ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18116.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

ABSTRACTProgress in appliances and methods of glass manufacture since 1877.— The article contains a brief summary of the personal experiences and observations of one who for over forty years has actively participated in the development of appliances and methods used in various branches of the glass industr

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18117.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

ABSTRACTManufacture of glass melting pots.—The raw materials used, the methods of grinding and mixing the raw clay and grog, and the way in which pots are built and dried arebriefly describedfor the purpose of impressing glass makers with the amount of labor and care involved. At present only one grade of pot is made; but the difficulty of getting a pot suitable for all kinds of glass suggests the desirability of making special grades of pot for use with specified kinds of glass.Proper treatment of pots by the glass maker.—The authors emphasize the importance of gently handling pots and of storing them in a warm and dry place. The precautions to be taken in preheating pots in arches are discussed at length for this is the critical period in the life of the pot. The batch should be properly crushed and mixed and should either be preheated or loaded in gradually; and the furnace temperature should be carefully regulated. It is particularly urged that the technical treatment of pots in the glass be entrusted to a man trained in ceramics and physical chemistry.Arches for heating glass melting pots.—After discussing the usual design the authorssuggest improvementsas to fire box locations, construction of walls and door

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18118.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

ABSTRACTAgeing of clay.—(1)Evolutionof CO2was found to continue for over 34 days after pugging and, like the change of plasticity, to proceed more rapidly between 80° and 90° F than below 60°. (2)Effect of replacing water by non‐aqueous liquidswas to inhibit the development of plasticity altogether. (3)Effect of a dilute solution of H2O2was to produce a pronounced increase of viscosity and also to stimulate the growth of filaments algae and the consequent evolution of both CO and CO2. It seems probable, therefore, that the change of plasticity of clays with time is due, in some way, to the growth of such algae. (4)This algae theorywould explain all the effects found.New chemical measure of the plasticity of clays.—The ratio of the amounts of Al2O3and SiO2dissolved by caustic potash was found, for the three clays tested (Cooley Ball, Edgar Plastic Kaolin and Harris Spruce Pine), to decrease rapidly with diminishing plasticity and therefore might well be used as a quantitative measure of pl

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18119.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

ABSTRACTEffect of calcined clay grog on the properties of fire‐brick.—A medium dense‐burning clay was calcined at cone 8, then ground and mixed with plastic clay in various proportions up to 40 per cent. An air spalling test of the burned bricks showed that the grog increased theresistance to spallingabout 5 per cent for each per cent of grog added. The results forother physical propertiesagreed with those found by previous observers; the bricks with grog were more porous and weaker mechanically but showed less drying and burning shri

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18120.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

ABSTRACTStability of calcined dolomite; effect of fineness of raw material, nature of flux and temperature of burning.—Dolomite is difficult to dead‐burn because the absorption of moisture from the air produces a gradual slacking due, probably, to the hydration of lime and various lime compounds, and this tends to cause disintegration. With all the fluxes tried, 100 mesh raw material gave greater resistance to slacking than 8 mesh size. This resistance decreased, however, with increasing temperature of calcining, by an amount which seems to depend on the silica and alumina content of the flux, being greatest for basic open hearth slag and kaolin, less for flue dust, and iron ore, and least for roll scale. The stability also varied with the proportions of flux used, being greater, as a rule, for smaller proportions.Shrinkage, porosity and vitrification of calcined dolomite; effect of flux and burning temperature.—The shrinkage and porosity curves for mixtures containing flue dust, iron ore or roll scale are very similar. The higher the proportion of flux, the lower the temperature required to get maximum shrinkage and minimum porosity. Kaolin and basic open hearth slag behaved peculiarly in that vitrification depended more on the burning temperature than on the proportion of flux used.Experiments in making dolomite brick.—It was found that ageing of the wet calcined material was necessary to prevent cracking of the bricks upon drying. With 5 per cent MgCl2as binder, comparatively strong brick were obtained. High shrinkage on firing caused excessive cracking, but the bricks were extremely dense and did not disintegrate until after four to six months. Unfired tar‐bonded brick were made with sufficient strength to stand shipping and with a storage life of about four months. Fired tar‐bonded brick showed less shrinkage and cracking than similar brick made with water. If dipped in tar to protect them from moisture, such brick will last five or six months before disintegration. It is possible, then to make dolomite brick with a storage life long enough to allow shipping and placing in furnaces.Stability, shrinkage and porosity of calcined magnesite; effect of flux and temperature of burning.—Unlike dolomite, magnesite showed less slacking effect the higher the temperature of burning. Roll scale gave greater stability than iron ore, probably because of its lower silica content. The product was comparatively porous and with low shrinkage, even with high proportions

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18121.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

ABSTRACTVariation of tensile strength of sanded gypsum plasters with composition and consistency before setting.—To each of a series of 12 plasters, containing various proportions of sand, 5 different amounts of water were added. The consistencies, determined by means of a Southard viscosimeter, and the tensile strengths of the set plasters are tabulated. The results vary both with the kind of gypsum and with the fineness of the sand.Suggested method of determining normal consistency of sanded gypsum plasters.—As a result of considerable experience the authors have reached the conclusion that material of the proper consistency to be used for plastering will show a slump of 1/2 inch when tested in the Southard viscosime

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18122.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18123.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1921.tb18124.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY