Transportation: Refrigerated Semi-trailers, Trailers & Vans
"Reefer" technology for refrigerated semi-trailers, trailers, vans, and ocean going containers makes a big impact on everyday life, making it possible to have and enjoy fresh produce almost any time of the year from anywhere in the world. The type of technology for refrigeration varies depending upon the particular situation, from water cooling, to cryogenic cooling, which utilizes dry ice, to high tech, high performance refrigeration units powered by the truck's diesel engine. The majority of long haul refrigerated transportation today is done by semi-trailers.
Refrigerated Semi-trailers, Trailers & VansRefrigerated transportation is also referred to as isothermal transportation, referring to the objective that the system temperature remain constant: ΔT = 0. That is "delta temperature, or difference of temperature change" = 0. Meaning that, although the outside temperature is different than that within, the refrigeration system must be able to control and maintain the integrity of the desired internal temperature.
This infers that trailers, vans and containers all need a well designed insulated structure, a factor which presents a range of new requirements for the manufacturing and machining processes of the composite panels from which their built, panels which are composed of steel laminated surfaces over thicker underlying insulation and frame structures, and which must provide good thermal stability and a structure still usable for transportation needs.
The typical thickness for various isothermal panels is:
- roof and floor, 100 mm, ~4"
- side walls, trailer head, 60 - 80 mm, ~2.7 - 3.2" foam, semi-finished parts, 30 - 80 mm, ~1.2 - 3.2"
In fact with CMS' powerful 5-axis 28 kW (37.5 hp) at 4,300 rpm working unit S1 rating, 24,000 rpm maximum, panels which reach a thickness of 240 mm (9.45") are being trimmed with an 800 mm (31.5") diameter saw blade: powerful, flexible machining for heavy work.
CMS' range of large format CNC machining centers provides the room and heavy duty power needed to handle these large composite steel clad panels such as roofs, floors, side walls, trailer heads, and foamed semi-finished parts, with their requirement for drilling, taping, general milling, sawing, and trimming processes.
PMT - large format CNC machining for refrigerated semi-trailers
PMT, CMS' moving gantry class CNC machining center, provides the 5-axis working envelop size and power needed for machining the large isothermal composite panels utilized in refrigerated trailers, semi-trailers, vans and containers. PMT's design makes it possible to machine very long panels, even in a pendular manner, if so required, for concurrent setup on one end of the machine, while work continues on the other. PMT's design also makes it easy for loading and unloading large panels, and is easily accessible for a crane.
PMT is available with CMS' powerful, 5-axis, working unit with 28 kW (37.5 hp) at 4,300 rpm S1 rating, maximum 24,000 rpm, liquid cooled spindle, for use with large diameter saw blades, milling, drilling and taping equipment, and available with oil mist lubrication system.
PMT - fully protected work envelop, central shield, pendular work cycles
As shown here, PMT is provided with CMS' complete perimeter protection system, so that the work area remains a safe place for everyone to work, with access doors provided on either end, and a central shield, permitting protected pendular work cycles, when needed. The central shield makes it possible for the operator to load, unload or prepare for the next project on one end of PMT's large work envelop, while work continues on the other end, avoiding lost machine productivity, and preventing injury to those working around PMT.
Poseidon - large format, moving bridge, CNC for isothermal panel machining
Poseidon, CMS' moving bridge class CNC machining center, provides another large work envelop alternative for isothermal panel machining. Poseidon's heavy, rigid, pillar and shoulder structure, provides the stable way surface upon which its massive bridge moves, completely surrounding the work envelop, reaching lengths of 41.0 m (134.5'), widths of 8.5 m (27.9'), heights from 1.3 m to 4.0 m (4.3' to 13.1') with a selection of CMS' powerful 5-axis working units available including its KX5 with 28 kW power (37.5 hp) at 4,300 rpm, maximum 24,000 rpm S1 rating, liquid cooled, with A axis +/- 120°, C axis +/- 270°. Poseidon can also be equipped for machining work with oil mist lubrication, or full flood, as may be required depending upon the work.
CMS' PMT and Poseidon range of CNC machining centers provide the heavy duty power, large work areas, 5-axis machining capability, with a range of sawing, milling, drilling and tapping tools necessary to work large, thick isothermal panels.
Typical long haul "Reefer"
A typical long haul, refrigerated, isothermal, semi-trailer outfitted with front end, "reefer" refrigeration unit. The side walls, roof, floor and trailer head are all designed and built with special concern for their isothermal properties.
Exploded view of the basic isothermal truck
The photo shows an exploded view of the basic isothermal truck components used for semi-trailers, trailers, vans and containers: floor, roof, side walls, trailer end and doors. To the right of the photo a view from the end is seen complete with load locking attachment strips, all securely mounted to the isothermal side wall and trailer end structure.
Composite isothermal panel structure
The photo shows some composite isothermal panel structures and their machining operations. The photo to the top left shows a composite isothermal panel composed of deck plate laminated over a heavy plywood sheet and thick internal foam insulation core, while the photo to the top right shows a large diameter blade being used in 5-axis mode to trim the panel to size. The photo to the bottom left shows a steel clad panel with a heavy rabbet construction joint and that to the bottom right shows a tapping operation for an M10 bolt, which followed the drilling of its 15 mm deep hole.
CMS' CNC machining center technology handles the range of processing requirements for isothermal panels, even when large, thick components, with heavy duty machining requirements are involved.
Setup for isothermal panel machining with vacuum pod placement, pod devices for adjustment of its position, automatic alignment devices, followed by—machining, milling, drilling, tapping, sawing...
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