TARAHERU FREEZING WORKS.

Poverty Bay Herald, Volume XXIV, Issue 8052, 30 October 1897, Page 4

TARAHERU FREEZING WORKS.

iteiE ; SSRS NELSON BROS. 5 ALTERA- '■"- tions. THE 'AMMONIA PROCESS. Sj-TiiE stress of "competition and depression of &StpricM,;iri ' connection with the frozen meat llfSLtraicle Have had the effect of awakening those ip3rho.: have capital sunk in the industry to Pisttta'SfAeceasity of taking extraordinary to maintain the trade upon a sound t§Gand satisfactory basis. Farmers are beginJ>~. ning to realise that they must revolutionise &?.i v their methods of sheepgrowing, that quality jfir.is the one thing to bo considered if they JjVV-- are to retain a command of payable prices, P" -and the refrigerating companies recognise „. jfthat economy of .working must be one of the §g£:inairi essentials of success. When prices are gJ-S cut fine, "working expenses must also be cut, -those who, grow and handle the meat are ; Vto receive remunerative returns. In the hour fj~ of depression, science and invention, twin I ; . helpmates of industry, have come to the - ■ rescue and have supplied the meaus by which if'j- economy of working can be obtained. Nelson Bros., who have so largely ft; > Contributed to build up the frozen meat ;->;T industry in this colony, have not been S^ 810W 1 to realise the advantages of new ?-"'. 'processes and appliances, and, though :- "'. . the alterations must involve a very con- *': '_ siderable outlay, they are refitting all their freezing works in various parts of the colony with new and up-to-date machinery. After ';, careful consideration, the firm adopted- the ; y Linde air circulation system as the one -:; - proved to be the most satisfactory of new ©-"^processes, and it is this system which was Sg^recently installed at their Tomoana head|£3> quarters, and more recently at their Taruheru !■'' ' works. The local installation complete, Mr '< t \ Dewing, the manager at Taruheru, invited •*£■•' His Worship the Mayor and several other , ■ v gentlemen who had expressed a desire to see \ the alterations, to visit the works, and accordingly at midday yesterday snmc half dozen of us were escorted to the spacious engine-room and introduced to Mr George Nelson, the gentleman who lias had charge of the alterations, and who, with Mr Dewing, .." ;, took us in hand and showed us round the ■."';" premises. ';--","' : Before starting on a tour of inspection of V 'the works Mr Nelson treated us to a small JL : . : - "object lesson iv chemistry, a lesson which '_?;■" . • gave us the whole secret of the new process i. .-that has been adopted for refrigerating at 7- >: these works. Taking a tin pannikin he f.--: drew into it from a large iron tube, weighing p. ".'fully 2cwt but called a bottle, a small !£ . quantity of that gaseous compound of £>; -'hydrogen and nitrogen, termed ammonia, *"s-i ? n< * 8O well known to everybody as the chief r-V ingredient of Bmelling salts. Everybody j _•_:■.- knows dlso that besides its pungent smell •"■ ammonia has the property of being exeeed- >.'". ingty volatile. If you leave the stopper out ; " of the bottle it quickly loses its strength and ;:• ' evaporates. It is this rapid evaporation, ;;:/■ combined with the fact that in vaporising I",™*: the" chemical assumes a very low degree of :/„; temperature, that gjves ammonia its value '-■; t yas a medium for refrigeration purposes. Mr «: '■■ JTelsoa.held out his pannikin of ammonia its fumes spread quickly through the y . air, causing several pocket handkerchiefs to y .be immediately produced. Then, we were : y asked to touch the bottom of the pannikin, ';*„ and those who approached caxitiously, afraid ; of being burned, were surprised to find it i ■_: • icy cold, the result of the evaporation. The .\*i ■ remaining contents of the tin were poured ;"/■• out on to a sheet of iron and quickly wasted 'fr'.y into air, causing the iron to become intensely :.,■'- " ' cold. There is the whole modm operandi of l-_" the ammonia refrigerating process. Pure b-:. anhydrous ammonia, stored in these large K ■ iron bottles at a pressure of lOOlbs to the ;.. : square inch, is taken and evaporated, and :> the evaporation causes sufficient chill to ■er ' freeze all the mutton and the beef that we »j'.y have for export. But of course it would '&:'. .not do to follow the extravagant method r?y adopted by Mr Nelson in his object lesson p.*; and to allow the ammonia to vaporise away *f- "into the atmosphere. That would involve

g:^. . an enormous expense in the purchase of : Zj,_ ammonia. Machinery is introduced thereE. ''■- f?re_ for conserving this precious volatile IpV liquid, and now we come to a more detailed I s'^ ■ explanation of what the new machinery at ij *- the works consists. There are in a central §}'''•■ "P a r fc o *.^the building a large number of b,:-. coils of iron tubing, and into tliese the ... r compressed liquid that we sa.w drawn ■j.'. ■ from the iron tube is forced, where it ' rapidly vaporises, with the result that the i" .. tubes become icy cold and expel all warmth ; . from the air around them. The vaporised • ammonia is forced then through pipes to • another series of coils of iron piping outside ■•-'• the building, and over these coils there is r,.-- flowing a delightful shower bath of water ■-..■'. ..pumped from the adjacent dam. At this 2-r- 'point the ammonia vapor is condensed or ••. distilled back again into liquid substance, V .. and the liquid flows back through the -::-inachiuery and into the evaporation coils ;.• • to create more cold air. Thus the same ;-.---_ ammonia is used over and over again; it t, is kept ever circulating, evaporating and I- makiDg more cold air, condensing and dis- ;.{; tilling again into liquid. The brightly ;■ polished machinery that we see at work, ;-.-/ moving slowly and smoothly, is performing ' the same function that the heart does for „--"..- the human body, it is keeping the life fluid : of the system in circulation. And just as ■ >-'- we have in the human frame another organ _- that must be kept in ceaseless operation, so ;- in the work of refrigerating it is essential ■:,_. that the air should be kept in motion around , .the cold coils in which the evaporation takes •.- place. For this purpose a huge Blackmail „.. fan is provided, and this, the lungs of the -'; ■ > establishment, drives the cooled air through ; _" ..-.-various air trunks throughout the chambers, >".- - an d caußea it to return again, to receive, if '-"■"'"- J? c muy so P ut '*> a frcsn supply of cold. ..'." Thus the same air, like the ammonia, is in constant circulation. In connection with the cold air circulation it may be mentioned .„■ that means are provided for driving a .'.. current of cold air through pipes into the • Company's barges, so as to thoroughly cool '.':' them before reception of the meat, and so :- that in the event of delays in shipment the -;'t barges may be converted into miniature ;. refrigerating chambers. t) ■■ It is easy now to explain the difference "■ x between the old and new methods of re- :-\~- frigeration. Under the old system you had •;.,>. to artificially manufacture your cold oir and pump it into your chambers, where it spent io - ItB ,T" ■ , had *? be for ever making fresh .;-. ,. cold air and pumping it in, and the expendi- :. . tnre of energy was enormous compared with -'.. ..what is now required. There was first the „. energy for manufacture and then the energy ■ i° c iE vm P' n E- N °w *«c only energy required ~ ' ."that exercised in pumping. The cold air '„" ?* provided by the simple natural process of k-,- .. evaporation, and all that the machinery has .•:;;.. to do is to keep the ammonia and air in :■ ■,'S,*n« ll ation. The' saving in power, and conr aeqneutly in fuel, will be seen by the state- +. %entthat under prosont conditions Messrs :=•"" Nekon Bros, refrigerating at 'L'aruheru can ; be done with the engine working ul 70 h.p " as against 260 h.p. that was required under \ the old system. One ton of coal does now what 3J to 4 tons did before. Thcntoo.it - must be noted that the new system is a dry air system. It is the natural fresh dry ,-' atmosphere of the freezing chamber, robbed i bf jts heat at the evaporation coils, that is ;... ; in constant circulation. Under the old '--'. system there was always a certain amount .. of fog in the atmosphere, and with it, of J- " ; cCjUrse, moisture which could not have been V' WWgethar good for the meat, whilst there -if was always the trouble to be encountered of ;.-. »now choking the air trunks. Nothing of [;-l that sort occurs now. As you step into the chamber to-day you realise the j':.xOleani«ss of the atmosphere, and there is a sharp's freshness about the air that smells ," healthy. Ten times the amount of air is ;.. ] circulated now that was circulated formerly. ;" Water freezes perfectly transparent, so that r. anew shilling placed in the bottom of a dish .■ shines through the ice. The meat also should nave -a, "better: appearance, and that' should i be worth- money. We are " personally con- _. .ducted!' (as they say in the guide books)

through the Arctic regions by Mr Nelson. The air is very cold. In one portion of the chamber, where some fine quarters of beef from the first kill of the season are hanging, the thermometer registers 12 degrees above zero. But we have worse than that to face. The party is taken upstairs and a door removed from a wall, exposing to view the fan beforemenlioned. From this comes an icy blast that would freeze the marrow in one's bones, and gives us visions of what the poor creatures in Dawson City, Klondyke goldfields, must be suffering. The air as it leaves the coils after its passage through this fan is at a temperature of zero. Under ordinary atmospheric pressure ammonia evaporates at 30 degrees below zero, but under the pressure at which it is here worked it evaporates in tiie coils at a higher temperature of 10 degrees below zero. With the old system tho interior of the building had to be divided up into a number of isolated compartments. Most of the partitions have been taken away, giving, of conrse, much more space, and there is now just one big chamber. We are glad (o be out of it, and never did the climate, of Poverty Bay feel more genial than it did to us as we stepped out into the warm sunshine. It is only necessary now to refer to tho alterations that have been effected in the engine-room, and wo think we have described pretty fully the changes that have taken place at Messrs Nelson Bios.' works. Here are two largo engines, both kept in splendid polish. One is still : it is the old-system refrigerator that has not been altered, but is still kept there as v stand-by in caso of any serious breakdown in the ammonia system, a contingency that is scarcely possible. The other, which is in action, is, so far as the power-developing portion of it is concerned, the same as it was before, but the rest of the machine has been converted to suit the new system, and instead of manufacturing cold air the machine now simply pumps the ammonia which cools the air and drives the fan which circulates it.

As already stated, the alterations have been carried out under the superintendence of Mr (Juorgo Nelson, who is engineer reprcscntii.g Messrs Jus. Nivcn and Company, nf Napier, New Zealand agents for the Linde British Refrigerating Company. As showing how smartly the work has been done, it may be stated that it has been completed within six weeks, and when one sees the amount of pulling down, alterations, and arrangement of new machinery that lias taken place it is evident that everyone must have worked with a will. But, as Mr Nelson says, " We ai c becoming expert at it, this being the fifth installation of the kind that we nave set up in Now Zealand." In conclusion, it must be slated that Messrs Nelson Bros, deserve credit for the enterprise that lias prompted them to make this important transformation of the works, the result of which, it is hoped, will be to place them in a position to secure for local farmers better prices than in the past. We heartily wish them success.