Pumps designed to pump liquids that contain solids, both soft and hard, are often referred to as trash pumps. The majority of these pumps are of the centrifugal type. With a large discharge opening and deep impeller vanes, these pumps are able process liquids that normally clog standard pumps, and at volumes as high as thousands of gallons per minute. The trash pump is used for various applications by industry, government, construction, mining, and many others such as paper manufacturers. Materials often processed by these pumps include kerosene, paraffin wax, lubricating oil, and even asphalt. There are many types of these pumps, such as those you will find below.
1 - Syringe pumps
For processing of materials that require exact flow amount and at exact time intervals, syringe pumps are used. These pumps can be separated into 2 types: a) withdrawal pumps that
automatically remove fluid, and b) infusion pumps that process fluids at higher, controlled, pressures. Power sources for syringe pumps include pneumatic, manual, solar-power, and electricity that can be AC or DC.
2 - Sanitary pumps
Used in processing of foods and other materials that require higher levels of sanitation, these pumps also move slurries and meter solutions. They include various pump types such as positive velocity, jet, airlift, and centrifugal pumps that generate speed by their use of rotating impellers and centrifugal force. These pumps typically offer such features as adjustable speed, run dry capability, battery back-up, and a variety of others. Applications include use by various industry and commerce applications such as distilleries, food processors, breweries, farms, and biotech companies.
3 – Progressing Cavity Pumps
Progressing cavity pumps typically move slurries and fluids with solids that are suspended. These fluids are moved from one side of the pump (suction side) to another side (discharge) and are usually transferred from storage tanks or pumped through pipelines. One advantage the cavity pump offers is that they can efficiently transfer slower moving viscous materials. Fluids from these pumps can been moved in a continuous flow, and in a single stage or in multiple stages. The progressive cavity pumps are at times used to transfer chemicals and foods requiring greater sterility and sanitation, such as those found in chemical companies and food processing companies. One feature favored by these companies is that these pumps can be easily cleaned by flushing or disassembling them.
4 - Positive Displacement Pumps
Liquids are transferred through the positive displacement pump by mechanical force from pistons, gears, diaphragms, and other devices in the pump. They are also moved by a vacuum created when the fluid is pumped into a fixed cavity and then pumped out again, creating a vacuum that sucks in other fluids. More viscous liquids that are under a greater pressure are often the typical product that is transferred by this type of pump. Rotary lobe pumps, a type of positive displacement pump, are used to transfer certain types of food, because of the pump's ability to process fluids with high concentrations of solids. Power for these pumps is normally supplied by compressed air, hydraulic technology, water, and even solar panels. Features include adjustable speeds controlled by the operator.