What are the types of EPS Pre-expander machine
About EPS Pre-expander machine:
What are the types of EPS Pre-expander machine?
Piston type EPS Pre-expander machine
EPS Pre-expander machine that expands the gas in a variable volume and outputs external work refrigeration (usually the motor is braked to absorb external work). There are two types of EPS Pre-expander machine: vertical and horizontal.
The vertical structure is mostly used. The crankshaft, connecting rod, crosshead, piston, intake valve and exhaust valve are moving parts, which are respectively installed in the fuselage, cylinder and intermediate seat, and their function is similar to that of reciprocating piston compression.
However, the intake and exhaust valves are opened and closed regularly by the intake and exhaust cams. Piston EPS Pre-expander machine due to the existence of inlet and exhaust valve flow resistance, incomplete expansion, frictional heat, external heat and internal heat exchange caused by the loss of cooling capacity, the general adiabatic efficiency is: high pressure expander 65 ~ 85%, medium Compression expander 60 to 70%.
In the 1950s, valveless and single-valve expanders without cam transmission mechanism appeared one after another, which reduced the moving parts of the expander and improved the reliability of machine operation, and has been widely used in small cryogenic equipment. In the 1960s, PTFE sealing elements with fillers were used instead of metal sealing elements lubricated with oil, which prevented the lubricating oil from being brought into the deep and low temperature rectification zone or liquefaction zone and ensured safety. 
Turbine EPS Pre-expander machine
EPS Pre-expander machine that transfers energy by the change of velocity energy when gas expands. This EPS Pre-expander machine has single stage and double stage, vertical and horizontal, impulse and reaction. Generally, a single-stage centripetal radial flow reaction type is adopted, and the outgoing external power is absorbed by the generator, blower or oil brake. It is similar to a single-stage centrifugal compressor, but with (adjustable vane) deflectors for adjusting the intake air volume. The low-speed bearings are forcibly lubricated with oil, and the high-speed bearings use gas bearings. Turbine EPS Pre-expander machine has nozzle loss, impeller loss, residual velocity loss, disc friction loss, leakage loss, channeling loss and external heat intrusion loss, the general adiabatic efficiency is: medium pressure expander 65 ~ 75%, Low pressure expander 75 to 85%. In the 1960s, liquid expanders have been made, and most of them are used in natural gas separation equipment.
About Wanlong Machinery:
Hangzhou Fuyang Wanlong Machinery Co., Ltd established in 1997, is a professional high-tech EPS (Expandable polystyrene) machinery & Mould manufacturer integrating R & D, production, sales and service. We have strong product design and innovation capabilities, with more than 10 of the provincial high-tech products, the invention patent, utility model and appearance design patent etc. In addition, we passed the certifications of quality management system ISO9001, the products has with high efficiency, low energy consumption, stability, durability, easy maintenance, etc.