An industrial ventilation system enabling access to exhaust generating processes while containing and controlling the resultant exhausted gases is provided. A cover assembly is attached to the structure generating the exhaust gases and is provided with a reciprocating cover having an open and closed position. The exhaust generating process is accessible only when the cover is open. A conventional exhaust system is also provided to maintain the low level of air circulation necessary to convey the generated exhaust to a treatment facility. The industrial ventilation system is optionally provided with a workload enclosures that travels to selected process structures and forms a fume containment region by inter engaging with the cover assembly located thereon.Many industrial processes generate fumes and gases that are environmentally harmful--both to the surrounding physical plant and to the operating personnel. This is particularly true in the chemical processing of metals. Therefore we make provisions for industrial ventilation. If left unrestrained and/or uncaptured, the saturated, heated fumes are a potentially deadly health hazard to plant personnel, with almost certain long-term exposure risks. Further, these fumes will eventually destroy all of the structural members in the manufacturing facility with which they come into contact. These solutions are, in fact, so corrosive that structural concrete rapidly ages to powder. The health and labor codes enacted early this century encouraged industry to capture and control these toxic fumes. Since ready access to the tank solution is required during operation, the conventional systems made use of high volume, negative pressure collection hoods located adjacent to the tank. In most cases, these collector hoods were placed opposite one another on the top edge of the chemical tanks developed from the fine-particulate collection methods, sufficient air was to be pulled through the ventilation hoods that, in theory, would capture all fumes escaping from the tank surface.
The industrial ventilation system, inefficient at best, was impractical for tanks having widths of greater than four feet. For the wider tanks, one of the pair of suction hoods was converted into a forced-air ventilator, with air blown from the hood, across the liquid surface, and into the corresponding exhaust hood. These latter systems, referred to as push-air systems, had the same air circulation entrainment problems of the conventional system, only exacerbated by the positive or forced air flow across the tank surface. Thermals created by the hot liquid tended to deflect the pushed air stream in an upward manner, frequently to a sufficient extent that a significant portion of the pushed air "escaped" over the exhaust hood and out into the surrounding environment. A second problem occurred each time that a workpiece was lowered or raised from the liquid surface. The workpiece acted as an air baffle, causing the pushed air to be randomly deflected--thereby again missing the exhaust hood and being discharged, saturated with fumes, into the surrounding air.
