EagleBurgmann Agitator Seals
"Agitator Seal" is the term used for single or double mechanical seals for sealing shaft passages through the vessel walls of agitator vessels and other processing machinery and apparatus. Though it is possible in principle to employ the same mechanical seals in agitators as in pumps, a number of characteristic differences arise in practice:
Agitator shafts run at lower speeds than pump shafts and have a larger range of diameters (from a few mm for laboratory agitators to shaft diameters of around 500 mm for large-scale agitators). As a rule, agitator seals are made as a cartridge unit, with or without a shaft bearing, shut-down bearing leakage removal and connections for a quick-change device integrated in the seal casing. A distinction is drawn between agitator seals for top, side and bottom drive, depending on the direction from which the shaft enters the agitation vessel.
New Generation of Dry-Running SeccoMix Agitator Seals
The new SeccoMix1 is characterized by noiseless run, patented heat dissipation and is prototype tested for use in ATEX category 1 (zone 0). Due to omission of supply systems, the seal scores high in efficiency.
EagleBurgmann, one of the leading manufacturers of industrial sealing technology, is launching a new generation of dry running shaft seals for agitators onto the market. In addition to the known benefits of this type of mechanical seal (there is no seal supply system, for example), the new SeccoMix1 is also silent running and has been prototype tested for use in ATEX category 1 (zone 0). These shaft seals are used in mixers, agitators, dryers and filter strainers.
Mechanical seals from the SeccoMix series have been used successfully for over a decade. This practice-oriented seal concept has become established on the market and proven its worth all over the world. They are designed as single seals in a semi-cartridge construction, and consist of a sprung seal face and a stationary seat unit, giving them the added benefit of being easy to fit.
Dry running SeccoMix seals need no supply system, so they are a significant advantage over liquid or gas-lubricated seals in this respect. Given this saving on the purchase and operation of a seal supply system, the investment costs for a dry running single seal are as little as 30 % of those for an equivalent liquid-lubricated seal.
Supply systems can also increase the work involved for the system operator if there are no incoming lines available for water and nitrogen, for example, as is often the case with mobile agitator tanks. Other difficult safety-related situations occur if the dimensions of the agitator tank require the supply system to be attached at a great height. Maintaining and topping up the supply medium can be very time-consuming in such situations.
Dry running seals used to cause quite considerable noise emissions, depending on the type and operating conditions, due to the lack of lubricating medium. In addition, the dry running seals generally gave off a great deal of heat during operation.
These disadvantages have been eliminated by the new generation SeccoMix1. The redesign means that the seal runs silently, and a patented air cooling system for the seal face has significantly reduced the temperature rise. SeccoMix1 can now even be used in potentially explosive areas (ATEX), making temperature monitoring unnecessary for category 1 (zone 0).
Standard SeccoMix1 single seals are used for top-driven machines and in non-hazardous process media. For side entires of the type often found in dryers, there is the SeccoMixR version with rotating stationary seat. There is so little abrasion that the SeccoMix1 can even be used without problems in food and pharma applications.
An overview of the advantages
- Compact, easy to fit unit (semi-cartridge)
- Torque transmission with no damage to the shaft
- No noise emissions, no squeaking
- Heat dissipated via patented circulation holes
- Extremely safe to operate with a long service life
- No temperature monitoring required for ATEX category 1 (zone 0)
- Wear marking improves seal maintenance planning
- FDA-compliant materials