Ned i dybden af Peak District er det største batteri brud og genbrug fabrik i Storbritannien. Virksomheden, der drives af HJ Enthoven & Sons på stedet for en historisk blyminde, genbruger virksomheden over 100,000 tons om året af industrielle og automotive blybatterier og er et af de mest miljøvenlige og effektive anlæg til blygenvinding i verden. I lyset af batteriernes giftige karakter er selskabet meget opmærksom på sine miljømæssige ansvar og har investeret betydelige ressourcer for at sikre, at lokalsamfundet ikke påvirkes af dets aktiviteter.
The breaking up of the batteries and the recovery processes involve crushing the complete battery and then separating out all the individual metals, plastics and chemicals. The first stage involves crushing the batteries in a high speed hammer mill, a process that breaks the components into small parts for subsequent separation. The next stage of the process sees the crushed parts passing through primary and secondary rotating filter screens to separate acid, plastic and metallic fractions. In order to optimise the overall separation process and removal of the lead sulphate sludges for recovery the internal surfaces of the screens require continuous cleaning with internal high pressure jet-washing sprays. However, the external surfaces of the screens can become blocked and regular cleaning is required. Without effective high pressure washing of the screens’ external surfaces, HJ Enthoven cannot achieved the required levels of material separation required to successfully operate the battery breaking aspect of its business.
Historically, external screen washing was performed using a single high pressure pump to feed the spray nozzles. However, the original and subsequent pumps used were not up to the demands of the breaking process and required frequent attention and maintenance, resulting in costly plant downtime. Having struggled with this situation for a number of years the Company decided in 2005 to instigate a major review of this aspect of the process in order to overcome these problems and reduce the associated costs.
It was at this time that Cat Pumps entered the scene, providing much needed information on spray nozzle performance curves. Working alongside Enthoven’s engineers, Cat Pumps brought its extensive knowledge of high pressure pumping gained on similar industrial applications to the table. “In many respects, we took on a consultancy role,” says Cat Pumps UK general manager Brian Hubbard. “Over a period of several months, we undertook an evaluation of the pumping requirements in order to provide HJ Enthoven with a number of alternative solutions that addressed the many issues that emerged from our meetings. It was time well spent as we were able to demonstrate not just the technical capabilities of our pumps to operate in an extremely challenging environment for long period, but also our engineering design resources.”
Efter meget overvejelse, der involverede at se på forslag fra andre udstyrsleverandører, valgte HJ Enthoven at gå med Cat Pumps, da de havde demonstreret en klar forståelse af vigtigheden af sprayrensningsprocessen til brydeanlægget og havde vist, hvor omkostningsbesparelser kunne gøres . Det var i slutningen af 2007, at Cat Pumps fik frem til at designe en "klar til brug" skidbaseret pakke bestående af tre individuelle højtryks 6811K Series triplex-pumpe pumper, to-duty og en standby, komplet med motorer, betjeningspanel, header tank og pulsationsdæmpere. 6811K-seriepumperne har 316 SSL-blokmoduler til styrke og korrosionsbestandighed og keramiske støddæmpere, som maksimerer tætningslængden. For at imødekomme det krævende miljø, hvor de opererer hos HJ Enthoven, var pumperne udstyret med støbejernsvaskekasser samt inkorporering af specielle portede indløbsrørledninger, der tillader en ekstern væskeflush.
According to Brian Hubbard the pumps offered higher levels of energy-efficiency than experienced in the past, so HJ Enthoven would get double the flow rate for similar electricity consumption. “We provided consultancy to help design the system and establish the pump requirements, balancing effective cleaning against water and energy consumption,” reports Brian Hubbard.
“Our pump package has the effect of doubling the output flow of the existing pump, enhancing the effectiveness of the process and also vastly increasing pump reliability and eliminating down-time. The inclusion of a standby pump provides built-in redundancy so the process could continue when any one of three pumps is out of service e.g. for routine inspection and parts replacement.”
The pumps feed a single pipeline into the spray heads which wash various screens which were previously prone to blinding. Motorised valves allow the plant operators to turn these individual areas on and off as required and set sequencing cycles. Capable of providing pressures up to 4000psi and giving a flow rate of 2.6m³/hr, the pumps are required to operate 24 hours a day in a very demanding environment. The water supply comes from flooded mineshafts and does contain dissolved carbonates, which can be a problem for some pumps but not for Cat Pumps.
In any application where high pressure pumping is required and a constantly smooth flow rate needs to be achieved, the triplex positive displacement pump is arguably the most economical choice. The triplex pump employs three synchronised plungers, which give it the ability to deliver a predictable, smooth and constant flow. The smooth flow greatly reduces the possibility of system failure caused by excessive pulsation. With Cat Triplex Pumps, the synchronised plungers can produce flows of 0.1 – 265l/min. at pressures up to 690bar.
HJ Enthoven installerede og bestilte Cat Pumps rig i tidlig 2008 og efter 12 måneder har præstationen mere end målt op til forventningerne. "Vi kører nu pumperne" under PLC-kontrol "indarbejdet i auto-opstart og nedlukningssekvens for batteribryderen," siger Paul Grainger Engineering Manager, HJ Enthoven & Sons. "Cat Pumps har leveret en professionel og venlig service fra de tidlige designstrin gennem idriftsættelse og efterfølgende vedligeholdelse og support af udstyret."
“Performance so far has been far better than anticipated,” he continues, “with pressure and flow satisfying our operating requirements. Overall there have not been any operational problems. We were advised by Cat Pumps in the initial stages that after 12 months continuous operation the pumps would require a routine service involving the replacement of seals and valves etc. When we inspected the pumps with Cat Pumps after more than 12 months, very little work was required, which even surprised Cat Pumps given the amount of work that they had been subjected to. We have been delighted with the performance of the equipment to date.”
Whilst the pump package meets the performance requirements in terms of pressure and flow, HJ Enthoven has been able to reduce substantially the costs incurred in pump maintenance, spare parts and downtime. In addition, the three pump set-up is far more efficient to run in terms of energy consumed.
For mere information kontakt;
Cat Pumps (UK) Ltd, Fleet, Hants.
Tel: 01252 622031 Fax: 01252 626655