Chemical plant equipment used for chemical processing includes a wide range of machines, tanks, and other parts. From the time raw materials enter a process, they are stored, moved, and processed in a great number of ways. One way to look at important chemical plant equipment is to move through the major process steps.
Raw materials may be delivered by boat, truck or rail, as liquids and solids. They are often stored in tanks for bulk materials, and warehouse storage may be used for bags or drums. Materials eventually enter the process through feeder tanks that store enough products to supply the reaction steps, or bagged chemicals may be added by hand.
The next step in the process is mixing and reacting the products. Mixing tanks with large agitator paddles or air jets can mix solids and liquids. Tower reactors move liquids and gases in the same or opposite directions to provide chemical reactions. Reactors can be heated to melt raw materials or provide temperatures needed for chemical reactions to occur. Heat may be provided by electricity, requiring electrical heating coils, or with steam provided by a separate steam plant. Some processes are performed at low temperatures and need cooling systems to maintain proper temperatures.
Once the reaction or multiple reactions have occurred, the next type of chemical plant equipment is separation and purification. In many processes, the desired product is mixed with raw materials or other chemicals used in the reaction. These products may be removed using tanks that separate liquids and gases or by towers that extract the desired product by mixing the stream with water or solvents. The final product may be dried in large tanks called spray towers, where the liquid is sprayed into drops that allow the liquid to evaporate, creating a dry final product.
Products may need to be dried in large rotating drums, called kilns, which remove water or solvents to create the final product. Liquids may need to be heated or cooled prior to shipping, and are stored in tanks that provide the needed temperatures. Dry products may be placed in bags or other containers, requiring a packaging plant to be installed that loads the bags from bulk storage.
A review of chemical plant equipment should also include the systems that support the operation of the plant. Chemical plants often require a large cooling capacity, and cooling towers may be used to provide cool water for plant use. Air compressors provide pressurized air for process and instrumentation needs. Instruments control everything by monitoring plant conditions and operating control valves, and may be powered by electricity or compressed air. Refrigeration systems may be needed for process cooling or for storage of temperature-sensitive products.
Another type of chemical plant equipment is used to move product through the plant. Pumps move liquids and liquid/solid mixtures through the various process steps, and load finished product onto rail cars, ships and trucks. Some solids can be mixed with air and moved through piping like a liquid, saving time and handling of bags or containers. Valves can start and stop movement of product in and out of reactors or tanks, or change the direction of flow to different reactors or storage tanks.
Conveyors using continuous belts move bulk or loose solids from place to place, and in or out of storage buildings or tanks. Groups of storage tanks called tank farms store products awaiting transportation or use in another plant. Warehouses store bags, containers, or drums of finished product for shipping, and can be temperature-controlled. There is normally a loading dock attached to a warehouse, and motorized loaders called fork trucks can pick up pallets or containers and place them in transport trucks.