Anhydrous Fire Resistant Hydraulic Fluids using Polyalkylene Glycols

Transcription

1 Anhydrous Fire Resistant Hydraulic Fluids using Polyalkylene Glycols ASTM D02 Symposium on Fire Resistant Fluids June 24 th, 2013 Authors Andrew Larson, The Dow Chemical Company Dr. Martin Greaves, The Dow Chemical Company The Dow Chemical Company

2 Contents Examine performance of non-phosphorus based anhydrous fire resistant hydraulic fluids Compare two conventional PAGs with a synthetic ester New class of PAG known as oil soluble polyalkylene glycols (OSPs) Examine fire resistance behavior of the formulated fluid containing an OSP and compare to other PAGs 2

3 Classification of Fire Resistant Fluids Classification HFAE HFAS HFB HFC HFC-E (a) HFDR Description Oil-in-water emulsions containing >95% water (v/v) and up to 5% of additives Chemical solutions in water containing >75% water (v/v) and an additive package and water soluble polymer thickener Water-in-oil emulsions that typically contain >40% water (v/v) and an additive package Water polymer solutions containing >35% water (v/v), a high molecular weight polyalkylene glycol thickener and an additive package HFC fluids with a lower water content of about 20% water (v/v) Anhydrous synthetic phosphate esters containing an additive package HFDU (a) Not an official ISO category Anhydrous synthetics (other than phosphate esters). For example polyol esters, vegetable oils and polyalkylene glycols. The base oil represents about 95% of the formulation with an additive package. 3

4 Anhydrous Fire Resistant Fluids for Evaluation Four fluids examined Fully formulated (i.e. contain a base oil and performance additive package) Based on an ISO-VG-46 classification Fluid A Polyol oleate ester product known to be a leading fire resistant fluid in the steel processing industry Fluid B Water soluble PAG Fluid C Water insoluble PAG Fluid D Oil soluble PAG (OSP) 4

5 Conventional Polyalklyene Glycol Technology Typical Synthesis Route to Polyalkylene Glycols Initiator (ROH) catalyst + +/or PAG ethylene oxide (EO) propylene oxide (PO) Types of PAGs by chemical family Homo-polymers of EO Homo-polymers of PO Block copolymers of EO/PO Reverse block copolymers of EO/PO Random copolymers of EO/PO 5

6 PAGs and OSPs and Their Chemistry Simplistic schematic of the types of oxides used in designing PAGs Fluid B EO/PO co-polymer Fluid C PO homo-polymer Fluid D PO/BO co-polymer 6

7 Physical Properties Base oil Chemistry Test Method Fluid A Fluid B Fluid C Fluid D Trimethylol-propane trioleate EO/PO co-polymer PO homo-polymer PO/BO copolymer Kinematic viscosity at 40 C, ASTM mm 2 /s D445 Kinematic viscosity at ASTM C, mm2/s D445 Viscosity Index ASTM D2270 Pour point, ASTM C D97 Flash point, ASTM C D92 Fire point, ASTM C D92 Density at 15 C, ASTM g/ml D7042 Water solubility at 5% v/v Visual n/s s n/s n/s Oil solubility at 5% v/v Visual s n/s n/s s s = soluble; n/s = not soluble 7

8 Hydraulic Wear Performance Testing Used an Eaton (Vickers) V-104C pump housing and Connestoga ring and vanes Explained in ASTM D Modified procedure Used 1 gallon reservoir instead of 5 gallons Comprehensive cleaning procedure before each run Experiment conditions Bulk fluid temperature = 65ºC Time = 100 hours Speed = 1200 rpm Pressure = 2000 psi Test Method Fluid A Fluid B Fluid C Fluid D Eaton vane pump V-104C, - total weight loss of ring and vanes, mg - kinematic viscosity at 40 C change, % - AN change, mg KOH/g ASTM D

9 Eaton 35VQ25A Performance Test on Fluid D Result Average cartridge wear, mg 18 Viscosity change, % 1.0 Water, before/after, % 0.07 / 0.05 Acid number before/after, mg KOH/g 0.19 / 0.24 Phosphorus, before/after, ppm 137 / 117 Iron, before/after, ppm <1 / <1 Zinc, before/after, ppm 2 / 6 Tin, before/after, ppm <1 / <1 Calcium, before/after, ppm 6 / 7 Copper, before/after, ppm <1 / <1 9

10 Oxidation Testing Measured in two ways Rotary Pressure Vessel Oxidation Test (RPVOT) Blown air oxidation RPVOT, minutes Blown air oxidation - KV100 change after 13 days, % - AN change after 13 days, mg KOH/g - KV100 change after 70 days, % - AN change after 70 days, mg KOH/g n/d = not determined Test Method ASTM D2272 ASTM D2893B modified Fluid A Fluid B Fluid C Fluid D n/d

11 Air Release Measurements made at 50ºC using ASTM D Entrained air is known to result in sponginess and lack of sensitivity of the controls in hydraulic systems Test Method Fluid A Fluid B Fluid C Fluid D Air release at 50 C, minutes ASTM D <1 11

12 Air release times of commercially available hydraulic fluids (ISO-VG-46) 12

13 Additional Performance Properties Test Method Fluid A Fluid B Fluid C Fluid D Base oil chemistry TMP trioleate EO/PO co-polymer Ester PAG PAG OSP PO Homopolymer PO/BO co-polymer Ferrous corrosion ASTM pass pass pass pass D665A Copper corrosion ISO b 1a 1b 1a Demulsibility, ml/ml/ml (minutes) Four ball anti-wear, mm ASTM D1401 ASTM D /38/2 water soluble poor 41/39/0 (20)

14 Fire Resistance Assessment often made based on a range of tests Spray Flammability Hot Manifold Ignition Hot Channel Wick Flame Soaked Cube test Fire point and flash point are also relevant Examined performance of Fluids A-D with two tests Stabilized Flame Heat Release method Hot Manifold Ignition test 14

15 Fire Testing Results RI Value ISO RI Factor ISO Manifold ignition test (ISO14935) Phosphate ester 28 Class F >700 (reference) Fluid A 5 Class H Fluid B 11 Class H Fluid C 12 Class H Fluid D 10 Class H (a) 7 th Luxembourg Report The ignitability factor (RI) is graded into ranges with the least flammable having a RI >100 15

16 Ignitability Values (RI) 16

17 Conclusions Examined three HFDU chemistries Synthetic ester Excellent VI and good low temperature properties Poor oxidation performance when compared to the PAGs and OSP fluids Viscosity deterioration after vane pump test Two PAGs (water soluble and water insoluble) OSP Has significantly lower air release Demonstrated good wear performance and excellent stability in Eaton 35VQ25A vane pump test OSP did not show any significant difference from PAGs in terms of fire resistance based on Stabilized Flame Heat Release method and Hot Manifold test OSPs have better hydrocarbon compatibility and superior oxidation and air release properties may lead to it being a better practical choice for future PAG-based fire resistant hydraulic fluids Further research is needed to determine suitability of OSPs for fire resistant hydraulic applications 17

18 Thank You