Coal Tar Distillation And Working Up Of Tar Products

PREFACE CONSIDERING the importance of the coal tar industry at the present day, it is surprising how few practical text-books there are on this subject. I feel, therefore, that no apology is needed for offering to students, gasworks and tarworks managers and others interested in this industry, and in chemical technology, a short treatise dealing in a practical manner with the distillation of coal tar and the working up of its chief products. In order that this book could be produced at a moderate price it has been necessary to deal with the plant and processes used in the working up of the chief products obtained by the distillation of coal tar in a more or less brief manner. Special attention has been given to the plant used for, and the process of distillation of tar, as this portion of the industry is the most important, there being many works in which tar is submitted to distillation, or a partial distillation, for special purposes, and the distillates sold to other distillers for working up. As far as possible I have adhered to descriptions of plant and processes with which I have had a practical acquaintance, and I have drawn many of the illustrations in a diagrammatic form in order to render them more easily understood. With reference to the figures relating to change over points, temperatures used, amounts of distillates obtained and so on, those given have been employed in actual practice at one time or another, but theymust notbe taken as guides, as coaltar and coal tar distillates, etc., are liable to variation. My thanks are due to the firms of Messrs. Thos. Broadbent Sons, Ltd., S. H. Johnson Co., Ltd., and Robert Middleton, for their kindness in lending me electros withwhich to illustrate Chapter xiv. Also to Mr.W. R. Ball for the great assistance he has given me in reading over much of the manuscript. Thanks are also due tomy wife for the assistance she has given me in the preparation of the index, and the correction of the proof sheets. Hull, 1913. vii ARTHUR R. WARNES. CONTENTS CHAPTER I COALTAR ITSCOMPOSITION EFFECTOFNATURE OFRAWMATERIAL AND HEAT OF CARBONIZATION ON PHYSICAL PROPERTIES AND CHEMICAL COMPOSITION OF TAR RESULTS OF PRACTICAL DIS- TILLATIONS . CHAPTER II How TAR is RECEIVED FROM GASWORKS TAR TIPS STORAGE OF TAR CONSTRUCTION OFSTORAGETANKS PUMPS CHAPTER III PLANT USED IN THE DISTILLATION OF TAR. . . . .10 Tar stills metals used in their construction design fittings building of still safety contrivances swan-neck steam pipes charge block dipping cock -manhole and lid tail pipe and pitch cock thermometer. CHAPTER IV PLANT USED IN THE DISTILLATION OF TAR continued . . 25 Still foundations settling ashpits fireplaces curtain arch flues burners for gas firing gas sewer coal v. gas firing. CHAPTER V PLANT USED IN THE DISTILLATION OF TAR continued ., 33 Preheaters corrosion of preheater coils advantage of preheaters condensing coils corrosion of condensing coils condenser coil tanks steam coils collecting and dividing boxes foul gas mains methods of dealing with foul gases methods of running distil- lates to receivers cocks types of receivers steam valves pitch coolers French weir cooler pitch gutters pitch bays emergency pumps. ix x CONTENTS DISTILLATION or COAL TAR .. . CHAPTER VI PAGE . . . . . 48 Charging preheater and still commencing the distillation crude naphtha and ammonia water stage light oil stage carbolic oil stage creosote stageanthracene oil or green oil stage- introduction of steam Wells oil method of testing used by stillmen examination of safety valves, etc...