. varied considerably.  The steels exhibited a high corrosion resistance in all the condensates.  The corrosion rate of Zn was 50-150 μm/yr.  The corrosion rate of Cu and brass CSN 423239 were 2, CaO, and MgO.

Panacek, F.; Bartonicek, A. R. Corrosiveness of cooling waters of power plants of metallurgical mills.  II. (1988), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv, D56, 239-50.

Testing of power plant cooling water for corrosiveness indicated that insignificant CaCO3 settling occurs when the water is concd. by a factor of

Panacek, F.; Bartonicek, R. Corrosiveness of cooling waters in power plants of metallurgical mills.  I. (1988), From Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D56, 223-37.  

In a power plant cooling system, the concn. of solids in the circulating water increases by a factor of 1.5-2.0 causing the Ryznar index to decrease to ≤6 indicating an almost equil. state.  The corrosion test results show that, in spite of a favorable water compn., a strong steel corrosion occurs.  The corrosion rate increases in summer when sand filters are down and makeup water is not treated.  In this period scale formation occurs.  Pit corrosion in 56 tests showed a rate of ≈1100 μm/yr under these conditions.  A decrease in the uniform corrosion was obtained when PO43- (from hexametaphosphate addn.) in the water reached 2 mg/L.  Nonuniform corrosion control was achieved by lowering the concn. of unsol. matter in the water.

Varga, L.; Vosta, J.; Holinka, M.; Pelikan, J.; Smrz, M.; Panacek, F. Decreasing the corrosion aggressivity of cooling media in power system condensers. (1987) patent CS 234627 B1 19850416.  

The corrosion rate was decreased by up to 70% by feeding benzothiazole inhibitors and other additives into the circulating water of power system condensers during interrupted performance.  EDs, based on 1 ton water, are: (a) 30 g Na salt of mercaptobenzothiazole; (b) 25 g 1,2,3-benzotriazole (I); (c) 2 g I, 2 g tannin, and 6 g coco fatty acid alkanolamides; (d) 50 g Na hexametaphosphate and 5 g I; or (e) 20 g N-contg. condensates.

Panacek, F.; Bartonicek, R. Corrosion activity of biologically purified wastewaters. (1986), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D55, 161-74.  

The corrosion of carbon steel by biol. purified wastewaters from various sources varied from 49 μm/yr (central Prague treatment plant) to 240 μm (in a paper plant).  The corrosion effect of wastewaters depended on the type of their bacterial flora, the presence of acids (e.g. lignosulfonic acids from the paper mill), and scale-forming (i.e. corrosion-moderating) Ca, Mg, PO43- ions.

Nemcova, J.; Bartonicek, R.; Sverepa, O.; Kulhavy, T.; Sladeckova, A.; Novotny, M.; Lohnisky, J.; Paulovic, M.; Panacek, F.; Vosta, J. Corrosion inhibitor with sequestrating effect for copper and its alloys.  (1986) patent CS 233153 B1 19850214.  

Aq. corrosion at pH 6-8 of Cu or Cu alloys is prevented without foulant deposition.  Thus, cooling water was treated with 2-mercaptobenzothiazole at 1:20 to 4:3 and a surfactant at 0.01-0.06 kg/L; the corrosion of Cu and brass was decreased by 85-99% and the foulant deposition was decreased by 79-95%.

Nemcova, J.; Bartonicek, R.; Sverepa, O.; Kulhavy, T.; Sladeckova, A.; Novotny, M.; Lohnicky, J.; Paulovic, M.; Panacek, F.; Vosta, J. Corrosion inhibitors with sequestration and dispersing effect. (1986) patent CS 233152 B1 19850214.  

The corrosion inhibitors contg. H3PO4 or salt, carboxylic acid, and a surfactant prevent corrosion and fouling by cooling water in steel or brass pipes.  Thus, a mixt. contg. H3PO4 30 kg,  Na3PO4 20, citric acid 5, and ethylene oxide-propylene oxide copolymer 45 kg was dispersed into 1000 m3 cooling water to show decreases of scale deposits by 80% and corrosion by 89% for steel pipes.

Bartonicek, R.; Nemcova, J.; Vosta, J.; Paulovic, M.; Sebo, T.; Spacir, J.; Maly, K.; Kulhavy, T.; Panacek, F.; et al. Agent with corrosion-inhibiting, dispersing, and sequestering effects. (1986) patent CS 231112 B1 19841015.

The corrosion of steel heat exchangers by cooling water is prevented by an inhibitor consisting of C2-3 alkylene oxide copolymers (250-3000 mol. wt.), such as ethylene oxide-propylene oxide copolymer 50-90, C2-8 alkanolamine phosphates, such as diethanolamine phosphate 5-30, and alk. polyphosphates, such as Na hexametaphosphate 0.5-20 wt.%. The inhibitor efficiency is increased by 0.5-10% C2-9 alkylphenol phosphate, such as nonylphenol phosphate, or C12-20 ethoxylated amine, such as ethoxylated hexadecylamine.  The inhibitor concn. is 3-100 g/m3.  Thus, 1000 m3 with water was treated with 1:1 ethylene oxide-propylene oxide copolymer 25, triethanolamine phosphate 15, and Na hexametaphosphate 10 kg to decrease the corrosion of steel by 85 and the deposition of org. substances and Ca salts by 70%.  Other components in various proportions were also used, such as Na tripolyphosphate, ethoxylated hexadecylamine, monoethanolamine or diethanolamine phosphate, and nonylphenol phosphate.

Nemcova, J.; Bartonicek, R.; Holinka, M.; Sverepa, O.; Mostecky, J.; Pelikan, J.; Vosta, J.; Panacek, F.; Eliasek, J.; et al. Corrosion inhibitor for brass with a biocidal effect.  (1985) patent CS 222108 B1 19830429.  

Corrosion inhibitors contg. alkanolamines, C12-18 alkylamines, mercaptobenzothiazoles, and surfactants prevent dezincification of brass ducts and condensers as well as their fouling with biol. deposits.  Thus, triethanolamine  [102-71-6] 54 was mixed at 60° with C18H37NH2 [124-30-1] 3 and 2-mercaptobenzothiazole  [149-30-4] 43. The mixt. was stirred at 60° for 2 h, cooled, and mixed with monoethanolamides of coconut acids 43 parts at 40°.  Using this mixt. in a brass cooler at 20 ppm in water gave 98% corrosion inhibition and 70% suppression of microbial growth.

 Kulhavy, T.; Brodsky, A.; Bartonicek, R.; Panacek, F.; Sladeckova, A.; Eliasek, J. Device and method for protecting water cooling systems. (1984)patent CS 216564 B1 19821126.  

A method is described which prevents corrosion, incrustation, and biol. fouling in water systems in which the circulating water is replenished from natural sources of surface waters.  It comprises periodical feeding of an antimicrobial agent, such as NaClO, passing through a magnetic field, filtration, addn. of Na Ca polyphosphate, and treatment with a dispersing agent, such as polyethylene polypropylene glycol  [9003-11-6].

Nemcova, J.; Bartonicek, R.; Vosta, J.; Sverepa, O.; Panacek, F.; Svoboda, M.; Jizba, J.; Kulhavy, T.; Sladeckova, A.; et al. Agent with dispersion-sequestrative and corrosion-inhibitive effects. (1984) patent CS 227447 B1 19840416.

Mixts. of H3PO4 or phosphates 20-50, org. hydroxy acids 20-50, alkanolamides of C6-24 fatty acids 5-30, and surfactants 5-30 parts are useful for aq. cooling medium and warrant satisfactory protection for steel, brass, and Al.  Thus, treating 1000 m3 cooling water of pH 7.2 with H3PO4 15, citric acid 15, diethanolamides of coconut acids 10, and polyethylene glycol ether phosphate 10 kg decreased formation of deposits by 74%, steel corrosion by 92%, and Al corrosion by 85%.

Bartonicek, R.; Panacek, F.; Pyrchala, B. Effect of adding biologically treated wastewater to the cooling cycle on corrosion and deposit formation. (1984), Vodni Hospodarstvi:  B , 34(4), 101-5.  

The use of biopurified wastewater instead of city water as make-up in the open air cooling towers somewhat increases the corrosion rates of steel, Al, Zn, Cu, or brass.  The corrosion increase is due to the increased elec. cond. of the make-up water which contains higher CO32-and NO3- concns. and has lower pH (by ≈1 unit) than city water.  The deposition of scale from cooling water contg. biopurified water is lower than the deposition from cooling water contg. only city water.

Bartonicek, R.; Panacek, F.; Pyrchala, B. Corrosion in a cooling circuit supplied with treated industrial wastewater.  (1984), Chemicky Prumysl , 34(7), 348-52.

Corrosion of metal parts in an industrial cooling circuit replenished by biol. purified water was investigated.  CSN 11331  [73695-05-3] steel parts and samples of CSN 11373  [37312-61-1] and CSN 17041  [53997-13-0] steels, 99.5 Al, 99.5 Zn, 99.6% Cu, and Cu70Zn29Al  [60746-82-9] brass immersed in the system were exposed to water for ≤21 days.  The corrosion rate and amt. of corrosion deposits were detd.  The biol. purified water had an acceptable corrosion behavior in spite of its high salt content.  The corrosion rate was 3in the water was considerably lower, COD did not change, but BOD was decreased by a factor of 4 compared to that of a conventional cooling circuit.

Bartonicek, R.; Sverepa, O.; Panacek, F. Corrosion of alloys and zinc-coated and uncoated steels in cooling waters. (1983), Vodni Hospodarstvi:  B , (2), 39-43.  

Cooling waters contg. Ca2+ corrode carbon steels at ≤3500 μm/yr.  The Zn coatings and phosphate-based inhibitors reduce the corrosion and scale deposition.  Thus cooling water contg. 2.28 mmol/L Ca2+ + Mg2+ (pH 7.78) gave a 200 μm/yr corrosion rate for carbon steel, but only 20 μm/yr for the Zn-coated carbon steel.  An AlMn alloy had no corrosion under the same test conditions.

Kocica, J.; Panacek, F. Effect of cooling water composition on the corrosion rate of steel. (1982), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D45, 27-49.  

The effect of cooling water compn. on the corrosion rate of steel was studied in a circulation app. at 1.0-1.5 m/s flow rates and 30°C during 96 h.  The corrosion rate was detd. from the wt. losses of the samples.  Decreases in Ca2+ and HCO3- concns. increased the corrosion rate of steel.  Addn. of Ca2+ to the cooling water did not influence the corrosion rate.  Addn. of Cl-, SO42-, and NO3- did not influence the corrosion rate of steel in cooling water, either.

Panacek, F.; Kocica, J.; Eliasek, J. The use of phosphonates for the treatment of cooling waters. (1980),  Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D 41, 5-15.  

Corrosion inhibiting action of several com. compds. contg. phosphonic acid used for treatment of water in open circulating cooling systems was evaluated from the wt. loss of a rotating disk and wt. loss of steel specimens in flowing water at 23°.  The latter had a hardness of 3.2-3.5 mequiv/L and alky. 2.1-2.5 mequiv/L.  The concn. of the inhibitors Ferrofos 509, Ferrofos 510, Nalco 4000, and Nalfloc 345 was 10-1000 mg/L.  Effect of Zn2+ was examd.  The highest corrosion inhibitor of ≤98.9% was obtained for combinations of 50 Ferrofos 509 or Ferofos 510 and 3 mg ZnSO4/L.

Mostecky, J.; Vosta, J.; Singer, P.; Panacek, F. Salt additives for spreading on roadways. (1979) patent CS 177216 B1 19770729.  

The combination of inorg. and org. corrosion inhibitors had a synergistic effect against corrosion produced by Cl-.  Thus, a mixt. of NaCl 85, MgCl 5, Na silicate 7, and aq. emulsion of octadecylamine  [124-30-1] 3 parts had a good deicing effect on roads and the silicate component affected the road surface favorably.

Pelikan, J.; Vosta, J.; Panacek, F.; Eliasek, J.; Mostecky, J. Corrosion inhibitor.  (1978) patent CS 174913 B1 19770429.

Mixts. of (NaPO3)6  [10124-56-8] 4-67, KMnO4 0.5-22, and/or KClO3 10-35, and/or optionally Na silicate 16-80 and CaCl2 0.1-3% inhibits the corrosion of steel  [12597-69-2] surfaces by road deicing mixts. and cooling salt solns.

Eliasek, J.; Panacek, F.; Kocica, J. Effect of flow on corrosion rate of steel in inhibited sulfuric acid. (1977), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D 35, 5-21.  

The rate of corrosion depends on the compn. of the material, its surface characteristics, temp., heat transfer and flow rate of the corrosive medium.  The flow effects esp. the processes in the region of the electrodes.  Through the flow, the reaction products are removed and inhibitors are shifted to the metal-liq. interface.

Eliasek, J.; Kocica, J.; Panacek, F.; Vcelak, L. Effect of flow in neutral environment on steel corrosion and its inhibition. (1977), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D 35, 23-33.  

The effect of flow on the corrosion rate of steel was studied in neutral 0.1 and 1% NaCl satd. with air at 25°.  In these solns. the most significant effect on the corrosion rate is the concn. of O.  O functions as a cathode depolarizer on the metal surface.  The corrosion rate of steel was dependent on the Re0.5 value.  Inhibitors for neutral solns. are K2CrO4 and Na3PO4.  Addn. of K2CrO4 (≥10-4M) is 95% effective.  Na3PO4 on the other hand is less effective and in concn.

Eliasek, J.; Kocica, J.; Panacek, F.; Pelikan, J.; Vcelak, L. Evaluating oxide layers in boiler tubes of steam generators. (1974), Acta Hydrochimica et Hydrobiologica , 2(3), 249-59.  

Exptl. results show a consolidation of the protective coating with increasing temp., heat loading, steam dryness, and time of exposure.  Disturbances in water circulation have a neg. effect on oxide-coating formation by leading to an increased thickness and porosity as well as to a lowering of the corrosion resistance.  The presence of primary corrosion products in the water phase result (in the absence of added corrosion products) in the formation of thick, porous coatings on the surface of the metal.  A comparison between equil. corrosion current, layer thickness, and corrosion resistance values show the first to be most useful as a measure of porosity of the protective layer.  X-ray studies of the oxide layers show the protective layer to be composed preferentially of magnetite.  Under industrial working conditions a thick, amorphous, Cu contg. coating is found, whose pores are nonhomogeneous and whose evaluation is more complex, magnetite being the preponderant constituent.  It is difficult to bring equil. corrosion current values into agreement with apparent thickness and corrosion resistance under these conditions.

Vosta, J.; Talasek, V.; Mostecky, J.; Eliasek, J.; Panacek, F.; Singer, P. Mixed corrosion inhibitor. (1973) patent CS 151601 B1 19731119.  

The mixed corrosion inhibitor consists of evapn. inhibitors (e.g., piperdine, nitrite, or cyclohexylamine nitrite), bivalent anions (e.g. chromates, tungstates) combined with NaNO2, silicates, phosphates, urea and its derivs., hexamethylenetetramine, and optionally volatile bases (e.g. piperidine, cyclohexylamine, NH4OH) and org. peroxides (e.g., perbenzoic acid and/or its salts, dibenzoyl peroxide).  Thus, metal sheet was protected by a passivation inhibitor contg. piperidine nitrite 0.65, cyclohexylamine nitrite 1.45, Zn hexametaphosphate 0.8, and piperidine 0.01 g/l.

Mostecky, J.; Nemcova, J.; Vosta, J.; Singer, P.; Panacek, F.; Sverepa, F. Additive ice-thawing mixtures for roads. (1973) patent CS 148729 B1 19730524.  

Cyclic polymers of the type (XPO3)n provide (in combination with Zn and Cd salts) efficient inhibition of metal corrosion by mixts. contg. NaCl.  Upon contact with thawing snow or ice, (XPO3)n is hydrolyzed with opening of the polymer polyphosphate ring.  The resulting uncoiled chain reacts through its exposed OH groups with the metal surface and the Zn and/or Cd component present to produce (on the protected surface) a compact layer with a high ohmic resistance which prevents contact of the surface with the atm. and inhibits surface corrosion, while the Zn ions inhibit (in combination with polyphosphate) slot corrosion.  Recommended compn. of the mixt. is, e.g., NaCl 90, Na hexametaphosphate 6.6, and ZnSO4 3.4 parts by wt.  The corrosion preventing effects can be increased further by addn. of org. compds. with a chemisorption and electrostatic effect, viz. guanidine, urea, PhCN, or BzONa.

Mostecky, J.; Vosta, J.; Panacek, F.; Singer, P.; Nemcova, J.; Voldrich, K. Additive for ice-thawing mixtures for roads. (1973) patent CS 148730 B1 19730524.  

The addn. of Al and/or Mg salts to the usual ice-thawing mixts. decreased (in combination with the other corrosion inhibiting components) the extent of crevice corrosion in exposed metal surfaces.  The compn. is given of 8 mixts. contg. NaCl 90, Al2(SO4)3 or MgSO4 2.5-6, Na silicate 1.5-3, and octadecylamine, urotropine, mercaptobenzotriazole, 2-naphthalenethiol, or thioglycol <3%.  The prepns. showed a 91-3% inhibitory effect in comparison with 65% obtained with Carguard.

Mostecky, J.; Vosta, J.; Singer, P.; Panacek, F. Mixed inhibitor of chloride corrosion.  (1973) patent CS 147354 19730215.  

Combinations of Na silicate or Na phosphate with octadecylamine, Me4NCl, urea, or urotropine show a synergistic effect in refrigerator brine solns. and ice-creep thawing mixts.  The inorg. component produces (on metal surfaces) an insol. film with a high ohmic resistance and the org. component markedly enhances (by its chemisorption effect) the corrosion inhibiting activity of the inorg. component.

Mostecky, J.; Vosta, J.; Panacek, F.; Singer, P.; Nemcova, J.; Voldrich, K. Mixed inhibitor of chloride corrosion. (1973) patent CS 147451 19730215.  

Al(III) and/or Mg(II) salts are combined with org. compds. with a chemisorption and/or electrostatic inhibition effect for use as additives in refrigerator brine solns. and ice-creep removing mixts.  The combinations contain Al2(SO4)3, MgCl2, MgSO4, Na hexametaphosphate, C12-18 fatty acids, octadecylamine, urotropine, mercaptobenzothiazole, phenylthiourea, 2-napthalenethiol, tannin, thioglycol, etc.

Mostecky, J.; Nemcova, J.; Vosta, J.; Singer, P.; Panacek, F.; Sverepa, O. Mixed inhibitor of chloride corrosion. (1973) patent CS 147355 19730215.

Na hexametaphosphate (I) affords, in combination with Zn(II) or Cd(II) salts, an efficient protection of steel surfaces from ice-creep thawing mixts. contg. NaCl.  Upon contact with thawing ice, the cyclic I polymer is hydrolyzed with H2O yielding an open polymer polyphosphate chain which reacts through its OH groups with the Fe surface and Zn2+ or Cd2+ to give a compact protective coating with a high ohmic resistance.  The coating inhibits surface corrosion, while the polyphosphate-metal complex inhibits crack corrosion.  The protective effect is further enhanced by addn. of org. compds. with chemisorption and/or electrostatic inhibition effect (guanidine, urea, PhCN, BzONa).

Panacek, F.; Kocica, J.; Eliasek, J. Necessity of cleaning steam generators. (1972), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D25, 37-48.  

The evaluation of tube samples taken periodically during shutdown of steam generators is used to indicate the possible need for chem. cleaning.  The most significant values are the wts. and elec. resistance of the oxide layers.  In elec. nonconductive deposits, a lower thermal cond. may be expected, the decrease in both the elec. and the thermal cond. being caused by the porosity of the oxide layers.  Consequently, the elec. resistance of the oxide layer is a measure of the thermal cond. of the oxide layers.  The elec. resistance of the oxide layers can be detd. more easily than the thermal cond.  Other properties evaluated, such as corrosion resistance, chem. compn., and thickness serve as complementary values characterizing the state of the oxide layer and surface deposits.

Panacek, F.; Pelikan, J.; Petrova, M. Steel corrosion in inhibited organic acids. (1972), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv, D25, 27-35.  

Steel corrosion in 2% citric, uvic, and oxalic acids at flow rates of 0.2 m-sec-1 was studied in dependence on temp. and time.  Urotropine, dibenzyl sulfoxide (DBSO), and Resistine N were used as inhibitors.  The highest inhibitory effect for citric acid was found with Resistine N, its effect increasing with temp., at 90° being as high as 95%.  The effect of DBSO was ∼10% lower.  With urotropine a 95% inhibitory effect was found at 60°, while at lower and higher temps. its effect was considerably lower.  Very good results of inhibition in uvic acid were obtained at 60 and 90° with DBSO.  A higher inhibitory effect of Resistine N was found only at 90°.  In oxalic acid the inhibitory effect of none of the inhibitors used proved to be satisfactory.  The values of the inhibitory effect were mostly <40%.

Panacek, F.; Kocica, J.; Eliasek, J. Evaluation of an oxide layer on the boiler tubes of steam generators. (1970) Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , D 20, 35-48.  

Measurements of the layer thickness, corrosion resistance, and equil. corrosion streams were carried out to evaluate the properties of the oxide layer on the inner walls of boiler tubes of steam generators.  The apparent thickness of the layer was detd.  The values obtained were compared with those obtained by measuring the magnetic layers formed in exptl. tubes under the defined conditions.  The exptl. samples of the industrial tubes were obtained from 2 different locations and 2 different types of steam generators.  The values obtained were characteristic, to a certain degree, for the oxide layer formed but were affected by the nonhomogeneous character of the layers, esp. by the presence of Cu and its compds. and by surface deposits.

Panacek, F.; Kocica, J.; Eliasek, J. Physicochemical processes in boiler tubes.  II. (1969), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , 18, 5-14.  

The comparison of magnetite protective layers prepd. on the chem. cleaned surfaces of boiler tubes in processes using neutral, distd., and thermally de-aerated water in a flow app. in an autoclave and in an elec. furnace was studied.  The protective layers were prepd. at temps. 210, 250, 275, and 300° during 24 hr.  With increasing temp., the corrosion protection and the apparent d. increased.  The protective layer was more porous under stabilized through flow conditions than under stationary conditions.

Panacek, F.; Kocica, J.; Eliasek, J. Physicochemical processes in stea, boiler tubes.  I. (1967), Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D:  Technologie Paliv , 15, 53-69.

The protective-layer formation on the inside wall of a pickled boiler tube was studied using neutral, thermally degasified, distd. H2O.  The formation was followed as a function of time, thermal load, and temp. of the inside wall of the boiler tube.  Expts. showed that time consumed by protective-layer formation after boiler pickling becomes shorter with increasing temp.  At 220° it varied ≈24 hrs.

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