Cryogenic pumps are a type of centrifugal pump that are used to transfer liquids with very low temperatures such as hydrogen, helium, nitrogen, etc. These pumps are specifically designed for industries that deal with ultra-low temperatures, such as oil and gas, refineries.
Cryogenic pumps as one of the products required by the oil and petrochemical industry, especially in South Pars projects (gas and petrochemical phases) as well as LNG fields and projects. These pumps are mainly used to transport cryogenic fluids such as N2, Ethylene, Ethane, LPG, etc. and are made to work at very low temperatures. The design of these pumps is aimed at minimizing heat leakage from the pump assembly to the process fluid.
Other features of this pumps include strong thermal insulation to prevent heat transfer from the environment to very low temperature liquids, managed cooling systems to maintain the appropriate temperature of liquids in very low temperature conditions, very accurate and stable performance to ensure transfer and Preventing their freezing, structural materials and pressure tolerance are considered suitable for resisting the pressures and hard cryogenic conditions.
In the meantime, Iran’s Industrial Pumps co. had started technical and economic studies for the design, manufacture and testing of these pumps in Iran years ago, and now various models of submersible cryogenic vertical pumps have been designed and manufactured by this company.
Considering the importance and sensitivity of the manufacturing, assembly and testing process of cryogenic pumps, Iran Industrial Pumps Company, looking at the horizon of the cryogenic pumps market in the country and the Middle East region, has established a separate workshop for this purpose, which includes the following equipment and facilities:
– Light and heavy machinery required for machining parts
– Assembly line of vertical cryogenic pumps
– Test line for cryogenic pumps
– Preparation, packing, delivery
The necessity of performing special performance tests of cryogenic pumps that are performed with liquid nitrogen at a temperature of minus 196 degrees Celsius, an independent workshop to install special equipment for the test line (including a large test tank, a large liquid nitrogen storage tank, test metal structure, 24 in and 16 in pipes in test line, precision measuring instrument equipment, nitrogen exhaust gas pipeline and test control room, was established, which was done before the first samples of these pumps were made in 2013 in this company.
Also, due to the special structure of the mechanical and electrical design of these pumps, an assembly line for cryogenic pumps has been created in this workshop, with an area of about 3000 square meters, in order to apply special and detailed supervision in the preparation process.
Structure and outline of cryogenic pumps
According to the classification and variety of cryogenic pump models and applications, Iran’s Industrial Pumps co. has designed and produced Retractable in tank cryogenic pumps. These types of pumps are used in large low pressure tanks. The design of these pumps is submersible and vertical with an electric motor that is close coupled. The cryogenic pump goes into the tank through a tube and sits on a suction valve at the end of the tube, near the bottom of the tank. The inlet valve of these pumps is of the type that allows installing and removing the pump inside the pipe without having to imagine the tank.
The fluid input to the pump is through a funnel and its output is through large holes on the pump shell, which is sent into the thrust tube of the fluid tank.
Mechanical design
In the mechanical design of the pump, by using modern methods, it has been tried to minimize the amount of radial and axial deviation of the pump by relying on design knowledge, and to ensure the increase of its lifespan and reliability. Reduction of axial and radial forces is done using a force balancing system and suitable rolling bearings.
Material of parts
Hydraulic parts and pump shell are made of special aluminum alloy suitable for cryogenic services. Casting methods for parts such as impeller, diffuser, inducer, etc. Developed by Iran’s Industrial Pumps Research and Development department to achieve proper quality of casting along with proper strength of parts.
Hydraulic design
The design of the pump’s hydraulic parts is diffuser type and the impeller of the pumps is a closed type with high efficiency. The pump is equipped with an inducer to increase the positive suction pressure in the impeller. Depending on the required head of the pump, the number of stages can be different. After designing the pump, the hydraulic components of the designed pump are analyzed by CFD. After this analysis, it is possible to be fully confident about the quality of the pump in meeting the design requirements.
Vibration monitoring system
A permanent vibration monitoring system equipped with accurate sensors suitable for cryogenic services along with protection panels and an alarm-shut down system with proper programming is considered for these pumps, which can also be upgraded to an advanced diagnostic system.
Accessories and components
Cryogenic pumps of tanks, equipped with peripheral equipment such as the inlet valve, which is one of the vital components of the cryogenic gas pumping system, is used to control the flow of gas entering the pump, the cable holding the weight of the pump to maintain the strength and stability of the pump, the input terminals of the feeding cable, which includes connections. Electrical connection to connect the power cable to the pump, the top cover of the thrust tube to protect the tank, safety protection and ease of access, etc. are included.
Test line for cryogenic pumps
All the necessary equipment to test the performance of cryogenic pumps with liquid nitrogen fluid at a temperature of minus 196 degrees Celsius in the form of a special cryogenic test line has been provided in the Iran Industrial Pumps Group factory, which is equipped with equipment for measuring flow, head, vibrations and also measuring electrical parameters. The goal is to obtain the functional curves of the pump and its electric drive. The test line is equipped with a complete control room to automatically analyze the performance characteristics of the pump.
Application
- They are used in the oil and gas industry to transport various gases such as methane, ethane, propane, and butane.
- In the chemical and petrochemical industries, they are used to transfer and pump gases such as ammonia, ethylene, and hydrogen.
- Electronic industries for transferring cooling gases
In general, cryogenic pumps are used in any industry that requires the transfer of gaseous or liquid materials at low temperatures.
| No. | Pump name | Rotational speed | Maximum flow | Maximum head |
| 1 | 760 KW | 1500 | ||
| 2 | 355 KW | |||
| 3 | 280 KW |