Thursday, August 23, 2012

Early warning signs of toxic gases at Langley mushroom farm ignored


WorkSafeBC officials had investigated at least two cases where toxic gases had knocked mushroom-farm workers unconscious before three people were killed at a Langley mushroom farm in September 2008.


Despite the previous incidents in 2006 and 2008, no broad warning was issued to the province’s five companies that produce mushroom compost or the 40 farms that use it.


On July 24, 2008 — six weeks before the fatal incident in Langley — a Central Composting employee was hospitalized, overcome in the composting barn by deadly fumes including ammonia and methane in an oxygen-depleted environment in Abbotsford.


Along with an ambulance, two WorkSafe officials attended the incident.


A stop-work order was issued over fears that gases in the composting barn and its bunkers presented a risk of injury, serious illness or even death.


The next day, work resumed when officials returned to the site and deemed the imminent risk to employees had passed.


The WorkSafeBC inspectors noted the worker who fell ill was likely dehydrated, exposed to toxic gases and not properly equipped with a respirator. They also found Central Composting lacked an “exposure control plan,” a long-standing requirement for workplaces with harmful air contaminants above an acceptable limit.


Composting facilities regularly produce hydrogen sulphide, ammonia, methane and carbon dioxide.


Numerous other safety violations were cited at Central Composting. The farm had no occupational health and safety program; workers were not wearing properly fitting respiratory equipment; and there was no safety program to manage hazardous chemicals.


Nearly two years before the incident at Central Composting a contractor was injured when overcome by methane after climbing into a tank at nearby Mountainview Mushrooms, which was found to be lacking first aid procedures as well. No further details were available, except that it took that company four years to achieve compliance for its own exposure control plan.


It wasn’t until after the fatal incident in Langley that officials took a close look at safety in the mushroom industry.


On Sept. 5, 2008, Han Pham, Ut Van Tran and Jimmy Chan, workers at now-bankrupt A-1 Mushroom Substratum Ltd., were killed after breathing in hydrogen sulphide and ammonia while in a pump shed at a facility in Langley. Michael Phan and Thang Tchen survived but with severe brain damage.


After the deaths, which prompted a two-year investigation and a coroner’s inquest, WorkSafeBC inspected the province’s five mushroom composting facilities and close to 40 white mushroom farms. It also renewed enforcement of the Workers’ Compensation Act regulation requiring employers to create and maintain an exposure control plan to educate workers on safety when there are toxic gases in the workplace.


A now-retired B.C. environmental worker, who also had a role in monitoring the farms, said the previous incidents should have raised a “red flag” for regulators and industry.


Linda Vanderhoek, who worked for the Ministry of Environment for 37 years before retiring in January, said she regularly visited both A-1 Mushrooms and Central Composting as an environmental protection officer. She knew about the problems at the Langley farm but was shocked to learn a worker had previously fainted at Central.


She said a “heads-up” from WorkSafe to inspectors and industry would have been helpful, to send a message the job sites could be unsafe.


But there’s no formal mechanism to relay the information, especially across departments, Vanderhoek noted. “Each agency has their own mandate and there should be better communication among us, I guess.”


It should have been “a red flag for something that killed people six weeks later,” Vanderhoek said.


WorkSafeBC said there was no reason to suspect the industry had widespread problems after the worker became ill at Central Composting.


The jobs being done were completely different. Everybody knows there’s gases produced at those types of job sites, but you wouldn’t have been able to infer from one that the other would be hazardous. It was a different set of circumstances,” said regional prevention manager Burt Goulding.


Workers at A-1 Mushroom were in a confined space with no understanding of the risks posed by hydrogen sulphide, and few safe work procedures were in place overall.


At Central Composting, workers were completing daily tasks when one entered an oxygen-depleted building without a safety mask. But WorkSafe considered the job site generally safe.


There was minimal attention paid to safety at the A-1 work site. The other one had safe work procedures that weren’t followed properly by the workers,” Goulding said. “There is a similarity in the hazards in that type of industry, yes. And the employer has to deal with the hazards appropriately. Which wasn’t done in A-1’s case.”


But Central Composting didn’t have a formal exposure control plan at the time, or even a health and safety committee. Though the employer had begun implementing both by August 2008, it was only considered compliant in June 2010, nearly two years after the incident.


After the A-1 thing happened, WCB came down and talked to us about it,” said Balbir Randhawa, manager of Central Composting. “We had to do the exposure plan and we complied to all that. Before that, a lot of people didn’t know about the H2S [hydrogen sulphide] gas. Even I didn’t.”


The injured worker recovered and still works for Central Composting, Randhawa said.


All 10 employees received better training, now wear gas monitors to ensure safe levels, and the building was retrofitted for better ventilation, he said.


Randhawa added he’s proud of the company’s safety precautions and there have been no serious incidents since 2008.


'We were fortunate there wasn’t anything major,” he said.









D12 Toxic / Combustible Gas Detector

Wednesday, August 22, 2012

Q45D Dissolved Oxygen Monitor


ATIs Model Q45D Dissolved Oxygen monitor provides reliable oxygen measurement and reduced maintenance costs. The galvanic dissolved oxygen sensor uses a rugged 5 mil Teflon membrane to resist mechanical abrasions and tears. The membrane serves as a barrier to allow molecular oxygen to diffuse into the reaction cell where it is reduced, producing a small current which is proportional to oxygen concentration.

In applications where process constituents adhere to the membrane, frequent membrane cleaning is required. To keep the dissolved oxygen system nearly maintenance free, an optional Auto-Cleaner can be included to remove those materials that build up on the sensor membrane. The cleaning cycle is user selectable to maximize the cleaning effectiveness. When sensor maintenance is required, our cartridge-based sensor makes it fast and easy. Where other manufacturers make you throw away the cartridge, we’ve made our cartridge field repairable. We also include enough replacement parts to rebuild your cartridge ten times.

All dissolved oxygen sensors are affected by process coating. Any material that slows the diffusion of oxygen into the reaction cell will cause an error in the oxygen reading. If the system doesn’t have a means to clean itself, the sensor will require frequent manual cleanings, which means higher maintenance costs. Our self contained Auto-Clean system generates a series of high pressure air blasts to remove foulants from the face of the sensor. Each cleaning cycle lasts approximately 3 minutes, during which the monitor outputs are placed in a HOLD condition to prevent false readings or alarms. The user can vary the cleaning cycle frequency from as often as once every two hours, to as little as once a day. ATI was the first to introduce a dissolved oxygen system that cleans itself with air. Others have tried to copy our system, but none are more effective at removing biological growth and other contaminants than the ATI Auto-Clean system. So don’t be fooled by imitation air pump cleaners that are minimally effective at cleaning your sensor. Trust the original Air-Blast system. Trust the best.
 

ATI’s Model Q45D Dissolved Oxygen monitor is designed to provide reliable oxygen measurement and reduce maintenance costs.  The galvanic dissolved oxygen sensor uses a rugged 5 mil Teflon membrane to resist mechanical abrasions and tears.  The membrane serves as a barrier to allow molecular oxygen to diffuse into the reaction cell where it is reduced at the working electrode. This reaction produces a small current which is proportional to oxygen concentration.
 
In applications where process constituents adhere to the membrane, frequent membrane cleaning is required.  To keep the dissolved oxygen system nearly maintenance free, an optional Auto-Cleaner can be included to remove those materials that build up on the sensor membrane.  The cleaning cycle is user selectable to maximize the cleaning effectiveness. When sensor maintenance is required, our cartridge-based sensor makes it fast and easy.  Where other manufacturers make you throw away the cartridge, we’ve made our cartridge fieldrepairable.  We also include enough replacement parts to rebuild your cartridge ten times.  When you consider the average cost of a competitor’s cartridge at $125, ATI can save you thousands of dollars in maintenance costs. 

  
Monitor Features
 
 Loop-powered, AC, or Battery Versions:  This line of microprocessor based instrumentation allows for easy implementation of loop-powered, line-powered, or batterypowered capability within the same instrument.  This instrument can be rapidly converted between any of these versions with no requirement for software change.

Loop-powered (16-35 VDC) Transmitter, 4-20 mA output• Line-powered (115/230 VAC) Analyzer, dual relays, dual 4-20 mA outputs• Battery-powered (9 VDC) Monitor/Data Logger, dual 0-2.5 VDC outputs
Large, Dual Line Display:  The large, high contrast, supertwist display provides excellent readability over a wide operating temperature range, even in low light conditions. The main display line consists of large, segmented characters with measurement units.  The secondary display line utilizes easily readable dot matrix characters for clear display of calibration and diagnostic messages.  Two of four measured parameters may be displayed simultaneously.
Interactive User Interface: Four-button programming provides intuitive navigation through the menu driven user interface
Dual Alarm/Analog Outputs: AC operated systems provide two relays that are configurable for either "control mode" or "alarm mode" of operation.  
Flexible Calibration: Air and sample calibration options include temperature, barometric pressure, and salinity compensation.  All calibration methods include stability monitors to check temperature and main parameter stability before accepting data.
  
Clean Running Means Better Performance
 
It’s a fact: A clean D.O. sensor performs better.

That’s because when there’s nothing between the sensing membrane and the water in the tank, you get uniform oxygen transfer for accurate measurement of dissolved oxygen content. And that translates into improved process performance, energy savings, and more effective water treatment.
Trouble is, not all D.O. monitors are easy to clean. Units that don’t clean themselves need to be removed for frequent maintenance. And those that do clean themselves with grindstones or brushes can be expensive and difficult to maintain. Still others use chlorine gas to kill contaminants on the sensor’s surface, but do nothing to remove contaminant buildup, leaving the source of the problem intact.
Enter ATI’s Auto-Clean D.O. Monitor, the first D.O. monitor to clean itself with air. Biological growth and other contaminants areliterally blasted from the Teflon membrane.  The result:  reduced maintenance, better performance, and more accurate D.O.monitoring.
 
Our Sensor Makes Sense.
 
 The Auto-Clean sensor uses the same rebuildable cartridge as our submersible-style sensor. The durable 5 mil Teflon membrane allows the sensor to perform in the most demanding applications. Modular design lets you easily remove the sensing element for service, reducing maintenance costs.
The sensor’s principle of operation is simple. Oxygen diffuses through a Teflon membrane and reduces on the surface of a working electrode, generating a small electrical current proportional to D.O. concentration. An RTD temperature element measures water temperature and corrects the sensor signal for its effect. The result is a D.O. measurement that’s accurate over an operating range of 0-50°C.
 
Model Q45D Dissolved Oxygen Monitor Specifications
Electronic Monitor

Display Range: 0 - 40.00 PPM  

Accuracy: 0.2% of span or better

Repeatability: 0.05% of span or better

Linearity: 0.1% of span or better

Temp. Drift: 0.01% of span/°C

Display: Large 4 digit main display, 0.75"
characters; 12 digit alpha-numeric
second line display

Power: 16-35 VDC for loop-powered unit
115/230 VAC, 50/60 Hz., 10 VA
max.; 9-Volt battery for battery
operated portable

Control Relays: Two SPDT relays, 6A @ 250 VAC,
5A @ 24 VDC, resistive

Relay Mode: Programmable for control, alarm,
or timer function

Analog Outputs: Isolated 4-20 mA, 550 ohm max.
load.  Two assignable 4-20 mA
outputs, 550 ohm max. (AC only)

Data Logger: Battery version only, stores 32,000
data points

Operating Conditions: -20-60°C., 0-95% R.H. non-condensing

Enclosure: NEMA 4X (IP-66) polycarbonate
wall, panel, or pipe mount 

Weight: 5 lbs. (2.3 Kg.) - standard system

15 lbs.  (6.9 Kg.) - Auto-Clean
Sensor

Sensor: Membrane-covered galvanic 
sensor 

Wetted Materials: Noryl and 316 Stainless Steel

Sensor Cable: 30 feet (9.0 M) standard, 
1,000 feet (300 M) maximum

Response Time: 90% in 60 seconds (2 mil membrane); 90% in 180 seconds (5 mil
membrane)

Temperature Limits: 0-50° C.

Monday, August 20, 2012

A12-17 Combustible Gas Transmitter


ATIs A12-17 Combustible Gas Detectors are used in a wide variety of industrial plants to detect gas leakage or buildup before it reaches explosive levels.  These detectors rely on thermal oxidation of any combustible gas or vapor on the surface of a heated catalyst. In other words, they simply burn the gas and measure the heat released in the combustion process.
While this type of sensor is generally stable and reliable, it is also subject to poisoning by silicon vapor, lead compounds, and other environmental contaminants.  To detect loss of sensitivity, most users test combustible sensors either weekly or biweekly to ensure response. The procedure is simple, but requires manpower to perform the test.

ATI’s Auto-Test Combustible Gas Transmitter eliminates the need for frequent response checks. This transmitter performs an automatic gas test on the sensing element every 24 hours. The result is a combustible gas detector system with a level of reliability beyond that of any other system available.  This daily sensor response verification is as close to a fail-safe detection system as you can find, with the added benefit of greatly reduced manual testing.

Combustible gas sensors are made up of two matched sensing elements, one active and one passive. Both are electrically heated and form two legs of a Wheatstone bridge circuit. When combustible gas contacts the sensor, the active element catalyzes the oxidation of gas, heating the active element and changing its resistance. The passive element remains unchanged, resulting in a change in the bridge circuit that is proportional to the gas concentration.  As long as the active element remains in good condition, the sensor will respond rapidly to the presence of combustible gas.

The Auto-Test sensor is actually a combination of a gas sensor and an electrochemical hydrogen gas generator (patent pending) integrated into an explosion-proof stainless steel housing. When activated by the electronic transmitter, the generator produces hydrogen that diffuses to the gas sensor through the flame arrestor protecting the sensor. If the sensor responds properly, the transmitter will show a “Pass” indication. Should the sensor not respond properly, an “Auto Test Fail” message will activate at the transmitter and the 4-20 mA output from the transmitter will drop to 3 mA, providing for remote fault indication.

Friday, August 17, 2012

ATIs Model Q45D Dissolved Oxygen


ATIs Model Q45D Dissolved Oxygen monitor provides reliable oxygen measurement and reduced maintenance costs. The galvanic dissolved oxygen sensor uses a rugged 5 mil Teflon membrane to resist mechanical abrasions and tears. The membrane serves as a barrier to allow molecular oxygen to diffuse into the reaction cell where it is reduced, producing a small current which is proportional to oxygen concentration.



In applications where process constituents adhere to the membrane, frequent membrane cleaning is required. To keep the dissolved oxygen system nearly maintenance free, an optional Auto-Cleaner can be included to remove those materials that build up on the sensor membrane. The cleaning cycle is user selectable to maximize the cleaning effectiveness. When sensor maintenance is required, our cartridge-based sensor makes it fast and easy. Where other manufacturers make you throw away the cartridge, we’ve made our cartridge field repairable. We also include enough replacement parts to rebuild your cartridge ten times.


All dissolved oxygen sensors are affected by process coating. Any material that slows the diffusion of oxygen into the reaction cell will cause an error in the oxygen reading. If the system doesn’t have a means to clean itself, the sensor will require frequent manual cleanings, which means higher maintenance costs. Our self contained Auto-Clean system generates a series of high pressure air blasts to remove foulants from the face of the sensor. Each cleaning cycle lasts approximately 3 minutes, during which the monitor outputs are placed in a HOLD condition to prevent false readings or alarms. The user can vary the cleaning cycle frequency from as often as once every two hours, to as little as once a day. ATI was the first to introduce a dissolved oxygen system that cleans itself with air. Others have tried to copy our system, but none are more effective at removing biological growth and other contaminants than the ATI Auto-Clean system. So don’t be fooled by imitation air pump cleaners that are minimally effective at cleaning your sensor. Trust the original Air-Blast system. Trust the best.

Find out more at: http://www.analyticaltechnology.com/public/product.aspx?ProductID=1029

Dissolved Gas Analysis


The numbers don't lie; the current state of monitoring transformer assets is a recipe for disaster.
Research shows that up to 75 percent of power transformers in the US are more than 25 years old, and much of the electricity grid is relying on 45-year-old transformers that were designed to survive 40 years. Electricity demand in the US is expected to increase 19 percent during the next 10 years, but resources needed for this demand will only increase some 6 percent. This means the existing, aged transformer fleet is going to be stressed further, and transformer failures are expected to increase 500 percent during the next 15 years.
In summary, the grid is relying on too many transformers that have aged past their originally intended lifecycles, and those transformers will only be pushed harder. Considering the move towards the smart grid, this is the worst time for this perfect storm of potential transformer failures.
One of the most proven-albeit imperfect-methods to determine when a transformer is starting to fail is dissolved gas analysis (DGA). Performing DGA on transformers and load tap changers (LTCs) is common practice globally and cited in many standards with specific action levels dependent on gas concentrations found in the dissolved oil of transformers and LTCs. For years, this analysis has been performed by taking samples of the transformer and LTC oil in the field for lab analysis. Unfortunately, this is typically done once or twice a year and can take up to two weeks for results. Much can happen between samples. And, if an abnormality is found with the oil sample, this would require many samples be taken in a shorter time period, which drains manpower resources and can become expensive.
Some 20 years ago, efforts were made to take DGA analysis online and attach them to transformers. This technique was slowly adopted, but has proven to be a supplemental technique many utilities use globally to gain additional information about their transformers performance and behavior. This analysis method is typically placed on larger power transformers because of their criticality and because of the cost of the monitors. In addition, there are high costs associated with the installation and maintenance of these monitors that, along with questions about the reliability and accuracy of the monitors, have proven barriers to wide-scale adoption of this method across transformer fleets and into the grid's distribution segment. As a result, less than 5 percent of transformers globally have online DGA monitoring.
So what can be done to increase this adoption rate? The industry's newest line of online DGA monitors plans to address this issue by using a well-known gas monitoring technology that has been used for decades in other industries: non-dispersive infrared (NDIR).
Drawing from more than 40 years of gas-sensing expertise and utility market knowledge, LumaSense Technologies recently launched its SmartDGA line of online monitors. The company has provided more than 400,000 NDIR instruments for applications such as automotive exhaust monitoring, environmental monitoring and anesthesia monitoring. Leveraging knowledge gained from supplying NDIR instruments to these industries and from supplying to industrial and semiconductor customers, LumaSense has developed a compact and easy-to-install DGA monitoring line that is half the cost of others.

Thursday, August 16, 2012

Study will monitor W. Pa. Marcellus gas emissions


Pennsylvania has begun a one-year air quality study in a region with heavy Marcellus Shale natural gas activity.
The Department of Environmental Protection says in a release Monday that the study will focus on areas with gas processing plants and compressor stations in Washington County, about 25 miles southwest of Pittsburgh.
The study will monitor the air for ground-level ozone, carbon monoxide, methane, and 60 other pollutants.
DEP says they'll conduct a long-term analysis of risk to the public to help determine if studies are needed in other parts of the state.
MarkWest Energy Partners spokesman Robert McHale says the company supports the study and believes regulations should be based on science and fact-based data.
MarkWest is based in Washington County.

Wednesday, August 15, 2012

B14 Gas Alarm Module

ATI’s Series B14 Gas Alarm Module Receivers are compact electronic modules that provide local alarm, display, and signal retransmission functions for gas detection systems. 

The modules are designed to accept input from either two, three, or four wire 4-20 mA transmitters located up to 10,000 feet from the receiver. They’re ideally suited for use with ATI’s Series A12 or B12 two-wire toxic gas transmitters, or Model A12-17 or B12-17 three-wire combustible gas transmitter.
B14 Alarm Receivers are DIN rail mounted modules that can be supplied in single or multiple unit enclosures.  Gas concentrations are indicated directly in PPM, PPB, percent, or percent LEL with the display range selectable by the user.
Each module provides separate caution, warning, and alarm setpoints with LED bar indicators of each alarm point. LED indicators flash on initial alarm condition and change to steady on when the alarm is indicated.  Modules contain individual alarm relays for each alarm setpoint. However, each relay can be assigned to any setpoint to allow multiple alarm functions at a single alarm point. Relays are configurable for either standard or fail-safe operation and for either latching or non-latching operation.  A fourth LED alarm bar and relay are provided to indicate trouble conditions.  The trouble alarm and relay will activate on loss of input signal or if the 4-20 mA input drops below a specific value.
 
FUNCTIONS.
 
ATI’s Model B14 Alarm Receivers are DIN rail mounted modules 
that can be supplied in single or multiple unit enclosures. Each 
alarm module offers a variety of functions:
 
LED Display: Gas concentrations are indicated directly in PPM, 
PPB, percent, or percent LEL with the display range selectable 
by the user.
 
Three Alarm Setpoints: Each module provides separate 
caution, warning, and alarm setpoints with LED bar indicators of 
each alarm point. LED indicators flash on initial alarm condition 
and change to steady on when the alarm is indicated.
 
Three Relay Outputs: Modules contain individual alarm relays for 
each alarm setpoint. However, each relay can be assigned to any 
setpoint to allow multiple alarm functions at a single alarm point. 
Relays are configurable for either standard or fail-safe operation and 
for either latching or non-latching operation.
 
.Separate Trouble Alarm: A fourth LED alarm bar and relay are 
provided to indicate trouble conditions. The trouble alarm and 
relay will activate on loss of input signal or if the 4-20 mA input 
drops below a specific value.
 
Remote reset Input: Isolated input contacts are provided to 
allow an unpowered switch input for acknowledgment of alarm 
conditions from a remote location or via telemetry equipment.
 
Internal Transmitter Power: Modules provide a 24 VDC power 
supply to operate either 2 or 3 wire transmitters.
 
Signal Retransmission: A 4-20 mA output is provided from each 
module, optically isolated from the input signal to avoid ground 
fault problems.
 
DC Powered: B14 modules are powered from a 12 VDC power 
supply available as an option. Up to 3 modules can be powered 
from one power supply (or 2 if battery backup is used). Customers 
provided 12-28 VDC supplies may also be used.
 
 
SYSTEM ENCLOSURES. 
 
A variety of NEMA 4X enclosures are available to assemble detection systems from receivers and power supplies. ATI offers 
standard enclosures to house up to 12 modules, and can supply larger enclosures for systems requiring more points of detection. 
 
System integrators can use standard 35 mm DIN rail for mounting modules in their own enclosures.
 
 Single Module Enclosure                              
Houses a single receiver module 
for use in DC powered applications 
where the user supplies the DC 
power to the system.
Two Module Enclosure
Houses two receivers or one receiver and 
one power supply. Normally used for single 
point AC powered detectors.
Three Module Enclosure
Accommodates two receivers and power 
supply or three receivers. Used mainly for 
two point detection systems.
Six Module Enclosure
Suitable for two power supplies 
and four receivers or six receivers. 
This enclosure is used primarily for 
four point gas detection systems.
Nine Module Enclosure
Twelve Module Enclosure
 
B14 Series SPECIFICATIONS
Concentration Display 4 Digit LED, Programmable Range
Input 2, 3 or 4-wire 4-20 mA Transmitter
Output Isolated 4-20mA, 1000 ohms max load
Power 12-28 VDC, 400 mA max
Concentration Alarms
Three adjustable concentration alarms. 
Setpoints adjustable from 5-100% of span.
Alarm Indicators LED bars for Caution, Warning, & Alarm
Indicator Function
Caution and Warning indicator non-latching.
Alarm indicator latching.
Alarm Relays
3 assignable relays, 7 A, 120 VAC (4 A, 220 VAC) resistive.
Alarms assignable to any one of 3 programmable setpoints.
Relay Function
Configurable for Normal/Fail-safe, Latching/Non-latching,
2/second/10 second delay, or external horn function.
Trouble Function
Front panel LED bar indicator and SPDT, 7 A relay.
Factory set for fail-safe operation.
Alarm & Relay Reset
Activated from front panel switch or through remote  
reset switch.
External Reset Input terminals provided for unpowered contact input.
Gas Indicator LED bar on front panel with gas symbol overlay.
Electrical Connections Quick disconnect pluggable terminal blocks.
Module Enclosure Noryl
Module Mounting Mounts to 35 x 7.5 mm DIN rail.
Size 2.8” W x 3.6” L 2.3” D (70 mm x 90 mm x 58 mm)
Operating Temp. -40°C to + 55°C
Humidity 0-99% RH, non-condensing.