tag:blogger.com,1999:blog-1500584444083499721.post1764750326736214949..comments2024-03-24T09:28:42.755+01:00Comments on CJ on Mathematics and Science: KlimatUpplysningen 2: The Big DLR/Back Radiation BluffClaes Johnsonhttp://www.blogger.com/profile/07411413338950388898noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1500584444083499721.post-35686712875207515172015-02-17T13:59:25.813+01:002015-02-17T13:59:25.813+01:00I am continually surprised at the people commentin...I am continually surprised at the people commenting about something they have little knowledge and experience. If one is to make a heat balance of a process (eg forming glass in a furnace, making cement clinker in a kiln, calcining alumina, dead burning magnesia for refractories etc), firstly one needs to understand the chemical and physical processes occurring, then one needs to understand the theory and errors behind the measurements and then make many measurements with appropriate instruments and finally cross check with known process equipment designs and process flows. Always, whether heat is transferred from hot exhaust gases to incoming raw materials, preheat combustion air or fuel; or to cool the product with cold air or even with water; or to heat raw materials upto reaction temperature ( maybe over 2000C for magnesia) the heat flux is only in one direction from higher temperature to lower temperature. In the furnace heat is transferred from the flame which maybe be 4000C mainly by radiation. Coal is the most efficient fuel because the flame has an emissivity close to one. However, contrary to any of the climate alarmists it is not the only method of heat transfer, convective heat transfer is also important. <br />If one understands heat and mass transfer (eg anyone who uses the Chemical Engineering Handbook as a working reference) it should be clear that there is no back radiation. The 4th postulate of Thermodynamics (or as some put it the 2nd law of Thermodynamics) has been found to apply for over 150 years for industrial practices. I have recently read on physics.org that it also applies on a scale for single atoms. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-90606769189412361512015-02-17T09:27:06.834+01:002015-02-17T09:27:06.834+01:00Petter: Man måste skilja på naturlig strålning uta...Petter: Man måste skilja på naturlig strålning utan förstärkning och där är svartkroppen optimum som sätter temperaturskalan som säger att uppvärmning kräver närvaro av en varmare kropp. Med förstärkning kan den naturliga jämvikt som detta medför sättas ur spel och en förstärkt lågfrekvent mikrovåg värma en biff över den temperatur som cut-off skulle sätta för en motsvarande svartkropp. OK?Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-23001059854427837502015-02-16T18:08:44.469+01:002015-02-16T18:08:44.469+01:00Thanks for your reply, but I am still confused (no...Thanks for your reply, but I am still confused (now on a higher level though)<br />So your statement in post Klimatopplysningen 1; " Effekten blir att uppvärmning kräver strålning från varmare kropp." is not correct?Anonymoushttps://www.blogger.com/profile/02410967642744666695noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-25768951085010168752015-02-16T16:32:18.184+01:002015-02-16T16:32:18.184+01:00Claes: an electromagnetic wave is a force field ac...Claes: an electromagnetic wave is a force field acting on electric charges like ions and dipoles. And the force is there how "warm" or "cold" the ion or dipole is. The force is independent of temperature. And it doesn´t matter if the em wave comes from a cold object and hits a warmer one. And these facts don´t violate the 2nd law of th dyn. I think this is more easy to understand than understanding your radiation model.Lasse Hhttps://www.blogger.com/profile/11510250462126238787noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-60456717478405160852015-02-15T22:17:44.778+01:002015-02-15T22:17:44.778+01:00Dear Petter: You are talking about forced amplifie...Dear Petter: You are talking about forced amplified radiation which of course can cause heating of a body which is warmer than a corresponding black body. But without forcing/amplifcation that does not work.Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-25444849718310339602015-02-15T13:20:15.662+01:002015-02-15T13:20:15.662+01:00Nevertheless, from Herman Harde: Radiation and Hea...Nevertheless, from Herman Harde: Radiation and Heat Transfer in the Atmosphere: A Comprehensive Approach on a Molecular Basis http://www.hindawi.com/journals/ijas/2013/503727/ <br />In the Conclusion: <br />"Thermal radiation is electromagnetic radiation and no heat. Therefore, in the same way, as radio waves can propagate from a colder antenna to a warmer receiver, microwaves can be absorbed by a hot chicken, or CO2-laser radiation (10.6 μm) can be used for welding and melting of metals up to several thousand °C, so any back radiation from colder and higher atmospheric layers can be absorbed by the lower and warmer layers, and this back radiation can also be absorbed by a warmer surface of the earth without violating the 2nd law of thermodynamics." <br /><br />These are examples showing that electromagnetic radiation from low temperature sources can heat warmer objects still, and this contradicts your explanations, or are there other explanations for these examples?<br />Grateful for your response.<br />Anonymoushttps://www.blogger.com/profile/02410967642744666695noreply@blogger.com