Conjet´s new compact hydrodemolition machine for tunnel repairs

2002-05-30 — Conjet AB has added the compact Conjet Robot 302 hydrodemolition machine to its comprehensive range of high pressure water jetting equipment which selectively removes weakened and damaged steel reinforced concrete from numerous structures.

The new Conjet Robot 302 is a remotely operated, computer controlled, high pressure water jetting machine designed primarily for use in repairing concrete tunnels as small as 1.5m diameter and other similarly confined spaces.

The small, lightweight, water resistant unit is exceptionally manoeuvrable and ideal for working in areas inaccessible to the standard larger Conjet Robot water jetting hydrodemolition equipment. It is exceptionally narrow and can pass through an 850mm wide opening making the Robot 302 ideal for working in small tunnels, culverts, inside concrete box girder bridge decks and under quay wall parapets. The unit is also exceptionally efficient for use in numerous industrial cleaning applications, especially in small spaces and other areas of restricted access.

The Robot 302 consists of a crawler mounted undercarriage unit powered by a remote and separate CCU 176 computer controlled, electrically powered hydraulic unit, which allows progress of the hydrodemolition process to be safely controlled and monitored away from the hazardous cutting area. The CCU can be located more than 50m from the Robot outside the tunnel, bridge deck box or on top of a dock or quay wall.

The remotely controlled tracked Robot, which can adjust its tracks to suit the shape of the tunnel invert, carries a special hydraulically driven rotor complete with two or four high pressure water jetting nozzles. The rotor is mounted on a rotating and telescoping boom which allows the cutter head to constantly follow the tunnel wall profile and maintain the nozzles' preset angle of attack to the concrete. Maximum concrete removal depth with the rotor cutter is 50mm. However, much deeper cuts can be made when fitted with the optional single nozzle mounted on an oscillating cassette and 1m long feed beam.

Water, at pressures of 1000bar, 1500bar or 2000bar and respective flows of 180litres/min, 120litres/min or 90litres/min, is fed to the rotor from a 350kW diesel driven high pressure pump housed in a sound insulated standard 20ft ISO container. The water jet penetrates the damaged surface creating a hydraulic pressure in the concrete, which breaks and lifts away when the internal pressure rises above the tensile strength of the concrete.

All functions on the Robot 302 are operated by the CCU 176, which incorporates an advanced computerised closed loop control, monitoring and display system. This system is extremely flexible and very easy for the operator to use and optimise production. It displays and stores all the relevant parameters and machine performance data, which can be printed or downloaded to a PC for future reference or used in estimating future hydrodemolition projects.

The operator chooses one of several pre-loaded software programs to ensure that only the concrete to a predetermined quality depth is selectively removed in a continuous, uniform and safe operation. Additional programs are available on request to suit customers' individual requirements and the operator can also easily adapt and program the computer on site to match a specific operation or set the computer to memorise and save specific working settings for future use.

For further information please contact:

Lars-Göran Nilsson or Carl Strömdahl

Conjet AB
P.O. Box 507
S-136 25 Haninge
Sweden.

Tel: +46-8-556 522 40
Fax: +46-8- 556 522 60
E-mail: conjet@conjet.se
Internet: www.conjet.com

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