The concept of place has been present in human geography for almost half a century. The human geographers looked for the answer about genesis of place category in different sociological or psychological aspects with the basis of space dimension. In last two decades a few of them referred that idea to communication processes. Inspired by the views expressed by the latter group of scientists, we are asking: how is creating a place? We put forward thesis that a special type of place making is social communication that works continuously on the principle of the palimpsest of overlapping meanings through messages arising in several dimensions. Our assumption is that every place is creating (overwriting) a social subject – an individual or a group, that will build communication in three dimensions: within a space/place (W), about a space/place (A), and/or between people and a space/place (B).
Examples of cast grates whose construction was based on previously used "old" patterns of the technological equipment for heat treatment furnaces (TEq) are presented. Manufacturers of this type of castings have at their disposal numerous earlier designs of the applied TEq. Their adaptation for the needs of a new order, i.e. the creation of a new design or modification of the already existing one, significantly reduces both cost and time of the implementation. It also allows making new grate constructions of various shapes and sizes, reducing in this way the number of patterns stored by the manufacturer of castings. The examples of cast grates shown and discussed in this study document the variety of ways that can be used when making them from the already existing patterns or castings. The presented grates were made using master patterns, entire castings or their fragments, and modular segments.
Various examples of the design of cast elements of the equipment used in furnaces for the heat treatment of machine parts are given. Shortcomings in their performance are indicated. Reasons for required stability of equipment are briefly discussed. Elements of equipment illustrate the possibilities of using a charge-carrying pallet with dimensions of 900×600×45 mm as a basis for multi-component technological equipment. Introducing additional elements, such as metal baskets, intermediate pallets or crossbars to the main pallet, it becomes possible to create different configurations of this equipment. The technological equipment presented and discussed here is offered to different plants which heat-treat a wide variety of produced parts. It was found that the reliability and durability of new designed equipment can be checked only during practical use. For large plants dealing with the heat treatment of bulk quantities of parts homogeneous or similar in shape is recommended to use the dedicated tooling.
The lifetime of guide grates in pusher furnaces for heat treatment could be increased by raising the flexibility of their structure through, for example, the replacement of straight ribs, parallel to the direction of grate movement, with more flexible segments. The deformability of grates with flexible segments arranged in two orientations, i.e. crosswise (perpendicular to the direction of compression) and lengthwise (parallel to the direction of compression), was examined. The compression process was simulated using SolidWorks Simulation program. Relevant regression equations were also derived describing the dependence of force inducing the grate deformation by 0.25 mm ‒ modulus of grate elasticity ‒ on the number of flexible segments in established orientations. These calculations were made in Statistica and Scilab programs. It has been demonstrated that, with the same number of segments, the crosswise orientation of flexible segments increases the grate structure flexibility in a more efficient way than the lengthwise orientation. It has also been proved that a crucial effect on the grate flexibility has only the quantity and orientation of segments (crosswise / lengthwise), while the exact position of segments changes the grate flexibility by less than 1%.
The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds. The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology, and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves the metal yield.
Creep-resistant parts of heat treatment furnaces are in most cases made from high-alloyed chromium-nickel and nickel-chromium iron alloys, both cast and wrought. This paper presents the types of casting alloys used for this particular purpose, since the majority of furnace components are made by the casting process. Standards were cited which give symbols of alloy grades used in technical specifications by the domestic industry. It has been indicated that castings made currently are based on a wider spectrum of the creep-resistant alloy grades than the number of alloys covered by the standards. Alloy grades recommended by the technical literature for individual parts of the furnace equipment were given. The recommendations reflect both the type of the technological process used and the technical tasks performed by individual parts of the furnace equipment. Comments were also made on the role of individual alloying elements in shaping the performance properties of castings.