TECHNOLOGY
Pneumatic Conveyor Now Handles Powders Fuller adds filter to pneumatic conveyor, extends handling range of standard Airveyor unit A filter has been designed for the Fuller Airveyor portable transfer units that enable them to pneumatically con vey powdered material. The Airveyor systems, made by Fuller Co., Catasauqua, Pa., heretofore handled only granular or pelletized materials. The standard Fuller portable Air veyor transfer unit is a packaged pneu matic system designed originally to transport materials such as grain, seeds, beans, or plastics in pelletized form. The unit is a combination vac uum-pressure type, with the vacuum side picking up the material, and the pressure side delivering it to the desti nation. The unit has a highly efficient cy clone that removes all materials from the vacuum stream. The material is then fed into the pressure side of the system by a dense stream rotary feeder, known as the "DA" type. A small scavenger tank containing a cartridge filter prevents carry-over of fines and stops solids from passing through the blower. The scavenger tank has a draft gage that indicates how full the tank is at all times. The tank can then be emptied as often as needed. The unit uses positive pressures and has a constant displacement blower of high efficiency. This means that for a given capacity a dense material can be conveyed through a relatively small diameter pipe. Fuller units are avail able in 3-in., 4-in., and 6-in. pipe sizes. All these units use the cyclonic prin ciple of separating material solids from the air stream. The 3-in. and 4-in. units have a single scavenger tank. The 6-in. unit has a two-stage receiver, whose second stage is equipped with a rotary lock so that its catch can be reincorporated with the main convey ing stream. A safety device is incorporated in the unit so that if foreign material stops the lock, the blower shuts down automatically. This disengagement de vice protects the airlock against dam age while the blower and motor coast to a stop. 134
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New Filter Units. The new 3-in. and 4-in. units which handle pulver ized materials have the filters mounted in place of the cyclone receivers. Such units don't, however, vary from the basic design of the standard line. The filter unit has four cylindrical cloth bags which act as a filter to trap dust resulting from conveying pulver ized material and prevent its passage through the blower. The filter oper ates continuously. Air-reversal action, controlled by an orifice arrangement mounted on top of the filter shell, selfcleans the cloth filtering elements. This air-reversal mechanism is oper ated by a Vs hp. gear motor. The motor is timed and arranged to control the cleaning air blasts, as well as the blast pattern through the cloth ele ments. The dust removed from the filter elements by the air reversal action then discharges through the rotary airlock together with the bulk of the material being handled. For accessibility, manholes are pro vided on each filter. Servicing and in spection are simplified as a result. The air-reversal mechanism is enclosed in a hood which protects the unit when it's used outdoors.
Ball Valve Has Teflon Sealing Capsule, Screw-in Base Plate While it may seem that there is little room for major design changes in the relatively simple design of a ball valve, nonetheless W-K-M division of ACF Industries, Inc., has done just that. The Houston firm has come up with a newly designed valve that features a conical Teflon sealing capsule and a screw-in base plate. Among other advantages, it's now possible to per form maintenance on the valve by re placing the internal mechanism while the valve body remains in the line. The conical-shaped Teflon sealing capsule in the Con-O-Sphere valve contains a metal ball, and the one-piece
ball and stem are heat-pressure molded within the Teflon block. This means that the sealing and flow-control fea tures are joined in the capsule, and as a result only a few other parts are used in the valve. They are the valve body, handle, screw-in base plate, locknut, set screw, and a Teflon stem seal (small washer). Leak-free Seal. An important fea ture of the Con-O-Sphere is its screw-in base plate. This enables all adjust ments in the valve to be made by simply tightening the base plate. As the base plate is tightened it forces the conical-shaped sealing capsule into increasingly closer contact with the smoothly finished valve body. It also activates the Teflon gasket which serves as a stem seal. Compression of the Teflon from be low brings it into even greater contact with the metal ball. Since Teflon cold flows toward the area of least resist ance, all minor irregularities in the sealing surface are filled under pres sure. As a result, a leak-free seal is obtained. Economics. The Con-O-Sphere offers several economic advantages. The ball molded within the Teflon block means that only a single part is used for the same functions that take several parts in conventional ball valves. Also a single mechanical adjustment regulates all seals within the Con-OSphere. This' saves time, labor, and equipment. And because of the ease of overhauling the valve, maintenance costs are minimized. To overhaul the valve the base plate is removed, allowing the capsule to drop out the bottom. The new capsule and stem seal can then be inserted, and the base plate and handle re placed. This operation should not take more than 3 min., W-K-M says. Availability. The valves are being manufactured in sizes from 1 s to 2 in. They have a working pressure range from vacuum to 1500 p.s.i., and are available in a number of metals including ductile iron, carbon steel, bronze, aluminum, and several stain less steel alloys. The Con-O-Sphei-c comes with screw, flange, or weld ends, and can be installed in any po sition. The valve should find applications in the chemical, petroleum, and phar maceutical industries. It offers maxi mum economy and minimum mainte nance to users who must control flow rates of gases, liquids, and slurries.
