Blowers and fans generally provide air movement for industrial processes and for ventilation. The difference between the two devices is the system pressure they operate against and the method used to move the air. Blowers by comparison tend to operate at higher pressures than fans.  When designing a system which utilises a blower, the engineer will typically need detailed knowledge of the application and its requirements. This means, an estimate of the blower design duty point, i.e. the flow rate required and the resistance to this flow rate arising from ductwork, bends, filters, fittings ..read more

Heat transfer between the fluid and the pipe’s surroundings is an important aspect of piping system design and a computer program is often a useful tool to use to help understand the effects of heat transfer. The addition or removal of heat to/from the pipe flow stream can change the fluid viscosity, change the fluid phase-state, i.e. change from liquid to solid phase, cause cavitation, it can cause the surroundings to freeze or melt and in the case of gas flow, can cause significant changes to the fluid density.   Pipe heat transfer can be quite a challenging task and can become increasi ..read more

District Heating Systems provide a method of delivering thermal energy to buildings (homes and businesses) in the form of hot water through a distribution network of highly insulated pipelines. In this way, heat rather than fuel is delivered to buildings which are connected to the district heating system. As such, the buildings don’t require independent and dedicated heating plant meaning there is also no requirement for gas or oil deliveries to the buildings. A heat exchanger at each building transfers the heat energy from the district heating system network to the building’s own water-based ..read more

In two-phase liquid-gas flow, the distribution of the respective liquid and gas phases in the pipeline is an important aspect of their description. Their description descriptions exhibit some commonly observed flow structures known as two-phase flow patterns or flow regime. These flow patterns have particular identifying characteristics. Pressure drops and heat transfer coefficients are closely related to the local two-phase flow structure of the fluid. As a result, the prediction of two-phase flow pattern or structure is an important aspect of modelling two-phase pipe flow.  Some of the ..read more

It has been quoted that the shipping industry is responsible for emitting around a billion tonnes of carbon dioxide (CO2) per annum. Efforts are being made by the IMO (International Maritime Organisation) to clean up the industry by introducing new limits for sulphur in fuel oil used on board ships. The current sulphur limit in fuel oil used on board ships for main and auxiliary engines and boilers for ships currently operating outside the Emission Control Areas is 3.5 % mass by mass up until 31 December 2019. The new limit set by the IMO will be in place from 1st January 2020 and will be 0.5 ..read more

The Bayer Process (the process of extracting alumina from bauxite) is an energy-intensive technology, consuming large amounts of fuel and energy. This Alumina or aluminium oxide (Al2O3) is then used to produce Aluminium at a ratio of 2:1. However, did you know that around 75% of aluminium ever produced is still in use in some form today? It is one of the most recyclable materials available and can be recycled over and over, using only 5% of the energy required for producing the original metal, thus somewhat off-setting the high amounts of energy required for its initial production. The flow of ..read more

Tee junctions are found in most piping systems in many engineering applications. As such, engineers need to determine the pressure losses across these junctions. Steady-state pressure loss coefficients can be calculated using experimental and analytical expressions. However, the calculation of pressure losses across tee junctions can be a tricky task owing to the fact that flow can be merging, dividing, diverging or converging. In some cases, when we have large complex piping systems, we may not even know what flow condition to expect. The calculation or solution of tee junctions can become fu ..read more

Natural gas distribution or utility systems are used to deliver natural gas to customers across different sectors including residential, commercial and industrial. Natural gas distribution pipelines tend to operate at higher elevated pressures which enables the gas to travel long distances via a network of underground pipework. This high pressure, although beneficial for delivery over long distances, is unsuitable for end-users and therefore needs to be reduced gas regulator stations to a lower pressure which customers can receive and use.    Gas pressure regulators are used to maint ..read more

This blog gives a general outline of the rules or laws which can be used to predict fan performance in a given system. Why are the fan laws important? As an example, let’s consider the fan curve typically provided by a manufacturer. This fan curve is usually measured at “standard” or other stated conditions. In real systems, it is unlikely that a fan will be spending its operating life at these identical conditions. Furthermore, suction pressure variations, density changes, composition changes, etc are common and can also affect how the fan will operate in the system. The fan laws help us est ..read more

Pump Sizing: We’ve probably all come across the topic oversizing of centrifugal pumps in the past but why can it happen and what are the effects? This blog takes a look at the condition of oversizing centrifugal pumps.  Pumps can be oversized for a number of reasons. Sometimes a pump is sized early-on in the planning or concept-design stage using estimated values for pipework and fittings losses. A degree of error can occur at this stage as it would be necessary to guesstimate the pipe lengths, quantity of fittings etc as well as the possibility of published literature having different re ..read more