Document yYeDkKNX6DbZLnRJX2nG2GbE

JM CONFIDENTIAL. N o t fo r gem nribution or rcpublicalion. t-. * JOHNS-MANVILLE RESEARCH AND ENGINEERING CENTER Report No. ^32-Int-7^7 Date May 18, 1970 Title: HARBISOH WALKER HARD FACED BLOCK INSULATION ANn .T-M SUPER' Conductance cs o Requested by: K. F. Greene (IID 2608 Complete IN-9 >1^ o r Ui CVJ X Summary % 12 T itjkl -J ICO The thermal conductance of a SUPEREX - SG bl o ck insulation was up to 15 per cent lower than that of a sample of Harbison Walker Hard Faced Block. Both insulations were 2.1-in. thick. Material Samples of Harbison Walker (H-W) Hard Faced Block Insulation, a composite of mineral wool block and a nominal l/2-in. pressed mineral fiber board for use in blast furnace stoves were submitted (NB 3988, p 124). Also received was a J-M SUPEREX -SG sample composed of SUPEREX 1900 and SPIN-GLASS 1000 designed for the same use. The H-W product claims include these features; lightweight, ease of application, surface adjusts to irregularities, resistant to impact compression and moisture, non-corrosive and incombustible, provide relief for stresses caused by expansion and a greater insulating value than calcined diatomaceous earth. The claimed physical properties include 1800F maximum service temperature limit, density of 15 lb per cu. ft. Flexural strength 40 lb/sq in. and linear change after heating at 18OOF - less than 3 per cent. Tests The thermal conductivities of the separate components (A. - mineral wool block and B. - pressed mineral fiber board) were measured in Rapid Heat Meter thermal con ductivity apparatus over a 300 to 1000F mean temperature range. The composite H-W product and the sample of J-M SUPEREX-SG composite were tested at temperatures up to 1800F hot face on an electric hot plate, using a woven heat meter at the cold face. In the H-W product the pressed mineral wool board is at the hot face, and in the SUPEREX-SG product the SUPEREX is at the hot face. With this arrangement the thermal conductance of a thick composite can be determined at higher temperatures, extending the capability of heat meter type apparatus. Results The thermal conductance (C) of the composite J-M SUPEREX - Glass Fiber sample block (2.1-in. thick) was up to 15 per cent lower than that of Harbison Walker Hard Faced Block Insulation. Notebook ijo. 4056, P l4, 15; 3929, p 86, 87; 4030, p 14 Rie 432 JOHNS-MANVILLE RESEARCH AND ENGINEERING CENTER Report No. U32-Int-71+7 Page 2 JM CONFIDENTIAL N o t fo r getter. trib u tio n or republicotion. The SUPER EX-SG J-M block showed a separation of the two components after heating and the SUPEREX was warped. The H-W block did not delaminate, but the hard faced portion was easily indented by thumb pressure. The conductances of the composite insulations were measured on an electric hot plate with a calibrated heat meter at the cold faces of the samples for de termination of the heat flow. This mode was used for the first time to provide a method of test of thick insulations at high temperatures. The conductances yielded by the test are in good order. The conductivities of the component measured at the same time can also be calculated. The "k" values so measured and calculated in this test are approximate. It is believed that with more exacting ways of locating the innerface thermocouples that reliable "k" as well as overall "C" values can be measured by this test method. Reported by tSl. & izjL i p . J. Bthqjry f\ Materials Evvaalluuaation Section br cc: F. L. Pundsack J. P. Leineweber Attn: S. Spe: L. R. Blair W. K. Hesse^"''^ J. 0. Collins K. F. Greene R. H. Neisel J. N. Anderson P. J. Behory K. L. Kinder Library (2) byThermal Conductance Sk 'Tf/ jJ. N. Annddee:rson Materials Evaluation Section JOHNS-MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 432-Int-747 Page 3 APPENDIX Table 1 Thermal Conductivity of H-W Hard Faced Block Insulation Components In Rapid Heat Meter Apparatus Mineral Wool Block Pressed Mineral Wool Board (This Hard Face portion at the Hot Face) Density Pcf 15-1 21.4 Thermal Conductivity Btu Per hr sq ft (F/in.) Mean Temp - F 400 600 boo 1000 0.45 0.50 0.57 0.57 0.71 0.66 0.87 0.81 JM CONFIDENTIAL i\o t fo r gene* inbuiion or rcpnbiication JOHNS-MANVILLE RESEARCH AND ENGINEERING CENTER F-port Mo. 432-Int-747 Page 4 JM CONFIDENTIAL. N o t fu r gent unbutton o r republicotion. APFEMDIX Table II Thermal Conductance of H-W Hard Faced Block and J-M SUPEREX --SG Block - Tested Ab Composites Size - in. _ Weight - lb/ft2 Thickness - in. Thermal Conductance (C) Btu per hr sq ft Mean Temp F 1*00 600 800 1000 1200 1300 H- W 24 x 24 2.11 2.1 0.21 0.24 0.29 O.37 0.1*7 0.53 J-M 24 X 24 1-95 2.1 0.22 0.24 0.27 0.32 0.40 0.46 Thermal Conductivity (k) of Components As Measured in the Test of the Composite H-W Pressed Mineral Mineral Wool Board Wool Block (At Hot Face) Thickness - in. "k" Btu Per hr sq ft (F/in.) at Mean Temp 1.4 0.7 200 400 600 800 1000 1200 1400 1600 0-33 0.43 0.54 0.66 0.80 0.95 - 0.32 0.40 0.49 0.60 0.71 0.84 1.00 1.21 J-M SPIN-GLAS SUPEREX 1000 At Hot Face 0.8 1*3 0.23 0.37 0.53 0.74 1.10 - - 0.68 O.69 0.71 0.73 O.76 0.80 O.85