Case 1:Description of Incident A loud sound was heard and a 20 foot long white to whitish-gray cloud was seen in the area of Sludge Pump. Inspection showed Pump was fractured and small pieces were found as far away as 35 feet.
Pump suction and discharge valves were found closed and the local pump run switch was found in the auto position. Autoignition temperature on actual pump sample was measured at C. Pump was started remotely 3 days after the shutdown. Common Features 1. Complete Isolation Suction and Discharge Blocked2. Communicate the hazard Identify potential pump explosion hazards in our areas Remote start capability.
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Carousel Previous Carousel Next. Jump to Page. Search inside document. More From khaiseah Hitul Joshi.Since January I have been puzzled by the reporting from all agencies and media that the explosion shown in the video below involved a fuel oil tank. I am very confident that what we are witnessing in the video is a HIT Heat Induced Tear of a process vessel used in the making of the fuel. Here is the video and my observations; I have inquired with the MS State Fire Marshal's office regarding this event and will update this posting with any facts that I obtain.
My observations regarding the video footage below:. Look just over the far left horizontal tank for the vapor.
The top vessel is a vacuum vessel where the feedstock oils are placed under a vaccum to lower their boiling point s. The vessel on the bottom is a "boiler type" vessel that burns fuel oil and boils the feedstock to "distill" feedstock.
We can also "sort of make out" the relief system for these four vessels are damn near exactly where we begin to see the white vapor first appearing from the flames. As a point of reference, the video is shot from a location off screen to the top of the image. We can see the four horizontal tanks and the four stacked vessels. I know NOTHING about their processing controls and safety systems for this process, but we do know from the workers on sight that one went to sample a tank, saw an "orange glow" - he knew what that meant, ran to the office to wake the sleeping employee and they ran to safety.
If this was the case and the lower distillation vessel was still "distilling" while the pool fire raged underneath it, it is my contention that we have all the ingredients for a BLEVE. A HIT Heat Indusced Tear occurs in non-pressurized containers and when the material is flammable like in this event we will get a large fire ball as a result. I am NOT picking on the bio fuels industry. A few of the adverse events as reported in media sources will be listed as examples of problems that can occur, most of which could be avoided with proper preparation.
American Biofuels, Bakersfield, Calif. The methanol was ignited and the fire spread into the process building. Apparently, the spill was not contained. Likewise, an ignition source was present around a flammable liquid in an upset condition. A PSM should have identified these two issues so that the spill would be contained and the area would be electrically classified so that no ignition sources should be present.Corrosion is typical of the damage that occurs in ageing pressure vessels and pipelines used in industrial processes as a result of reactive products inside or harsh environmental conditions on the outside.
Motivation for this article is to summarize cases, causes, consequences, and prevention in terms of models for the prediction of explosion pressure from BLEVEs. The contribution deals with real scenarios of accidents associated with transport and storage pressurized facilities with corrosive flammable chemicals.
While the LPG, propane, and butane BLEVEs are well described in the literature, the information about corrosive and toxic flammable substances are rather scarce. The study presents the results of hazardous zone calculation for the event of ammonia corrosive non-flammable chemical releases.
Rupture of vessels model were used for this study. Request Permissions. Abbasi, S. Baker, P. Cox, P. Westine, J. Kulesz and R.
Bubbico, B. Mazzarota, Analysis and comparison of calculation methods for physical explosions of compressed gases, Chem. All Rights Reserved. Registration Log In. Paper Titles. Corrosion Protection of Infrastructure of Power Industry p.
Article Preview. Abstract: Corrosion is typical of the damage that occurs in ageing pressure vessels and pipelines used in industrial processes as a result of reactive products inside or harsh environmental conditions on the outside. Add to Cart. Materials Science Forum Volume Edited by:.
Cite this paper. Online since:. December DOI: Cited by. Added To Cart. This paper has been added to your cart. To Shop To Cart.A centrifugal pump is dead-headed when it is operated with no flow through it, for example, with a closed discharge valve or against a seated check valve.
54 Years Ago: Explosion Kills 19 Texas Firefighters at the Shamrock Oil Refinery
If the discharge valve is closed and there is no other flow path available to the pump, the impeller will churn the same volume of water as it rotates in the pump casing. This will increase the temperature of the liquid due to friction in the pump casing to the point that it will flash to vapor.
The vapor can interrupt the cooling flow to the pump's packing and bearings, causing excessive wear and heat. If the pump is run in this condition for a significant amount of time, it will become damaged. When a centrifugal pump is installed in a system such that it may be subjected to periodic shutoff head conditions, it is necessary to provide some means of pump protection.
One method for protecting the pump from running dead-headed is to provide a recirculation line from the pump discharge line upstream of the discharge valve, back to the pump's supply source. The recirculation line should be sized to allow enough flow through the pump to prevent overheating and damage to the pump.
Protection may also be accomplished by use of an automatic flow control device. Centrifugal pumps must also be protected from runout. Runout can lead to cavitation and can also cause overheating of the pump's motor due to excessive currents.
One method for ensuring that there is always adequate flow resistance at the pump discharge to prevent excessive flow through the pump is to place an orifice or a throttle valve immediately downstream of the pump discharge. Properly designed piping systems are very important to protect from runout. Membership Register Login. Copyright Notice. Centrifugal Pump Protection Review. Pump Knowledge Menu Centrifugal Pumps Suppliers Centrifugal Pump Protection Review A centrifugal pump is dead-headed when it is operated with no flow through it, for example, with a closed discharge valve or against a seated check valve.Jump to content.
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What firefighters need to know about BLEVEs
New Article Product Viscosity vs. Featured File Vertical Tank Selection. This topic has been archived. This means that you cannot reply to this topic. Posted 21 August - AM Hey friends. I'm sure this is a basic chemical engineering calculation but I've been out of engineering for 6 years now and I don't have my books around me. I've been scratching my head for a couple of days so hope you can help. Hoping you can help.
Regards M. Because it is a closed system, and you have known the P and T of both initial state and final state, what u want to do is just two steps. To simplify this problem, u can use ideal gas to approah it. But u should know that it may be not a good approximation, because the pressure is a bit high. The problem is far simpler but you need to furnish additional data. What is all the background to this query? It helps to have ALL the facts. Therefore, I suspect there is a longer story behind this query.
I have to assume you are a student and the pressures are those from a text book and, as such, in absolute terms. This is the normal way Propane is stored in real-life.
You also failed to state the real-life information regarding your propane tank: its dimensions and its water capacity or total internal volume.
I think it can be solved without knowledge of total volume of the system vessel or whatever it is. Sign In Need an account? Register now! I've forgotten my password. Remember me This is not recommended for shared computers.This method has been the mainstay of liquid pressure systems for many years. There are two categories of PRV used in systems, depending on location and application.Tanker blows up, killing driver in Fresno, California
From an energy consumption point of view, this is an acceptable method given that pressure must be constant within one system throughout a whole community where there are huge variations in volume and pressure needs. When usage shuts off completely and the set pressure is reached, the valve then diverts the flow through a bypass to the pressure tank to restore the backup capacity. This method maintains a constant pressure for a time, however allowing the pump to run at maximum head conditions and restricting the flow to this degree, greatly reduces the running efficiency of the pump.
The pressure transducer acts simply as an information source. This information is provided typically to a variable frequency drive or VFD. This is done by changing the frequency of the electrical pulses through what is known as an inverter. This allows for full control of the output of the system.
Coupled with a modestly priced VFD the user is also able to monitor and subsequently protect the system from damage.
Problems occur when the operating conditions of the system change. Without a method of detecting these conditions, the system continues to run; causing physical damage to pumping equipment and potentially causing substantial physical damage beyond the system itself. Even before noticeable external damage, substantial increases in electricity usage results from most of these conditions, when not detected promptly. A properly sized variable frequency drive, motor and pump, coupled with a pressure transducer, provides for; a constant pressure within the pumping range, maximum energy efficiency for the given system, and peace of mind knowing the drive is monitoring the system, shutting it down to protect it, other equipment in the system, and external physical damage in the area.
Society has come to expect that when they turn on the faucet, the water will flow at the same rate and pressure regardless of how many people are using the system at one time. Without getting too technical, the drive does this by reproducing the AC sine wave at a variable frequency. This frees us from the limitations given by the electrical utility that typically provides electricity at sixty pulses per second or 60 hz.
Historically motors were designed to run most efficient at this speed; however new electric motors, windings and insulating material, are designed specifically to take advantage of this ability. By changing how fast the pulses are fed to the motor, the output of the pump can be controlled variably without restricting the flow and reducing efficiency of the pump. The monitoring abilities provided by modern VFDs, are only limited by the imagination of the designer and the ways in which the system is intended to be used and protected from damage.
The most commonly used protections in water pressure applications are discussed below. Basic to water systems, the pressure of the water is monitored constantly.
BLEVE - Cases, Causes, Consequences and Prevention
This information is used in many ways to determine the health of the overall system. This protection requires a pump motor equipped with a sensor that can detect when a seal on the motor has failed and there is water getting into the motor. Typically used in larger systems, this notifies the user that maintenance is required to restore the system to health. By setting the maximum amperage based on the nameplate, the motor is not damaged by over-current.
Branch circuit protection is still provided by the breakers required by local code. Advanced functions available in most modern drives, allows that the drive will not only shut down on over-current, but will also report by error code when the condition occurred. This is very helpful when diagnosing the root cause of the failure; during startup, running, or deceleration. Damage to the motor is prevented should there be a brownout or other under voltage condition on the input line power.
In three phase systems, the VFD protects the drive and motor, should an unexpected phase loss occur in the incoming power supply. Parameters can also be set to protect from an un-acceptable amount of phase imbalance.
These measurements are on the incoming side of the VFD, and depending on how the drive is sized; a larger amount of error can be tolerated, without affecting the output of the drive to the motor.
In fact, many drives are used just for this purpose. Running a 3 phase motor, where 3 phase power is not available, drives can be sized and setup to convert single phase incoming power to three phase output motor power.Make FireRescue1 your homepage. Here's a breakdown on what a boiling liquid expanding vapor explosion is, how it occurs and how it can be prevented. Inthe Kansas City Fire Department suffered its second largest loss of life in the line of duty when a 20, gallon gas tank exploded in a fire, killing five firefighters.
This kind of dangerous explosion would later come to be known as a BLEVE, but what exactly does that mean? If the vessel can no longer contain the pressure inside of the sealed tank due to the high temperatures, it will mechanically fail, causing the explosion.
Whether or not a fire occurs is contingent on if the liquid inside of the tank is flammable. If it is, a fire will often occur. If the vessel contains non-flammable liquid such as a steam boilera BLEVE will occur, but the vapors will not ignite.
Mechanical damage or overfilling can also cause the vessel to explode. A second-stage BLEVE can occur if a vessel releases combustible vapor into an area where it then mixes with air in the presence of a source of an ignition. Then, the explosion can stress the heated vessel and cause it to rupture, resulting in an explosion of the vapor. The complete rupturing of a vessel can be prevented by incorporating a sort of vent mechanism to let vapors eject directly up into the atmosphere. If the vapor is not able to be ejected straight up, the pressurized vessel should be kept in an enclosure that will contain any explosion pressure and control the blast.
More FireRescue1 Articles. More Education and Training News. More Product Listings. More Product news. More Education and Training Videos. Make FireRescue1 your homepage Open the tools menu in your browser. How to buy radios eBook. Are first responders eligible for a stimulus check? Nearly Courses and hours of CE. Sign up for FR1 Academy today! How firefighters can continue to train in a time of social distancing.
COVID concerns from the company officer perspective. At the epicenter: Seattle FD prioritizes testing and member safety. Topics Education and Training. Email Print Comment. By Shelbie Watts, FireRescue1 Editorial Assistant Inthe Kansas City Fire Department suffered its second largest loss of life in the line of duty when a 20, gallon gas tank exploded in a fire, killing five firefighters. Flood containers with large quantities of water to cool them until well after the fire is out.
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