scholarly journals Stability Analysis of Mechanical Sludge Dewatering Machine Frame Based on Numerical Simulation

2022 ◽  
Vol 2152 (1) ◽  
pp. 012047
Author(s):  
Li Chen

Abstract Sludge is the inevitable product of sewage treatment plant and sewage treatment. Before sludge treatment, dewatering is generally required. Mechanical sludge dewatering machine is a common sludge dewatering equipment. Due to the complex operation conditions, the stability of sludge dewatering machine frame directly affects its reliability. In this paper, a mechanical sludge dewatering machine frame as the research object, based on ANSYS Workbench finite element analysis platform, static analysis and modal analysis. The analysis results show that: under normal working conditions, the maximum variable of the frame is 0.07mm, which can effectively ensure the normal operation of the sludge dewatering machine; the equivalent stress is 4.22Mpa, which is far less than the Xu Yong stress of the material; the vibration of the first two modes of the frame is relatively concentrated, and the corresponding motor speed under the interference frequency is 1241.4-1595.4r/min, which should be avoided in the use process.

2010 ◽  
Vol 62 (6) ◽  
pp. 1213-1220 ◽  
Author(s):  
K. Fujisaki

The effectiveness of a newly developed lamellar settler was confirmed by onsite experiments. The device had inclined parallel plates arranged in a vertical direction in a settling tank. This vertical arrangement method enables many more plates to be set compared to the conventional horizontal arrangement. As an original and distinctive innovation, both the right and left edges of the plates were closed, for removing the clear water between the plates, The tube settler modules were installed in a final settling tank of a sewage treatment plant. Tests conducted over a 9 months period showed that the system operated successfully and under normal operation conditions, the new device could treat almost the same flow rate as that treated by a conventional tank, 5,000 m3/day. For storm water, the new tube settler was demonstrated to enhance the settling tank capacity by up to 3 times.


1997 ◽  
Vol 36 (12) ◽  
pp. 117-124 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan

Chemical conditioning improves sludge dewatering. Choice of chemical conditioners is very much dependent on the characteristics of the sludges and the type of dewatering devices. Lime, alum, ferric chloride and polyelectrolytes are commonly used chemical conditioners. Anaerobic digested sludge samples collected from a sewage treatment plant with different oil contents varying from 1.8% to 8.0% by weight have been examined in the laboratory to find out their specific resistance, capillary suction time and filter yield. Lime and alum were used separately as conditioners. Different dosages of conditioner varying from 2% to 12% by weight were used to determine the optimum chemical dosage for varying oil contents. Lime dosages of about 6% were found to yield favourable characteristics. Addition of alum decreases the specific resistances and capillary suction times of oily sludges rapidly up to 4% dosages. Alum dosages beyond 4% only increase the solids content in the sludge cake and increase the sludge volume to be handled. A correlation between CST and specific resistance to filtration was established. CST can be measured easily and quickly in the laboratories. Using the CST and the correlation a quick prediction on dewaterability can be established.


1998 ◽  
Vol 38 (7) ◽  
pp. 207-215 ◽  
Author(s):  
H. Takigami ◽  
N. Taniguchi ◽  
Y. Shimizu ◽  
S. Matsui

The toxicity of organic polymer flocculants used for the dewatering of municipal sludge was evaluated by using two different toxicity assays: the Closterium ehrenbergii algal toxicity test and the Bacillus subtilis rec-assay. The algal toxicity of the effluents from a pilot-scale sewage treatment plant was investigated with and without the addition of a flocculant (0, 0.05, 0.10 and 0.20 mg/L). No clear evidence on the toxicity caused by the flocculant was observed on both asexual and sexual reproduction tests of C. ehrenbergii. It was also found that the algal growth inhibition of various types of flocculants (i.e., cationic, anionic, amphoionic and non-ionic) was in the order of 1 to 20 mg/L, which was mainly due to a molecular weight (MW) fraction of greater than 100,000. The results of the B. subtilis rec-assay for these flocculants indicated that eight out of ten cationic flocculants caused the direct DNA damage with LC50 =0.1 to 10 mg/L. One of the genotoxic flocculants was also fractionated into their components by MW. The experimental results showed that the lethal effects were mainly contributed by the polymer fraction of MW greater than 100,000, although the genotoxicity was not detected in that fraction. Therefore, the detected genotoxicity of the flocculants could be caused by the combined effects of various components, such as polymers, oligomers, monomers and additives.


1990 ◽  
Vol 22 (12) ◽  
pp. 249-258 ◽  
Author(s):  
T. R. Bridle ◽  
I. Hammerton ◽  
C. K. Hertle

A four month pilot plant program, evaluating all unit operations comprising an integrated Oil from Sludge (OFS) plant has been successfully completed for the Sydney Water Board. The unit operations of sludge dewatering, drying and conversion to oil in the patented OFS reactor system were set up at the Malabar Sewage Treatment Plant in Sydney. Pilot testing of the char combustor was conducted off site. Extensive heavy metal and organochlorine monitoring across each unit operation has revealed the following information. There is no loss of contaminants across the dewatering and drying operations. With the exception of arsenic and mercury, all heavy metals fed to the OFS reactor are retained in the char. Greater than 75% of PCB's and 85% of HCB present in sludge are destroyed in the OFS reactor. Greater than 99.7% of the heavy metals fed to the fluid bed combustor are retained in the ash (with exception of mercury, which reported 3% in the flue gas). The FBC ash is classified non-hazardous, using the Toxic Characteristic Leaching Procedure.No organochlorines were detected in the dryer or FBC off-gases. The OFS technology offers decoupling of heavy metal and organochlorine control mechanisms, thus allowing each to be optimally controlled.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 59-66 ◽  
Author(s):  
C. Andersson ◽  
M. Tendaj ◽  
M. Rothman

The requirements for purification of the sewage will be more stringent in Sweden. For the three plants in Stockholm - Henriksdal, Bromma and Loudden the proposed limit concentrations for BOD7, total phosphorus and total nitrogen are 10, 0.3 and 15 respectively. A limit value of 0.3 mg/l of phosphorus in the effluent will require a filtration stage. In this paper results are presented from filter tests at Bromma sewage treatment plant. The tests were carried out during almost two years and included operation of different types of sand dual-media downflow filters and an upflow filter. The filters were tested with respect to sludge accumulation capacity, suspended solids removal and phosphorus removal at different operation conditions including chemical precipitation in the filters.


2013 ◽  
Vol 409-410 ◽  
pp. 182-186
Author(s):  
Jun Yin ◽  
Jun Xiang Wang ◽  
Jia Ni Li ◽  
Jing Yi Cui

Based on the problem which is water quality instability and high energy consumption in the running of modified A2/O system in Changchun northern sewage treatment plant, we established the optimum parameters and optimized the operation conditions to provide technical support for the stable operation of the wastewater treatment plant by analyzing effect of the system in different conditions Test results showed the best dissolved oxygen concentration in the end of the aerobic tank, sludge recycling ratio and inner recycling ratio should be chosen 1.5~2.5mg/L, 80% and 180%. The operation results with optimal operation conditions showed that COD, ammonia nitrogen, SS, TN and TP removal rate were 89.07%, 80.44%, 95.27%, 61.09% and 89.88%. The process system effect is stable and effluent can satisfy the sewage discharged standards.


1989 ◽  
Vol 21 (10-11) ◽  
pp. 1319-1324 ◽  
Author(s):  
Gunter Schrank ◽  
Clive Murren

The dehydration of sewage treatment plant sludges has become one of the major problems in the treatment of waste Water. Very high costs, especially those of flocculation additives, increasingly call for optimisation of this phase of the process. Taking the dewatering of sludge by centrifugation as an example, two different approaches can be considered: mechanical excess sludge thickening without the use of additives and the dehydration of sewage sludge with use of chemical additives. A prerequisite of any automation is the reliable acquisition of data of the parameters required for control. Continuous measurement of the concentration of suspended solids in the sludge that is to be dewatered, of sludge flow and of the turbidity of the clear phase (centrate) leaving the centrifuge, make it possible to design several methods of effective control.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Maciej Walczak

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operationThis paper reports the results of studies of microbiological changes in the water quality of the Vistula and Brda rivers after the opening of sewage treatment plants in Bydgoszcz. The study involved determining the microbiological parameters of water quality. Based on the results obtained, it was found that the quality of the water in both rivers had improved decidedly after the opening of the plants, although an increased number of individual groups of microorganisms was found at the treated sewage outlet from one of the plants.


Sign in / Sign up

Export Citation Format

Share Document