Rheological properties of sieved beef-cattle manure slurry: Rheological model and effects of temperature and solids concentration

Chen, Y.R.

doi:10.1016/0141-4607(86)90123-x

Cited by 41 publications

(17 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Chen (1981) discussed a method of estimating mixing power requirements through the applicability of Metzner and Otto's (1957) procedure for correlating the impeller power consumption with slurry's rheological properties. Later, Chen (1986) proposed a rheological model for manure slurries and applied this model to the experimental data of cattle manure slurry to show that the Bingham plastic, Herschel-Bulkley, and Casson models were not applicable. Achkari-Begdouri and Goodrich (1992) studied the rheological properties of Moroccan dairy manure, and concluded that the manure behaves as a pseudo-plastic suspension fluid in the range of 2.5-12.1% TS at temperatures between 20 and 608C.…”

Section: Introductionmentioning

confidence: 99%

“…As stated by Moilanen et al (2006), in a typical fermentation, the broth rheology is initially similar to water, but often becomes viscous and non-Newtonian at the end. As far as manure properties are concerned, some studies (e.g., Metzner and Otto, 1957;Kumar et al, 1972;Chen, 1981Chen, , 1986Achkari-Begdouri and Goodrich, 1992;Landry et al, 2004;El-Mashad et al, 2005) have shown that livestock manure slurry is a non-Newtonian fluid. Metzner and Otto (1957) developed a general relationship between impeller speed and the shear rate of non-Newtonian fluid.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

CFD simulation of non‐Newtonian fluid flow in anaerobic digesters

Chen

2007

Biotech & Bioengineering

145

View full text Add to dashboard Cite

A general mathematical model that predicts the flow fields in a mixed-flow anaerobic digester was developed. In this model, the liquid manure was assumed to be a non-Newtonian fluid, and the flow governed by the continuity, momentum, and k-epsilon standard turbulence equations, and non-Newtonian power law model. The commercial computational fluid dynamics (CFD) software, Fluent, was applied to simulate the flow fields of lab-scale, scale-up, and pilot-scale anaerobic digesters. The simulation results were validated against the experimental data from literature. The flow patterns were qualitatively compared for Newtonian and non-Newtonian fluids flow in a lab-scale digester. Numerical simulations were performed to predict the flow fields in scale-up and pilot-scale anaerobic digesters with different water pump power inputs and different total solid concentration (TS) in the liquid manure. The optimal power inputs were determined for the pilot-scale anaerobic digester. Some measures for reducing dead and low velocity zones were proposed based upon the CFD simulation results.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

CFD simulation of non‐Newtonian fluid flow in anaerobic digesters

Chen

2007

Biotech & Bioengineering

145

View full text Add to dashboard Cite

show abstract

“…The information that is available on the properties of human faeces (Patel et al, 1973) and the rheology of similar matter, namely, cattle manure slurries (Chen, 1986;El-Mashad et al, 2005), has been used to estimate the behaviour of fresh human faeces. Moisture content has been identified as the most significant parameter in the variation of the rheological properties of faecal matter (Chen, 1986).…”

Section: Introductionmentioning

confidence: 99%

Shear rheological properties of fresh human faeces with different moisture content

Woolley¹,

Cottingham²,

Pocock³

et al. 2014

WSA

View full text Add to dashboard Cite

Dry sanitation requires the handling of faeces, which vary in age and degree of transformation. Rheological data are necessary to support the design of equipment to handle faeces. The rheological properties of fresh human faeces were measured using a variable-speed rotational rheometer. Samples were further tested for moisture content, total solids, volatile content, and ash content. Faecal samples were found to have a yield stress; there was a decrease in apparent viscosity with increasing shear rate. For any given shear rate, higher apparent viscosities are associated with lower moisture contents. Across a range of water contents of 58.5% to 88.7%, apparent viscosities of 27 Pa•s to 2 014 Pa•s were measured at a shear rate of 1 s -1 . During constant shear tests, the apparent viscosity of all faeces was found to decrease asymptotically, where the minimum apparent viscosity value increased with decreasing moisture content. A structural recovery test indicates that human faeces are thixotropic in behaviour, where the viscosity permanently decreases to 0.5% of the initial value after a 20 s exposure to a shear rate of 10 s -1 . A linear relationship between viscosity and temperature was found, with a recorded 30.6% decrease in viscosity for a 35.6 °C increase in temperature from 13.4°C.

show abstract

“…Rheological behavior and bioreactor hydrodynamics are the key parameters that determine the efficiency of any mixing equipment [27]. The rheological properties of slurry at various temperatures, TS content, and the type of substrate have been extensively studied by many researchers [49][50][51][52][53][54][55][56][57][58]. According to literature results, cattle manure and waste water sludges are non-Newtonian fluids because there is no linear relation between their shear rates and shear stresses [59].…”

Section: Effect Of Viscosity Shear Stress and Ts Contentmentioning

confidence: 99%

“…Chen [49] observed that at TS 2.84% slurry behaved like Newtonian fluid, whereas for TS > 2.8% the behavior was non-Newtonian. It was concluded that the values of limiting viscosity (g o ) and the consistency index (k) increases as TS increases and on other hand, decreases as temperature increases.…”

Section: Effect Of Viscosity Shear Stress and Ts Contentmentioning

confidence: 99%

Impact of mixing intensity and duration on biogas production in an anaerobic digester: a review

Singh

Szamosi

Siménfalvi

2020

Critical Reviews in Biotechnology

View full text Add to dashboard Cite

This paper is a critical evaluation of the effect of mixing on biogas production rates in an anaerobic digester. Mixing plays a prominent role in determining the efficiency of the anaerobic digestion process. This review analyzes the miscellaneous effects of mixing (on the microbial community, methane content and volatile fatty acids) at various mixing intensities and during different stages of the digestion process. Intermittent mixing (mixing at intervals) seems preferable in terms of the quality and quantity of biogas produced, and results in lower power consumption and maintenance costs associated with large-scale biogas production. Preferable mixing time (the length at intervals) and the intensity depends on the geometry of the digester and impeller. The conclusion is drawn that the study of the slurry rheology is very crucial in the designing of the mixing equipment, the shape and size of the digester, and the pipe transport system which can assist in minimizing the initial investment and operational costs. Accordingly, this paper focuses on the parameters which determine the potency of mixing, such as viscosity, total solid content and digester design. Empirical data demonstrated by various researchers regarding rheological characteristics is compared and reviewed. Consequently, close attention should be paid toward the optimization of mixing in terms of its speed, mixing time and impeller geometry, especially during different stages of the digestion process (hydrolysis, acidogenesis, acetogenesis and methanogenesis). Finally, readers will be guided to the extensive publications regarding optimization, directions of future research, and troubleshooting of the mixing operation in an anaerobic digester. This investigation will help to improve mixing efficiency with biogas plants. HIGHLIGHTSEffect of shear rate on different stages of an anaerobic digestion process. Methane content varies with the variation in mixing speeds. Mixing effect is significant when the total solid content is higher. Intermittent mixing is favorable when compared to continuous mixing. The geometry of the digester and mixer is essential to evaluate digester mixing. ARTICLE HISTORY

show abstract

Rheological properties of sieved beef-cattle manure slurry: Rheological model and effects of temperature and solids concentration

Cited by 41 publications

References 7 publications

CFD simulation of non‐Newtonian fluid flow in anaerobic digesters

CFD simulation of non‐Newtonian fluid flow in anaerobic digesters

Shear rheological properties of fresh human faeces with different moisture content

Impact of mixing intensity and duration on biogas production in an anaerobic digester: a review

Contact Info

Product

Resources

About