July i, 1884.] 



THE TROPICAL AGRICULTURIST. 



57 





a question of this sort. There are many stringent objec- 

 tions to the us.- of charcoal in tea drying. The crude 

 apparatus used in which one can never be certain that 

 his tea is not burned, (except when the old- fashioned 

 " dhool " is used, as it is by some noted tea-makers to 

 this day,) the great cust and trouble of making charcoal, 

 the growing scarcity of wood in the tea districts, and the 

 great space taken up by the charcoal drying choolas, thus 

 necessitating large tea-houses, have long led the minds 

 of practical tea-planters into desiring a quicker and cheaper 

 method of drying tea than by the charcoal choola. And 

 I think the credit must be given to the Messrs. Jacksous 

 for the first attempt, not a great success, however, on their 

 part at that time, to dry tea by means of hot air. It is 

 strange that the Jacksons, certainly the most successful in- 

 ventors of rolling machines, havebeen so unsuccessful in bring- 

 out a successful tea drier, lam glad to s;iy, however, that the 

 latest Jackson drying machine premises fairly to beat any- 

 thing in the market. The new machine has not been 

 tried yet, but the foundations are being erected for it at 

 Oinnamara, and before the end of the present season it 

 will have been thoroughly tested. The first successful 

 machine was brought out by Mr. S. Davidson of Belfast. 

 I mean the weli-kuown " Sirocco." There have been several 

 changes and improvements iu this apparatus since it was 

 first introduced, but all along the same principles have 

 been studied, and as far as quality of outturn is concerned 

 with the most undoubted success. Like all hot air machines 

 it consists of two parts; first the furnace in which the air 

 is heated ; ami second the part of the apparatus in which 

 the tea is exposed to the action of the hot air. Tie' 

 heating part consists of a series of perpendicular rectang- 

 ular chambers, divided by thin sheets of disphragms of 

 wrought-iron, the frames holding the sheets themselves be- 

 ing of cast-iron. These are so arranged that a current 

 of air passes upward from the external atmosphere to the 

 tea drying portion of the apparatus, through every alter- 

 nate cell or chamber hot smoke and gasses from a furnace 

 iu the centre passing down through the adjoining chambers. 

 The heat from the adjoining smoke cells passes through 

 the. thin sheet of iron separating them from the air cells, 

 and is taken up by the air : it being so arranged that the 

 hottest air in ascending, meets the hottesr smoke in 

 descending, so as to take as much heat from the 

 smoke as possible. The air, after being thus heated, 

 goes on through a series of four trays on which the leaf 

 is spread. The leaf is first spread on the topmost tray, 

 and as soon as the leaf on the bottom tray becomes pro- 

 perly dried, the tray with its quantum of leaf is removed, 

 and the other trays are brought a place lower down. The 

 process is repeated as each bottom trayful of leaf is pro- 

 perly dried, and 60 on ad infinitum. It will be seen that 

 the nearly dry tea in the bottom tray gets the drie-t and 

 hottest air, for if the air were not well dried and hot 

 . it would fail to extract the last particles of moisture from 

 the toa, ar.d render it liable to mould or became musty. 

 The hot air after having done its duty as far as the tea 

 is coucerned passes into a chimuej', where being joined 

 by the smoke, it helps to cause the upward draft necessary 

 to draw it through the heating cells and tea, as in this 

 machine no fan is used. The teas turned out by the 

 Sirocco are noted for their fine flavour. They acquire a 

 crisj , malty, brisk flavour much prized in the market. 

 Tkejoidy objection to the Sirocco is, that one machine 

 only turns out at the very outside about 40 lb. of tea 

 per hour, and then under very exceptional circumstances. 

 I see by a recent number of the Indigo and tea Planters 

 Gazette that the proprietors of the Sirocco suggest giving 

 all teas fired in other machines a final fire in the Sirocco 

 in London, and promise an improvement in flavour and 

 a consequent increase in price. The experiment is well 

 worth trying. It is to be regretted that the outturn of 

 the Sirocco is not greater. 



Mr. Kinmond about the same time appeared on the 

 scene w T ith his well-known tea-drier. The first machine, 

 like the first of his rolling machines, was a crude attempt 

 and not very successful, but has been greatly improved 

 Upon by the inventor. The principle chiefly relied upon 

 by the inventor in this machine is that the air once used 

 to dry the leaf is re-heated and used over and over again, 

 being supplementad by a small portion of fresh air con- 

 tinuously admitted. On the face of it, this supposition 



is a fallacy, as it must be quite apparent that a certain 

 number of units of weight of air must be admitted to 

 to carry off a certain weight of water, pro- 

 vided that the air be admitted at a constant temperature 

 and released at a constant higher temperature. Any 

 iii.oi may be claimed by Mr. Kinmond in his 

 machine is in the quantity of tea it turns out. Many tea- 

 makers find fault with it on account of the very r 

 which the iuveutor considi rs an advantage, namely, that 

 the same air is used over and over again. This air is 

 necessarily heavily charged with moisture and less :i 

 take the moisture from the leaf. Planters ib I ving 



their tea dried by a mixture of hot air and aqueous vapour, 

 no matter how highly heated. Another objection to the 

 machine is that, the air being forced through by a fan, 

 a lot of the dhool ghoerie, or fino tea is blown about. This, 

 however, can easily be attended to. The great quantity 

 of dry tea turned out of the machine, must be an argu- 

 ment to some extent in its favour, and I think if the 

 old idea were given up that the same air should be passed 

 over and over again through the machine, a better fla- 

 voured tea would bo turned out. Or this drier might be 

 used with advantage in combination with another machine, 

 the Sirocco for instance, the latter being used to finish 

 the tea partially dried iu the Kinmond drier— or the tea 

 might be finished over charcoal. 



This machine is made inthree sizes, to dry respectively one, 

 two and three maunds of pucka tea per hour. The No. 

 2 size is the one mostly used. They are alike in con- 

 struction and principle, and only differ in size. A furnace 

 below the machine gives the necessary heat to a curr nt 

 of air passing over an iron plate which foi ms the roof of 

 the furnace and smoke flue. In an iron-casing standing 

 above the furnace there are no less than 18 drying trays 

 and others besides to catch the dhool ghoorie. One pecu- 

 liarity, and a very commendable one,"in the machine is, 

 that each tray has a separate current of air to itself. 

 The current of air, heated by passing over the hot flue, 

 is driven by a fan through the trays on which the tea 

 is spread, and after passing through them is again sucked 

 in to the fan forced by it over the hot flue and on again 

 through the tea. 



This machine is much used in Assam, and is highly 

 spoken of by many persons who use it. Others again 

 condemn it tor the reasons above-stated. It is very sub- 

 stantially and neatly constructed, (a6 indeed is also its 

 rival, the Sirocco), and is far ahead of any other tea- 

 drier in the quantity of its outturn. 



8 



JACKSON'S NEW TEA DRYING MACHINE 

 from which so much is expected, is thus noticed 

 by the writer on tea machinery in the Indigo and Tea 

 Planters' Gazette. 



As mentioned above, however, the Messrs. Jackson are 

 bringing out from England a new patent drier of their 

 invention, which is shortly to be erected in Assam ; and 

 having seen the drawings of it, I am able to describe it. 

 It is to be erected at the Cinnamara Tea Estate, Jorhat, 

 and the foundations are now being laid down for it. It is 

 to be a continuous feeding and discharging machine. 



A furnace at one end of the sub-structure of the machine 

 communicates with a horizontal smoke flue running rather 

 more than the vjhole length under the drying portion. In 

 this smoke flue there are four rows of cast-iron pipes 

 running horizontally and having their ends curved up into 

 the air drying chamber. These pipes communicate at the 

 other end with the outer air and a constant current of air 

 is drawn through them and exposed to the heating action 

 of the hot furnace gases in the smoke flue. The roof of 

 this flue is a corrugated plate of cast-iron, the corrugations 

 being given for the purpose of strength, and the plate is 

 still further strengthened by deep narrow bars being cast 

 on its upper side. The flue is furnished with iron doors 

 on the side for the purpose of cleaning it, and on the end 

 opposite the furnace sits the chimney. Upon tins flue rests 

 the hot air chamber iu ,vhich the drying of the tea is 

 effected. This consists of an iron chamber oblong iu its 

 horizontal section, but gradually narrowing towards the 

 top lengthways, one of the ends being sloped. Within 

 this drying chamber there are five travelling webs of wire 

 gauze on which the tea is dried. By ft peculiar app 

 the tea is shaken on to the eud of the top web, and by the 



