The CMM-6/7 machine is used for the following purposes:

1. heating, pumping and treatment of oil used as insulators or coolers in electrical equipment (transformers, OLTC , transformer bushings, high voltage switches etc). The oil treatment includes removal of particulate matter, gas and water.
2. removal of air and gas from transformer tanks, if the gases enter the transformer in the course of repairs or servicing.

The processing capacity of the machine is 3000 to 7000 liters per hour and depends on the selected mode of operation.

Design of the machine

The CMM-6/7 is built in a container. The container houses all the components of the machine:

• a cylindrical chamber, from which air is removed to reduce pressure and create vacuum;
• the components removing the air from the vacuum chamber (the booster and backing pumps);
• oil pumps;
• an oil heater;
• components that remove particulate matter from the oil (coarse and fine filters;
• a control system (control buttons and lights).

Operation of the machine

The CMM-6/7 machine is multifunctional, i.e. it has several operation modes.

The simplest mode is oil pumping. Only the filters and the pumps are engaged in this mode.

The second mode allows to heat the oil and remove particulate matter. First, the pump transports the oil to the heater. Then the oil passes through the filter. In the end, filtered warm oil is pumped to the outlet of the unit.

In the degassing mode the oil is pumped through the heater, where its temperature is increased to 50-55°С, then it goes into the filter section. From the filter, the oil goes into the metal chamber, where the vacuum pumps remove the air and the pressure is low. The chamber is equipped with special filler, which is necessary to increase the surface area of the oil. As the oil passes along the filler, the vacuum and heat extract water and gas from the oil.

In the evacuation mode the machine is connected to external equipment by a hose, then the vacuum pumps remove air from that equipment.

Operator involvement

The degree of operator involvement in the operation of the CMM-6/7 varies depending on the automation of the machine, which is chosen by the client at the time of order placement (there are fully automatic and automation assisted options). In general, the operator starts the machine and selects the required mode of operation.

In the basic version, the operator also sets and adjusts the processing rate by turning manual valves. In the case of a fully automatic version, the processing rate is selected by the operator on the control panel  and is maintained automatically with no further human interference.

Safety

The safety of the CMM-6/7 is ensured by control of the physical oil treatment process parameters and special protection measures:

• electrical protection from overcurrent and overloads;
• protection against oil leaks due to hose rupture or overheating of oil;
• protection of possible process control device failures;
• protection against power supply cable break.

If a protection trips, the system turns on a siren and notifies the operator of the failure. The control system safely stops the machine if process parameters exceed limits.

Who this machine is designed for

The CMM-6/7 is built for transformer manufacturers, as well as service and repair facilities for equipment which contains insulation oil.