Industrial furnaces and methods of control

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 Excerpt: ...to works managers, but we maintain that it is insufficient to estimate the value of a furnace, since it is not given together with the length of the operation and the dimensions of the furnaces. PART II METHODS OF CONTROL PYROMETRY. GAS ANALYSIS BY A. L. J. QUENEAU CALORIMETRY. ELEMENTARY FUEL ANALYSIS BY MYRICK N. BOLLES PART II. CONSIDERATION OF PRACTICAL PROBLEMS. CHAPTER XI. Pyrometry. From the preceding chapters we have seen that it is necessary, in making furnace tests, to be able to measure rapidly and accurately the temperatures in the various parts of the furnaces. The instrument to be selected for the work should therefore be portable, accurate, easy of handling, and should allow the reading of temperatures at widely distant points. Of the many types of instruments the Le Chatelier thermoelectric pyrometer offers all of the mentioned desiderata. The thermo-electric instrument being small can be introduced into any part of the furnaces, and since a few seconds are sufficient for the establishing of an equilibrium of temperatures, it can serve to measure temperatures close to 1780 C., the melting point of pure platinum, without endangering the life of the wires. On account of the electric current generated, any number of thermocouples can be connected with a single galvanometer by means of a switch-board; for the same reason the instrument may be placed at any convenient distance from the furnace. The Le Chatelier pyrometer is thoroughly reliable, if ordinary care is taken of the wires. However, in order to be successful with the instrument, its limitations should always be borne in mind; these are due entirely to the nature of the metals forming the couple. Practically the same care that is to be taken with platinum ware is required with the wires ...