http://www-personal.umich.edu/~mswool/publications/cofire_prog_official_reprint.pdf

Co-firing of coal and biomass fuel blends

Thermally stable diamond constructions comprise a diamond body having a plurality of bonded diamond crystals and a plurality of interstitial regions disposed among the crystals. A metallic substrate is attached to the diamond body. A working surface is positioned along an outside portion of the diamond body, and the diamond body comprises a first region that is substantially free of a catalyst material, and a second region that includes the catalyst material. The diamond body first region extends from the working surface to depth of at least about 0.02 mm to a depth of less than about 0.09 mm. The diamond body includes diamond crystals having an average diamond grain size of greater than about 0.02 mm, and comprises at least 85 percent by volume diamond based on the total volume of the diamond body.

Thermally stable diamond polycrystalline diamond constructions

Thermally stable ultra-hard compact constructions of this invention comprise an ultra-hard material body that includes a thermally stable region positioned adjacent a surface of the body. The thermally stable region is formed from consolidated materials that are thermally stable at temperatures greater than about 750° C. The thermally stable region can occupy a partial portion of or the entire ultra-hard material body. The ultra-hard material body can comprise a composite of separate ultra-hard material elements that each form different regions of the body, at least one of the regions being thermally stable. The ultra-hard material body is attached to a desired substrate, an intermediate material is interposed between the body and the substrate, and the intermediate material joins the substrate and body together by high pressure/high temperature process.

Thermally stable ultra-hard material compact constructions

A polycrystalline diamond (PCD) body with improved thermal stability is disclosed which comprises a PCD body which has had at least one of its previously empty pores infiltrated by a silicon containing alloy. According to the process of the invention, a porous PCD body is obtained, preferably by acid leaching a PCD body which was formed in the presence of a metal catalyst such as cobalt. The porous PCD body is then surrounded by either the desired silicon containing alloy, or by the constituents of that alloy, each preferably in powdered form. The PCD body with its surrounding material is then heated and pressed to temperatures sufficient to melt the surrounding material (thereby forming the silicon alloy if not already formed) and to cause it to infiltrate into the pores. After the infiltration, it is preferred to remove the excess silicon containing alloy from the external surfaces of the PCD body, such as by an acid bath. It is also preferred to include several porous PCD bodies per process cycle. The metal component of the alloy together with the relative amounts of silicon can be selected in order to achieve the lowest melting point of the alloy and the best performance characteristics of the infiltrated PCD bodies.

Infiltrated thermally stable polycrystalline diamond

PCD materials comprise a diamond body having bonded diamond crystals and interstitial regions disposed among the crystals. The diamond body is formed from diamond grains and a catalyst material at high pressure/high temperature conditions. The diamond grains have an average particle size of about 0.03 mm or greater. At least a portion of the diamond body has a high diamond volume content of greater than about 93 percent by volume. The entire diamond body can comprise high volume content diamond or a region of the diamond body can comprise the high volume content diamond. The diamond body includes a working surface, a first region substantially free of the catalyst material, and a second region that includes the catalyst material. At least a portion of the first region extends from the working surface to depth of from about 0.01 to about 0.1 mm.

Polycrystalline diamond materials having improved abrasion resistance, thermal stability and impact resistance

A high thermal conductivity substrate is formed by making a sintered diamond composite and thereafter modifying the electrical properties of the composite by leaching graphite and other non-diamond materials from the composite and subsequently infusing the leached composite with material having known electrical properties. Alternatively, a diamond composite having high thermal conductivity known electrical properties if prepared and subsequently leached to remove graphite and other materials which interfere with the known electrical properties of the composite material.

High thermal conductivity substrate

Propagation of laminar pulverized coal-air flames

Publisher Summary
This chapter discusses the measurements and theory dealing with premixed, laminar, and coal-dust flames. Most of the available knowledge of these flames has been obtained with various burners producing standing flames. A common feature of the burners is the use of some sort of flame-stabilizing device that is required to generate a standing flame. A complete understanding of flames requires description of turbulence and its role in the combustion of gaseous hydrocarbon and pulverized coal systems. As the air containing coal-dust enters the flame, the particles are heated to the onset of devolatilization or ignition. Thereafter, the exothermic reaction of the particles and/or liberated volatiles further increases the temperature until reaction is complete and the flame front is passed. Flame velocities can be calculated as the volumetric feed rate divided by the cross section of the burner tube.

M. Duane Horton

Papers

High thermal conductivity substrate

Propagation of laminar pulverized coal-air flames

Propagation of laminar pulverized coal–air flames