Show TO HE BE INSTALLED AT HOOVER OAM DAM work was waa started last week on a refrigeration system for hoover dam which allt include luclus air cooling towers ammonia coni compressor pumps and miles 0 of ions inch tubing this will keep the heat beat 0 of t the curing concrete in the dam a at t 40 degrees below the surrounding temperature and when tile the mass has hall set it will expand to a 0 snug fit with the canyon walls whereas it if no artificial means of 0 cooling were usel used the heat of the chemical c hei reaction in the freshly poured concrete would expand it with sufficient pressure to push the walls of black canyon back one half inch on each side then when tho the mass cooled in about years to the atmospheric tent temperature pera ture it would contract and gapa gap between the dam abutments men ts and the cliffs more afore than 2000 gallons of water a minute will be cooled by the tern tem mid and this brine solution n will be circulated through the allea in as of pipe which will be embedded imbedded Im bedded per manelly in the tha dam the refrigeration plant be just downstream from the end of the nevada halt half of the tha powerhouse tind and cork insulated latea pipes will conduct the refrigerant to the dam system sylbern bern A two story steel and concrete building will house the a ammonia in tanks while an aerating and 16 teet feet wide set on a concrete tower 48 45 feet high feet fee t long reservoir Ls Is now under construction during the pouring of the concrete c oil expected within the next five weeks the water cooled by the aerator will be circulated through the dam structure As the concrete crete tries dries find and there is no danger of freezing the moisture in th the a mixture the ammonia system will bo be put into use and a constant below temperature throughout the pound structure |