Oil Cooler / Air Aftercooler - Guidelines for installation, operation startup and temperature regulation

Cooler Installation

The ROTORCOMP product range:

Our range of products includes all components for air-cooled screw compressor systems, such as combined coolers, oil thermostats, oil filters, axial fans, etc.

Application:

ROTORCOMP supplies the right cooler for every screw compressor system, regardless of whether it is a combined cooler or a single cooler. The design of the cooler, the fan and the fan casing are all closely interconnected, and must be exactly adapted to each other.

Function:

In air-cooled screw compressor systems, the circulating oil is cooled down from the compressor outlet temperature to the compressor injection temperature. The cooling air is blown through the cooler by the fan. The distance between cooler and fan must be as large as possible in order to achieve a uniform distribution of cooling air over the entire effective cooler surface.

Material:

Aluminium

Installation:

Compare the specifications listed on the cooler rating plate with the operational data of the screw compressor. When installing the cooler, make sure that it is mounted without any mechanical strain.
During operation, the cooler must have the possibility to expan without any obstruction. The transmission of vibrations to the cooler must be avoided. If the system vibrates strongly, the cooler must be isolated and installed tension-free with flexible elements. When attaching pipelines, filters, etc., make sure that pressure-counter is applied at the connection sleeve by means of suitable tools, so that no force and torques are transmitted to the cooler. The connection sleeve of the cooler must not be subject to any static or dynamic loads exerted by such components as pipelines and filters.

The oil coolers are connected to the oil circuit of the screw compressor system by means of a relatively long pipeline. No flexible tubes should be used since they age and then have to be replaced.
The oil circulation volume should be chosen in an way that the system can be operated with a small temperature difference [ Δ t ]. Standard value: Δ t ≤ 20 °C. Make sure that the pressure surges and pressure vibrations in each oil circuit do not exceed the maximum permissible static operational pressure.

Operation startup:

Coolers with a nominal output rate of more than 37 kW / 50 HP must be ventilated after the screw compressor system is filled with oil.
Switch on the screw compressor system briefly in order to remove any air pockets from the pipelines and the cooler. After this, check the oil level in the separator tank. Refill if the oil level has dropped .

Temperature regulation:

If possible, a screw compressor system should always be run at the ideal operational temperature. Bearing in mind the formation of condensate in the oil tank and in the oil circuit, this temperature should be 70 to 80 °C / 158 to 176°F, and should be achieved as fast as possible after switching on the system. Temperature regulation should be effected by means of an oil thermostat (ROTORCOMP product range). The fan may not be switched on or off for the purpose of temperature regulation, especially in the case of screw compressor systems with a drive output rate of more than 11 kW / 15 HP.