The Heil Series 770 Water Jet, also known as Eductor, Scrubbers are designed for the removal of soluble gases and particulate matter, and direct-contact condensation. The open design combined with a high liquid flow-rate permits collection of sticky and/or gummy particulate, as well as gas which decomposes upon contact with water, e.g. SiCl₄, H₂SiF₆.
A high liquid flow at pressures up to 100 psig directed into the throat of the venture induces a gas flow into the venturi. Gas/liquid contact occurs in the throat of the venture where the contaminant gas or particulate matter is scrubbed. Leaving the throat, the gas is allowed to expand in the venturi’s diverging section prior to entering the separator tank. Once in separator tank, the gas stream makes several sharp changes in direction, causing entrained water droplets to impinge on the tank wall or the liquid surface. The scrubbed gas then exits the separator and is exhausted to atmosphere. Where extremely high efficiencies are required, water jet scrubbers can be arranged in series.
The standard Series 770 Water Jet Scrubbers are custom designed to meet the specific requirements of each application. 4-Bend Mist Eliminator Blades or mesh pad). The gas is then exhausted to atmosphere.
Series 770 Applications
Heil Series 770 Water Jet Scrubbers have been used successfully for control corrosive and/or noxious gases and particulate matter in fertilizer, pulp and paper, pharmaceuticals, and chemical plants.
The design of the Series 770 Water Jet Scrubber makes it the ideal choice for control of exhausts from epitaxial reactors. The scrubber is selected to provide adequate dilution (up to 100:1) of the incoming gas. The high liquid flow deluges the incoming gas, trapping most of the silicon dioxide (a decomposition product of SiCl₄) while also absorbing the HCL gas. Two Series 770 Water Jets in series have been tested in excess of 98% efficiency.
Series 770 Features
Principal features of the Series 770 Water Jet Scrubber are:
Low initial cost – The Series 770 Water Jet is capable of inducing gas flows up to 95,000 CFM against static resistances up to 8” W.C. without using a fan. Pre-engineered standard designs are available over the range of capacities.
Low maintenance cost – No moving internal parts to wear. The spray nozzles used to direct the spray to the throat have large orifices to eliminate the potential for plugging. The open design enables the Series 770 Water Jet Scrubber to be highly effective controlling heavy solids loadings, as well as sticky or tacky materials which could clog other scrubbers.
High efficiency – Proper sizing of the unit and selection of irrigation rate, pressure, and chemical addition will result in efficiencies up to 90% for soluble gases for a single Series 770 Water Jet. Particulate collection efficiency can exceed 99%.
Versatile – The Series 770 Water Jet Scrubber can be specified for a wide variety of gas scrubbing applications. In addition, they can be operated in series with another Series 770 Water Jet or other type scrubbers, e.g. Series 730 Countercurrent Scrubber, etc., to achieve maximum efficiencies even for the most difficult of applications.
Extended Service Life – Individual units are designed with maximum corrosion resistance as a primary consideration. The wide selection of corrosion resistant material feature Rigidon FRP (Fiber Reinforced Polymer) as a standard material with stainless steel and other alloy construction available.
Series 770 Equipment Selection
The air or gas volume required to ventilate the process is the principal guide in selecting the proper sized scrubber. Where the specific volume of air required is not already known, references such as the Industrial Ventilation Handbook (ACGIH) should be consulted.
After determining the total air volume to be scrubbed, the efficiency of the unit must then be selected. The required efficiency will depend upon several factors including type of particulate, solubility, size distribution, density/specific gravity, quantity, concentration, plant environment, local, state and federal codes.
Heil’s engineers will then assist in determination of pressure drop, recirculation rate, specific material selection, as well as sizing and specification of accessory items (pumps, recirculation tanks, fans, etc.) to make the system complete. Heil’s engineers will then provide a specific quotation on the appropriate scrubber and/or system.