Flow-Through Filters for Thermal Fluid Heating Applications
FLOW-THROUGH FILTERS are used for filtration of buffer solutions, which are high in contamination and contain minimal fouling components. The prime objective in such applications is to filter a defined fluid volume quickly while minimizing operational downtime. To achieve this, membranes must be formatted to provide the required structural strength and filtration surface area. They are generally coiled sheets or thin tubes, with layers of separating mesh in between to provide channels for flow.
The filter is usually surrounded by a valve. It prevents fluid flow problems and limits the pressure drop caused by the filter. The valve also limits the filtration particle size, essentially a bypass filtration unit. The maximum size of a flow-through filter is dependent on the type of backwashing process used. The filtration process is conducted under a hood mounted on a gantry that runs along the main sidewalls.
Doorstroomfilter vijver differ in their design. The difference between flow-through filters and non-flow-through filters lies in the thickness of the membranes. Thinner membranes increase flow rate, while thicker membranes reduce the filter’s retentiveness. Thinner membranes may allow organisms to penetrate the filter. Some flow-through filters are single-membrane while others are double-layered.
The Immedium filter was developed in the Netherlands in the 1960s. This filter features a metal grid that runs across the filter bed. The grid sits 15 cm below the surface of the sand to delay the penetration of particles into the water. The low-resistance flow paths remove particles while high flow paths fluidize the sand in the upper flow path. The Immedium filter is the most widely used flow-through filter in the world.
The benefits of using a full-flow filtration system in a thermal fluid heating application are many. For example, it helps to reduce maintenance on the pump and gauges and increases the efficiency of the heating/cooling system. When used properly, it can also improve the quality of heat transfer fluid, preventing premature degradation of the material. And, it’s important to choose a filtration system that will not compromise the process or make the process difficult or costly.
High-flow systems require a high flow rate, which may reduce the effectiveness of some filters. The axial pressure gradient can lead to an increased fouling rate. However, short-automatic backwashes can help reduce fouling because they reverse the flow and reverse the imposed pressure gradient. Moreover, high-flow systems may not be suitable for adsorption filtration, due to the lack of recirculation.
Flow-through filtration systems must also be tested to ensure that they are capable of meeting the required quality standards. Filter manufacturers should conduct a series of performance qualification trials to evaluate the reliability of their products. These trials should include all aspects of the filter, including the design and membrane, effective filtration area, pleat density, fleece thickness, and sensitivity to flow and pressure variations. Performance qualification trials should also be conducted to ensure that the filters work as designed in the end-user process.