PRODUCTION

NEW EQUIPMENT Filter Elements

Poroxis stainless steel filter elements have been announced by the Micro Me­tallic C o r p . Designated Surfamax, these elements a re i n t h e form of corrugated assemblies and are available in six pore openings, ranging from 5 to 165μ. Stand­a r d units with p ipe connections range from 1-25 to 2, inches. Special units up to 10 inches a n d capacities up to 10,000 gal . pe r minute can b e supplied on special order. Ε 1

Classifier The Dorr Co. h a s developed a new

combined mechanical and hydraulic classi­fier, t o b e known a s the Dorrco Hydro-scillator. The basic principle involved is t h e inducing of mechanical mobility of t h e se t t led oversize. The term, Hydro-scillator, is derived from the fact that this essential mobility i s attained by a com­binat ion of upward-flowing hydraulic water and oscillation.

The Dorrco Hydroscillator consists of t w o major parts—a shallow, cylindrical oscillating classifying compartment and, direct ly below, a reciprocating rake de-water ing compartment. A vertical motor drive unit imparts to t he cylindrical os­cillation compartment rapid circumfer­ential oscillation abou t a vertical axis. Feed enters t h rough a radial t rough or l aunder terminat ing in an open-bottomed annu la r feed box at t he center. Water unde r pressure is introduced into the bot­tom of the classifying compartment t h rough a multiplicity of close-spaced per­forations in an oscillating constriction plate . As a result, a "teeter b e d " is set u p , consisting of particles ranging verti­cally from fines, close to the mesh of sepa­ra t ion at the top, t o very coarse granular particles at t h e bo t tom. Fine particles w h i c h have reached the top of t h e "teeter b e d " are swept outward by the radial flow of hydraulic water , and eventually leave t h e unit as a n overflow product across a per iphera l weir.

T h e coarse, oversize particles work to t h e bo t tom of the " teeter bed," flow to the per iphery of t h e classifying compartment, and pass under a stationary side wall and over an oscillating lip into the reciprocat­ing rake compartment. T h e oscillating effect maintains fluid mobility in this seal. T h e s e coarse particles settle rapidly through the water in this lower compart­men t , are picked u p by the reciprocating rakes, and a r e advanced u p t h e steeply inclined slope to t h e point of discharge.

At the point where the oversize particles rise i n t h e annulus between the stationary side wal l and the oscillating lip under the head imposed by the bed of teetering solids, they meet and must overcome a

For furfher information on any item mentioned here, see coupon

on page 1871

back pressure or resistance set up by the head of water in the reciprocating rake compartment, t h e water level of which is maintained at a higher elevation than the pulp level in the oscillating compartment. This results in a "U" t u b e effect or hy­draulic balance. An adjustable overflow in the reciprocating rake compartment may b e manipulated upward and down­ward to control the pressure exerted at this point which, in turn, controls condi­tions in t h e oscillating compartment and consequently t he fineness at which the separation is made. Ε 2

Humidity Control An instrument which records and auto­

matically controls humidity has been an­nounced b y the Weston Electrical Instru­ment Corp. Utilizing the psychrometric wet- and dry-bulb principle, the controller automatically regulates the wet-bulb ( rela­tive-humidity) depression for which it is set, regardless of any fluctuations in the dry-bulb temperature

Two pens operate on a circular 10-inch chart, simultaneously recording the dry-bulb temperature and t h e wet-bulb de­pression. The flow of the humidifying agent, moisture, steam, or oil fog, is regu­lated by a valve which is operated by the control instrument. This system was de­veloped for process industries and utilities, such as textile, chemical, tobacco, food, natural gas, and others which require pre­cise humidity control during the process­ing of a product or material. For applica­tions involving gas, such as t he saturation of natural gas in the main, bars can be clamped on the case of t he instrument, to make it gas-tight. Ε 3

Air-Gas Proportioning Valve Accuracy of air-gas mixing and versa­

tility of application are two features of t he McKee Consta-Mix proportioning valve which has been announced by Eclipse Fuel Engineering Co.

Accuracy of air-gas mixing is obtained b y incorporating regulating features that will enable minute adjustment of the air-gas mixture a t any point in t h e range of valve capacity and also b y providing for a n over-all B.t.u. change that is required from t ime to t ime on special applications.

Within the valve capacity range, this valve can handle brazing, soldering opera­tions, flame hardening, small-furnace heat requirements, or atmosphere gas generat­ing requirements.

I t is suitable for use with manufactured, natural, or liquefied petroleum gases mixed with air in any predetermined proportion. The mixture is compressed by a turbo compressor and delivered at a constant pressure, depending upon the booster selected for the specific application. Mix­ture ratio is independent of fluctuations in gas pressure or changes in output de­mand.

T h e valve may be used with exothermic or endothermic generator or a full premix requirement for burner applications. Ε 4

Viscosity Measurement In Centipoise Units

Viscosity measurements directly in cen­tipoise units and without tlie need for calculations are now provided by use of the new Fisher Electroviscometer. The instrument provides reproducible results, has good sensitivity over its full range, and is simple t o operate. It is useful for testing such widely diversified materials as glycerol and water, salad dressings, and maple syrup; in fact, any liquid of the free-flowing Newtonian type. T h e pat­ented Electroviscometer was designed and developed in t h e laboratories of t he Fisher Scientific Co.

The new instrument comprises a stand on which the sample is held in a sample cup and revolved at constant speed around a '^bobbin." This central element is mov­able and can b e turned in opposition to the natural pull of t he liquid under study as shearing force is exerted against the bobbin. A magnetic field, to which vari­able amounts of electrical force can be applied, is created around the bobbin adjustable by control knobs on t h e sepa­rate power supply and meter unit. When the magnetic force applied to the bobbin exactly counterbalances the mechanical force exerted by the rotating liquid, the viscosity is expressed in centipoise units read directly from the scale of the instru­ment.

Features include the choice of two sizes of bobbins, one for liquids of low viscosity (0—500 centipoises ) , and one for heavier liquids of 500 to 5,000 centipoises. The stand incorporates a constant temperature ba th which is readily placed and removed; also a ventilating fan to cool the magnetic coil above the bobbin. The 110-volt a.c. power supply is regulated to ensure con­stant speed of the sample cup rotation and force applied to the bobbin. Ε 5

Door Switch Assembly Micro Switch has announced a new

small door interlock switch assembly for automatically cutting off the power cir­cuit when a high frequency cabinet door is opened. This interlock switch assures positive safety to personnel who have oc­casion to open cabinet doors on high fre­quency radio, radar, x-ray, television, in­duction heating, and other electronic con­trol equipment. Ε ô

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