Mechanistic modelling of water partitioning behaviour in hydrocyclone

A new mechanistic model on water split behaviour in a hydrocyclone has been developed based on the convoluted hydrodynamics of swirling flows in a confined environment. A comprehensive study has been accomplished on the genesis and subsequent distribution of G force based on the characterization of internal flow features of a 2 in hydrocyclone through computational fluid dynamics (CFD) approach. The difference between the magnitude of G force in cylindrical and spigot regions is taken into account as a new hydrodynamic parameter to compute the water split behaviour. Specifically, our analysis reveals a semi-empirical relationship between the water split with G force difference (ΔG), the vortex finder diameter (Dvf) and the spigot diameter (Dsp). The developed model is validated against experimental data and show good prediction accuracy. Unique aspect of the developed empirical model is that the underlying mechanism of incipient flow peculiarity is implicitly accounted to rummage the separation characteristics in a quantifiable manner. In addition to rationalize the flow split behaviour of hydrocyclones, this new hydrodynamic indicator seems promising to be used as a scale-up parameter in envisaging the separation performance for a given application

Performance monitoring of a hydrocyclone based on underflow discharge angle

The performance of a hydrocyclone as a separation device is never perfect and rigorous research efforts are still continuing along various directions towards achieving optimum solutions. The modus operandi of performance optimization is important for quick and non-invasive monitoring of hydrocyclone performance. Therefore, in the present study, an application potential of spray angle as a performance monitoring tool has been explored to investigate the operation state of a hydrocyclone. In this context, phenomenological features of spray discharge over a wide range of injection pressure and feed solid concentration have been investigated. The emphasis of the present study is to verse the amendment of the hydrocyclone operational state with the corresponding change in underflow discharge pattern. The pattern of the underflowdischarge profilewas captured using a digital camera and analyzed based on an image processing algorithm to detect the discharge angle under different operating and design conditions. Stability and reproducibility of the spray angle at fixed operating condition have also been confirmed. Subsequent analysis shows that the spray angle is sensitive to variations of operating and design variables. More specifically the effect of feed slurry concentration has been characterized and is of major importance for the transition to roping. On this basis, an attempt has also been made to develop an empirical correlation based on experimental data. The developed correlation shows that the discharge angle could possibly be used as a reliable tool to monitor hydrocyclone performance

A study on efficacy of mechanical bowel preparation in case of elective colorectal surgery

Background: There has been a resurgence of interest in the use of mechanical bowel preparation (MBP) and antibiotics before elective colorectal surgery. In the era of antibiotics, the use of MBP is controversial. Aims and Objectives: The aim of the current study was to analyze the effect of MBP over “no MBP” on outcome in patients undergoing elective colorectal surgery. Materials and Methods: This study was an institution-based prospective, randomized and comparative study. Fifty patients, who were planned for elective colorectal surgery between February 2018 and July 2019 in Department of General Surgery, were included in this study. The patients were divided into two groups. Group 1: Surgeries with use of MBP; Group 2: Surgeries without use of MBP. Outcomes of surgeries were analyzed in terms of post-operative anastomotic leak, intra-abdominal septic collections, wound infections, hospital stay, return of IPS, and start of enteral feeding. Results: This study demonstrates that risk of anastomotic leak, wound infection, intra-abdominal collection, and hospital stay were higher among MBP group over non-MBP group and also better outcomes in non-MBP groups in respect to early return of IPS, early oral feeding. Conclusion: Our study proves that no advantage is gained by preoperative MBP in elective colorectal surgery and can be easily avoided to save patients from unwanted exhaustion, distress, and adverse effects related to it

Primary antral carcinoma managed by en-bloc radical maxillectomy with orbital exenteration

The prognosis of maxillary sinus carcinomas is not very promising. Maxillary sinus carcinomas are usually diagnosed at advanced stages and the proximity of important organs such as the eyes and cranial nerves makes complete surgical resection difficult. We here present a case that presented late with squamous cell carcinoma and was treated by radiotherapy (RT) followed by radical maxillectomy with en-bloc orbital exenteration. Patients who undergo RT followed by en-bloc radical maxillectomy with orbital exenteration as salvage, in these cases may have promising results. We had raised forehead fascio cutaneous flap and translocated it deep to the upper eyelid to bridge the cutaneous defect. Forehead defect was covered with split-thickness skin taken from left thigh. No microvascular surgery was done, but cosmetic results were comparable. In rural setups of developing countries where facilities for microvascular surgery are lacking flap translocation may have a positive outcome

A Prospective Study on Clinical Profile and Management of Obstructive Jaundice

Background: There are various causes of obstructive jaundice, choledocholithias is the commonest. Patients with obstructive jaundice usually present with complain of yellow skin and eyes, pale stools, dark coloured urine, jaundice, and pruritus. A correct pre-operative diagnosis in almost always possible today because of advances in imaging techniques over the decades. The objectives of the study were to study the clinical profile and management of patients with obstructive jaundice.Methods: This was institution based, interventional, prospective, randomised, analytical studyprospective andobservational study. Study was conducted at Burdwan Medical College & Hospital, West Bengal from March 2018 to August 2019 including 80 patients.Thorough history taking and clinical examination was done. Patients undergone for various laboratory investigations, and radiological evaluation. Template was generated in MS excel sheet and analysis was done on SPSS software. Results: Among 80 Obstructive Jaundicepatients, 37 (46.25%%) were male and 43 (53.75%) were female. The majority of patients (53.75%) were 31-50 yrs of age.Jaundice as per history in benign conditions was in 38 patients (73.08%) and in malignant condition 26 patients (92.87%). Conclusion: In the present study the occurrence of obstructive jaundice was maximum in the 31-70 year age group. Open exploration of CBD under experienced hands was a good treatment modality in the management of obstructive jaundic

Oscillation dynamics of the air-core in a hydrocyclone

Tangential introduction of liquid results in a swirling flow within a cylindro-conical hydrocyclone. Upon continuous feeding with water, the central axial region experiences local low pressure across the height yielding the formation of an air-core, which executes meandering motion similar to the oscillation of an elastic string. We investigated the vortical flow and the induced oscillating behavior of an air column submerged in a water flow field inside a hydrocyclone. Through a series of experiments in a transparent hydrocyclone and subsequent full scale multiphase flow simulations with the Reynolds stress model, we analyzed the morphological characteristics of the air-core (mean and fluctuating properties). Air-core oscillations are characterized in terms of spatial wavelength and frequency. We show that hydrodynamics driven oscillating behavior of the air-core shares an analogy with the vibration of an elastic beam. Following this analogy, we obtain a scaling relationship between the wavelength and air-core radius, which is in good agreement with our experimental data and numerical results