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Mass flow measurement of pneumatically conveyed solids is a common requirement in many industrial processes. The direct approach of solids mass flow measurement, in which an appropriate sensing element is used, which responds directly to the mass flow rate is less likely to be affected by interfering and modifying factors. As a possible direct approach, several thermal methods have been investigated and developed over last two decades, however all implementations up to the present have significant drawback. A reliable non-invasive and direct thermal mass flow measurement technique needs to be developed further to achieve an efficient utilization of energy and raw materials.

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The simultaneous measurements of liquid density and refractive index on the same liquid sample are desirable. This thesis investigates the development of a micro- fabricated liquid density sensor that can be integrated into existing refractometers. A discussion of density sensing techniques and review of suitable sensors is given, leading to the choice of a Love mode surface acoustic wave (SAW) device. Love modes are formed by focussing the acoustic energy in a thin waveguide layer on a surface acoustic wave device. The horizontal-shear wave motion reduces attenuation in liquid environments, and the high surface energy density theoretically gives the highest sensitivity of all SAW devices. This study follows the development of a Love mode liquid density sensor using a polyimide waveguide layer. The novel use of polyimide offers simple and cheap fabrication, and theoretically gives a very high sensitivity to surface loading due to its low acoustic velocity. Love mode devices were fabricated with different polyimide waveguide thicknesses. The optimum thickness for a compromise between low loss and high sensitivity was 0.90 - 1.0 μm. These devices exhibited a linear shift in frequency with the liquid density-viscosity product for low viscosities. The response was smaller for high viscosities due to non-Newtonian liquid behaviour. Dual delay-line structures with a smooth 'reference' and corrugated 'sense' delay- lines were used to trap the liquid and separate the density from the density-viscosity product. A sensitivity up to 0.13 μgcm(^-3)Hz(^-1) was obtained. This is the highest density sensitivity obtained from an acoustic mode sensor. Experimental results show a zero temperature coefficient of frequency is possible using polyimide waveguides. These are the first Love mode devices that demonstrate temperature independence, highlighting the importance of polyimide as a new waveguide material.

A major challenge faced by the oil and gas industry is the minimisation of scale formation within installations; new regulations are requiring conventional inhibitors to be replaced by green scale inhibition strategies, which may involve anti-fouling surfaces. In order to improve inhibition methods, understanding scale formation on surfaces, and the kinetics of surface scaling processes is a necessity. This study focused on two main objectives. Firstly, the ability of different surfaces to reduce or modify calcium carbonate scale formation was assessed with the final objective being to understand what constitutes a surface that minimises the potential for scaling. Seven different surfaces have been tested, stainless steel, stainless steel pre-treated with Polyphosphinocarboxilic Acid (PPCA), Polytetrafluoroethylene (PTFE), Diamond-Like Carbon (DLC), ceramic and polymer coated stainless steels and an isotropic superfinished stainless steel surface (ISF). A subset of these surfaces was eroded within a Submerged Impinging Jet (SIJ) to assess the possible effect of in-service performance. The surfaces were first characterised by contact angle, roughness measurements, and Energy Dispersive X-ray (EDX). The amount of scale and the morphology of the crystals were assessed using Scanning Electron Microscopy (SEM). The second part of the project uses a relatively new way to assess both precipitation and deposition in-situ and in real-time. A new rig has been designed permitting in-situ and real-time measurements of turbidity in the bulk and observation on the surfaces. Twelve different conditions were tested involving 4 brines and 3 temperatures. Image analysis of the image capture was used to assess the surface coverage, number of object and average size of the particles with time, allowing the kinetics to •be evaluated. From the results, a systematic ranking of the surface resistance to scaling has been established together with an improved description of the scale deposition process. The characteristics of the surface involved in the scale process appear to be a combination of surface chemistry, roughness, and topography and varies from one substrate to another. The kinetics (rate constant) of precipitation and deposition differed but a polynomial relation of third order was discovered between both. The kinetics of both processes was found to be highly temperature dependant.

The orifice plate flow meter is the most common form of differential pressure flow meter used in industry. The standard discharge coefficient, which is defined by both British Standard and [SO 5167, is only valid if the flow approaching the meter is perfectly settled and fully developed. However, in practical applications the flow approaching the orifice meter is often disturbed by pipe-fittings and consequently the measurements become inaccurate. Basically, the design of the orifice plate meters that are independent of the upstream disturbances is a main goal for orifice plate metering. Either using a long straight pipe, or a flow conditioner upstream of an orifice plate, usually achieves this goal. In this project the effect of the fractal flow conditioner for both standard and non-standard flow conditions has been investigated in an experimental rig and simulation work. The results of using a combination of the fratal flow conditioner and orifice plate for non-standard flow conditions including swirling flow and asymmetric flow show that this package can preserve the accuracy of metering up to the level required in the Standards. The simulation results also show that the device can be used as a part of a flow metering package that will considerably reduce installation lengths. According to the main idea to introduce a predetermined turbulence flow caused by a flow conditioner for orifice plate flow metering, author was introduced another type of flow conditioner known as a metal foam flow conditioner. Open-cell metal foams with a porosity of 78.8% was formed and fashioned as a flow conditioner. Again the experimental results using the metal foam flow conditioner showed this metal foam flow conditioner demonstrated a good performance in terms of removing swirl and producing a repeatedly same flow profile within a short distance downstream of the flow conditioner. Furthermore, the low pressure drop across the metal foam is another advantage of this flow conditioner where the pressure loss coefficient for this flow conditioner is approximately 2.5.