All chemical machinery, including chemical equipment, are tools used to realize chemical production in chemical plants. The normal operation of chemical product production process, the control and guarantee of product quality and output are inseparable from the adaptation and normal operation of various chemical equipment. The selection of chemical equipment must be based on the detailed calculation, design, processing, manufacturing and selection of the whole chemical production process to meet the needs of chemical production.

The whole set of chemical production plant is composed of chemical equipment, chemical machinery and other components such as chemical instruments, chemical pipelines and valves. In order to ensure the safe, stable and reliable production of the whole set of plant, the chemical equipment is required to have the following properties:

(1) It should be suitable for the performance, quantity, process characteristics and production scale of raw materials, products, intermediate products, etc. of the production unit;
(2) A set of production equipment, whether continuous or intermittent production, is composed of many kinds of equipment. Therefore, it requires reliable coordination and adaptability between chemical equipment and other equipment, equipment and pipeline, valve, instrument, instrument, electrical circuit, etc;
(3) Chemical equipment is required to have enough sealing performance and mechanical strength in structure, material and strength under normal operating conditions such as temperature, pressure, flow rate and material corrosion performance. We should be able to withstand, prevent, deal with and deal with the possible abnormal or even extreme conditions;
(4) Both continuous and batch chemical production plants need to be operated for a long time. Therefore, it is necessary to consider the factors such as wear and corrosion of chemical equipment and ensure a long enough normal service life;
(5) While meeting the above conditions, the material, type selection, manufacturing cost, efficiency and energy consumption of chemical equipment should be optimized to the minimum;
(6) Most of the chemical equipment with various structures and properties are also suitable for industrial sectors such as oil refining, light industry, food and so on.
There are many kinds of chemical equipment, and there are many ways to classify them. For example, according to structural materials, they can be divided into carbon steel equipment, stainless steel equipment, non-metallic equipment, etc. According to the pressure can be divided into high-pressure equipment, medium pressure equipment and vacuum equipment, atmospheric equipment.

According to the function, it can be divided into:

(1) Chemical containers: tank, tank, kettle, etc;
(2) Separation tower: packed tower, floating valve tower, bubble cap tower, rotary tower, etc;
(3) Reactor: tubular reactor, fluidized reactor, stirred tank reactor, etc;
(4) Heat exchanger: tubular, plate heat exchanger, snake tube heat exchanger, etc;
(5) Heating furnace: electric heating furnace, tubular cracking furnace, waste heat boiler, etc;
(6) Crystallization equipment: solution crystallizer, melting crystallizer, etc;
(7) Other kinds of special chemical equipment, etc.