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The purpose of this paper is to set out a study of the film‐forming characteristics of octadecylamine (ODA), estimate the feasibility of shutdown protection using ODA at high temperatures, and determine the optimum process condition of shutdown protection for units under full load if ODA has a good film‐forming effect at high temperatures.

An autoclave was used to simulate the water‐vapor environments at 350‐560°C in the water‐steam system of power plants. The decomposition test of ODA was investigated and the ODA film‐forming characteristics were studied for furnace tube materials used in gas‐fired power plants.

Results showed that ODA had a decomposition equilibrium and the decomposition products did not contain harmful organic substances such as low molecular organic acids. ODA would form a satisfactory protective film in the range of 350‐560°C with the best film at 480°C. The protection effect of the film formed by ODA at 560°C was much stronger than was that of its oxide film, which showed the feasibility of shutdown protection using ODA for gas‐fired power plants operating under full load. The optimal conditions of shutdown protection under full load were as follows: the temperature was 560°C, the concentration of ODA was 80 mg/L, the pH was 9.5 and the exposure time was 2 h. From the experimental results of X‐ray photoelectron spectroscopy, it was known that the surface film on the specimens was composed of a compound of ferroferric oxide and ODA, and the film‐forming mechanism was chemical adsorption between N in the ODA and Fe.

It was found that ODA has a good film‐forming effect at high temperatures and it is practicable to implement shutdown protection for base‐load units. The research results can provide theoretical guidelines for shutdown protection of gas‐fired power plants.

This work was focused upon the main factors that influence the formation of a hydroxypropyl-β-cyclodextrin (HP-β-CD) supramolecular complex with octadecylamine (ODA) and their optimal processing conditions. The anti-corrosion properties of the products in the simulated boiler water condensate of power plants also needed to be tested. The paper aims to discuss these issues.

A grinding method was applied to synthesize the supramolecular structures. Using Fourier transform infrared, X-ray diffraction and proton nuclear magnetic resonance spectroscopy (1H NMR), the specific structures of the complex were clarified. The anti-corrosion properties were obtained from gravimetric results, potentiodynamic polarization tests and electrochemical impedance spectroscopy measurements.

The results reveal the highly soluble supramolecular complex could be formed between two HP-β-CD molecules and one ODA molecule at 85°C with a processing period of 15 minutes. In the condensate, the corrosion inhibition efficiency of the complex was over 95 percent, much higher than the inhibition efficiency of the hydrophobic ODA compound.

The supramolecular corrosion inhibitor could be used as an anti-corrosion method for industrial boiler condensate to reduce the content of corrosive ions. In this way, it is easier to reuse the condensate without re-polishing.

The research introduces supramolecular chemistry into corrosion science for the first time. The results provide a new option to modify the traditional corrosion inhibitors.

The advantages of reclaiming as much condensate as possible in any steam‐generating system are manifest. The return of hot water to the boiler results in a considerable reduction in fuel and water consumption. In addition, a low make‐up will give rise to a lower rate of corrosion attack due to carbon dioxide generated from dissolved bicarbonates. However, such a procedure greatly increases the length of piping and number of fittings which are exposed to attack. The corrosion of steam and condensate return lines, and also of steam‐using equipment, can become a major problem. Perforation of steam jackets, steam coils, pipes and fittings; choking of steam traps with corrosion products; leaking valves and joints are serious enough in themselves. The cost of replacing the corroded equipment is often considerable and excessive damage may be caused by the ingress of steam or water to the product being manufactured. In addition, a very high labour cost is often involved. Repairs to damaged plant must usually take place at weekends and during holiday time, when overtime rates are paid.

It does not need much imagination to picture fairly vividly the immense problems occurring in industry due to the ravages of corrosion. Water is a universal service, but by reason of the impurities • it contains in its natural state it may rapidly corrode the heating system or the cooling system or the process system in which it is employed. The photographs in the following article show examples of what may happen.

Houseman manufactures a number of amine based water treatment products to inhibit corrosion in steam condensate lines; the way that amines work and the advantages to be gained by their use is examined below by Keith McGlone BSc, marketing support manager, Houseman (Burnham) Ltd.

This paper aims to investigate and prepare the composite polyurea greases with excellent thermal stability and tribological properties.

In this paper, composite Ba-based (Ba, barium) tetra-polyurea lubricating greases were prepared with two different methods: mixing Ba-based gelatinizer and tetra-polyurea gelatinizer by a physical method; and introducing barium carboxylate into tetra-polyurea molecules by a chemical method. The properties of the products, such as heat stability, water resistance and friction performance, were analyzed with thermogravimetry, water-resistance test and four-ball friction test.

The results indicated that the products obtained by chemically introducing barium carboxylate into tetra-urea molecules showed better elevated temperature tribological properties, and the disadvantages of the polyurea greases with high temperature hardening were also obviously improved. The cone penetration rate at 180°C for 24 h is only 3 per cent. The friction coefficient can be decreased to 0.44 and the last non-seizure load value was increased from 560 N to 1,120 N without any other additives.

The research is significant because the prepared composite grease showed excellent performances, such as the outstanding thermal stability, water resistance and excellent extreme pressure and anti-wear properties, which may be widely applied in steel, metallurgy, bearings and other industrial fields.

Zinc is one of the most important nonferrous metals and finds extensive use in metallic coatings. It is resistant to atmospheric attack and corrodes rapidly only in highly polluted air. It is resistant to most fresh waters but its resistance to sea water and to very soft water is lower. In many aerated hot waters, reversal of polarity between zinc and iron occurs at temperatures of 60°C or above. The corrosion products of zinc are readily soluble both in alkalis and acids and protect the metal surface only in neutral media. In neutral solutions, zinc is corroded mainly by oxygen depolarisation. The dissolution rate of zinc in acids is greatly affected by the over‐potential of hydrogen evolution at cathodic inclusions.

Hydraulic draw bending machines. The range of Staffa tube‐bending machinery has recently been enlarged by the introduction of a series of hydraulic draw‐bending machines in seven sizes. These are suitable for bending steam pipes, and other tubes and sections in all sizes from 1‐in. up to a 12‐in. bore. In most respects the machines are similar throughout the series. Indeed, with the exception of the motor‐driven pump, the whole of the hydraulic system of each machine is made up of units from the standard Staffa range.

Long before calories and joules were used to indicate energy values in relation to food, popular belief had it that some foods could increase man's output of labour, his physical strength and endurance, even his fertility. The nature of the foods varied over the years. From earliest times, flesh foods have inspired men to “gird their loins” and “put on armour”, but too long at the feasting tables produced sloth of body and spirit. Hunger sharpens the wit, which makes one wonder if that oft‐quoted statement of poverty and hunger before the Great War—“children too hungry learn”—was quite true; it is now so long ago for most of us to remember. Thetruism “An army marches on its stomach” related to food in general and relating feats of strength to individual foods is something more difficult to prove. The brawny Scot owes little to his porridge; the toiling Irish labourer moves mountains of earth, not from the beef steaks he claims to consume, but for the size of the pay‐packet at the end of the week!