摘要:

AbstractRationalizing drawings for chemical apparatus. For small and medium‐sized manufacturers of apparatus, producing drawings may constitute a disproportionate waste of time and personnel, particularly when no new designs are involved but only modification or improvement of drawings supplied by the customer. One possibility for rationalizing drawing is to simplify the old‐fashioned approach by using symbols for frequently drawn or standard items, or by listing alphanumerically. This presumes a kind of systematization permitting determination of those symbols and their reasonable use, as well facilitating rationalization by means of data processing. There are different approaches to computer‐aided drawing (from computer controlled drawing‐board to interactive screens); here a CAD programme is presented which was especially developed for graphic presentation of chemical apparatus, and which can be used without learning a programming l

ISSN:0009-286X    

DOI:10.1002/cite.330570502

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330570503

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractDosage of solids and liquids. Dosage of reaction components is an important step in chemical engineering processes. In an age of increasing automation, the development of dosage procedures is highly topical; electronics and data processing have long made inroads into dosage procedures. However, today's more stringent demands with regard to pressure, temperature, viscosity, and abrasion necessitate intensified research and development efforts. The present article considers mainly volumetric and geometric dosage methods. The many types of metering pumps cover a large area of dosage of liquids. Minimal flow rates, pressures up to several 1000 bar, and also dangerous and difficult fluids can all be safely handled. Leakproof designs with membranes, tubes, or bellows as displacement devices are particularly important nowadays. Volumetric dosage of solids requires establishment of a reproducible packing density. The survey considers the principle methods of dosage (also against pressure) with special emphasis on screw dosage. Gravimetric dosage methods are extremely reliable and accurate but generally require volumetric systems for energy supply. Especially when used in combination with metering pumps or screw dosage, differential balances have numerous possible applications.

ISSN:0009-286X    

DOI:10.1002/cite.330570504

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330570505

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractScale‐up under conditions of partial similarity. When appropriate physical properties of the system are not available, it is impossible to accurately simulate the working conditions of an industrial plant in a laboratory‐scale experiment, and it then becomes necessary to resort to experiments under conditions of partial similarity. In these cases the laboratory‐scale experiments must be carried out in devices of various sizes and the results extrapolated to the industrial‐scale conditions. This expensive and inevitably unreliable procedure can occasionally be substituted by a systematic experimental approach based on dividing the process in question into individual parts which are then investigated separately (Examples 1 and 3), or by deliberately abandoning certain similarity criteria and checking the subsequent effects on the process as a whole (Example 2). In mixing technology, volume‐related mixing power is often taken as the scale‐up criterion, while in the design of bubble columns, the superficial velocity of the gas is taken as a basis. Both these cases are examples of scale‐up under conditions of partial similarity, and their validity is subjected to a critical examination (Exam

ISSN:0009-286X    

DOI:10.1002/cite.330570506

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractMixing in screw mixers, Part 1: Homogenization. During the treatment of thermoplastic synthetic materials in screw mixers the powder or granular material has to be melted as well degassed, mixed, and delivered against higher pressure. The mixing operations are: Mixing of soluble liquids, suspending of solids in liquids, deagglomeration, mixing of immiscible liquids and mixing of particulate solids. The efficiency of mixing of soluble liquids is poor in conventional single‐screw extruders under low pressure. Additional mixing elements are therefore placed on the screw. The distribution of the components is better in co‐kneaders and multistage screw mixers than in conventional single‐screw mixers. Co‐rotating screws which mesh together show a more careful treatment and more steady mixing of soluble liquids than contrarotating screws. The manufacturers of such continuously working machines are venturing increasingly into the area of reaction technology with treatment of highly viscous materials. A new development is the new programmable

ISSN:0009-286X    

DOI:10.1002/cite.330570507

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330570508

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractSystematic planning in the design of waste gas cleaning installations. Since the passing of the ordinance for largescale power stations and in view of the expected stiffening of the clean air regulations, many users of waste gas emitting plants are being forced to reduce these emissions. This paper describes a systematic and system‐oriented method of planning waste gas cleaning installations regarding a simple and general example. The method assures that the best waste gas cleaning installation is ultimately buil

ISSN:0009-286X    

DOI:10.1002/cite.330570509

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330570510

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330570511

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY