Flow of Dry Bulk Solids on Bin Walls

1969 ◽  
Vol 91 (2) ◽  
pp. 489-492 ◽  
Author(s):  
P. L. Bernache
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Case Studies ◽  
Mass Flow ◽  
Smooth Wall ◽  
Steel Mill ◽  
Bulk Solids ◽  
Angle Of Friction

The assumption that a smooth wall finish, such as stainless-steel mill finish as opposed to carbon steel, will give mass flow in a less steep cone is not always valid. This paper presents case studies of how the kinematic angle of friction (φ′) between dry bulk solids and bin walls affects the design of mass flow hoppers and how it varies for different materials.

Effects of the properties of bulk solids on the relative performance of polyethylene and stainless steel wall lining materials in mass flow hoppers and other applications

2000 ◽  
Vol 214 (1) ◽  
pp. 53-62 ◽  
Author(s):  
M S A Bradley ◽  
M Bingley ◽  
R J Farnish ◽  
A N Pittman ◽  
G Lee
Keyword(s):  
Stainless Steel ◽  
Mass Flow ◽  
Wall Friction ◽  
Friction Test ◽  
Low Friction ◽  
Flow Discharge ◽  
Flow Problems ◽  
Bulk Solids ◽  
Bulk Solid ◽  
Ultra High Molecular Weight

Reducing the friction between the walls of storage vessels and the bulk solids that they contain is widely known to be beneficial in obtaining more satisfactory flow patterns in such vessels, and to reduce flow problems. In particular, the advantages of low friction in promoting a mass flow discharge pattern are well understood; means of obtaining data to design a hopper for mass flow are also well established. In recent years a number of polyethylene materials have come on to the market, intended for use in lining silos and claimed by their manufacturers to offer low wall friction in comparison with other materials. In this paper, one particular commercial grade of ultra-high molecular weight polyethylene (UHMWPE) material has been tested alongside a commonly used type and finish of ferritic stainless steel. The wall friction has been measured for both materials, with a variety of bulk solid materials and conditions, and the hopper half-angles needed for mass flow computed for each combination. The results show that the UHMWPE material does not always offer a lower friction than the stainless steel; in some cases it offers much lower friction and hence much greater scope for obtaining mass flow discharge. However, in other cases it gives significantly higher friction and is a bad choice for promoting flow. The principal conclusion is that, under certain circumstances, UHMWPE offers substantial advantages over other wall materials. However, this advantage is by no means universal and, if it is to be considered for employment in a hopper design, then a wall friction test should be undertaken. This test should use a sample of the bulk solid to be handled against both the UHMWPE material and other possible materials.

Case Studies on Field Repairs of Stainless Steel Components in Refinery

2013 ◽  
Vol 794 ◽  
pp. 375-379
Author(s):  
B.S. Negi
Keyword(s):  
Stainless Steel ◽  
Heat Exchanger ◽  
Carbon Steel ◽  
Case Studies ◽  
Weld Joint ◽  
Stainless Steels ◽  
Pressure Vessels ◽  
Dissimilar Welding ◽  
Premature Failure ◽  
Steel Type

Stainless steels (SS) possess excellent corrosion, creep and high temperature oxidation resistance and are invariably used in refinery for construction of heater tubes, tube supports, Heat exchanger bundles, piping and internal lining of pressure vessels. Ferritic stainless steel type 405 is used for column strip-lining, martensitic stainless steel type 410 is used for column trays and heater tubes and austenitic stainless steel family is used very extensively for lining, piping, heat exchanger, heater tubes and tube supports. On-stream and turnaround condition monitoring of plant and equipment are carried out for health assessment and mitigation of premature failure. However, catastrophic failures of stainless steel due to stress corrosion cracking, thermal fatigue and stress relaxation cracking are encountered in addition to bulging and cracking of strip-lining. Field repairs of these components are required to be done. Stainless steels are difficult to weld due to low thermal conductivity, higher coefficient of thermal expansion, fissuring and solidification cracking problem during welding. Lower heat input and fast cooling facilitate the welding process. Welding of service exposed stainless steels is more challenging, as it has already undergone metallurgical degradation. Welding of stainless steels is carried out using TIG and SMAW process with matching electrode after establishing the welding specification procedures and welders qualification. Field repairs of stainless steels components are also attempted with original procedures and in case of difficulties, a buttering layer of inconel (ERNiCr3) or ER 309Mo is provided on the welding surface before using matching electrodes. Quality assurance of weld joint is ensured by stage-wise inspection and non-destructive testing. Dye penetrant test of root run and radiographic examination of final weld joint are most common. Post weld heat treatment is done as per code requirement. This Paper highlights three case studies on field repairs of stainless steel components in refinery. 1. Welding procedure followed for repair of bulged and cracked SS 316 strip-lining and cladding on carbon steel backing material. It is a dissimilar welding of SS 316L with degraded carbon steel. 2. Field welding of SS 347 Piping components, which has undergone thermal relaxation cracking at fillet joints. 3. Welding repair of SS 310 cast heater tube support conforming to A 297 Gr HK 40. The Paper also presents brief failure analysis with reasons and remedies.

Pyrolytic carbon filaments and associated catalytic particles formed in steel tubes

1984 ◽  
Vol 42 ◽  
pp. 662-663
Author(s):  
Y. L. Chen ◽  
J. R. Bradley
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Catalyst Particle ◽  
Pyrolytic Carbon ◽  
Plain Carbon Steel ◽  
304 Stainless Steel ◽  
Hydrocarbon Gases ◽  
Steel Tubes ◽  
Filamentous Carbon ◽  
Carbon Filaments

Considerable effort has been directed toward an improved understanding of the production of the strong and stiff ∼ 1-20 μm diameter pyrolytic carbon fibers of the type reported by Koyama and, more recently, by Tibbetts. These macroscopic fibers are produced when pyrolytic carbon filaments (∼ 0.1 μm or less in diameter) are thickened by deposition of carbon during thermal decomposition of hydrocarbon gases. Each such precursor filament normally lengthens in association with an attached catalyst particle. The subject of filamentous carbon formation and much of the work on characterization of the catalyst particles have been reviewed thoroughly by Baker and Harris. However, identification of the catalyst particles remains a problem of continuing interest. The purpose of this work was to characterize the microstructure of the pyrolytic carbon filaments and the catalyst particles formed inside stainless steel and plain carbon steel tubes. For the present study, natural gas (∼; 97 % methane) was passed through type 304 stainless steel and SAE 1020 plain carbon steel tubes at 1240°K.

Estimation of Some Mechanical Properties for Similar & Dissimilar Welded Joints

2014 ◽  
Vol 2 (1) ◽  
pp. 59-76
Author(s):  
Abdullah Daie'e Assi
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Austenitic Stainless Steel ◽  
Base Metal ◽  
Welded Joints ◽  
Plate Thickness ◽  
Low Carbon Steel ◽  
Dissimilar Metals ◽  
Low Carbon ◽  
Steel Type

This research deals with the choice of the suitable filler metal to weld the similar and dissimilar metals (Low carbon steel type A516 & Austenitic stainless steel type 316L) under constant conditions such as, plate thickness (6 mm), voltage (78 v), current (120 A), straight polarity. This research deals with three major parts. The first parts Four types of electrodes were used for welding of dissimilar metals (C.St A516 And St.St 316L) two from mild steel (E7018, E6013) and other two from austenitic stainless steel (E309L, E308L) various inspection were carried out include (Visual T., X-ray T., δ- Ferrite phase T., and Microstructures T.) and mechanical testing include (tensile T., bending T. and micro hardness T.) The second parts done by used the same parameters to welding similar metals from (C.St A516) Or (St.St 316L). The third parts deals with welding of dissimilar weldments (C.St And St.St) by two processes, gas tungsten are welding (GTAW) and shielded metal are welding (SMAW).        The results indicated that the spread of carbon from low carbon steel to the welding zone in the case of welding stainless steel elect pole (E309L) led to Configuration Carbides and then high hardness the link to high values ​​compared with the base metal. In most similar weldments showed hardness of the welding area is  higher than the hardness of the base metal. The electrode (E309L) is the most suitable to welding dissimilar metals from (C.St A516 With St.St 316L). The results also showed that the method of welding (GTAW) were better than the method of welding (SMAW) in dissimilar welded joints (St.St 316L with C.St A516) in terms of irregular shape and integrity of the welding defects, as well as characterized this weldments the high-lift and resistance ductility good when using the welding conditions are similar.

ATI 409HP

Alloy Digest ◽  
2013 ◽  
Vol 62 (2) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Carbon Steel ◽  
Physical Properties ◽  
Tensile Properties ◽  
Ferritic Stainless Steel ◽  
Temperature Performance ◽  
End Use ◽  
Oxidation And Corrosion

Abstract ATI 409HP (UNS S40900) ferritic stainless steel was introduced by ATI Allegheny Ludlum to provide improved oxidation and corrosion resistance for automotive exhaust systems in comparison to carbon steel. The alloy was designated "MF-1", indicating its end use: automotive mufflers. The good fabricability of this alloy, combined with its basic corrosion resistance and economy have significantly broadened the utility of ATI 409HP stainless steel. ATI 409HP consists of four grades: UNS S40900, S40910, S40920, and S40930. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, and joining. Filing Code: SS-1135. Producer or source: Allegheny Technologies Inc..

SANDVIK 3R12/4L7

Alloy Digest ◽  
1996 ◽  
Vol 45 (7) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Black Liquor ◽  
Heat Treating ◽  
304L Stainless Steel ◽  
Design Load ◽  
Recovery Boilers ◽  
Major Application ◽  
Outside Diameter

Abstract Sandvik 3R12/4L7 is a composite tube consisting of type 304L stainless steel for corrosion resistance on the outside diameter and having carbon steel (A210 Gr. A1) as the inside component for both water wetted service and the design load. The major application is tubing to handle the corrosive conditions in black liquor recovery boilers. This datasheet provides information on composition, physical properties, microstructure as well as fatigue. It also includes information on forming, heat treating, and joining. Filing Code: SA-482. Producer or source: Sandvik.

AK STEEL 409 ULTRA FORM

Alloy Digest ◽  
2007 ◽  
Vol 56 (4) ◽  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Carbon Steel ◽  
Physical Properties ◽  
Tensile Properties ◽  
Corrosion Protection ◽  
Automotive Exhaust ◽  
Standard Type ◽  
Temperature Performance ◽  
Complex Shapes

Abstract AK Steel 409 Ultra Form was created for applications needing oxidation or corrosion protection beyond the capability of carbon steel and some coated steels. AK Steel 409 Ultra Form is more formable than standard Type 409 stainless steel and is particularly suitable for parts requiring more complex shapes and improved weldability. Examples of applications include automotive exhaust tubing and stampings. This datasheet provides information on physical properties, hardness, elasticity, and tensile properties as well as deformation. It also includes information on high temperature performance as well as forming and joining. Filing Code: SS-990. Producer or source: AK Steel, Butler Operations.

ACI TYPE HP

Alloy Digest ◽  
1975 ◽  
Vol 24 (3) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Sigma Phase ◽  
Heat Treating ◽  
Steel Mill ◽  
Temperature Performance ◽  
Formation Type ◽  
Rupture Properties ◽  
Roll Service ◽  
Iron Chromium

Abstract Type HP is an iron-chromium-nickel alloy with a combination of elements that makes it resistant to both oxidizing and carburizing atmospheres at high temperatures. The alloy has good creep-rupture properties in the 1800-2000 F temperature range. It has an austenitic structure at all temperatures, thus it is not susceptible to embrittlement from sigma phase formation. Type HP was developed for rugged steel-mill furnace-roll service; no comparable wrought alloy exists. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-307. Producer or source: Stainless steel foundries.

Interfacial Bonding Behavior of Stainless Steel / Carbon Steel in Cold Rolling Process

2020 ◽  
Vol 982 ◽  
pp. 121-127
Author(s):  
Shuo Li ◽  
Qing Dong Zhang
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Great Influence ◽  
Rolling Process ◽  
Interfacial Bonding ◽  
304 Stainless Steel ◽  
Nanoindentation Test ◽  
Real Contact Area ◽  
Steel Matrix ◽  
Bonding Quality

A cylindrical indenter was designed to simulate the roller and 304 stainless steel / Q235A carbon steel plate with different roughness were bonded together. The interfacial bonding behavior was investigated by SEM, ultrasonic “C” scanning detection and nanoindentation test. The result reveal that with the increase of contact pressure between interfaces, the atoms of dissimilar metals begin to diffuse across interfaces in some regions, then form island-like bonding regions, and eventually extend to the whole interface. There are no obvious cracks on the surface of stainless steel and carbon steel after deformation. The cold roll-bonding mechanism of stainless steel and carbon steel is that elements on both sides of the interface diffuse and form a shallow diffusion layer under pressure to ensure the joint strength, and the joint bonding strength is greater than the strength of carbon steel matrix. In addition, the surface morphology of base metal has a great influence on the interfacial bonding quality. The higher surface roughness values increases the hardening degree of rough peak, which makes real contact area difficult to increase and reduce the interfacial bonding quality.

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