ATYPICAL MITIGATION OF AN OIL SPILL, SAM HOUSTON NATIONAL FOREST

1987 ◽  
Vol 1987 (1) ◽  
pp. 81-84 ◽  
Author(s):  
Warren B. Zehner ◽  
James R. Mullins
Keyword(s):  
Oil Spill ◽  
Forest Restoration ◽  
Flow Line ◽  
Additional Stress ◽  
National Forest ◽  
Control Methods ◽  
Production Flow ◽  
Unknown Quantity ◽  
Controlled Burning ◽  
Rapid Control

ABSTRACT In March 1986 an unknown quantity of paraffin-based oil and brine was spilled in the Sam Houston National Forest, San Jacinto County, Texas. The source of the spill was a ruptured production flow line. A tributary to the East Fork of the San Jacinto River and 12.5 acres of the forest were affected by the spill. Mitigative options were evaluated for speed and environmental acceptability. Two atypical control methods were selected: freshwater flushing in areas principally affected by brine, and controlled burning in oil-saturated areas. These techniques provided rapid control of the contaminants and exerted the least additional stress on the forest. Restoration methods were suggested after the initial mitigation of the spill by burning and flushing.

scholarly journals Hydrodynamic Model of Transport System

2020 ◽  
Keyword(s):  
Hydrodynamic Model ◽  
Transition Period ◽  
Initial Conditions ◽  
Flow Line ◽  
Conveyor Belt ◽  
Deformation Model ◽  
Longitudinal Vibrations ◽  
Production Flow ◽  
Dynamic Stresses ◽  
Transportation Route

A hydrodynamic model of production systems with a flow method of organizing production is considered. The basic macro-parameters of the state of the production flow line and the relationship between them are determined. The choice of a lot of moment approximation for modelling the production line is justified. It is shown that the conveyor-type flow line is a complex dynamic system with distributed parameters. The boundary value problem is formulated for the longitudinal vibrations of the conveyor belt when the material moves along the transportation route. It is assumed that there is no sliding of material along the conveyor belt, and the deformation that occurs in the conveyor belt is proportional to the applied force (Hooke's elastic deformation model). The significant effect of the uneven distribution of the material along the transportation route on the propagation velocity of dynamic stresses in the conveyor belt is shown. When constructing the boundary and initial conditions, the recommendations of DIN 22101: 2002-08 were used. The mechanism of the occurrence of longitudinal vibrations of the conveyor belt when the material moves along the transportation route is investigated. The main parameters of the model that cause dynamic stresses are determined. It is shown that dynamic stresses are formed as a result of a superposition of stresses in the direct and reflected waves. Analytical expressions are written that make it possible to calculate the magnitude of dynamic stresses in a conveyor belt and determine the conditions for the occurrence of destruction of the conveyor belt. The characteristic phases of the initial movement of the material along the technological route are considered. The process of the emergence of dynamic stresses with the constant and variable acceleration of the conveyor belt is investigated. The dynamics of stress distribution along the transportation route is presented. It is shown that the value of dynamic stresses can exceed the maximum permissible value, which leads to the destruction of the conveyor belt or structural elements. The transition period is estimated, which is required to ensure a trouble-free mode of transport operation during acceleration or braking of the conveyor belt. The use of dimensionless parameters allows us to formulate criteria for the similarity of conveyor systems.

Controlled Burning of Crude Oil on Water Following the Grounding Of the Exxon Valdez

1991 ◽  
Vol 1991 (1) ◽  
pp. 213-216
Author(s):  
Alan A. Allen
Keyword(s):  
Crude Oil ◽  
Oil Spill ◽  
North Slope ◽  
Exxon Valdez ◽  
In Situ Combustion ◽  
Entire Area ◽  
Exxon Valdez Oil Spill ◽  
Original Volume ◽  
Controlled Burning

ABSTRACT During the evening of the second day following the Exxon Valdez oil spill, an estimated 15,000 to 30,000 gallons (57,000 to 114,000 L) of North Slope crude oil were eliminated using in-situ combustion techniques. The oil was collected with the 3M Company's Fire Boom, towed in a U-shaped configuration behind two fishing boats. Working with 500-foot (152-m) tow lines, a 450-foot (137-m) boom was moved at about one-half to one knot (0.26 to 0.52 m/s) through slightly emulsified oil patches downwind of the spill. Once oil had filled the downstream portion of the U-shaped boom and the boats were clear of any surrounding slicks, a gelled-fuel igniter was released from one of the tow boats. Shortly after ignition, flames gradually spread out over the entire area of the contained oil. As flames reached 200 to 300 feet (61 to 91 m) into the air, the area of the contained oil layer (and therefore the size and intensity of the fire) could be controlled by adjusting the speed of the vessels. The total burn time was approximately 75 minutes; however, the intense part of the burn lasted for about 45 minutes. The original volume of oil, likely between 15,000 and 30,000 gallons, was reduced to approximately 300 gallons (1,136 L) of stiff, taffy-like burn residue that could be picked up easily upon completion of the burn. The controlled elimination of crude oil therefore resulted in an estimated 98 percent or better efficiency of burn.

The Study of Buffer Allocation with Travel Time in Stochastic Production Flow Line

2013 ◽  
Vol 397-400 ◽  
pp. 2589-2594
Author(s):  
Xiao Yong Pan ◽  
Jiang Wu ◽  
Quan Wei Zhang ◽  
Dong Lai ◽  
Xin Fu ◽  
...  
Keyword(s):  
Travel Time ◽  
Queueing Theory ◽  
Flow Line ◽  
Computational Results ◽  
Buffer Allocation ◽  
Production Flow ◽  
Production Lines ◽  
Flow Lines ◽  
General Rules ◽  
Stochastic Production

This paper studies the problem of allocating buffers in stochastic production flow lines with product travel time. We build a model that decomposes the production line into the S-B-S (Station-Buffer-Station) subsystems, and use queueing theory to aggregate the subsystems. Experiments are designed for both balanced and unbalanced production lines, and with the computational results, some general rules for the buffer allocation problem are proposed.

Design of a Heuristic for Balancing a Multi-Stage Production Flow Line

2015 ◽  
Vol 1115 ◽  
pp. 610-615
Author(s):  
H.M.E. Kays ◽  
A.N. Mustafizul Karim ◽  
M.N.B. Tajudin ◽  
M. Abdesselam
Keyword(s):  
Flow Line ◽  
Line Balancing ◽  
Sheet Metals ◽  
Production Flow ◽  
Production Lines ◽  
Processing Times ◽  
Multi Stage ◽  
Effective Manner ◽  
Assembly Operations ◽  
Positional Weight

A production flow line balancing problem for automotive industry has been studied. A batch of an end item is produced by transforming sheet metals into parts at different manufacturing stages followed by assembly operations. The forming operations of the sheet metals into various parts and their assembly works are illustrated through 22 different tasks. Some of the tasks have the processing times greater than the takt time and are categorized as extra-long tasks. Attempts were made to solve this intricate line balancing problem by adopting the Ranked Positional Weight (RPW) method. But the solution given by the RPW model loses its exactitude due to the presence of the extra-long tasks. In this research a heuristic approach based on RPW is developed through which the problem has been resolved in an efficient and effective manner and hence the proposed heuristic is deemed to be capable of balancing production lines having such extra-long tasks.

scholarly journals Methodological aspects of system forming of control methods of technological flow of sugar production

2019 ◽  
Vol 81 (2) ◽  
pp. 162-169
Author(s):  
M. I. Egorova ◽  
E. V. Shirokih ◽  
I. S. Mikhaleva ◽  
L. N. Puzanova
Keyword(s):  
Methodological Approach ◽  
Measurement Methods ◽  
Quantitative Chemical Analysis ◽  
Control Methods ◽  
Sugar Production ◽  
Control Parameters ◽  
New Paradigm ◽  
Production Flow ◽  
Case Methods ◽  
Package Principle

Under conditions of increasing of industrial consumption of sugar in Russia and applying specific requirements for sugar as primary commodity, issues of flexibility and readjustment of process lines for production of sugar of prescribed properties become relevant. Maintaining the quality and safety of products in this case can be ensured by the transition of the process control system to a new paradigm, including the improvement of tools in the form of measurement methods. As a basis for the methodology of forming the system of control methods, three principles have been proposed: the package principle, the acquisition of standard and extended case methods, and the unification of methods presentation. The package principle as a tool of the rule-making methodology, with its detailed elaboration in standardization, has been considered in detail. It is shown that in order to ensure the compatibility of operational control methods, it makes sense to provide unified approaches to their development, essential content, construction and presentation, which is possible by adopting the package principle used in standardization. The necessity of expanding the nomenclature of control parameters of the technological flow of sugar production was considered in detail; the existing prerequisites were shown. It was proposed to provide the implementation of nomenclature variations of control parameters on the basis of the formation of two case methods, differentiated according to the destination of the sugar produced - for population or industrial consumers. It is noted that control parameters of the technological flow of sugar production are the quantities related to the subject of quantitative chemical analysis, the practical side of which is reflected by analytical methods. Due to the current variety of attributes of methods presentation, their harmonization is required both by means of the unification of the presentation of measurement methods of the same parameters for different control objects according to their substantive essence, and by means of the unification of the text presentation of the methodology. The principles considered together constitute the essence of the methodological approach to the formation of the system of control methods of the technological sugar production flow.

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