Numerical investigation of a chamber filter press on flow characteristics and influence of parameters under variable working conditions

ABSTRACT

In natural gas extraction, the usual solution for some gas wells that have encountered gravel blockage is to inject water, and it is necessary to separate the slurry to save water. While there are a variety of solid-liquid separation technologies, a chamber filter press is the best way to deal with this situation. At present, the research on chamber filter press has shortages, such as a lack of theoretical guidance for structural optimization, incomplete analysis of filter chamber flow, and constant velocity inlet. A numerical model of a single square filter chamber is developed to investigate slurry flow and deposition process based on the theory of Euler multiphase flow and porous media. The effects of feed concentrations, feed pumps, and feed modes on the filter press characteristics are discussed by adopting the variable pressure-velocity inlet. Gravel was deposited from the bottom of the filter chamber, and the solid concentration on both sides was 6% higher than in the middle, and the sand slurry flowed in the shape of a “spider” and “umbrella.” The filtration capacity increases with feed concentration. The large flow feed pump reduces filtration time and increases gravel speed and energy consumption. For example, the filtration time of the 75LZ2 is 1.5 times that of the 100LZ2. Center feed is optimal when comparing center, center-lower, center-upper, and lateral feed. The current study provides new insight into the fundamental mechanism underlying the sand slurry filtration process and the direction for the chamber filter press in application of oil-gas wells and structure optimization.

KEYWORDS:

• Numerical investigation
• chamber filter press
• flow characteristics
• sand slurry
• filter cake formation

Abbreviations

Nomenclature	=
A	=	Cross-sectional area, m2
${\vec{B}}_{\mathit{f}}$	=	Volume force, N
$\mathit{C}$	=	Volume fraction of the solid phase
$C_2$	=	Inertial drag coefficient
C1ε, C2ε	=	Constants
D	=	Viscous drag coefficient
${\vec{F}}_{\mathit{q}}$	=	External volume force, N
${\vec{F}}_{\mathit{lift},\mathit{q}}$	=	Lift force, N
${\vec{F}}_{\mathit{vm},\mathit{q}}$	=	Virtual mass force, N
${\vec{F}}_{\mathit{td},\mathit{q}}$	=	Turbulent dispersion force, N
Gkl	=	Turbulent kinetic energy caused by mean velocity gradient, m2·s-2
$\vec{g}$	=	Gravity, m·s-2
H	=	Pump head, m
k	=	Permeability coefficient
kl	=	Turbulent kinetic energy, m2·s-2
$\mathit{K}$	=	Kozeney’s constant
Ksq	=	Momentum exchange coefficient
l	=	Thickness of the sand bed, m
$\dot{m}$	=	Interphase mass transfer
P	=	Feed pressure, Pa
△P	=	Pressure, Pa
Q	=	Volumetric flow rate, m3·s-1
Qi	=	Pump flow, m3·s-1
Si	=	Momentum consumption source term
Sv	=	Specific surface area, m2
$\mathit{v}$	=	Velocity, m·s-1
$V_q$	=	Volume of phase q, m·s-1
$v_s$	=	Feed velocity, m·s-1
Greek symbols	=
$\mathit{\alpha }$	=	Volume fraction of phase
$\mathit{\delta }$	=	Specific resistance of filter cake
ε	=	Volume fraction
${\epsilon }_l$	=	Turbulence dissipation rate
${\stackrel{=}{\tau }}_{\mathit{q}}$	=	Strain tensor
$\mathit{\rho }$	=	Fluid density, kg·m3
${\rho }_s$	=	Solid density, kg·m3
$\mathit{\mu }$	=	Hydrodynamic viscosity, N·s·m−2
$\mathit{\gamma }$	=	Porosity
Πkl, Πεl	=	Source term
Subscripts	=
p	=	Same pressure of the phases
q	=	Phase
s	=	Solid phase
l	=	Liquid phase
i	=	Species i

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the National Key Research and Development Program of China, Grant [No. 2016YFC0802100].

Notes on contributors

Liang Zhang

Liang Zhang is an associate professor at Southwest Petroleum University. He has been engaged in teaching and scientific research in the field of oil and gas equipment for a long time, and has been researching in the field of oil and gas field ground equipment. He has published more than 40 relevant papers, of which more than 20 are included in SCI and EI.

Zhongchao Yan

Zhongchao Yan is a master’s student at the School of Mechatronic Engineering, Southwest Petroleum University, with research interests in fluid mechanics and triethylene glycol dehydration tail gas treatment. He has published 3 SCI articles.

Jiyu Zheng

Jiyu Zheng is a Ph.D. student at the School of Mechatronic Engineering, Southwest Petroleum University, with research interests in heat transfer of concave and convex tubes, specializing in fluent simulation.

Bojia Wei

Bojia Wei is a master’s student at the School of Mechanical Electrical Engineering, Southwest Petroleum University, with research interests in chemical process optimization. He specializes in process simulation with Aspen HYSYS.