In recent years, with the rapid development of chemical fiber industry, more better raw materials are provided for people's clothing. However, with the expansion of production capacity, waste water cotton pulp production, viscose preparation spinning production in chemical fiber industry has become a key factor restricting the development of the industry. In order to protect the ecological environment, protect people's health, improve the quality of water environment realize the sustainable development of the industry, the sewage can only be discharged after the purification treatment reaches the standard. In the process of sewage treatment, a certain amount of organic sludge will be produced. These wastes have high moisture content contain cellulose, hemicellulose, organics, etc. if effectively disposed, it will seriously affect the local environmental quality cause secondary pollution.
At present, sludge dewatering equipment includes vacuum suction filter, belt filter press, plate frame filter press, common horizontal screw settling centrifuge. The moisture content of sludge is different with different dewatering processes, ranging 87% to 93%. For the follow-up drying incineration process, the moisture content of the dewatered sludge directly affects the scale of the follow-up treatment structure the heat balance of the drying incineration. Theoretically, the lower the moisture content of the dewatered sludge is, the better. When the sludge is burning, the water in the sludge evaporates under high temperature, which will lose a lot of heat energy. In order to reduce the loss of heat energy, it is the key to get the cement cake with high dryness when the sludge is dehydrated mechanically. In order to solve the problem of higher sludge dewatering rate in the wastewater treatment of chemical fiber industry, obtain more dry cement cake, reduce the comprehensive energy consumption of sludge treatment, our company has researched developed a high-efficiency horizontal screw centrifuge, which contributes to the environmental treatment of chemical fiber industry.
Characteristics of chemical fiber industry
Sludge in the chemical fiber industry is the sewage (commonly known as black liquor) in the process of cotton pulp production viscose production, which enters the sludge tank after fiber recovery, sedimentation biochemical treatment. The main components are cellulose, hemicellulose, inorganic salt, organic impurities, mud, etc. the solid content is 1% ~ 2%, the color is high.
After centrifugal dehydration, the treatment process of mud cake has used composting, drying, burning, melting other methods. The perfect treatment disposal system can make sludge return to the nature completely after giving full play to its benefits. However, due to the difficulty of final disposal technology, low resource value, high equipment cost operation cost, although it has valuable social benefits, its popularization use are restricted. Improper disposal of sludge will cause serious secondary pollution. Explore develop the ways methods of sludge treatment disposal as soon as possible, speed up the investment of sludge treatment disposal, give consideration to the environmental economic benefits, balance the production, disposal environmental protection of sludge, gradually realize the reduction, harmlessness, stabilization resource of sludge. Based on the layout of sewage treatment system, the basic principles of sludge treatment disposal are determined: intensive treatment is the main treatment, decentralized treatment is the auxiliary, short-term long-term combination, phased step-by-step implementation. The sludge disposal method is "landfill, incineration utilization". The disposal method determines the treatment method degree.
When the land is tight the content of toxic harmful substances in sludge is high, it is difficult to landfill comprehensive utilization, the incineration of sludge can be considered. The sludge of chemical fiber enterprise has a high calorific value, it can burn on its own under a certain moisture content. Incineration can reduce sludge, the heat generated by combustion can be used for drying wet sludge, can also be reused as other energy sources.
The volume of the sludge after thickening dehydration is greatly reduced, which only reduces the secondary pollution to the environment, but also creates favorable conditions for the comprehensive utilization of sludge resources. At present, the horizontal screw discharge settling centrifuge (hereinafter referred to as horizontal screw centrifuge) with full closed continuous operation has been widely used as the main machine of sludge dewatering in the world, so as to avoid the disadvantages of traditional process, such as belt filter press plate frame filter press (such as: sludge dewatering open operation, poor site environment, large water agent consumption, many vulnerable parts, high operation cost, equipment volume It is huge, covers a large area, has high capital construction cost, poor automation, high labor intensity, is suitable for continuous operation, etc.). However, the use of centrifuges for sludge dewatering can ensure that the odor does overflow, the sewage does flow out, the sludge does land, the degree of automation is high, the number of vulnerable parts is small, the energy consumption is low, the drug consumption is small, it is convenient for continuous operation, the operation cost is low. However, general horizontal screw centrifuges have many disadvantages, such as high speed, high power consumption, easy plugging, maintenance technology is easy to master compared with belt machine. So the market share of belt machine is still higher than that of centrifuges in China. However, with the continuous development application of new technology, the use of high-efficiency horizontal screw centrifuges tends to increase gradually. Combined with the current sludge treatment disposal process, in order to get low moisture content sludge cake, low energy consumption high dryness centrifugal dehydrator will be the trend of future use.
Scheme composition dynamic demonstration
Structure characteristics of core host high efficiency horizontal screw centrifuge
Main structure working principle of high efficiency horizontal screw centrifuge
The structure diagram of high-efficiency horizontal screw centrifuge is shown in the attached figure, which is composed of drum, screw conveyor, hydraulic differential, hydraulic station, main bearing, underframe, liquid-solid collection chamber, upper cover, motor drive device, frequency converter (customized by the user), etc. The working principle of the machine is: first, start the hydraulic pump to rotate the screw, then the speed of the centrifuge is gradually increased through the main frequency converter. Driven by the main pulley, the drum reaches the rated speed n1. Due to the role of the hydraulic differential, the screw produces a stable differential speed Δ n leading the drum, In order to realize the screw discharge function, after the machine speed is stable, the suspension enters the centrifuge the high-level tank feed pump, flow control valve feed pipe, then enters the drum after being accelerated by the screw accelerator. Under the strong centrifugal force field, the more important solid-phase particles are dumped on the inner wall of the drum for sedimentation, the sediment is continuously pushed to the small end of the drum after being pushed by the screw, then passes through the solid-phase outlet Collect the hood to drain. After separation, the clear night is further clarified by the separation blade discharged by the overflow hole of the drum the liquid phase collection cover. In the whole separation process, the suspension is continuously input the clarified liquid phase sediment are continuously discharged, so it is a continuous automatic separation.
Characteristics of high efficiency horizontal screw centrifuge
In order to reduce the moisture content of sludge after centrifugation, we choose the hydraulic differential, which can work with small differential speed large torque, so that the whole process of sludge dewatering can reach the requirements of centrifugal force + two-way extrusion pressure, the sludge can be dried more. Compared with ordinary horizontal screw centrifuges, high efficiency horizontal screw centrifuges have the following characteristics:
(1) Adopting the international advanced hydraulic differential, it has high torque, which is 2-4 times of the torque output of the general mechanical differential (compared with the differential of the same volume), differential automatic adjustment, automatic compensation of pushing power (torque), it can operate at a very small differential speed, so that the material stays longer the solid-phase discharge is drier.
(2) High efficiency horizontal screw centrifuge is a new type with large length diameter ratio, which increases the effective length of drum, greatly increases the distance of settlement section, increases the residence time of materials in the machine, makes the discharged liquid clearer.
(3) High safety reliability, high efficiency horizontal screw centrifuge control system adopts automatic control interlock protection. In the process of operation, when any moving parts are overpressure, overtemperature, overspeed other conditions, there will be an alarm to prompt the operator to handle automatically stop the machine on site, effectively preventing the failure of centrifuge other supporting systems, ensuring the safety reliability of operation.
(4) The installed capacity of the motor is low, the LW500 centrifuge is 25kW ~ 35kw lower than that of the same type of centrifuge. Achieve the effect of energy saving consumption reduction. If the price of electricity is calculated as 0.5 yuan / kWh, a centrifuge can save 100000 to 150000 yuan of electricity expenditure per year.
(5) With the same treatment effect, the mechanical wear is effectively reduced, the service life of the centrifuge is prolonged, the operation cost is greatly reduced.
As the centrifuge adopts the international advanced hydraulic differential with differential automatic feedback regulation, automatic load adaptation automatic push power compensation, it has higher mechanical reliability good adaptability to sludge treatment process compared with the ordinary horizontal screw centrifuge.
When the feed concentration is 1-2%, the single processing capacity of LW500 centrifuge is 20-30m3 / h, the solid recovery rate is over 97%; the solid water content is 80-83%, the COD content of the clear solution is about 300ppm. The clear solution is transparent clear through naked eyes. The whole system runs well has stable performance. The problem of high moisture content of sludge dehydrated by imported belt conveyor common centrifuge is solved.
LW500×4600 Application data of horizontal spiral discharge settling centrifuge in a chemical fiber factory in Shandong Province
Treatment capacity M3/h
Feed concentration %
Moisture content of mud cake %
COD content of clear liquid ppm
October 13, 2010
October 14, 2010
October 15, 2010
The scheme features that the main engine adopts the high dryness centrifuge with the international advanced level, the hydraulic control screw pushing speed pushing power can be automatically adjusted compensated according to the feedback of load change, the sludge can form a drier mud cake under the joint action of centrifugal force field two screw blades at the front end of the cone section, so as to improve the dehydration efficiency. PLC is used for automatic monitoring of sludge cutting, crushing, feeding, dewatering, sludge discharge, transportation, flocculant delivery operation, so that the whole system can become a complete set of automatic sludge dewatering operation unit with international advanced level of unmanned operation. The whole system has compact structure overcomes the faults of high energy consumption, high noise blocking of general mechanical differential. Compared with the traditional centrifugal dehydrator, the core main machine has more obvious advantages than the belt machine plate frame filter press.
For more details scheme customization, please call us to discuss: Mobile: 13524882850; Tel: 0573-83589508