Glover tower

The final products are then sulphuric acid, nitrogen oxide and oxygen the two latter react and the cycle goes on. Theoretically therefore, the nitrous fumes are never used up. In practice, however, some slight replacement is needed and this is achieved by adding a little concentrated nitric acid to the mixture in the Glover tower ... 

Glover-saure, /. Glover acid (acid from the Glover tower), -tunn, m. Glover tower. Glucinerde,/. glucina (beryllia). 

While the lead-chamber process increased the amount of sulfuric acid that could be produced, it relied on a source of nitrate that usually had to be imported. The process also produced nitric oxide gas, NO, which oxidized to brown nitrogen dioxide in the atmosphere. To reduce the supply of nitrate required and the amount of nitric oxide produced, Gay-Lussac proposed that the nitric oxide be captured in a tower and recycled into the lead chamber. Although Gay-Lussac first proposed this modification to the lead-chamber method around 1830, it was not until the 1860s that John Glover (1801-1872) actually implemented Gay-Lussac s idea with the Glover tower. 

Another purpose served by the Glover tower is that it relieves the lead chambers of the production of part of the acid, and it may account for as much as 16 per cent, or more of the total yield of acid, due to the conversion of sulphur dioxide into sulphuric acid inside the tower indeed, a tower of similar type is sometimes interposed between two of the chambers with a view to the same result.2... 

The capacity of the Glover tower is usually 2f to 3 per cent, that of the chambers, and in order to obviate the need for inconveniently large towers, two are sometimes employed in series. 

The Gay-Lussac Tower.—On leaving the chambers the gases contain only traces of sulphur dioxide, and are red in colour on account of the presence of the oxides of nitrogen. The latter are removed by leading the mixture to a circular tower, or sometimes two towers, the height of which may be 26 to 65 feet and the capacity about 4 per cent, that of the chambers. For convenience in the arrangement of the works the Gay-Lussac towers are usually built near the Glover tower. 

There is, however, some loss of the valuable nitrous gases, necessitating the introduction of small quantities of nitric acid at or before the Glover tower or into the chamber itself (see before) the loss is probably due mainly to the reduction of the oxides to nitrous oxide and even nitrogen, which are not absorbed in the Gay-Lussac tower.1... 

Theory of the Action in the Gay-Lussac and Glover Towers.— The gases issuing from the chambers consist mainly of nitrogen dioxide, nitric oxide and atmospheric nitrogen. The two former are dissolved by the sulphuric acid in the Gay-Lussac tower with formation of a solution of nitrosylsulphuric acid in excess of sulphuric acid (see also below) ... 

As the formation of nitrosylsulphuric acid is a reversible process, dilution of the sulphuric acid solution in the Glover tower tends to cause hydrolysis, which is aided by the high temperature the oxides of nitrogen resulting from the decomposition pass on with the sulphur dioxide and excess of air to the chambers, whilst the sulphuric acid descends and issues at the bottom of the tower. 

In addition to the foregoing process, however, the Glover tower actually produces sulphuric acid. This is brought about by interaction of the sulphur dioxide in the burner gases with nitrosylsulphuric acid, as follows ... 

In the first chamber, and also in the Glover tower, the gases are usually colourless, and it is possible that the excess of sulphur dioxide here causes a reduction to nitric oxide ... 

An advantage possessed by this series of changes is that it explains more satisfactorily than the preceding theory why much sulphuric acid can be formed in the Glover tower. In the lead chambers the acid formed is so weak that the nitrososulphonic acid stage is possibly absent from the series. 

Subsequent Treatment of the Acid.—The acid from the Glover tower generally contains flue dust (largely ferric oxide), on which account it is used up in the acid factory itself, part being returned to the Gay-Lussac tower and part being used for the preparation of sodium sulphate. For this reason it is not essential that pure nitric acid should be introduced at the Glover tower, and frequently an aqueous solution of the cheaper sodium nitrate is used in its place. 

A recently adopted method 6 for minimising the amount of arsenic in the acid is to pass the gases through a closed vessel placed between the Glover tower and the chambers and containing an oxidising agent such as nitric acid, which will retain the arsenic. 

Extraction.—(1) From Pyrites.—In the oxidation of the pyrites (or other sulphur mineral) for the formation of sulphur dioxide in the manufacture of sulphuric acid, foreign elements like arsenic and selenium also undergo oxidation and pass ofC as vapours with the sulphur dioxide. The selenium dioxide produced in this manner their suffers more or less complete reduction by the sulphur dioxide, when finely divided selenium separates, mainly in the lead chambers, as a red, amorphous powder, accompanied possibly by some of the greyish-black form a portion of the dioxide is also found in the Glover tower acid. The amount of selenium in the chamber mud depends, of course, on the nature of the pyrites relatively large quantities of compounds of arsenic, zinc, tin, lead, iron, copper or mercury are always present, arising almost entirely from impurities in the pyrites. 

A further method of extraction of the selenium from the mud is based on the solubility of the element in solutions of potassium cyanide, forming selenocyanide. The solution deposits selenium when acidified, and any sulphur is retained in solution as thiocyanic acid.2 Treatment with a solution of an alkali hydroxide, or fusion with sodium carbonate (the latter more especially for the extraction of selenium from the dust of the flues between the pyrites burners and the Glover tower), has also been applied, the mass being extracted with water in the latter case. The resulting aqueous solutions deposit selenium on atmospheric oxidation, whilst any extracted sulphur passes mainly to thiosulphate.3... 

The presence of much selenium in the Glover tower acid imparts a red colour to the liquid. The element can be separated by dilution followed by treatment with sulphur dioxide.5... 

In addition to the gaseous mixture that enters the chambers from the Glover tower, steam is introduced. Consequently, all the reactants necessary for the formation of sulfuric acid are present. 

The kind of sulphuric acid used varies with the nature of the nitric acid it is desired to produce. For a dilute nitric acid of 1.35-1.4 sp. gr. it is sufficient to use 60° Be. (141° Tw.) sulphuric acid direct from the Glover tower. The first distillate will be strongest, and the last nearly pure water. Should, however, a stronger H.N03 of over 1.5 sp. gr. be required (as is now nearly always the case), a more concentrated 66° B6. (167° Tw.) sulphuric acid must be employed, and the NaN03 is often previously melted. 

A nitric acid of r.35-1.40 sp. gr. is also used for the Glover towers in the manufacture of sulphuric acid. 

We have, so far, only dealt with the commonest forms of apparatus for evaporation, not only for the reason that they are used more extensively than others, but because they illustrate most clearly the principles on which such apparatus is constructed. In the space at our disposal, it is impossible to deal with every kind of known apparatus, and special modes of evaporation, such as Brine towers, the Glover towers, and others, have therefore not been mentioned. These and many other kinds of apparatus may be, and have been, constructed for special purposes, but there is no necessity to describe every one in detail. They are all based on the principles which we have explained,—that is, to give as much surface to the evaporating vessel as possible, and to use up waste heat. 

In the 1904 edition there is, for example, a sample calculation of the heat balance on a Glover tower treated as an evaporator, which shows how inefficient it was then ( what a heat waster it is (23)), There is also a discussion on the efficiency of various packings, explaining in terms of surface areas why coke is 1.5 to 2 times more efiBcient than bricks (23, 26), But in general, Davis approach was still empirical the operations are described as procedures of practical utility, and are not based on fundamental physics. Neither the work of Osborne Reynolds nor dimensionless group theory had been assimilated yet into the profession. 

The Gay-Lussac tower in sulphuric acid plants was invented in 1827 but first used in 1842. The Glover tower, invented in 1859 by a chemical plumber, John Glover (Newcastle on Tyne 2 February 1817-1 May 1902), came into general use in Widnes in 1868-70. Gay-Lussac s son Jules worked with Pelouze on salicin and with Liebig in Giessen on paraffin. ... 

Sulfuric acid production was for decades the industrialization index of any country due to its use for the production of a number of chemicals from dyes to explosives. The first method available was the lead chambers by Rosenbrock in 1746. The need for more concentrated sulfuric acid improved the process with the addition of the Gay-Lussac Tower in 1835 and the Glover tower in 1859. However, the concentration of sulfuric acid, around 60%, was not enough for the growing ch ical industry. Thus, the contact method was developed based on heterogeneous catalysis. The method consists of obtaining SO2 from sulfur or pyrite by burning them. The next stage involves the equilibrium ... 

Throughout the rest of the period under review the chemical technology came to Denmark from, or at least via, Germany 1873, beet sugar 1880 (approx.), Gay-Lussac and Glover towers in sulphuric acid production 1888, Portland cement and 1900 (approx.), refining of edible oil. 

Chaumy, Gay-Lussac tower Nitrogen oxides absorbed at outlet of lead chambers to allow catalyst (oxides of nitrogen) recovery. First use at Chaumy in 1842 and Glasgow in 1844. Little used until Glover tower became available. 

Glover tower Nitrous oxides recovered from Gay-Lussac tower. Slow acceptance. First use 1859 at Washington, Co Durham, UK. 

H2SO4) from a total of 15,400 tonnes of pyrites. The tower cost 450 and annual repairs over a 6-year period cost only 11. Even so, despite the bargain prices, Glover towers were slow to gain acceptance, and by 1890 were used by only about half of US acid plants. Until the lead chamber process was fully developed, concentrated sulfuric acid could only be produced by evaporation in glass or platinum vessels. 

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