Pressure vessel refers to the closed devices that can contain gas or liquor and bear a certain pressure. The application of pressure vessel is extremely extensive. They have taken the important position and role in many fields such as industry, civil use, military industry, and scientific research. Among them, the most of pressure vessels are used in the chemical industry and petrochemical industry. Pressure vessels used only in the petrochemical industry account for about 50% of the total pressure vessels. Pressure vessels in the chemical and petrochemical industries are mainly used for heat transferring, mass transferring and reaction processes, as well as the storage and transportation of pressurized gas or liquefied gas. They are also widely used in the other industries and civil fields, such as air compressor. Various types of special compressors and auxiliary equipments for refrigeration compressors (For example, coolers, buffers, oil-water separators, gas tanks, evaporators, liquid cryogenic storage tanks, etc.) are all pressure vessels.
Type of Pressure Vessel
There are many methods for classifying pressure vessel. There are several types of pressure vessels. From the perspective of use, manufacture and inspection, we can classify them.
According to the pressure level, it can be divided into low pressure vessel, medium pressure vessel, high pressure vessel and super high pressure vessel.
According to the contained medium, it can be divided into non-flammable pressure vessel, non-toxic pressure vessel, flammable or toxic pressure vessel and highly toxic pressure vessel.
According to the function and process, it can be divided into the below as follows:
- A. Reaction vessel: A vessel is used to complete the physical and chemical reactions of the medium.
- B. Heat exchange vessel: A vessel is used to complete the heat exchange of the medium.
- C. Separation vessel: A vessel is used to complete the mass exchange of the media, gas purification, solid, liquor, and gas separation.
D. Storage vessel: A vessel is used to hold liquor or gas, plays the functions of pressure balance and buffer of storage and transportation of the medium.
Specification of Pressure Vessel
- Reaction pressure vessel (code R): It is mainly a pressure vessel used to complete the physical and chemical reactions of the medium. In life, we know many reaction vessels such as reactor, reaction vessel, decomposition pot, sulfidation vessel, decomposition column, polymerization vessel, autoclave and ultrahigh pressure, kettle, synthesis towers, shift furnaces, paper pulp digester, steaming ball, gas generators, etc.
- Heat exchange pressure vessel (code E): It is mainly a pressure vessel used to complete the heat exchange of the medium, such as shell-and-tube heat recovery boiler, heat exchanger, cooler, condenser, heater, sterilizer, dyer, steaming pot, preheating pan, solvent pre-heater, steamer, steam offline, electric steam generator and so on.
- Separation pressure vessel (code S): It is mainly used to complete the fluid pressure balance and buffer and gas purification separation, such as separator, filter, oil collector, buffer, scrubber, absorption tower, copper wash tower, drying tower, stripping tower, cylinder division, de-aerator and so on.
Storage Pressure Vessel (Code C; spherical tank code B): It is mainly used to store and hold gas, liquor, liquefied gas and other media, such as various types of storage tanks.
In a pressure vessel, if there are more than two processes based on different working principles at the same time, it shall be divided according to main role of the processes.
Pressure Vessel Used in Paper and Pulp Industry
A shell and tube heat exchanger is a class of heat exchanger designs. It is the most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows over the tubes (through the shell) to transfer heat between the two fluids. The set of tubes is called a tube bundle, and may be composed of several types of tubes: plain, longitudinally finned, etc. The heat exchanger belongs to one kind of heat exchange pressure vessels.
Paper pulp digester
Chemical pulping process refers to the fact that the fiber raw material is heated in a cooking device together with an appropriate amount of chemicals (cooking liquids) under a suitable pressure, and the heat and pressure are maintained for a certain period of time, so that most of the lignin in the fiber raw material is dissolved. In the liquid, cellulose is dissociated into the whole process of the desired pulp. The cooking device, named paper pulp digester, belongs to one kind of reaction pressure vessels.
Our cooking digesters can compare favorably with similar productions made by GLV or other famous international companies of chemical pulp production line equipments. Paper pulp digester usually includes conventional digester and displacement digester.
Disc filter is a kind of white water recovery equipments, belonging to one kind of separation pressure vessels. It can save energy, reduce water consumption and fiber loss content, meantime protect environment and prevent pollution. It is mainly applied to white water recovery in paper-making. Its performance has successfully reached the national advanced standards. It has the following advantages:
- A. Good yield of fiber recovery, make you achieve water circulation, reduce water consumption and prevent white water pollution.
- B. Large effective filtering area so as to be characteristics of economic benefit and high strength.
- C. Compact structure, less floor space required, high production capacity.
Rotating shaft of disc filter
Fan blade of disc filter
During wood pulp manufacturing process, we will use many types of pressure vessels. We must master their relevant know-how.
Anyang Machinery Co., Ltd. (AM) was founded in 1968. It is one big state owned enterprise licensed to manufacture pulp and paper-making machinery, cement equipment and chemical equipment under the state owned assets supervision and administration commission of the state council.
Anyang Machinery Co., Ltd. has won high reputation at home and abroad by contributing to the market with high-quality and good service. Our products have been exported to Indonesia, Vietnam, Pakistan, Malaysia and other countries with stable and reliable performance of equipment in paper-making industry.