1) Now one more question or point of discussion...while using exothermic or insulating sleeves through which we pour metal we have ceramic foam filters.now when we pour metal some times the foam filter float on metals and some times donot.in some foundries they poke the filter to make them float...they say or else they get less feeding thru risers or shrinkage...now should filters float or not after pouring..do we need to poke them or lift them with rod 2) It is always recommended that filters should float 3) Aksay.if they donot float should we poke is it necessary.and when do they float and when not.any thing to do with sleeve base shape and size..can you pl ellobrate 4) Normally filters are placed in the running system, either below the downsprue or further in the runner bar. The basic idea is filtration and not feeding. Thus to my mind they need not be floated. How does one use them with sleeves during risering, I am not aware. 5) These are direct pour sleeves 6) I have used these sleeves. Foseco sleeve name is Kalpur 7) If they dont float it is necessary to poke them out to get full efficiency of sleeve. Normally direct pour sleeves will have the taper inside which allows the filter to float up 8) I have learnt something new about direct pour sleeves. Thanks đ&#x;™?đ&#x;™? 9) My understanding is - initial metal only filtered. Later when cup(sleeve) is full, filter should float. If I am wrong correct 10) Absolutely right sir 11) Yes i am mention of direct pour sleeves and about ceramic foam filters 12) Filter should float. If not floating, one has to poke it to float 13) What bad effect it has if it doesnt float.because in poking sometime the filter gets slanted position and slag enters system and some time sand at the base on which it is dwells moves into the system....that what i feel pl correct me if i am wrong 14) Direct pour sleeves need foam filter, perhaps not ceramic filter, ceramic may not float, needing poking. We use foam filter in sleeves, that floats up when sleeve is full. Sometimes it gets stuck up in sleeve or remain vertical, relating to pouring practice not proper. 15) It depends on clearance between filter and sleeve , internal finish of sleeve as well. 16) In foseco sleeves filters always floats
17) If at all...It should float up at the end of pouring. ..In case it gets slant at the end...doesn't matter at all as far as filtration is concerned...but it could/must affect feeding as modulous of filter might obstruct feed path... 18) With due apology; Sleeve suppliers importing foam filters from China (due to less rate) and supplying with their sleeve. So size does not match perfectly. This problem started. 19) As qty of metal passed through the filter slag is adhered to filter material which may restrict metal feeding after completion of pouring . That is why filter should float. 20) Once pouring is completed slag can not enter to casting. If filter slant or breaks. 21) Variation in filter dia is major cause of filter stuck in sleeve. 22) Use a gauge to qualify filters instead of poking after pouring...always act upstream.... 23) The question is filter 'status and location' during pouring. Not after pouring is over 24) Yes and keep a check on OD of filters 25) I think Vinaysir is talking about after completion of pouring only 26) And ID of sleeves 27) If it float in between it Wil be harmful 28) Either of if needs be... 29) We've made a gauge of both 30) Another is is blockage of foam filter as we pour.then we get unpoured or badly fed casting and booked as short pour on name of supervisor.then supervisor pour casting by removing filters and for name sake puts filter in sleeve to convince others that he has poured rightly.and next day we struggle on why there is defects in casting.so is there any method to check foam filter before use.I think only foseco has its own filtet mfg unit rest all sleeve mfg out source. 31) Foseco is also outsourcing 32) In fact the shrinkage in castings caused due to filters choked is known at a very later stage 33) All filters are either manufactured in Germany or China 34) Selection of filter for required bunch weight is more important to avoid filter blockage. 35) Each size of filter has a definite filtration capacity. Different for grey n ductile iron 36) Sir foseco also gets filter from thrir german manufacturing unit. As i see casting shrikage can be more reduce by providing bigger riser and various air vent in the mould
37) Or else increasing the size and hight of pouring sprou so as to get more pressue for meal to flow and get converted into laminar flow 38) Or you can two type of filter in single mould one with bigger grid 39) Yes we are using for iron and steel different types and sizes 40) Has anybody used woven ceramic cloth filter in molds.share ur experience Pl..we 41) One measure function of ceramic foam filter which is not taken into discussion here is that filter is used to make the turbulent flow in upstrem into a laminar flow of down stream passing through the filter 42) So far after total pouring gets complited the filter must float on the liquid metal surface in the sleeve 43) To avoid the blocking of filter one must also select the correct PPI of filter (pores per inch) 44) One must undergo the filtaration capacity of a filter too while selecting 45) The zig zag paths through the cross sections of filters helps reduce the pressure of flow lines and not the velocity 46) Hence it converts the turbulent flow into laminar flow which reduces the possibilty of errosion of sand grains inside mould and ensures good feeding. 47) Dear gorpade ..can you put up the chart of ppi and the metal flow rate and kg of metal to be poured thru that filter and std filter size on common I'd of our group for all or pass it to Sandeep ji 48) It is supplied by the manufacturer. Ci, sg &steel.