Drill head cooling lubricant for tunnel boring machine
Modern tunnel boring machines are highly complex underground mobile factories. The high drilling performance can only be guaranteed by the latest technology and only be achieved by lubrication and cooling via the supply of cooling lubricants.
In order to achieve an efficient lubrication, flushing, and cooling, the drilling emulsion is fed with pressures up to 500 bar to the drill head.
For data acquisition in the drill head control, a robust measuring system is needed that can provide output signals and can withstand harsh conditions.
Solution: Kobold BGN Variable Area Flowmeter – High-Pressure Version
By design our BGN variable area flowmeters are equipped with a cylindrical measuring tube, which may easily be designed for 500 bar or higher pressures with the use of thick-walled pipes. The float is kept in position via guiding stars, which are also robustly designed and do not constitute a weak point as many other rod-guided floats typically available in the market.
The measurement is coupled to the mechanical display or output transmitter via a contact-free magnet system. The transmitters are available with 4-20 mA HART®, Profibus®or Fieldbus®.
|Measuring / switching range: 0.5 – 5 … 13000 – 130000 l/h water 0.015 – 0.15 … 240 – 2400 Nm³/h air|
|Connection: flange DN15 … DN 150, ANSI ¾ … 6″|
|Material: stainless steel 1.4404, PTFE-lining, Hastelloy®|
|pmax: PN40 (16) bar|
|Accuracy: ±1.6 % of full scale (Gases: ±2 % of full scale)|
|Options: contacts, analogue output, totalizer, Hart®, Profibus® PA, ATEX|
|Protection: IP65 (aluminium housing) IP67 (stainless steel housing)|
|Explosion protection: BVS 03 ATEX H/B 112|