I haven't worked in a copper refinery, but I once spent a week in the Anaconda tankhouse, which, if I remember right, had 400, 600 gallon tanks. I have deposited copper from this solution quite a few times.
If you want to do this right, you should start with a solution already made up in the following manner. I haven't worked with it in a long time and didn't remember the exact operating conditions. However, there is a ton of information on the internet. In general, here's a typical solution formulation and operating conditions.
CuSO4.5H2O = 100-160 g/l
H2SO4 = 180-250 g/l (I calculate this as about 10-14% conc. H2SO4, by volume)
[Cl-] (added as HCl) = .02-.05 g/l
Thiourea = .0001-.0005 g/l
Bone glue = .0001-.0010 g/l
Temp. = 55-65 C
Cathode Current Density = 130-170 A/m2
If I remember right, the bone glue is dissolved in hot water before adding. The thiourea and glue act as grain refiners and are basically what will produce the smooth finish you're after. They also prevent treeing of the deposit. Their consumption is proportional to the number of amp-hours used and can be controlled by keeping track of the bath usage. You can probably get away without these additives, but the deposit will not be nearly as smooth and could be stressed. I have also used iron-free blackstrap molasses or dissolved gelatin as a grain refiner
At 100% efficiency, copper deposits at the rate of 1.185 gram/A-hr. The efficiency of this bath is about 92-96%.
What immediately caught my eye is that you're using 70% H2SO4, by volume. That's 5-7 times stronger than what you should be using. I can see many problems with using the strong acid. Both the cathode and anode efficiencies will be quite low. The solubility of the copper will be very low. The deposit will probably look terrible, if it deposits at all. Think of the sulfuric gold stripper. According to the patent, I think it can be run as low as 65% H2SO4, yet it neither dissolves or deposits copper, to any great extent.
In acid copper plating, which uses a very similar formula, air agitation is used. This further improves the deposit and makes it more uniform. It is supplied from a blower and not a compressor, since oils can be very detrimental. I don't know if air agitation is used in a copper refinery, or not. Also, constant filtration is used in a plating tank.
Like Harold said, bag the anodes to prevent undissolved impurities from fouling the solution and the deposit. A polyester bag sewn with polyester thread works well.
I would imagine that the anode area should be at least as large as the cathode area. In plating, it's usually 2/1, anode/cathode.