904 THE COLLIERY GUARDIAN. May 2, 1913. the saturators, whilst the washed salt is drained in spitzkasten, centrifugalised and removed to the store- house. The tar from the saturators runs through a gutter h (fig. 1) into the tar pit i, from which it is removed into heated tanks where it is washed with hot water and an air agitator until free from acid, and discharged into the storage tanks VB (fig. 2). All the washing waters are run into the saturators to dilute the sulphuric acid. The heating coils for the tar, &c., are heated with the exhaust steam from the tar and liquor pumps. An improvement was afterward effected by the I W 771- -.Ti, PRESSURE TO FROM SUCTION FAN Fig. 3. GAS INTAKE' FROM OFF NS insulating’material. The hot gases enter the compart- ment C at E, passing upward through R and down through r, which latter is covered thickly with flowing tar from the sprinkler 6. The tar vapours in the gas are thus condensed and deposited. From the compart- ment D the gas escapes through a and is forced by a fan or the like into the compartment F, where a further deposition of tar vapour is effected in the perforated bell G-, the gas escaping at A and the deposited tar draining away through the pipe h into the bottom of Q, where it is joined by the tar from the attemperator and drains away through i into the pit B for use over again. The flow of air from L to Z regulates the temperature of the gas so as to produce in A the most suitable temperature for the acid bath. After passing through a saturator the gas traverses an injection condenser and a water condenser under the force of an exhaust. If benzol is to be recovered a final cooler has to be passed. The salt is expelled from the saturator by an ejector, operated by air or steam, and when dried in the hydro- extractor is put into store. The small residue of tar GAS COOLER TO THE O'/ENS TO THE OVENS HYDROEN TRACTOR ACID TANA Sl/CT/ON FAN TAX TANK STEAM ELECTRICITY AC/D C00LIN6 WATER & § z * ^6 11 AC® itjlJZPARA TOA GAS PLATER O I ST!LI AMMONIA l/ouop pump Fig. 4.—Koppers Direct Process. The gases coming from the ovens first enter the cooler, where they are freed from tar and water of condensation. The coolers are in part arranged to act as preliminary heaters, in which an interchange of heat is effected between the crude gas and the cooled gas. After passing the last water-tube condenser, the gas goes through this pre-heater, and is forced by a fan through a Pelouze apparatus, which removes the final traces of tar. A heater between this apparatus and the saturator forms a temperature regulator characterised by extreme simplicity and efficiency. The admission of the gas into the closed saturator and the recovery of the sulphate of ammonia are effected in the usual manner. The tar and tar water are separated in a settling tank, the tar water being then treated in a still with steam and milk of lime in the usual manner. The liberated ammonia vapours are not led direct to the saturator, but introduced into the main current of gas in front of the coolers. The advantages of the method over the older process consist mainly in the very simple and readily-accessible appliances, the saving TAR SPRAYER REGENERATOR PLANT 'RA SUCTION FAN PRESSURE FAR TAR COOLER RE COOLER TAR PUMP TO COKE OYENS DRAINER] SUCTJ ON FAN [NAPHTHALENE WASHER' WASHING-O/E TANK GAS DELIVERY MA/N TO NOZZlE P/PE UNOFR OVENS li CRANE U TAR SEPARATOR FRACK GAS METER PURIF/ER 888gg OOOOQ 8S88&-- OOOOQ QQOOO qoooo OOQOQ OOOOQ ooooo ooooo -SB QOOOO QQOOO §§8§g Qfiiaa. ooooo ooooo ! 111 J l| § GAS COOLER - I GAS COOLER CT/jP OB O6Q ’ ■ ooooo * , Fig. 5.—Otto Direct Process. adoption of the English pattern of large enclosed saturators, which by preventing loss of temperature at that stage of the process enabled the gases to be cooled to 85-90 degs. Cent, before entering the saturators, thus facilitating the deposition of the tar. Recently the apparatus cZ and/have been still further simplified and combined as shown in fig. 3, the attemperator W with the pipes R and r, and the condenser P with balanced ball cover G-, being arranged on the top of the tank Q, which is divided into compartments CDF. The tar employed for sprinkling the pipe r is drawn from the tar pit B by a pump S and forced through the cooling pipe K into the sprinkler b. The pipes R and r are gilled on the outside to increase the cooling surface, and the attemperating air is admitted at L and escapes at Z, both the intake and outlet being regulated automati- cally. The outer shell m of the attemperator is of deposited in the saturator is freed from acid by washing, and added to the bulk. The gas water from the condensers is cooled by trickling over re-coolers, and is then used for cooling the condensers. The chief advantages of the Brunck system of direct recovery of ammonia, in comparison with the old indirect method, consist in the simpler and less expensive plant, and also in the saving of steam, lime and water, amounting in the case of a battery of 60 ovens to about £1,500 per annum The Koppers Process.—This (fig. 4) is of the semi-direct type, the gas being freed from tar and water by cooling before it reaches the acid bath, because the inventor regarded extensive cooling as the only sure way of separating the gas and tar. At the same time, the object of reducing the dew point of the gases to a very low temperature is achieved by the process. in steam through omitting the distillation of the ammo- niacal washing liquor (which contains about half the total ammonia), and the abolition of the ammonia scrubbing plant, pumps, &c. Assuming that 550 lb. of steam are required to distil 220 gallons of ammoniacal liquor containing about 1 per cent, of ammonia, the cost of steam per hundredweight of sulphate of ammonia is about 4Jd., as compared with double that figure in the old method; and, in addition, the effluent from the ammonia works is reduced in volume by about 50 per cent. The process has been in operation for several years at a number of works, and with apparent success. The Otto Process.—This direct method, in which the ammonia washing operations and distillation of the ammoniacal liquor are entirely dispensed with, was introduced into the coking industry in 1908, the first plant being set up at the Julia Colliery, near Herne, in