After learning from foreign countries, our company successfully develops crushing type rotary dryer for sludge. This system combines features and performances of many kinds of rotary kilns. 

Process flow and introduction of tail gas sludge drying system 

Process introduction:
1. Technical road
  The main equipment of the project uses Japanese universal application of special sludge rotary drum dryer. The device holds high mechanized degree drying equipment. it holds advantages of small tube body resistance and low energy consumption. According to the characteristics of the sludge, insider cylinder set crushing blades can effectively prevent the agglomeration of the material, and promote the smooth progress of the drying process. The equipment after drying the sludge and coal mixed burning, can realize sludge reduction, stabilization and harmless treatment.
2. Key technology and products
   Key technology of this system is fast drying processing of large quantities of sludge by low temperature flue gas at this request on the basis, by our company for domestic and foreign manufacturers of all types of related equipment inspection, under the premise of the argument, combining a by wet sludge automatic quantitative delivery -- special sludge dryer, dust collector sets and other equipment supporting the processing production line. The characteristics of the system is giving full consideration to the sludge drying characteristics, the existing heat source were reasonable and effective distribution, to achieve each device play the best efficacy. Under the existing venues such as the objective conditions that maximize the treatment of excess sludge, but also reduce the project investment, reduces the risk of funds.
  Through the first collaboration with a company in Wuhan, sludge (500kg / h, flue gas temperature of 650 degrees) to the desired effect, and Changzhou Changjiang heat energy Co., Ltd. signed up to use 75 tons of circulating fluid bed boiler exhaust gas (per unit amount of exhaust gas 10.1 times 104m3/h, temperature of 120 - 140 DEG C), daily processing 100 tons of municipal sewage sludge (85% moisture content) equipment and in March 2016 a 50 tons / day has been put into operation, which fully meet the design requirements.
Inner situation of traditional rotary kiln.
                       

                       
   From relevant figure, we can see that the traditional rotary kiln in the drying process will produce sludge agglomeration. In the inner join, chain effect is broken not obviously. as a result,  chain will need frequent replacement. Effects of continuous operation of equipment results in huge waste of energy and larbor force.
   The structure of crushing type rotary drum can avoid these problems. through the broken spindle of high-speed operation, sludge clump is refined, the ratio of surface area gets enlarged. sludge moisture will be  evaporated quickly,which will help reducing viscosity.  Drying process will be runned smoothly.
Parameter reference of rotary kiln with two structures

Name of project	Changzhou  （common rotary kiln）	Wuhan crushing type rotary dryer	Changjiang thermal energy 50 tons per day （crushing type rotary drum dryer）
Temperature of inlet air	850℃	600 to 650℃	150℃
Equipment model	ф2.2*24 +ф2.0*20（V=150m3）	ф1.4*4 （V=6.2m3）	Ф2.8*6.5 (V=27.1m3)
Handling capacity	100 tons per day	15 tons per day	50 tons per day
Material parameters	85%-30%	85%-15%	85%-30%
Evaporation strength	31.4kg/m3	83kg/m3	60.6kg/m3
Air amount	Blower: 55kw,  Induced draft fan: 75kw Hot air amount: 34000m3/h	Blower: 5.5kw, draft fan: 11kw， Crushing shaft motor: 4 kw	Motor of draft fan: 75kw  Motor of Broker shaft: 7.5 kw
Coal consumption (5500 kcal)	25 ton per day	Refer to sludge; coal consumption hasn’t been calculated	no
Total power	180kw	21kw	95kw
Equipment investment	2200000 RMB(five years ago)	220000 RMB (not include air furnace and water bathing dust wiper)	850000RMB (not include water bathing dust wiper）