For a thermal treatment process of metals in the manufacture of helicopters, a specific methanol dosage is required at several points of use in the furnaces. The pressure and flow conditions must remain stable.
This type of industrial systems using methanol to their operation are characterized by their constant, uninterrupted operation (24 x 7) without breaks for maintenance tasks. The methanol pumping units are designed with components to comply with the highest safety and reliability requirements, with a redundancy system to avoid single failure points. That redundancy system is managed by a control panel that requires a follow-up of the status of the components and their automatic commutation in case of failure. The control panel can be managed remotely with BMS systems.
Therefore, the design given to the consulting engineers and subcontractors had to focus on improved system diagrams for critically important installations.
The main challenges are
- Design aimed at a 24-7 operation, with automatic alternating system, providing the possibility of selecting pump 1 or 2 manually.
- Double filter system in parallel. Maintenance tasks can be carried out without shutting off the unit.
- Extremely accurate pressure adjustment, even when one of the furnaces does not need supply
- High-quality components that are also highly compatible with methanol, compliant with the highest safety and reliability requirements.
- Magnetic coupling between pump and motor to avoid mechanical sealing, decreasing the importance of a sensitive maintenance factor.
- Compatible with protection systems for explosive atmospheres (ATEX) according to Directive 94/9/ CE.
Solution provided by Inpro
Methanol pumping system
An RL 140 D ZW ZY methanol supply unit with double motor pump is used, with a control panel mounted on a cabinet outside the danger zone.
Stainless steel gear pumps with magnetic couplings are used; they provide airtight sealing of the pump and an excellent suction power. Pressure and vacuum displays in a compact unit provide accurate measurement of the installation parameters.
Stainless steel gear pumps with magnetic coupling that provide airtight sealing of the pump and an excellent suction power. Pressure and vacuum displays in a compact unit provide accurate measurement of the installation parameters.
All components will comply with ATEX based on European Directive 94/9/CE if in the zone classified as explosive atmosphere.
Double-filter system
The cabinet of the propulsion body must contain a double-filter system, with two parallel filter with their respective shut-off valves; we will choose whether to transfer Methanol from one or the other, so cleaning processes can be done without interrupting the fluid transfer.
Pressure regulator valve
In the ring main pipe system, a pressure regulator valve is installed consisting of a spring -adjustable with an adjustment screw- that will maintain a stable operating pressure in the line under different flow demands, returning the excess fluid to the main storage tank.
Automatic control panel
It’s placed outside the EX risk zone, as per European Directive 94/9/CE. It manages the system alarms (low pressure, motor overheating) and automates periodical pump alternation, or alternation if one of the motor pumps fails.
IMAGES OF THE PROJECTS
Elements of the installation supplied by INPRO
RL 140 ME ZUZW
RL 140 ME ZUZW, double motor pump pumping unit for the ring transfer system, special version for methanol, in steel cabinet.
- 2 gear pumps and hermetically sealed magnetic coupling, self-priming, with ATEX protection (Ex 11 z GDC X (1))
- Maximum flow of 140 L/h, nominal flow 70 L/h
- 2 230/400 Vca three-phase motors, ATEX protection (11 EX 2G EEx and IP55 T4 11 (1))
- 2 retention valves mounted on steel pipe
- 5 shut-off valves
- Filter with sintered bronze sieve and brass vessel
- Vacumeter, 6.5 manometer and radial outlet (Glycerin)
- Overpressure valve (safety)
- Low pressure shut-off pressure switch, to prevent no-load operation (loss of water tightness during suction or broken pipe). ATEX protection (EX 11 2 GD EEX from 11C T6 IP65(1))
- Connections (suction, pressure, return): 1/2” F
- Protection: IP54
- All parts are assembled in a protection cabinet, dimensions: 800 x 800 x 300 mm
All ATEX certificates of individual components are supplied with the unit.
DOUBLE-FILTER SYSTEM
Two ½” brass filters in parallel, with 40ų shut-off cartridges and 4 shut-off valves.
This configuration allows conducting maintenance tasks without interrupting the operation of the unit, using the corresponding shut-off valves.
Control panel
Automatic alternation system with internal timer:
- 2 motor thermal protection switches
- Start-up button
- Status pilot light (Operation)
- Fault warning pilot light
- Adjustable timer (to determine the operation time of each pump)
- Relay with timer to absorb pressure drops
- Galvanic isolator
- Automatic block in case of fault
- Automatic alternation between pump 1 and pump 2
- Manual selection between pump 1 and pump 2
PRESSURE REGULATOR VALVE
Constant pressure and flow regulator valve according to consumption variations
- For gas oil, lubricant and hydraulic oils
- Maximum temperature of the fluid: 250ºC
- Hydraulic cast iron. Piston, needle and tempered steel spring
