WO1994008174A1

WO1994008174A1 - A return system for a circulating lubrication system

Info

Publication number: WO1994008174A1
Application number: PCT/FI1993/000396
Authority: WO
Inventors: Simo Teuvo Juhani Saarinen
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-05
Filing date: 1993-10-04
Publication date: 1994-04-14
Anticipated expiration: 1995-04-05
Also published as: FI924468A0

Abstract

The return system for a circulating oil system includes a pipe network (2, 4), which consists of several pipe sections (2), connecting to one or several collector pipes (4), leading from the lubrication points (1) to an oil reservoir (3). The lubrication oil flows along the pipe network from the lubrication points (1) to the oil reservoir (4), the network (2, 4) being otherwise full of gas, i.e. there is a gas space above the flowing lubrication oil. The pipe network (2, 4) includes oil traps (5), by means of which the gas space of the network is divided into several zones (2.1, 2.2, 2.3, 2.4), each consisting of one or more pipe sections (2). The system includes a control system (6, 7, 8) for adjusting the pressures of the separate gas spaces independently of one another.

Description

A RETURN SYSTEM FOR A CIRCULATING LUBRICATION SYSTEM

The object of the invention is a return system for a circulating oil system, which includes a pipe network, which consists of several pipe sections, connecting to one or several collector pipes, leading from the lubrication points to an oil reservoir, and in which the lubrication oil flows along the pipe network from the lubrication points to the oil reservoir, the network being otherwise full of gas, i.e. there is a gas space above the flowing lubrication oil. Here lubrication oil means in general any lubrication medium.

Large lubrication systems are used for the lubrication of bearings, gearboxes, etc. in paper machines, rolling mills, and other large machine units. In particular, water and dirt mixing with the oil is a problem in the lubrication system of a paper machine. In order to remove such problems various mechanical arrangements, filters, and separators are used. In addition, there is the problem of a vacuum arising on the return side, which either prevents or retards to flow of the lubrication medium.

In present methods the attempted removal of dirt and foreign substances from the system takes place only after they have entered the circulating lubrication circuit. In order to prevent a vacuum bleed holes for air have had to be added, which in turn have increased the amount of dirt in the system. By means of this invention it is desired to remove the defects in the aforementioned known systems by denying external dirt and moisture entry to the circulating lubrication system. In ad¬ dition, it is possible, by means of the invention to remove detrimental gasses and dirt arising in the system, as well as prevent the creation of a vacuum. Furthermore, by means of the invention an improved separation of water from oil is sought. The characteristic features of the invention are presented in the accompanying Patent Claims. A system in accordance with the invention makes possible the maintenance of a desired pressure throughout the entire return system. For example, in a paper machine the pressure varies considerably in the upper and lower parts of the drying section cover. Other forms of application of the invention will become apparent in connection with the later example.

Due to the increase in the level of the pressure in the pipe network, the gas or air flows begin away from the oil trap in the direction of the lower pressure level. The pressure in every zone can be adjusted by means of the control components in the pipes or channels and thus a pressure level and gas flow ap¬ propriate to each zone can be created. Should the increase in pressure take place by means of clean dry gas or air at a suitable temperature, the gas or air flowing to a lower pressure transports detrimental gasses and dirt arising during lubrication, or that have otherwise entered the system, with it and out of holes or opening made in the construction. These opening and holes are most advantageously equipped with filters and pressure control valves.

In what follows the invention is depicted by reference to the accompanying Figures, which present one return system in accor¬ dance with the invention, as well the oil trap used in it.

Figure 1 shows schematically the return system of a lubrication system in a paper machine.

Figure 2 shows the oil trap used in the system in Figure 1.

In Figure 1 those points, from which the return oil travels to the reservoir, are marked by reference number 1. The lubrication medium is led through pipe networks 2 and 4 to oil reservoir 3. Of these, pipe network 2 is composed of separate zones 2.1, 2.2, 2.3, and 2.4, which are separated from the rest of the system by means of oil traps 5. To be more precise, their gas spaces are separated from one another. The lubrication medium flows along sloping pipes that always connect to a collector pipe of increasing size. Normally, however, there is always a gas space above the lubrication medium flow. As the oil traps 5 separate the zones from one another air or another gas is led into them to keep the pressure stable. For this purpose, a source 7 of pressurized gas is connected to these separate zones through pipe network 6. The air feed pipe 6.1...6.4 of each zone in¬ cludes a valve 8.2, which adjusts 8.3 the level of the pressure in the zone, depending on what is measured by sensor 8.1.

Either a compressor unit 7.1, or a bottle of gas 7.2 ,or both together can be used as the source 7 of pressure. The compressor unit here includes, in addition to a fan, a heating and cooling radiator, and a mechanical and chemical filter. The source of pressure to be used is selected by means of shut-off valves 9.2 and 9.3. The air or other gas supplied to the pipe networks 2 leaves the structure either through the lubrication points or through bleed holes 9 located in a separate system, these including a filter and pressure control valve.

The pressure control 8.3 may be simply of the so-called PIC type, in which there is thus pressure sensing indication and adjustment. According to the invention it is most advantageous to use oil traps in which there is minimum flow resistance to the oil. Figure 2 shows such an oil trap 5. Apart from connec¬ tions 11 and 12, it is formed by a closed vessel, in the centre of which there is a gas space divider 14. The inlet and outlet connections 11 and 12, and the lower edges of the gas space divider 14 are essentially at the same height. The oil trap thus begins to operate only when the surface of the oil reaches the lower surface 15 of the gas space divider 14, when the gas spaces are separated from one another. It is advantageous to use a dewatering valve 13 in the oil trap, by means of which water that has circulated can be removed and intervals. The water is advantageously removed before it reaches the reservoir and pumps.

The lower surface 15 of the gas space divider 14 is curved, in which case the oil flow is laminar when is passes the gas space divider 14. By means of this the outlet side even creates a slight vacuum, when the pressure loss remains very small. The surface 15 may also be a part of some wing section. The gas or air used to raise the pressure also acts as replace¬ ment gas, thus preventing the possible formation of a vacuum.

Depending of the processes various amounts of water enter the circulating lubrication system through holes and axle collars. When it flows with the oil this water is in the forms of drop¬ lets and being heavier than the oil it descends to the bottom of the pipe and then to the oil traps, where it is removed.

Claims

Patent Claims

1. A return system for a circulating oil system, which includes a pipe network (2, 4), which consists of several pipe sections (2) , connecting to one or several collector pipes (4) , leading from the lubrication points (1) to an oil reservoir (3) , and in which the lubrication oil flows along the pipe network from the lubrication points (1) to the oil reservoir (4) , the network (2, 4) being otherwise full of gas, i.e. there is a gas space above the flowing lubrication oil characterized in that the pipe network (2, 4) includes oil traps (5), by means of which the gas space of the network is divided into several zones

(2.1, 2.2, 2.3, 2.4), each consisting of one or more pipe sections (2) , and that the system includes a control system (6, 7, 8) for adjusting the pressures of the separate gas spaces independently of one another.

2. A return system in accordance with Patent Claim 1, characterized in that the control system (6, 7, 8) includes a source (7) of compressed gas, a gas pipe network (6) for leading the gas to each separate zone (2.1...2.4), each zone having a control valve (8.2) in the gas feed pipe (6.2), a pressure measurement device (8.1) in the zone (2.1...2.4) and an ad¬ justment device (8.3) to direct the control valve (8.2).

3. A return system in accordance with Patent Claim 2, characterized in that the source (7) of gas includes a compres¬ sor unit (7.1), which consists of a filter, a cooling and heating radiator, and a fan to led air to the zones.

4. A return system in accordance with Patent Claim 2 or 3, characterized in that the source (7) of gas includes a gas bottle (7.2) to lead a neutral gas into the zones.

5. A return system in accordance with one of Patent Claims 1 - 4, one or more oil traps (5) include a dewatering valve (13) in order to remove water collected on the bottom.

6. A return system in accordance with Patent Claim 1, characterized in that at least one oil trap (5) is formed by a vessel (10) , in which the inlet and outlet connections (11, 12) and the lower edge of the gas space divider (14) are essentially at the same height.

7. A return system in accordance with Patent Claim 6, characterized in that the surface (15) of the gas space divider (14) lying against the oil layer is curved or is some other surface that creates a laminar flow.