Abstract: To remove salts from a solution containing the salts, hot air is injected downwards into the solution in a concentrator, and the solution is concentrated by direct contact with the hot air, thereby enhancing an evaporation efficiency in the concentrator and preventing scale deposition in the concentrator and piping system. The solution is forcedly cooled in a crystallizer by direct contact with cool air, thereby making crystals grow in the solution within a short time. The solution and air are circulated in a closed cycle, thereby preventing a secondary environmental pollution.

Abstract: A tubular membrane separation apparatus and process, for reverse osmosis or ultrafiltration, with an arrangement for removing undesirable deposit from semipermeable membrane surfaces. The apparatus is of the multiple-stage type wherein the number of tubular modules per stage gradually decreases in a pattern like a Christmas tree laid on its side. Elastic elements are forced through the tubular modules lined with the semipermeable membrane, the number of the elements being gradually decreased stage by stage, so that the deposit is mechanically rubbed off from the membrane surfaces with an optimum number of elastic elements for each stage.

Abstract: Dialysis apparatus has dilution and concentration chambers arranged alternately, which chambers each are defined by ion exchange membranes and frames each disposed therebetween. Passages for introduction of air into the dilution and concentration chambers are provided at lower portions thereof. The air introduced through the passages into the dilution and concentration chambers rises upward between the ion exchange membranes and is exhausted from upper portions thereof out of the dialysis apparatus. By the introduction of the air, solutions in the dilution and concentration chambers are driven to flow upward. Condensed phosphates are added to liquid to be treated before dialysis of the liquid.

Abstract: In a process for electro-dialysis which comprises passing an electrolyte through dilution chambers and concentration chambers formed between a large number of alternately counterposed anion exchange membranes and cation exchange membranes, and applying an electric potential to a pair of electrodes provided at both ends of a plurality of these chambers, thereby migrating ions in the electrolyte through the membranes and effecting dilution or concentration of the electrolyte, such a volumic rate of air bubbles is introduced to the lower parts of the dilution chambers as to make the thickness of a diffusion layer formed by concentration polarization near the ion exchange membranes in the dilution chambers smaller than when air bubbles are not introduced thereto, and make the resistance between the electrodes smaller than when the air bubbles are not introduced thereto. Superficial air velocity of air bubbles introduced into the dilution chambers is preferably 1-4 cm/sec.

Abstract: Waste water issued from a wet type desulfurization apparatus and containing thionic acid ions is introduced into ion-exchange towers filled with weak-basic anion-exchange which has to effect anion exchange therein. The weak-basic anion-exchange resin which has adsorbed the thionic acid ions is desorbed by contacting an alkaline solution. The thionic acid ions included in the desorbing solution are decomposed by heating them in the presence of acid. A decomposed solution is issued out of the system after its neutralization.

Abstract: A rotary valve disposed in a conveying passage for a powdery or granular material and comprising a valve casing and a valve member of arcuate cross section. In full closed position, the inner peripheral surface of the valve member is directed toward the flow of powdery or granular material to shut off the material flow, but in full open position, the valve member is rotated to permit conveyance of the powdery or granular material through an opening bored therein.

Abstract: An insulator bushing for high d-c voltage input to be used in an electric precipitator, etc. is designed to internally produce jet flows of sealing gas covering the insulator member. While ingress of dust-laden gas passing through the precipitator into the bushing is thereby prevented thus keeping the interior of the bushing clean, the necessary quantity of sealing gas to be supplied can be economically reduced.

Abstract: An improved sprinkler head for use in fire retarding systems including means for confirming the presence of water pressure at the sprinkler head. The confirming means includes a valve means provided in the sprinkler head and coupled to the water input of the sprinkler head and a pressure detection port provided in the sprinkler head coupled to the water input of the sprinkler head via the valve means whereby a pressure gauge may be connected to the port and the valve means opened so that the water pressure may be determined.

Abstract: A system is provided for separating waste water or solution into a permea solution and a concentrated solution by feeding the waste water or solution to a reverse osmosis apparatus using a membrane.A chemical pretreating apparatus is provided to prevent hard scales contained in the waste water or solution from precipitation during the concentration in the reverse osmosis apparatus using the membrane. An apparatus for charging sponge balls is further provided to mechanically remove suspended solids and other suspended matters, that is, soft scales when deposited on the surface of membrane. The sponge balls are desirably recyclically used.